CN102078842B

CN102078842B - An electrostatic fluid accelerator for and method of controlling a fluid flow

Info

Publication number: CN102078842B
Application number: CN2010105824620A
Authority: CN
Inventors: I·A·克里克塔弗维奇; V·L·格罗伯特斯
Original assignee: Tessera LLC
Current assignee: Adeia Semiconductor Solutions LLC
Priority date: 2002-06-21
Filing date: 2003-06-23
Publication date: 2013-06-05
Anticipated expiration: 2023-06-23
Also published as: JP2006501630A; EP1537591A1; CN1675730A; CN102078842A; EP1537591B1; CN102151611A; MXPA04012882A; EP2540398A1; CN1675730B; JP2012134158A; JP2010010138A; CA2489983A1; EP1537591A4; NZ537254A; AU2003247600C1; CN102151612A; JP5010804B2; JP5011357B2; AU2003247600A1; WO2004051689A1

Abstract

An electrostatic fluid accelerator for and method of controlling a fluid flow. A device for handling a fluid includes a corona discharge device (602) and an electric power supply (601). The corona discharge device (602) includes at least one corona discharge electrode (603) and at least one collector electrode (605) positioned proximate each other so as to provide a total inter-electrode capacitance within a predetermined range. The electric power supply (601) is connected to supply an electric power signal to the corona discharge and collector electrode (603, 605) so as to cause a corona current to flow between the corona discharge and collector electrodes (603, 605). An amplitude of an alternating component of the voltage of the electric power signal generated is no greater than one-tenth that of an amplitude of a constant component of the voltage of the electric power signal. The alternating component of the voltage is of such amplitude and frequency that a ratio of an amplitude of the alternating component of the highest harmonic of the voltage divided by an amplitude of the constant component of the voltage being considerably less than that of a ratio of an amplitude of the highest harmonic of the alternating component of the corona current divided by an amplitude of the constant component of the corona current, i.e., (Vac/Vdc) < (Iac/Idc).

Description

Control electrostatic fluid accelerator and the method for Fluid Flow in A

The application is that to be called electrostatic fluid accelerator and the method for Fluid Flow in A " control ", the applying date be that February 21, application number in 2005 are 03819690.5, international filing date is that June 23, international application no in 2003 are dividing an application of PCT/US2003/019651 to name.

Related application

The full content that this paper quotes following patent is for your guidance: " spark control method and the device " of the series number 10/187,983 that on July 3rd, 2002 submitted to; " method of electrostatic fluid accelerator and control Fluid Flow in A " of the series number 10/352,193 that on January 28th, 2003 submitted to; " electrostatic fluid accelerator " of the series number 09/419,720 that on October 14th, 1999 submitted to; " method and apparatus that is used for the electrostatic fluid acceleration control of Fluid Flow in A " of the series number 10/175,947 that on January 21st, 2002 submitted to; " method of electrostatic fluid accelerator and control Fluid Flow in A " of the series number 10/188,069 that on July 3rd, 2002 submitted to.

Technical field

The present invention relates to produce the method and apparatus of corona discharge, specifically, relate to the method and apparatus that accelerates for fluid, so that this type of electric field that utilizes ion and be used for motion provides speed and the momentum of a fluid (especially air), and to the control of such fluid.

Background technology

Many patents (for example, see the United States Patent(USP) Nos. 4,210,847 of authorizing the people such as Shannon and Spurgin 4,231,766) have realized that such fact: corona discharge can be used to produce ion and charged particle.Such method is widely used for electrostatic precipitator and electric fan, as by Chapman﹠amp; Described in " practical electrostatic precipitator " book that Hall (1997) publishes.Corona discharge assembly can apply a high voltage and form on paired electrode (for example, a corona discharge electrode and attracts electrode).Wherein, a high voltage source is applied on paired electrode, produces thus corona discharge.All electrode structures produce an inhomogeneous electric field near an electrode (being referred to as corona discharge electrode) therein with being arranged to, so, produce a corona and towards near the synthetic corona current of the electrode (being referred to as to collect or attract electrode) of complementation.The geometric form that corona discharge electrode needs requires a tip or cutting edge of a knife or a sword mouth towards direction of corona current flow usually, for example, and towards collecting or the attraction electrode.

Therefore, corona discharge electrode should be little or comprises tip or cutting edge of a knife or a sword mouth at least, in order to produce the electric-force gradient that needs near electrode.Corona discharge occurs in relatively narrow voltage range, between the lower voltage limit and higher puncturing (or spark) voltage of a corona outbreak.Begin below voltage at corona, do not have ion to launch from corona discharge electrode, therefore, do not produce the acceleration of air.On the other hand, if the voltage that applies can cause spark and electric arc near dielectric breakdown or electric spark level, the corona process of wherein cutting off the power supply and the offending electric arc sound of formation.Therefore, generally advantageously, keep high voltage between these values, specifically, approach but slightly lower than spark level, like this, it is the most effective that fluid accelerates.

There are many patents to put forth effort on and solve the pyrophoric problem of product in electrostatic equipment.For example, the U.S. Patent No. 4,061,961 of Baker has been described a circuit that is used for controlling the duty cycle of two-stage electrostatic precipitator power supply.This circuit comprises that a switching device and that is connected in series with the armature winding of power transformer can work the circuit of control switch device.One capacitor network that is suitable for electric current in the armature winding of monitoring power supply transformer is set operates this control circuit.Under normal working, that is, when in the restriction of the electric current in the armature winding of power transformer in nominal, capacitor network operates this control circuit, flows through the armature winding of power transformer to allow electric current.Yet, one detects the primary current of the increase relevant to the high instantaneous voltage of starting the arc generation, electric arc occurs between the parts of deduster and is reflected to the armature winding of power transformer by the secondary winding of power transformer, and at this moment, capacitor network operates this control circuit.Echo mutually therewith, control circuit causes switching device to suppress the armature winding that electric current flows through transformer, until the starting the arc operating mode relevant to high instantaneous voltage is pressed or alternate manner suppresses.Behind certain hour interval after high instantaneous voltage stops, switching device has automatically rebulid power supply to armature winding, thus, and the normal operation of recovery electrostatic precipitator power supply.

The people's such as Baker U.S. Patent No. 4,156,885 has been described an automatic current overload protecting circuit for the electrostatic precipitator power supply, and it carries out work after an overload that continues being detected.

The U.S. Patent No. 4,335,414 of Weber has been described an autoelectrinic restoring current that is used for the electrostatic precipitator air cleaner power supply and has been cut off.One protective circuit utilizes an iron resonance transformer to come protection power source, and described transformer has a primary source winding, provides relatively high-tension secondary winding and that the tertiary winding of relative low-voltage is provided.If transship in ion generator or current-collector unit, protective circuit by detecting from a high-tension voltage and with the voltage and fixed reference comparison that detect, suppresses the work of power supply with this operation protection circuit.When detecting voltage falling to lower than a predetermined value time, by the electric current of primary suppressed predetermined time.Electric current automatically recovers, and circuit will cause power-off circularly, until fault is eliminated.Reference voltage is taken from tertiary winding voltage, and the time of overload operating mode is shortened in the sensitivity that causes improving circuit.

Be familiar with any high-tension danger that can present discharge that applies as prior art.Desirable for some applying charge.To many other high-tension application, electric spark is the undesirable thing that avoid or prevent.In high voltage remained to application near a spark level (that is, dielectric breakdown voltage), this situation was especially true.For example, electrostatic precipitator like this, inevitably produces electric spark with possible maximal pressure level work.Electrostatic precipitator keeps the spark incidence at 50-100 time per minute usually.When a spark occured, power supply output dropped to zero volt usually, only through after being called the predetermined amount of time of " ionization time ", just resumed work, and in described " ionization time " process, atmospherical discharges also rebulids the front resistance of spark.Each spark event reduces the gross efficiency of high voltage device, and is that electrode becomes bad and aging one of the main reasons.The generation of spark also form a kind of in many environment and relevant application unacceptable offending sound, for example, static air accelerator, filter and various apparatus that family uses.

Except the undesirable noise that is produced by spark, other the invalid prior art of also bothering.For example, paired corona discharge and attraction electrode should be constructed and arranged to produce an electric field heterogeneous, at least one electrode, namely, corona discharge electrode, normally relatively little and/or comprise tip or cutting edge of a knife or a sword mouth, in order to a suitable electric-force gradient is provided near electrode.There are several known structures to be used for applying voltage between electrode, in order to the electric field of needs occurs effectively for the generation of ion.The people's such as the U.S. Patent No. 4,789,801 of Lee and Taylor patent Nos.6,152,146 have described and apply a pulse voltage waveform and traverse paired electrode, and this waveform has the duty cycle between 10% and 100%.These patents have been described by the corona discharge assembly that generates, and compare with the application of the D.C. power supply of stable state, and such voltage reduced the generation of ozone.No matter for how reducing actual benefit that this kind voltage that ozone occurs occurs, by using the generation that reduces significantly air stream less than 100% duty cycle, and the air stream of synthetic pulsation is considered to offending.

The high voltage source that the people's such as Sherman U.S. Patent No. 6,200,539 has been described with high frequency produces the approximately alternating voltage of 20kHz of frequency.Such high-frequency high-voltage produces and requires an a large amount of quite expensive power supply, and such power supply causes high energy loss usually.The U.S. Patent No. 5,814,135 of Weinberg has been described a kind of high voltage source, and it produces the potential pulse of very narrow (that is, steep, short duration).The air stream of a small amount of and little ratio relatively only occurs to produce in such voltage, and is unsuitable for acceleration or the motion of high air stream.

The U.S. Patent No. 4,789,801 of Lee, Weinberg 5,667,564, the people's such as Taylor people such as 6,176,977 and Sakakibara 4,643,745 air movement device has been described also, they accelerate air with an electrostatic field.The air velocity that reaches in these devices is very low, for business or application industry and impracticable.

The United States Patent(USP) Nos. 3,699,387 and 3,751,715 of Edwards has been described and has been used the multistage static air accelerator (EFA) of placing in succession to improve flowing of air.These devices use a conductive mesh as attracting (collection) electrode, near the corona electrode this net separates.Net presents a sizable air drag and slow down air flows, and thus, stops EFA to meet the requirements of higher flow rate.

Regrettably, these devices do not have to produce the throughput of viable commercial.Provide multistage traditional air movement device itself can not provide an answer.The electrostatic fluid accelerator of five series winding levels of for example, placing in succession only than the accelerator of independent one-level more and is supplied 17% air-flow.For example, referring to the U.S. Patent No. 4,231,766 of Spurgin.Similarly, electrode relative to each other changes relative position, only provides limited improvement to performance and the fluid velocity of EFA.For example, U.S. Patent No. 4,812,711 have reported and have produced the only air velocity of 0.5m/s, are expected to reach and available speed far below commercial fan and air blast.

Therefore, the electrostatic fluid accelerator of a practicality need to be arranged, it can produce commercial useful flow rate, simultaneously, the undesirable and parasitic effect such as spark is reduced to minimum.

Summary of the invention

The present invention includes all features that relate to ion generating device and process, export so that high efficiency, height to be provided, and reduce or eliminate such as the spark of minimizing and the ghost effect the ozone generation.

Even have found that spark begins voltage level phase electrode is not on the same group had a steady state value yet.Spark is the accident that can not be sure about and foretell.The generation of electric spark is a uncertain event that can be caused by many reasons normally, and if not all so, many situations are instantaneous situations.The beginning of spark is tending towards with such as (that is, dielectric) condition such as the fluid of humidity, temperature, contamination etc. and change.For same group of electrode, sparking voltage can have greatly to 10% or the variation of above beginning nargin.

High voltage applications and device known in the industry are processed usually only at the later spark of spark generation.If avoid all sparks, operating voltage must remain on relatively low level.The voltage level that necessity reduces has reduced the flow rate of air, also reduces the device performance of the relevant apparatus such as electrostatic fluid accelerator and deduster.

As noted above, prior art and device are only processed spark and are begun spark event afterwards; Also do not have the technical scheme of commercially practical to stop the generation of spark.Provide a dynamic mechanism to avoid spark that (rather than only extinguishing an existing electric arc) occurs, simultaneously, within voltage level is remained on the issuable scope of spark, this will cause one more effectively to install work, simultaneously, avoid following the electric arc sound of spark generation.

A feature of the present invention is to provide high-tension generation for the device such as (but being not limited to) corona discharge systems.The invention provides the beginning of surveying spark in whole dielectric breakdowns and the certain hour before sparkover.Use " mertialess " high voltage source, a feature of the present invention can be controlled the electrical discharge relevant to spark.Therefore, actual way is, uses such high voltage level, its haply more close spark begin level, prevent again the spark generation simultaneously.

The spark that many features of the present invention and aspect also relate in situation is below controlled, and for example, does not require that absolute spark suppresses, or can be even the situation that does not require.

According to an aspect of the present invention, a spark control device comprises that high power supply and a structure monitor the detector of the parameter of the electric current that offers a load device.Identify condition before spark in response to these parameters.The identification of the condition of one switching circuit before in response to spark is in order to control the electric current that offers load device.

According to a feature of the present invention, high voltage source can comprise such high voltage source, and it is configured to that a primary source is transformed into a high-voltage power and presents, for induced current.

According to another characteristic of the invention, high voltage source can comprise the power transformer of rising progressively, and high voltage source comprises an alternating current (ac) pulse generator, and it has an output that is connected to the armature winding of the power transformer of rising progressively.One rectification circuit is connected to the secondary winding of the power transformer of rising progressively, so that the electric current of high voltage level to be provided.

According to another characteristic of the invention, high voltage source can comprise that one has the high voltage source of low inertia output circuit.

According to another characteristic of the invention, high voltage source can comprise that one can work the control circuit of standby current.In response to the condition before the spark that detects, the lower voltage to of electric current does not guide the level that spark the occurs level of spark (for example, lower than).

According to another characteristic of the invention, load circuit can be connected on high voltage source, in order to accept selectively a suitable part of electric current in response to the condition before the spark of identification.Load circuit can be that an electric device (for example, converting electric energy to the resistor of heat energy) or that is used for dissipating electric energy is used for the electric device (for example, capacitor or inductor) of store electrical energy.Load device also can comprise some equipment, for example, corona discharge assembly not at the same level, it comprises that a plurality of electrode structures accept electric current and form a corona discharge.Corona discharge assembly can be the form that is static air accelerator, electric air cleaner and/or electrostatic precipitator.

According to another characteristic of the invention, switching circuit can comprise circuit, and except by the elementary load device of Power supply, described circuit also is used for powering to servicing unit selectively.Therefore, if detect an initial spark, in response to the condition before the spark that recognizes, at least a portion that is fed to regularly the power of primary device can be diverted to servicing unit, thus, reduce the voltage in primary device and avoid spark to occur.One or two elementary load device can be the static air processing unit, and it is configured to accelerating fluid under by the impact of the electrostatic force of corona discharge structure generation.

According to another characteristic of the invention, detector is responsive to following phenomenon: comprise the variation of variation, voltage level or the waveform of current level or waveform, or magnetic, the event electric or light relevant to condition before spark.

According to a further aspect in the invention, the method for controlling spark can comprise device provisioning one high-tension current, and monitors the condition before high-tension current is with the spark of surveying this device.Control high-tension current in response to the condition before spark, in order to control the generation of the spark event relevant with the front condition of spark.

According to another characteristic of the invention, the step of supervision can comprise the current spike that detects in high-tension current.

According to a feature of the present invention, the step of supply one high-tension current can comprise a power supply from the secondary voltage level of a primary voltage level translation to higher than the primary voltage level.Then, the power supply of secondary voltage level carries out rectification and high-tension current is fed to device.This can comprise the voltage that reduces output voltage or device place, for example, and the voltage level on the corona discharge electrode of the air accelerator of a corona discharge.Voltage can be reduced to the level that does not guide spark to occur.Control also and can realize to auxiliary load device by at least a portion that arranges high-tension current.Can be by implementing above-mentioned arrangement in an output circuit that a resistor is switched to the high voltage source of supplying high-tension current.

According to another characteristic of the invention, additional step comprises that the guiding fluid to a corona discharge electrode, switches on to corona discharge electrode with high-tension current, produce a corona discharge and enter into fluid, and under the impact of corona discharge accelerating fluid.

According to a further aspect in the invention, electrostatic fluid accelerator can comprise array electric corona and collector electrode, and the high voltage source that is connected to array on electric, to corona discharge electrode supply high-tension current.One detector can construct to monitor the current level of high-tension current, and responsively identifies the condition before spark.One switching circuit can be controlled high-tension current in response to the condition before the spark of identification.

According to a feature of the present invention, switching circuit can be configured to be fed to corona discharge electrode by suppressing high-tension current in response to the condition before spark by high voltage source.

According to another characteristic of the invention, switching circuit can comprise a bleeder resistance, and it is configured to accept at least a portion high-tension current in response to the condition before the spark of identification.

Having found that before the corona discharge spark first has certain observable exposure one imminent electrical events of spark event, and can monitor to foretell when dielectric breakdown is about to occur.The indication omen of spark can be the increase of an electric current, or change or the variation (for example, increases progressively) near the magnetic field corona discharge, or in circuit or other domestic capable of being monitored situation of electrode retaining collar.Especially, determine by test method that the increase of corona current is first arranged before spark event occurs usually.The increase of this electric current occurs in the short time interior (that is, 0.1-1.0 millisecond) before spark event.The increase of electric current can be the form of the current spike of a short time, and it manifested approximately 0.1-1.0 millisecond (msec) before relevant electrical discharge.The increase of this electric current is basically irrelevant with change in voltage.In order to prevent spark event, must survey initial current spike event, and will be applied to sharp and/or drop under spark level at the voltage level of corona discharge electrode.

Two kinds of conditions should be met, in order to can control such spark.At first, high voltage source should be able to be before spark event occurs, that is, and and from incident detection until within the time period that spark event begins, output voltage rapidly descends.The second, corona discharge assembly should be able to discharge and store electrical energy, that is, and and the discharge before spark.

Time between corona current increase and spark is on the magnitude of 0.1-1.0msec.Therefore, the electric energy that is stored in corona discharge assembly (corona discharge electrode that comprises power supply and energising) should be able to be in the short period, that is, and and the energy that dissipates and store within the time of inferior millisecond scope.In addition, high voltage source should have the circuit of " low inertia " characteristic (that is, can change rapidly a voltage level in its output) and interrupt voltage generation, preferably in inferior millisecond or millisecond scope.It is practicable that such quick voltage descends, the high voltage source work that this can use a high frequency to switch, and working range is in 100kHz to 1MHz, and it has the circuit that low storage can and descend rapidly or closes output voltage.For such ability is provided, power supply should " a closing " cycle (namely, the discontinuous high voltage needed time of output) work under the high-voltage switch frequency, described " closing " cycle is less than the time between the spark event of corona current spike detection and any generation.Because the power supply of the state of the art of present technique industry can be worked under the switching frequency up to 1MHz, specifically, the power supply of an appropriate designs (for example, noninertia) can be in the generation of the inferior millisecond scope interruptive current of needs.That is, can powered-down, and output voltage is reduced to safe level significantly, that is, drop under the level that begins far below the electrical discharge that is the spark form.

There is different technology to be used for surveying electrical events before electric spark.One current sensor can be used to measure peak value or mean value, or RMA (root mean square), or the quantity of any other output current or value, and the rate of change of electric current, that is, and and dI/dt.Perhaps, can survey the voltage level of power supply or the voltage level of an AC component with a voltage sensor.Another parameter that can be used for monitoring the upcoming spark event of identification is the drop of output voltage, or the voltage of the alternating current component of output voltage to the first derivative of time (that is, dV/dt).Also other variation in detectable electric field or magnetic field intensity or the corona discharge before the electrical discharge that is the spark form.A common trait of these technology is, the increase of corona current spike is not attended by increase or any significant power-supply fluctuation of output voltage.

Can adopt different technology to reduce rapidly output voltage by power generation.One better method is to close power transistor, or SCR, or any other switch block of power supply, and they form the high frequency ac electricity of the elementary pulsation that is supplied to step-up transformer, in order to interrupt the process that electrical power produces.In this case, the switch block inoperative that becomes, and do not have electrical power produce or be fed in load.The shortcoming of the method is, be accumulated in residual amount of energy in power supply unit, especially, must be discharged into some place at the energy of output filtering in the stage such as capacitor and inductor (comprising stray capacitance and leakage inductance), namely, be discharged into a suitable energy sink, usually be referred to as " ground connection ".If there is no certain discharging mechanism fast, the residual amount of energy that is stored by power supply just may be discharged in load, therefore, makes the speed of output voltage decline (that is, " falling ") slow down.Perhaps, the armature winding of one better structure and method " short circuit " magnetic part (transformer and/or multiturn inductor) on electric (namely, the terminals of interconnection winding), puncture stored any energy with dissipation magnetic field, guaranteeing does not thus have Energy Transfer to load.The output of the method short circuit power supply that other is more basic reaches the resistance than lower value.Yet this resistance should be more much higher than spark resistance, simultaneously, should be less than the operating resistance of corona discharge assembly to be powered, just the moment before spark event occurs occur like that.for example, if a high voltage corona unit (for example, one electrostatic fluid accelerator) just consumed the 1mA electric current before spark detection, and in a spark event process (or, other short-circuit conditions) by a current-limiting apparatus (for example, the current-limiting resistance of series winding) limit the 1A that outputs current to from power supply, traverse load (namely, between the corona discharge electrode and attractor electrode of corona discharge assembly) " releasing " resistance of applying should progressively proceed to greater than 1mA (namely, one lower resistance is provided and conducts thus electric current greater than the normal operation load current), but less than 1A (namely, the electric current that limits less than maximum short circuit current).Bleeder resistance that should be additional can pass through a high voltage reed type relay or other high voltage high-speed relay or switch block (for example, SCR, transistor etc.) and be connected to power supply output.Mertialess high voltage source common and important being characterised in that very, it can interrupt the generation of electrical power constantly in short time and certain, the described short time is less than from before electrical events and indicate time between an initial spark event, the described moment is when spark has occured practically under there is no certain intervention situation, that is, normally inferior millisecond or millisecond scope.

Another key character of such noninertia power supply is, any accumulation and the residual amount of energy that is stored in power supply unit should not slow down significantly, or alternate manner hinders in load, for example the discharge process in corona discharge assembly.For example, if the electric energy of corona discharge device discharges its oneself in 50 milliseconds, and the minimum expectation time before spark event be 100 milliseconds,, power supply should not add greater than 50 milliseconds to drain time, like this, the actual discharge time is no more than 100 milliseconds.Therefore, high voltage source should not used the energy storage component of any picture capacitor or inductor and so on, and they can discharge its energy in corona discharge assembly after the active parts such as power transistor is closed.For this ability and function are provided, any high voltage transformer should have a relatively little leakage inductance and or little or there is no an output filter capacitor.The layout that has found that the traditional high voltage source that comprises voltage amplifier and flyback inductor generally is not suitable for such spark control or prevention.

The present invention also puts forth effort to solve the deficiencies in the prior art, and to be familiar with or to estimate such fact: the ion generating process comes complicatedly than only a voltage being applied to two electrodes.On the contrary, the system and method for prior art generally can not produce suitable air-flow, can not limit the generation of ozone simultaneously.

The process relevant to corona has three common aspects.First aspect is the generation of the ion in fluid media (medium).Second aspect is to emit fluid molecule and foreign particles by the ion of emission.The third aspect is to emit particle towards the acceleration (that is, along power line) of relative (gatherer) electrode.

The air that is caused by ion or other fluid accelerate to depend on the quantity (that is, number) of ion and its near the fluid ion and so the repelling fluid ion towards the ability of the charge inducing of comparative electrode.Simultaneously, the generation of ozone is proportional to the power that is applied on electrode basically.When ion is sensed when entering into fluid, they are tending towards and will itself be attached on the fluid molecule of particle and neutral charge.Each particle can accept to depend on the only limited amount electric charge of special particle size.According to following formula, maximum amount of charge (so being referred to as saturated charge) can be expressed as follows:

Q _p={ (1+2 λ/d _p) ²+ (1/ (1+2 λ/d _p)) * ((ε _r-1)/(ε _r+ 2)) * π ε _od _p ²E, wherein, d _p=particle size, ε _rThe dielectric constant of the dielectric material between electrode pair, and ε _oIt is the vacuum medium dielectric constant microwave medium.

From then on equation as seen, it defers to such rule: be incorporated into a certain amount of ion in fluid will make near molecule and ambient particles charged to certain maximum level.The quantity representative of this ion flows to the amount of charge of another electrode from an electrode, and determines corona current mobile between two electrodes.

In case charged, fluid molecule attracted to relative collector electrode along the direction of electric field.The molecule with charge Q is moved in this directive space that electric field force F applies thereon, and charge Q depends on electric field strength E, that is, it is proportional to again the voltage that is applied on electrode:

F＝-Q*E

If the ion of Rr maximum quantity is incorporated in fluid by corona current, and the voltage that the electric charge that generates is applied separately accelerates, and produce a suitable air-flow, and average power consumption descends significantly.This can be achieved like this: how the numerical value of controlling corona current changes to certain maximum from certain minimum value, and simultaneously, it is constant that the voltage between electrode keeps basically.In other words, have found that, farthest reduce to be applied to the supply voltage of electrode (as the average high-tension part that applies) the high voltage ripple (or, alternating component), simultaneously, compare with overall average or the RNS amplitude of electric current, keep current ripple quite high and idealized, this is useful.Unless (separately point out or in use have hint, as used herein, term " ripple " and phrase " alternating component " refer to the time change component of signal, comprise all time-varying signal waveforms such as sine wave, square wave, sawtooth waveforms, irregular wave, complex wave etc., also comprise bidirectional waveform (also being referred to as " alternating current " or " ac ") and such as the pulsation direct current or the unidirectional waveform of " dc of pulsation ".In addition, unless separately point out in literary composition, the adjective such as " little ", " greatly " etc. that uses together in conjunction with the such term that includes, but is not limited to " ripple ", " ac component ", " alternating component " etc., relative or the absolute amplitude of special parameter has been described, special parameter such as signal potential (or " voltage ") and signal flow rate (or " electric current ").) because the component of the reactivity (capacitive character) of the corona generation array of corona and attractor electrode, so the such difference between the voltage and current waveform is possible in the technology of relevant corona and device.Capacitive component causes the voltage alternating component of relative low amplitude value, produces the alternating component of relatively large corresponding current.For example, can use a high-tension power supply that produces with ripplet in corona discharge assembly.These ripples should be relatively high frequency " f " (that is, greater than 1kHz).Electrode (that is, corona electrode and collector electrode) is designed to when high frequency voltage applies, and their mutual capacitor C is enough high and present relatively little impedance X _C, it is expressed as follows:

X _c＝1/2πfC

Electrode can represent the parallel connection that maybe can regard non-reacted dc resistance and reactive ac capacitive reactances as.Ohmic resistance causes corona current to flow to another electrode from an electrode.This current amplitude is approximate is proportional to the voltage magnitude that applies, and substantial constant constant (dc).Capacitive reactances is responsible for the ac part of the electric current between two electrodes.This part is proportional to the amplitude of the ac component (" ripple ") of the voltage that applies, and is inversely proportional to the frequency of voltage alternating component.According to amplitude and the frequency thereof of ripple voltage, the amplitude of the ac component of the electric current between two electrodes can be less than or greater than the dc component of electric current.

Have found that, can produce with the high voltage of small magnitude ripple (namely, the dc voltage that filters) but provide traverse electrode with relatively large ac component (namely, the power supply of the electric current amplitude current ripple), can provide the ion of raising to occur and the fluid acceleration, simultaneously, in the situation of air, reduce significantly or farthest reduce the generation of ozone.Therefore, current ripple is expressed as a ratio or mark, and its amplitude of ac component that is defined as corona current is divided by amplitude (that is, the I of the dc component of corona current _ac/ I _dc), current ripple should be greater than ripple voltage (namely considerably, at least 2 times), preferably at least 10 times, 100 times, be even more preferably 1000 times, ripple voltage is defined as the amplitude of the time dependent component of the voltage that is applied on corona discharge electrode or ac component similarly divided by amplitude (that is, the V of dc component _ac/ V _dc).

Also have been found that in addition, corona discharge assembly can reach optimum performance in following state: output voltage has the alternating component with respect to the small magnitude voltage of average voltage amplitude, and the dielectric material by electrode and intervention (namely, accelerated fluid) electric current is at least 2 times of alternating component (with respect to dc voltage) greater than voltage, be preferably 10 times (with respect to dc current components), namely, the ac/dc of electric current compares much larger than the factor 2,10, or even greater than executing alive ac/dc ratio.That is, be preferably and traverse corona discharge electrode generation one voltage, so that the electric current that generates satisfies following relation:

V _ac＜＜V _dcAnd I _ac～I _dc

Or V _ac/ V _dc＜＜I _ac/ I _dc

Or V _ac＜V _dcAnd I _ac＞I _dc

Or V _RMS≈ V _MEANAnd I _RMS＞I _MEAN

If any one in above-mentioned requirements is met, the ac/dc with electric current and voltage compares than approximately equalised power supply, the corona discharge assembly that generates consumes less power on every cubic feet of mobile fluid, and produces less ozone (in the situation of air).

In order to satisfy these requirements, power supply and corona generating device should carry out design and structure suitably.Especially, power supply should produce a high Voltage-output, and it is with just minimum and simultaneously relatively high frequency ripple.Corona generating device itself should have designed spuious or parasitic capacitance predetermined value, and described electric capacity provides the electric current that suitable high frequency is provided by electrode (that is, from an electrode to another electrode).If power generation low frequency ripple, X _cTo be quite large, and the amplitude of alternating component electric current can not be compared with the amplitude of the DC component of electric current.If power generation is ripplet or there is no ripple very, alternating current can not be compared with direct current.If corona generating device (that is, electrod-array) has a low electric capacity (comprising parasitism and/or stray capacitance between electrode), alternating current will can not be compared with direct current on amplitude again.If the resistance that installation one is large between power supply and electrod-array (for example, U.S. Patent No. 4 referring to Lee, 789, Fig. 1 and 2 in 801), the amplitude of ac current ripple with suppressed (namely, descend), and can not compare with the ripple of dc (that is, the constant) component of electric current on amplitude.Therefore, if only have certain condition to be met, so that predetermined voltage and current relation exists, corona generating device could be brought into play best function and provide enough Air Flows, the ozone levels of increasing work efficiency and requiring.The power supply cost that generates is also lower.

Especially, a power supply that produces waveform does not require suitable output filtering, and otherwise, providing of filtration is quite expensive, and connects physically large high voltage capacitor in power supply output place.List makes power supply become more cheap with regard to this point.In addition, such power supply has less " inertia ", that is, being tending towards reducing the storage that in output, amplitude changes can be less, and therefore, it can change output voltage rapidly than maybe not ignoring the high inertia power supply of ripple.

The present invention also puts forth effort on some deficiencies of the prior art, and its limitation is air stream and the common unable theoretical optkmal characteristics that reach.One of these deficiencies comprise the undue dimensional requirement for multistage EFA device, because the EFA of some grades places continuously, so, need suitable length along air duct (that is, along air-flow direction).This long passage also presents the larger resistance to Air Flow.

When multistage placement close to each other, also cause other problem.The spacing that reduces between level can produce " back of the body corona " between the corona discharge electrode of an attractor electrode of one-level and a contiguous next stage, it causes reverse air stream.In addition, due to the electric capacity between adjacent level, have parasitic electric current between adjacent level.This electric current is caused by asynchronous high voltage ripple or the high voltage pulse between adjacent level.

Use large or multistage EFA, so that the level of (or in groups) of each separation is provided with its oneself high voltage source (HVPS), also can produces other problem.In this case, form the spark that the needed high voltage of corona discharge can cause producing between all electrodes and reach a unacceptable level.When a spark occured, HVPS must fully close a period of time, this time be resume work before deionization and to extinguish spark needed.When number of electrodes increased, the generation of spark was than more frequent with one group of electrode.If a HVPS presents some groups of electrodes (that is, some level), must close more continually to extinguish the spark of the increase number of times of generation.This causes increasing the interruption of power supply for whole system undesirablely.In order to address this problem, advantageously, be fed at different levels from its own special-purpose HVPS.Yet, use independent HVPS to require continuously the level interval to get wider, with the undesirable electrical interactions of avoiding being caused by the stray capacitance between the electrode of adjacent level, and avoid producing back of the body corona.

The present invention proposes the solution of an innovation, increases air stream by all levels near the EFA at interval, simultaneously, farthest reduces or avoids introducing undesirable effect.The invention process comprises geometric electrode, mutual position and is applied to the combination of the voltage of electrode, so that augmented performance to be provided.

According to feature of the present invention, a plurality of corona electrodes and passive electrode are located in parallel with each other, or extend between corresponding flat perpendicular to airflow direction.All electrodes of adjacent level are parallel to each other, make all electrodes of same type (namely, corona discharge electrode or passive electrode) be placed in identical parallel plane, all parallel planes are orthogonal to the electrode of same type or electrode edge and are positioned at wherein all planes.According to another feature, multistage closely interval is to avoid or at utmost to reduce any corona discharge between adjacent level multipole.If the most close spacing between adjacent electrode is " a ", be applied to the voltage V1 of the first electrode and be applied to electrical potential difference (V1-V2) between the voltage V2 of hithermost the second electrode, and the ratio of distances constant between all electrodes, a normalized distance " aN ", aN=(V1-V2)/a.Normalization distance between the close part of the corona discharge wire of one-level and adjacent level, should surpass the corona outbreak voltage that applies between these electrodes, in practice, this means that corona outbreak voltage should be not less than 1.2 to 2.0 times of normalization distance, described normalization distance is to be correlated with (namely from the corona discharge electrode to the correspondence, the most close) the attraction electrode, the formation that prevents from thus carrying on the back corona.

At last, the voltage that is applied to adjacent level should be synchronous and homophase.That is, the ac component of voltage that is applied to the electrode of adjacent level should side by side rise and fall, and basically has identical waveform and magnitude and/or amplitude.

The present invention increases EFA electrode density (usually measuring) in the per unit length level, and eliminates or reduce significantly parasite current between electrode.At this moment, the present invention eliminates the corona discharge (for example, back of the body corona) between the electrode of adjacent level.Pass through with substantially the same voltage waveform, adjacent EFA level to be powered to the implementation section of this point, that is, the electromotive force on adjacent electrode has identical or closely similar alternating component, in order to eliminate or reduce the differential voltage of any ac between level.Carry out work in such one synchronous mode at inter-stage, the electrical potential difference between the adjacent electrode of adjacent EFA component keeps invariable, reduces to minimum from an electrode to the parasite current of any generation of another electrode or avoids fully.Synchronously can implement by diverse ways, but the easiest method is to use synchronous and voltage homophase from the correspondence of the power supply of correspondence to adjacent EFA component power supply, or the ac component of the similar amplitude of the voltage that correspondence applies is provided with synchronous power supply.This can realize with the identical power supply that is connected to adjacent EFA component, or realizes with different (being preferably coupling) power supply of synchronous and ac component homophase that produces the voltage that applies.

The present invention also solves other deficiency of the prior art, and it comprises the restriction of air-flow and usually can not reach theoretical optkmal characteristics.The other aspect of these deficiencies comprises the limited capability that produces a large amount of Fluid Flow in As that are used for commercial use.Also have other deficiency to be, must avoid producing high-intensity electric field with large electrode structure (outside corona electrode).Use physically large electrode also to increase fluid flow resistance and restriction EFA capacity and efficient.

During when a contiguous heap(ed) capacity of EFA or in the work of heap(ed) capacity place, also cause other problem, that is, certain maximum apply voltage and power consumption.In this case, remain near dielectric breakdown voltage to the operating voltage feature that applies, the undesirable electrical events such as spark and/or electric arc consequently can occur.If by mistake contact one of them electrode, can produce the shortcoming that also has other, may produce a large electric current and flow through the person, this is both unhappy also normally dangerous.

Normally come also can cause other problem as corona electrode with fine rule.Therefore such line must be considerably thin (usually be about 0.004 " diameter) and frangible, is difficult to clean or other work.

When must or require a stronger flow (for example, higher fluid flow rate), also other problem can occur.Traditional multipole layout causes a relatively low multipole density (therefore, being not enough to accessible electrical power the largelyst), because corona electrode must be positioned at minimum distance each other, in order to avoid, its corresponding electric field is interfered with each other.Spacing requires to increase volume and limits electrode density.

A feature of the present invention provides the solution of an innovation, utilizes highly resistant material in the structure of accelerating electrode and processing, and the geometric electrode by using an innovation and the electrode position each other (that is, interpolar is how much) of optimization improve flowing of fluid.

According to feature of the present invention, a plurality of corona electrodes and accelerating electrode are located in parallel with each other, and some electrode extends between the corresponding flat perpendicular to the direction of air-flow.Corona electrode is made by electric conducting material, for example, and metal or conductivity ceramics.Corona electrode can be the shape of fine rule, blade or band.Should be noted that, corona discharge occurs on the narrow zone of corona electrode, and these narrow zones are referred to as " ionization edge " here.These edges are usually located at the downstream with respect to the corona electrode of the fluid flow direction that requires.Other electrode (for example, accelerating electrode) is the shape of bar or faciola, and faciola extends along the main direction of Fluid Flow in A.In general, the quantity of corona electrode equals the quantity of accelerating electrode+1.That is, each corona electrode be positioned at respect to be parallel to one or two contiguous accelerating electrode.

Accelerating electrode is made by the highly resistant material that high resistance pathways is provided, that is, made by the material of high resistant rate, and this material is easy to the conduct electricity corona current, does not cause significant voltage falling and traverse electrode.For example, accelerating electrode is made by relatively high-resistance material, for example, and the plastics of filling carbon, silicon, GaAs, indium phosphide, boron nitride, carborundum, cadmium selenide etc.The electricalresistivityρ that these materials should have usually is in the scope of 103 to 109 Ω cm, and preferably between 105 to 108 Ω cm, more better scope is between 106 and 107 Ω cm.

At this moment, the geometry of electrode is selected like this, so that the local event such as spark or electric arc or disturbance can be terminated, and does not have remarkable electric current to increase or produces noise.

The present invention increases EFA electrode density (usually using ' electrode length ' of every volume to measure), and reduces significantly the aerodynamic fluid resistance that is caused by the electrode that relates to the electrode physical thickness.Additional advantage of the present invention is, no matter the operating voltage that is applied to electrode how near-earth near the limit value of a dielectric breakdown, always it provides actual nonarcing work.Of the present invention also have additional advantage to be, a more solid corona electrode shape is provided, and makes electrode more firm and reliable.The design of electrode makes it can form the EFA of " fault-free ", for example, if there is the people to be not intended to touch, can not have the harm of fail safe.

Of the present invention also have additional advantage to be, provides corona discharge with the electrode except solid material.For example, a conductor fluid can be used for the emission of corona discharge effectively, supports the ability that larger electrical power is processed, and therefore, increases the speed of fluid.In addition, fluid can change electrochemical process near the sheath of corona discharge, for example, the ozone of generation (in the situation of air) lacks than the ozone by solid corona material production, or the chemical change by fluid (harmful gas of moment destroys) is provided.

Brief description of drawings

Fig. 1 is the circuit diagram with the signal of the high voltage source (HVPS) of low inertia output circuit, described output circuit can be controlled and rapidly a Voltage-output level is reduced to level lower than certain nargin of dielectric breakdown triggering level, this punctures the dc voltage that triggering level also produces a high amplitude, and it has low amplitude value high frequency voltage ripple;

Fig. 2 is the circuit diagram of the signal of another high voltage source, and it is configured to prevent such as the spark event in the high voltage device of corona discharge assembly;

Fig. 3 is the circuit diagram of the signal of another high voltage source, and it is configured to prevent flashing event in high voltage device;

Fig. 4 is the circuit diagram of the signal of a high voltage source, and it is configured to prevent flashing event in high voltage device;

Fig. 5 is the output corona current at corona discharge electrode place of electrostatic fluid accelerator and the oscilloscope trace of output voltage, and electrostatic fluid accelerator is from constructing to expect and avoiding accepting electric energy the HVPS of spark event;

Fig. 6 is the figure that is connected to the HVPS of the HV power supply of supplying with an electrostatic equipment;

Fig. 7 A is the schematic diagram that produces the power supply of dc voltage and dc+ac electric current;

Fig. 7 B illustrates respectively the voltage and current amplitude to the waveform of the power supply output of time;

Fig. 8 A is the schematic diagram with corona discharge assembly of insufficient interelectrode capacitance, in order to (i) optimize air stream, (ii) reduces power consumption and/or (iii) farthest reduce ozone to occur;

Fig. 8 B is the schematic diagram of a corona discharge assembly, its optimize come from all power supplys as shown in Figure 1 to benefit and with described power supply cooperation;

Fig. 9 is applied to the high voltage of corona discharge assembly and the oscilloscope trace of the corona current that synthesizes;

Figure 10 A is the schematic diagram of electrostatic fluid accelerator (EFA) assembly, and it is with the single high voltage source of presenting contiguous corona discharge level;

Figure 10 B is the schematic diagram of an EFA assembly, and it is with a pair of synchro source of presenting each contiguous corona discharge level;

Figure 11 A is the timing chart of the voltage and current between the electrode of adjacent EPA level, there is no ac differential voltage component between level;

Figure 11 B is the timing chart of the voltage and current between the electrode of adjacent EPA level, wherein, has little ripple voltage between level;

Figure 12 is the schematic diagram of a power subsystem, and this power subsystem comprises a pair of high voltage source subcomponent with synchronous output voltage;

Figure 13 A is the vertical view of signal of implementing the two-stage EFA assembly of how much of one first arrangement of electrodes;

Figure 13 B is the vertical view of signal of implementing the two-stage EFA assembly of how much of one second arrangement of electrodes;

Figure 14 is the schematic diagram with the EFA assembly of the corona electrode that forms fine rule, and all fine rules are spaced apart with relative high resistance accelerating electrode on electric;

Figure 15 is that the latter's current-carrying part is completely enclosed within shell with the schematic diagram of the corona electrode that forms fine rule with the EFA assembly of the accelerating electrode that forms the high resistance rod;

Figure 16 is with the corona electrode that forms fine rule and forms the schematic diagram of EFA assembly of the accelerating electrode of high resistance rod, and it is with the adjacent segmentation along change width or conductivity step of accelerating electrode;

Figure 17 is the schematic diagram with the EFA assembly of the corona electrode that is the faciola shape, and described faciola is electric between relative high resistance accelerating electrode;

Figure 18 A illustrates the chart that fluid intrinsic corona current interior and corresponding accelerating electrode distributes;

Figure 18 B is the chart that the path of the electric current that is produced by spark or arc event is shown;

Figure 19 is the schematic diagram of a comb shape accelerating electrode; And

Figure 20 is the schematic diagram that is filled with a conductor fluid and is inserted in the drop shape corona electrode of the hollow between the high resistance accelerating electrode.

Embodiment

Fig. 1 is the circuit diagram of the signal of high voltage source (HVPS) 100, and it constructs to prevent flashing event in the high voltage device such as electrostatic fluid accelerator.HVPS 100 comprises the high voltage step-up transformer 106 with armature winding 107 and secondary winding 108.Armature winding 107 is connected to an ac voltage, and ac voltage is provided by half-bridge converter (power transistor 104,103 and capacitor 105,114) by dc voltage source 101.Gate signal controller 111 produces control impuls at transistor 104,113 door place, and its frequency is definite by the value of the resistor 110 that forms the RC time circuit and capacitor 116.Secondary winding 108 is connected to voltage rectifier 109, and it comprises four high voltages (HV), and high-frequency diode is configured to a full wave bridge rectifier circuit.HVPS 100 produces a high voltage between terminals 120 and ground connection, terminals 120 and grounding connection are to a HV device or electrode (for example, corona discharge assembly).The AC component that is applied to the voltage of HV device (for example, traversing the corona discharge electrode of an array) is detected by high voltage capacitor 119, and detected voltage is by Zener diode 122 restrictions.When the voltage fluctuation characteristic before output voltage demonstration spark, the AC wave component of feature causes traversing the sizable signal level of resistor 121 1, thereby opens transistor 115.Transistor 115 is grounded on the needle pin 3 of signal controller 111, and the voltage of the door of power transistor 104 and 113 is traversed in interruption.Make transistor 104 and 113 not conductings, one almost instantaneous voltage interruption have influence on armature winding 107, therefore, be delivered to close-coupled secondary winding 108.Because a similar quick voltage drop causes beginning level lower than a spark at the corona discharge assembly place, so, puncturing of any upcoming electric arc or dielectric material can be avoided.

Spark prevents that technology from comprising two steps or stage.At first, being stored in energy in the stray capacitance of corona discharge assembly discharges by corona current and drops to corona and begin voltage.This voltage always far away from spark begin voltage below.If this discharge occurred in the time cycle that is shorter than about 0.1msec (that is, less than 100mksec), the whereabouts of voltage will prevent effectively that spark event from occuring.Determined with test method, voltage begins voltage level from higher spark and drops to corona and begin level, can preferably approximately realize in 50mksec.

Reach corona at supply voltage and begin after level and corona current stop, it is much slow that discharge process becomes, and voltage drops to zero on the time of several milliseconds.By the natural capacity in the door source of resistor 121 and transistor 115 after identical predetermined time of limiting, power supply 100 recovery voltages generations.Predetermined time on the magnitude of several milliseconds, has found that usually, and such scheduled time is enough for ionization process and normal operation recovery.Again be applied to transformer 106 in response to power supply, the voltage that is provided to corona discharge assembly approximately begins electrical level rising to the normal operation level from the corona power supply within several milliseconds of times.Adopt such structure, even when output voltage surpasses certain value, can the flashing event yet, same corona discharge is arranged and structure causes spark frequently otherwise the described magnitude of voltage that surpasses can traverse.Power supply 100 can form with the electronic unit that provides; Do not need special parts.

Fig. 2 is the circuit diagram of the signal of a power supply 200 that changes, and it is with spring strip contact 222 and additional load 223.Power supply 200 comprises the high voltage two winding electric sensors 209 with armature winding 210 and secondary winding 211.Armature winding 210 is connected to ground connection by power transistor 208, and is connected to the dc power supply that is arranged on terminals 201.PWM controller 205 (for example, a UC3843 loop Current-type PWM Controller) is in door place's generation control impuls of transistor 208, and its operating frequency is determined by the RC circuit that comprises resistor 202 and capacitor 204.Typical frequency can be 100kHz or higher.Secondary winding 211 is connected to voltage multiplier circuit, and it comprises HV capacitor 215 and 218, and high frequency HV diode 216 and 217.Power supply 200 produces HV dc electricity between the outlet terminal 219 and 220 that is connected to a HV device or electrode (that is, load), its between 10 and 25kV between, and be generally 18kV.When the electric current by by-passed resistor 212 surpasses a default level and allows an electric current to flow through one when comprising the control coil 221 of reed type relay of spring strip contact 222, control transistor 203 and open.When electric current passed through coil 221, in the certain hour of being determined by resistor 207 and capacitor 206, spring strip contact 222 was closed, and HV outputs to HV drain resistor 223 along separate routes, loaded output and reduction output-voltage levels.Use this spark control circuit and make up various EFA parts and/or install and to cause eliminating practically all sparks in course of normal operation.Anchor relay 203/222 can be the ZP-3 by the Ge-Ding Information Inc. product in Taiwan.

Fig. 3 is the circuit diagram of signal that is similar to another HVPS structure of structure shown in Figure 2.Yet in the situation that HVPS 300 comprises spring strip contact 322 and directly be connected to the additional load 323 of the outlet terminal of HVPS, HVPS 300 comprises a high voltage transformer 309 with armature winding 310 and secondary winding 311.Armature winding 310 is connected to ground connection by power transistor 308, and is connected to a DC source that is connected to power input terminal 301.PWM controller 305 (for example a, UC3843) is in door place's generation control impuls of transistor 308.The operating frequency of these control impuls is determined by resistor 302 and capacitor 304.Secondary winding 311 is connected to a voltage multiplier circuit, and it comprises HV capacitor 315 and 318 and high frequency HV diode 316 and 317.HVPS300 produces the approximately high voltage output of 18kV at the outlet terminal 319 that is connected to HV device or electrode (load) and 320 places.When the electric current by by-passed resistor 312 surpassed certain predetermined predetermined level and allows electric current to flow through control coil 321, spark was controlled transistor 303 and is connected.When electric current flows through coil 321, spring strip contact 322 close and along separate routes the HV of HVPS output to HV drain resistor 323, thus, reduce output-voltage levels within a time period of being determined by resistor 307 and capacitor 306.Use this initial spark detection and slow down structure, causing in fact not having spark to occur within the operating time that extends.

Fig. 4 illustrates a power supply architecture that is similar to structure shown in Figure 2, and HVPS400 also comprises relay and power drain load 423, and described relay comprises normally open contact 422 and coil 421.HVPS400 comprises a power transformer 409 with armature winding 410 and secondary winding 411.Armature winding 410 is connected to ground connection by power transistor 408, and is connected to the dc power supply at terminals 401 places.PWM controller 405 (for example a, UC3843) is in a string control impuls of door place's generation of transistor 408.The operating frequency of these control impuls is set by resistor 402 and capacitor 404.Secondary winding 411 is connected to a voltage multiplier circuit, and (for example, 9kV), multiplier circuit comprises HV capacitor 415 and 418 and high frequency HV diode 416 and 417 to supply a high voltage.Power supply 400 produces high voltage output at the terminals 419 that are connected to HV device or corona electrode (load) and 420 places.When the electric current by by-passed resistor 412 surpassed the predetermined level of certain feature that is predefined for initial spark event and allows electric current to flow through coil 421, spark was controlled transistor 403 and is connected.When electric current flow through coil 421, relay contact 422 was closed, and made armature winding 410 short circuits by drain resistor 423.The additional load that is provided by drain resistor 423 reduces output-voltage levels rapidly within a time period of being determined by resistor 407 and capacitor 406.

Fig. 5 is an oscillographic demonstration, and it comprises two sweep traces with the power supply output of corona current 501 and output voltage 502 expressions.As seen in FIG., the characteristic narrow spike 503 of corona current tool, the initial spark event that it was illustrated in approximately in time of 0.1 to 1.0msce is shown as the approximately 2.2msce after current spike here.Survey corona discharge or the similar current spike 503 in the HV device, but excitation control circuit disconnects HVPS, and the storage power of any needs of preferably releasing, an electrode potential is dropped to or lower than the safety level of dielectric breakdown.Therefore, except for example passing through, stop the work of a high frequency pulse generator (for example, PWM controller 205) to be interrupted outside the primary source of HVPS, also can take other step to come to be applied to rapidly the lower voltage of HV device to starting or the dielectric breakdown potential level lower than spark.These steps and support circuit to comprise the electric charge of any storage " is released " in suitable " recipient ", for example, a resistor, capacitor, inductor, or their certain combination.Physics circle that recipient can be positioned at HVPS encloses, and/or is positioned at the device place of energising, that is, and and HV device or load.If be positioned at the load place, recipient can accept to be stored in the electric charge in load quickly, and a recipient that is positioned at HVPS place can be directed reducing the voltage level that HVPS exports.Should be noted that, use the HV resistor, recipient can dissipation power reduce the voltage level that is applied to the load place or is positioned at the load place.Perhaps, solved and after rapidly device being turned back to best effort in spark event, energy can be stored and again apply.In addition, there is no need under any circumstance to reduce the voltage to the zero potential level, but voltage level is reduced to certain known or predetermined value, to avoid spark event, this is gratifying.According to an embodiment, HVPS with specific pre-spark indicators (for example comprises processing and memory capability, current spike intensity, waveform, time etc.) feature and suitable response interrelate, to avoid or farthest to reduce the probability of spark event on certain default level.For example, HVPS can be in response to an absolute amplitude or (that is, the ∫ of the area under a current spike _t1 ^t2(i _t-i _Average) dt), be used for inserting selectively a plurality of previous load of determining, so that a spark event controlled quentity controlled variable that requires to be provided, for example, avoid a spark event, postpone or reduce the intensity of spark event, the quantity or the speed that provide spark event etc. to require.

Referring again to Fig. 5, if the output of HVPS all is interrupted, do not have electric current to flow into corona discharge assembly, the voltage that traverses corona discharge assembly is fast-descending as shown in Figure 5 and as described above.After certain short time, can be observed current spike 504, it indicates moment that actual spark event occured and does not take action to reduce to be applied to the voltage level of HV device.Fortunately, due to output voltage far below spark level, so, do not have spark or electric arc to produce.On the contrary, visible one medium current spike only, it is enough little and do not cause any disturbance or undesirable arc hissing.After certain hour section on 2-10msec magnitude after probe current spike 504, or after the 1-9msec after current spike 503, HVPS connects and recovers and works.

Fig. 6 is the figure according to HVPS601 of the present invention, its connection and the HV electricity is fed to an electrostatic equipment 602, for example, a corona discharge fluid accelerating attachment.Electrostatic equipment 602 can comprise a plurality of corona discharge electrodes 603, and they are connected to HVPS601 by public connection 604.Attractor or collector electrode 605 are exported by connecting 606 HV that are connected to complementary HVPS601.After the HV electromotive force is applied to corona discharge electrode 603, corresponding corona discharge electron cloud is formed near electrode, for the fluid of getting involved (for example, air) molecule charges, and described fluid molecule rises does one between the attractor of corona discharge electrode 603 and relative charging or the dielectric material between collector electrode 605.The accelerated relative electric charge towards collector/attractor electrodes 605 of the fluid molecule of ionization causes a desirable fluid motion.Yet due to all-environment disturbance with other, the dielectric property of fluid can change.This kind variation can be fully, so that dielectric breakdown voltage can drop to certain a bit, at this moment, electric arc can occur between the corona discharge and attractor electrode 603,605 of many groups.For example, the variation of dust, moisture and/or fluid density dielectric breakdown level can be reduced to lower than the operating voltage that is applied to device a bit on.By monitoring the electric characteristic (for example, current spike or pulse etc.) for the power supply signal of spark front signal event, can implement suitable step and come the control event to occur, for example, reduce the operating voltage in these situations, wherein require to avoid spark to occur.

Although above-mentioned the present invention is directed to eliminated or reduce a plurality of spark event and/or spark event intensity, other embodiment also can provide ability and the function of other spark control device.For example, can control spark event according to the method for one embodiment of the invention, it changes voltage level (for example, changing the duty cycle of PWM controller) rapidly makes sparkover more even, one spark intensity and/or the speed that requires is provided, or is used for any other purpose.Therefore, other application and enforcement of embodiments of the invention comprises that detection before spark and voltage change to a special level rapidly to obtain the result to require.

According to above-mentioned feature with other of the present invention, three features provide controls spark event effectively.At first, power supply should be mertialess.This means that power supply should be able to change an output voltage rapidly within the time less than the time period between pre-spark indicators and spark event generation.This time be generally a millisecond or less than.The second, one effective method with the front detection of spark fast should be included in power shutdown circuit.The 3rd, load device (for example, corona discharge assembly) should have low natural capacity, and it can discharge within the time less than the time period between spark front signal and actual spark event.

Fig. 7 A is consistent with an embodiments of the invention block diagram that is suitable for the power supply of corona discharge assembly power supply.High voltage source (HVPS) 705 produces the supply voltage 701 (Fig. 7 B) that can change amplitude Vac+dc.Voltage 701 is the alternating component of stack one ac or amplitude Vac on the average dc voltage of Vdc, and described Vac has an instantaneous value (that is, the alternating component of voltage) by distance 703 representatives.The typical average dc component (Vdc) of voltage 701 is preferably and equals 18kV in 10kV to 25kV scope.Ripple frequency " f " is about 100kHz normally.Should be noted that, the harmonic wave of low frequency, for example, the mains frequency of multiple 60Hz comprises that 120Hz can be presented in the waveform of voltage.Most important harmonic wave is only considered in following calculating, that is, high-frequency harmonic is 100kHz in this case.The peak of ripple can preferably be less than or equal to 900V to peak amplitude 703 (Vac is the ac component of voltage 701) in the scope of 0 to 2000 Fu Feng to the peak, its RMS value is approximately 640V.Voltage 701 is applied to paired electrode (that is, corona discharge electrode and attractor electrode).Resistor 706 represents the internal resistance of HVPS705 and HVPS705 is connected to the resistance of the electric wire of electrode, and this resistance has a relatively little value usually.Electric capacity 707 represents two stray capacitances between electrode.It should be noted that, the value of electric capacity 707 is not constant, but can generally be estimated as approximately 10pF level.

Resistance 708 represents the feature of dc ohm load resistor R of the non-impedance of the air gap between corona discharge electrode and attractor electrode.This resistor R depends on the voltage that applies, and usually has the representative value of 10M Ω.

The dc component flows through resistor 708 from HVPS705, and ac component Main Current is crossed capacitor 707, and its working range at 100kHz presents quite low impedance than resistor 708.Especially, the impedance Xc of capacitor 707 is functions of ripple frequency.In this case, it equals approx:

Xc＝1/(2πfC)＝1/(2*3.14*100,000*10*10 ^-12)＝160kΩ

Flow through the ac component I of the electric current of capacitor 707 _acEqual:

I _ac＝V _ac/X _c＝640/160,000＝0.004A＝4mA。

Flow through the dc component I of the electric current of resistor 708 _dcEqual:

I _dc＝V _dc/R＝18kV/10MΩ＝1.8mA 。

Therefore, between electrode, the ac component of resultant current is approximately 2.2 times of dc component of resultant current.

The work of device 700 can be described with reference to the timing chart of Fig. 7 B.When the electric current of ionization arrived certain maximum amplitude (Imax), ion was launched from corona discharge electrode, with the molecule around convection cell and particle (that is, air molecule) charging.At this moment, produce maximum power and the maximum ozone generating (in air or oxygen) of generation.When electric current is reduced to I _minThe time, produce less power, in fact do not have ozone to occur.

At this moment, the molecule of charging and particle with the maximum current situation in identical power (because voltage keeps substantially constant) accelerated towards relative electrode (attractor electrode).Therefore, fluid acceleration rate is basically unaffected, and does not reach the degree as reducing the ozone generation.

The acceleration of surrounding fluid produces by forming the moment of corona discharge electrode to the ion of attractor electrode.This is because ion forms from the corona discharge electrode emission " ion cloud " that surrounds corona discharge electrode under the impact of voltage 701.This ion cloud moves towards relative attractor electrode in response to electric field strength, and the intensity of electric field is proportional to the value of the voltage 701 that applies.The electric current that is applied by power supply 705 is proportional to output current 702 (supposition voltage 701 keeps substantially constant) approx.Therefore, the pulse characteristic of electric current 702 causes the pure dc electric current of the identical amplitude of energy loss-rate lower.The alternating component 703 of the output voltage of the relation between such current waveform and the ac of electric current and dc component by having a low internal resistance 706 and small magnitude is guaranteed.Method by test determined, when the relative amplitude of the alternating component of electric current 702 (that is, Iac/Idc) (that is, in the time of Vac/Vdc), can reach the most effective electrostatic fluid and accelerate greater than the relative amplitude of the alternating component of voltage 701.In addition, because these ratios change, so, realize other improvement.Therefore, if Vac/Vdc less than Iac/Idc (namely considerably, be not more than half), and preferably be not more than 1/10,1/100 of Iac/Idc, or (wherein, Vac and Iac measure similarly even preferably to be not more than 1/1000, for example, be all RMS, peak to the peak, or similar value), can reach the other efficient that fluid accelerates.Changing other mode with mathematical method explains, the constant component of corona current and the product of executing alive time dependent component, product divided by two kinds of the components of the constant of the time dependent component of corona current and the voltage that applies, the gained business should be minimum, for some initial step, the step of various discrete provides significant improvement at quantitative aspects:

Fig. 8 A illustrates the corona discharge assembly that does not satisfy above-mentioned equation.It comprises the corona discharge electrode 800 that is aciculiform, and its sharp-pointed geometric form provides the electric field of necessity to produce a corona discharge near needle tip.Relative collector electrode 801 is much bigger, and it is the form of a smooth shaft.High voltage source 802 is supplied

electric wire

803 and 804 by high voltage and is connected to two electrodes.Yet, because sparking electrode is perpendicular to the relative orientation of the central axis of collector electrode 801, so this structure does not form any significant electric capacity between electrode 800 and 801.In general, any electric capacity be proportional between electrode towards effective area.This area is very little in the device shown in Fig. 8 A, because one of them electrode is the shape of the needle point with cross-sectional area.Therefore, the electric current that flows to electrode 801 from electrode 800 will not have significant ac component.The structure that is similar to the corona discharge assembly of structure shown in Fig. 8 A shows that the ozone of low-down air acceleration capacity and relative significant quantity occurs.

Fig. 8 B illustrates another kind of corona discharge assembly.A plurality of corona discharge electrodes are the shape of long and thin corona discharge wire 805, and its relative collector electrode 806 is the shape of much thick rod, and they are parallel to corona wire 805.High voltage source 807 is connected to corona discharge wire 805 and collector electrode 806 by the high-

tension electricity streamline

809 and 810 of correspondence.This structure provides much bigger area between electrode, therefore, form betwixt much bigger electric capacity.Therefore, the electric current that flows to collector electrode 806 from corona wire 805 will have significant ac component, if high voltage source 807 has enough electric current deliverabilities.When with having significant high-frequency current ripple but during the power supply of the high voltage source of less ripple voltage (that is, alternating component), the structure of the corona discharge assembly as shown in Fig. 8 B provides larger air acceleration capacity and less ozone to occur.

Referring again to Fig. 1, high-voltage power circuit 100 can be constructed to be permeable to have the high voltage of little high-frequency ripple.As mentioned above, power supply 100 comprises the high-tension doublewound transformer 106 with armature winding 107 and secondary winding 108.Armature winding 107 is connected to a dc voltage source 101 by half bridging parallel operation (power transistor 104,113 and capacitor 105,114).Gate signal controller 111 produces control impuls at transistor 104,113 door place by resistor 103 and 117.The operating frequency of these pulses is determined by the value of selected resistor 110 and capacitor 116.The secondary winding 108 of transformer 106 is connected to bridge-type voltage rectifier 109, and it comprises four high-voltage high-frequency power diodes.Power supply 100 produces a high voltage output between terminals 120 and ground connection, grounding connection is to the electrode of corona discharge assembly.

Fig. 9 illustrates scope sweep trace as described below: the high voltage 901 at the waveform of output current and voltage, corona discharge assembly place is together with the synthetic electric current 902 that produces and flow through array electrode.This shows, voltage 901 has approximately 15, the relatively constant amplitude of 300V, and have minimum or there is no alternating component.On the other hand, electric current 902 has the relatively large electric current alternating component (ripple) over 2mA, far surpasses current average (1.189mA).

Therefore, except above-mentioned feature, the present invention also comprises all embodiment, wherein, the corona discharge cells of power source combination an array of low inertia, they present a high reactive load to power supply.That is, the capacitance load of array surpasses any impedance component in power supply output widely.This relation provides the voltage of constant, a low ripple and the electric current of high ripple.This result is, the generation of electrostatic fluid accelerator and the ozone that reduces efficiently.

Figure 10 A is the schematic diagram of electrostatic fluid accelerator (EFA) device 1000 according to another embodiment of the present invention, and it comprises two EFA levels 1014 and 1015.The one EFA level 1014 comprises corona discharge electrode 1006 and relevant accelerating electrode 1012; The 2nd EFA level 1015 comprises corona discharge electrode 1013 and relevant accelerating electrode 1011.Two EFA levels and all electrodes all schematically illustrate in the drawings.Only have one group of corona discharge electrode and collector electrode that every one-level is shown, so that diagram, but be expected corona electrode and the accelerating electrodes that comprise that a large amount of one-tenth arrays is right at different levels.Important being characterised in that of EFA1000, between corona discharge electrode 1006 and collector electrode 1012 apart from d ₁Between comparable collector electrode 1012 of intending rear class 1015 and its corona discharge electrode 1013 apart from d ₂, namely the hithermost distance between the element of adjacent level is not too greater than with the distance between the electrode in one-level.Normally, the stage distance d between the corona discharge electrode 1013 of collector electrode 1012 and adjacent level ₂The inter-stage spacing d between interior corona discharge electrode 1006 at the same level and collector electrode 1012 ₁(or the spacing between corona discharge electrode 1013 and collector electrode 1011) 1.2 and 2.0 times.Because the spacing that this is consistent is so the electric capacity that reaches between 1006 and 1013 between electrode 1006 and 1012 is identical magnitude.It should be noted that, in this structure, the electric capacity that is coupled between corona discharge electrode 1006 and 1013 can allow some stray electrical current to flow between electrode.This stray electrical current be with electrode pair 1006 and 1012 between the identical magnitude of the amplitude of capacity current.In order to reduce unnecessary electric current between electrode 1013 and 1006, each electrode should be supplied with synchronous high voltage waveform.In the embodiment shown in Figure 10 A, two EFA levels namely, are presented the power supply of the single voltage conversion circuit of having of parallel two-stage (for example, current transformer, rectifier and filtering circuit etc.) by 1005 power supplies of common power supply.This guarantees that the voltage difference between electrode 1006 and 1013 keeps invariable with respect to electrode 1006 and 1011, like this, does not have electric current or only has very little electric current to flow through between electrode 1006 and 1013.

Figure 10 B illustrates the alternative structure of an EFA1001, and it comprises a pair of respectively by the power supply 1002 that separates and the 1003

EFA levels

1016 and 1017 of powering.The one EFA level 1016 comprises corona discharge 1007 and collector electrode 1008, and they are at the electrode of a pair of complementation of the interior formation of level 1016.The 2nd EFA level 1017 comprises corona discharge electrode 1009 and collector electrode 1010, and they form the electrode of one second pair of complementation.Two

EFA levels

1016,1017 and all electrode 1007-1010 be schematically illustrated in figure.

The one EFA level 1016 is by power supply 1002 power supplies, and the 2nd EFA level 1017 is by power supply 1003 power supplies.Two EFA levels and two

power supplys

1002 and 1003 can be identical designs, and be synchronous to simplify, but different designs can be used as the layout of holding suitably another

kind.Power supply

1002 and 1003 is realized synchronous so that synchronous output to be provided by control circuit 1004.Control circuit guarantees that two

power supplys

1002 and 1003 produce the output voltage of homophase synchronous and that basically equate, so that the electrical potential difference between

electrode

1007 and 1009 keeps substantially constant (for example, not or have very little ac component of voltage).(note: although term " synchronously " usually comprises the consistent of frequency between signal and phase place, but further emphasize the requirement of phase alignment by using term " homophase ", its require signal at the position of correspondence homophase each other, for example, as be applied to and be present at different levels in.) keep this electrical potential difference be constant (namely, farthest reduce or eliminate any ac component of voltage) can limit or eliminate flowing of any capacity current between

electrode

1007 and 1009, to reach an acceptable value, for example, usually less than 1mA, and preferably less than 100 μ A.

With reference to waveform as shown in Figure 11 A and 11B, can see the minimizing of the parasitic capacitive electric current between the electrode of contiguous EFA level.As shown in Figure 11 A, being presented on the voltage V1 (Figure 10 B) on electrode 1007 and being presented on voltage V2 on electrode 1009 is synchronous and homophase, but needn't equate on the dc amplitude.Because synchronous completely, so, be presented on poor V1-V2 between the voltage on

electrode

1007 and 1009 near constant, be illustrated between signal an only dc deviation value (that is, there is no the ac component).The electric current I c that flows through the capacitive coupling between electrode 1007 and electrode 1009 is proportional to the time rate of change (dV/dt) of the voltage that traverses electric capacity:

Ic＝C*〔d(V1-V2)/dt〕。

Can directly draw from this relational expression, keep constant (that is, there is no the ac component) if traverse the voltage of any electric capacity, not have electric current to flow through this path.On the other hand, if voltage changes (that is, d (V1-V2)/dt is large) rapidly, what for extremely little change in voltage can form large capacity current.Go out excessive electric current for fear of the different electrode stream from adjacent EFA level, the voltage that is applied to the electrode of these adjacent levels should be synchronously and homophase.For example, with reference to Figure 11 B, corona voltage V1 and V2 are slightly asynchronous, cause at poor d (V1-V2)/medium and small ac component of voltage of dt.This little ac component of voltage causes a parasite current Ic who flows through significantly between adjacent EFA level.One embodiment of the invention comprise the synchronous of the power that is applied to all grades, flow through inter-stage to avoid electric current.

The hithermost spacing of the electrode of adjacent EFA can be similar to as follows.Notice, typical EFA works on a rather narrow voltage range effectively.Be applied to the voltage V between corona discharge electrode and at the same level passive electrode _cShould surpass so-called corona and begin voltage V _Onset, in order to carry out suitable work.That is, as voltage V _cLess than V _OnsetThe time, do not have corona discharge to occur and do not have air movement to occur.At this moment, V _cShould be no more than dielectric breakdown voltage V _b, to avoid electric arc.According to the geometry of electrode and other condition, V _bCan be V _OnsetTwice.For typical electrode structure, V _b/ V _OnsetRatio be about 1.4-1.8, like this, any special corona discharge electrode should not be positioned at the distance from adjacent passive electrode that one " back of the body corona " may occur.Therefore, the normalization between the most close electrode of adjacent level apart from aNn should be at least, and corona discharge electrode and with 1.2 times of the distance of the normalization between the passive electrode of one-level " aNc " preferably is not more than 2 times of distance " aNc ".That is, the electrode of adjacent level should be spaced apart, begins voltage to guarantee the voltage difference between electrode less than the corona between any electrode of adjacent level.

If above-mentioned condition is not being met, necessary result is that adjacent level must further and than other situation be spaced apart from each other widelyr.The spacing that increases like this inter-stage causes adversely affecting several situations of air movement.For example, the spacing of the increase between adjacent level causes the pipeline grown, therefore, causes the resistance larger to air-flow.Whole volume and weight of EFA also increases.For synchronous and HVPS homophase, the generation that does not lower efficiency or improve spark by reducing spacing between the HFA level can be avoided these negative aspects thus.

With reference to Figure 12, the EFA1200 of a two-stage comprises a pair of HVPS 1201 and 1202, they to corresponding first and second grade 1212 and 1213 relevant.Two-stage is substantially the same, and by identical HVPS1201 and 1202 supplied with electric power.HVPS1201 and 1202 comprises pulse width modulation (PWM) controller 1204 and 1205 separately, power transistor 1206 and 1207, high voltage inductors 1208 and 1209 (that is, filtering choke), and voltage multiplier 1201 and 1202.The EFA corona discharge electrode of HVPS 1220 and the 1221 pairs of levels 1212 and 1213 correspondence provides power.As mentioned above, although level 1212 and 1213 EFA electrode is schematically represented as a single right corona discharge electrode and accelerations (or attractor) electrode, at different levelsly will generally include how right electrode, they are configured to two-dimentional array.PWM controller 1204,1205 produces (with being provided at needle pin 7) high-frequency impulses to separately filtration transistor 1206 and 1207 door.The frequency of these pulses is determined by the RC timing circuit of the correspondence that comprises resistor 1216 and capacitor 1217 and resistor 1218 and capacitor 1219.In general, the difference slightly between these component values of inter-stage can cause the slightly different operating frequency of two HVPS levels.Yet even slightly a variation of frequency also can cause nonsynchronous work of the level 1212 and 1213 of EFA1200.Therefore, in order to ensure power supply 1201 and 1202 synchronous and homophases (namely, zero phase-shift or differ) work, connect controller 1205 by a synchronous input circuit that comprises resistor 1215 and capacitor 1214, come to accept a synchronous signal pulse from the needle pin 1 of PWM controller 1204.This structure is synchronized to PWM controller 1204 with PWM controller 1205, so that the potential pulse of two PWM controller outputs not only synchronous (same frequency) but also homophase (same-phase).

Figure 13 A and 13B are the sectional views of two different structures of two-stage EFA device.Although two-stage only is shown, the details of principle and configuration aspects is identical.With reference to Figure 13 A, an EFA device 1311 by two series or one in front and one in back level 1314 and 1315 form.The first order 1314 comprises a plurality of parallel corona discharge electrodes 1301 that are aligned in the first vertical column, and the passive electrode 1302 that is aligned in the second post of the post that is parallel to corona discharge electrode 1301.All electrodes are presented in the cross section that longitudinally passes in and out the paper extension.Corona discharge electrode 1301 can be the form of wire as shown in the figure, but also can use other structure.It is conducting rod that passive electrode 1302 is shown as horizontal extension.Moreover, for the purpose of illustrating, can implement geometry and the structure of other consistent with various embodiment of the present invention.The second level 1315 comprises the corona discharge electrode 1303 (also being shown as the thin wire that extends perpendicular to paper) of an alignment similarly, and passive electrode 1304 (being also bar).All electrodes are arranged in air duct 1305.First and second grade 1314 and the 1315 independent HVPS (not shown) power supplies by correspondence of EFA1311.HVPS is synchronous and homophase, so the corona discharge electrode 1303 of the second level 1315 can be placed on from the hithermost possible normalization distance of the passive electrode 1302 of the first order 1314, and can not adversely interact and reduce the EPA characteristic.

For the purpose of illustrating, we suppose that all voltages and its component (for example, ac and dc) on the electrode that is applied to

adjacent level

1314 and 1315 equates.Suppose further that also high voltage is applied to

corona discharge electrode

1301 and 1303, and

passive electrode

1302 and 1304 ground connection namely, remain on public ground potential with respect to the high voltage that is applied to corona discharge electrode 1301 and 1303.All arrangement of electrodes flatly align counter electrode not at the same level in parallel vertical column, and vertically depart from the electrode of the complementation of stagger arrangement post in its own level.Corona discharge electrode 1301 and the vertically normalization between the most close contiguous passive electrode 1302 preceding limbs distance 1310 equal aN1.Normalization between the tail edge of the corona discharge electrode 1303 of the second level and the passive electrode 1302 of the first order should be a bit larger tham aN1 apart from aN2 (1313), and actual range depends on the concrete voltage that is applied to corona discharge electrode.In any case, aN2 should namely, in 1 to 1.2 times of scope of distance aN1, be preferably 1.1 to 1.65 times of aN1 just greater than aN1, even more preferably is approximately 1.4 times of aN1.Especially, as shown in FIG. 13A,, flow through therebetween corona and begin voltage between voltage to avoid forming an electric current just greater than necessary distance apart from aN2.Let as assume that this normalization " stant " equals 1.4 * aN1 apart from aN2.Then, the horizontal range between adjacent level 1312 is less than distance aN2 (1313).As shown in the figure, when the electrode of the same type of adjacent level is positioned at a plane 1320 when (as shown in FIG. 13A), the inter-stage spacing minimizes.Plane 1314 can be defined as a plane (plane 1317 in Figure 13 A) on the plane that is orthogonal to the edge that comprises corona discharge electrode.If the electrode of the same type of adjacent level is positioned at different but parallel plane, for example, plane 1321 and 1322 (as shown in Figure 13 B), the synthetic minimum spacing between all electrodes of adjacent EFA level equals with the aN2 shown in line 1319.It should be noted that, the length of line 1319 is identical with distance 1313 (aN2), and greater than distance 1312, the inter-stage spacing increases like this.

Therefore, these features of the present invention comprise the structure of the one or more conditions in three kinds of conditions that satisfy in various embodiment:

The electrode of adjacent EFA level is powered with substantially the same voltage waveform, that is, the electromotive force on adjacent electrode should have substantially the same alternating component.These alternating components should approach on quantity and phase place or be identical.

Adjacent EFA level is the interval closely, and the spacing between adjacent level is limited and determined by such distance, and this distance just is enough to avoid or farthest reduces any corona discharge between the adjacent level electrode.

The electrode of the same type of adjacent level should be positioned at identical plane, and this planar quadrature is in the plane of electrode (or electrode preceding limb) location.

Figure 14 is the schematic diagram of EFA device 1400, it corona electrode 1402 that comprises wire is (for the purpose of this example, illustrate three, but also can comprise other quantity, one typically installs have into ten or become hundred electrodes in suitable array, so that a characteristic that requires to be provided) and accelerating electrode 1409 (in this simplified example as two).Each accelerating electrode 1409 comprises relative high resistance portion 1403 and a low resistance part 1408.The electricalresistivityρ that high resistance portion 1403 has is 10 ¹To 10 ⁹In the scope of Ω cm, preferably 10 ⁵With 10 ⁸In scope between Ω cm, more be preferably 10 ⁶To 10 ⁷In the scope of Ω cm.

All electrodes are presented in the cross section.Therefore, corona discharge electrode 1402 is form and the shape of thin wire, and accelerating electrode 1409 is shown as the shape of bar and plate." downstream " part of the corona electrode 1403 of the most close accelerating electrode 1409 forms and ionizes edge 1410.The low resistance part 1408 of corona electrode 1402 and accelerating electrode 1409 is connected to the terminals of the relative polarity of high voltage source (HVPS) 1401 by line conductor 1404 and 1405.The electricalresistivityρ that low resistance part 1408 has≤10 ⁴Ω cm, and preferably be not more than 1 Ω cm, even more preferably be not more than 0.1 Ω cm.EFA1400 produces a fluid along the fluid flow direction of asking shown in arrow 1407 and flows.

HVPS1401 is configured to produce a predetermined voltage between electrode 1402 and passive electrode 1409, in order to form an electric field between electrode.This electric field represents with point-like line of flow 1406.When voltage surpassed one so-called " corona begins voltage ", the movable beginning of a corona discharge caused from corona electrode 1402 process of emitting ions accordingly near corona electrode 1402.

Corona discharge process causes fluid ions from corona electrode 1402 emission and along with follow power line 1406 and accelerate towards accelerating electrode 1409.Be the corona current of free ion and other charged particle form near the most proximal end of accelerating electrode 1409.Then, corona current flows by the electrode relative with some high resistance path of surrounding fluid along the path of most low-resistance.The lower resistance that has the encirclement ionized fluid due to the high resistance portion 1403 of accelerating electrode 1409, so, the major part of corona current flows through the body of accelerating electrode 1409, namely, flow through high resistance portion 1403 to low resistance part 1408, complete by connecting wire 1405 to the return path of HVPS 1401.Due to the width (see Figure 14) mobile (principal direction that is parallel to Air Flow 1407, a voltage drop Vd along current path form) of electric current along high resistance portion 1403.This voltage drop is proportional to the resistance R long-pending (this moment omitting the resistance of low resistance part 1408 and connecting line) that corona current Ic multiply by high resistance portion 1403.Then, the virtual voltage Va that applies between the most proximal end of the correspondence of corona wire 102 and accelerating electrode 1409, due to the voltage drop that resistance causes, the virtual voltage Va that applies is less than the output voltage V of HVPS1401 _out, that is,

Va＝V _out-V _d＝V _out-I _c*R (1)。

Notice, corona current is the voltage Va of ratio between the end of corona electrode 1402 and accelerating electrode 1409 non-linearly, that is, current ratio voltage increases sooner.The empirical representation that the voltage-to-current relation can be expressed as approx:

Ic＝k ₁*(V _a-V _o) ^1.5，(2)

Wherein, V _o=corona begins voltage, and k ₁The coefficient that=experience is determined.This non-linear relation provides a desirable feedback, and in fact, it is automatically controlled and traverses the synthetic magnitude of voltage Va that electrode occurs, and prevents, farthest reduces, slows down or alleviate disturbance and the scrambling of corona discharge.Notice, corona discharge process is considered to " irregular " because of its characteristic (that is, " unpredictalbe "), and the corona current value depends on the multiple environmental factor that stands to change, for example, and temperature, contamination, humidity, foreign matter etc.If become larger in a position of inter-electrode space than some other position for some reason corona current, along the voltage drop V of corresponding high resistance portion 1403 _dTo become large, therefore, at the virtual voltage Va of this position with step-down.The generation that this limits again the corona current of this position and prevents or farthest reduce spark or electric arc.

Following example is used for the purpose of explanation, the typical component value that it uses as uses in one embodiment of this invention.In the embodiment of the EFA1400 as shown in schematically as Figure 14, a corona begins voltage and is assumed to and equals 8.6kV, to reach the field minimum intensity of 30kV/cm near corona electrode 1402.This value can be by calculating, measure or other method is determined, and for the corona electrode diameter of the corona of 10mm/accelerating electrode spacing and 0.1mm, this value is a corona initial value normally.The all-in resistance R that is used for the high resistance portion 103 of accelerating electrode 1409 _TotalEqual 0.5M Ω, and high resistance portion 1403 equals 1 inch along the width (seeing Figure 14) of airflow direction 1407.Length transverse to the accelerating electrode 1409 of airflow direction (that is, enter in figure plane direction) equals 24 inches.Therefore, the accelerating electrode 1409 for each inch has resistivity R _InchBe

R _inch＝R _total*24＝12MΩ

The empirical coefficient k that is used for this particular design ₁Equal 22*10 ^-6At the voltage Va place that applies that equals 12.5kV, corona current Ic equals

Ic＝4.6×10 ^-9*(12,500V-8,600V) ^1.5＝1.12mA。

Yet, flow through the corona current I of the semiconductor portions 103 of each inch _C/inchEqual

1.12mA/24inches＝47μA/inch。

Therefore, traverse the voltage drop V of this inchage of semiconductor portions 103 _dEqual

V _d＝47*10 ^-6A*12*10 ⁶Ω＝564V。

V from HVPS1401 _outEqual to be applied to the voltage V of electrode _aVoltage drop V with the semiconductor portions 1403 of traversing accelerating electrode 1409 _dSum is expressed as follows:

V _out＝12,500+564＝13,064V

For a certain reason, be increased to the twice of whole Distribution Values of 47 μ A/inch as the corona current at certain regional area, like this, it equals 94 μ A at certain some place, and V falls in resultant voltage _dTo reflect this variation and equal 1,128V (that is, V _d=94 * 10 ^-6μ A*12 * 10 ⁶Ω).Then, V _a=V _out-V _d=13,064-1,128=11,936V.Therefore, the voltage drop V of increase _dSlow down the actual voltage level at regional area place, and limit this regional corona current.According to formula (2), by the corona current I of this length of inch _cCan be expressed as 4.6*10 ^-9(11,936-8,600V) ^1.5/ 24inch=0.886mA is with respect to 1.12mA.If even some local irregularities's property should the work of " negative feedback " effect be recovered normal EFA work thus.By entering during foreign matter (for example, dust etc.) in interstage space causes the extreme situation of short circuit, the maximum current by circuit is subject to the restriction of resistance of the regional area of foreign matter contact electrode effectively.

The foreign matter that let us is considered picture finger or screwdriver and so on namely, provides the electrical path of a relatively low resistance (being compared to the resistance of the fluid of insertion) with two electric pole short circuits together between corona electrode 1402 and accelerating electrode 1409.Can reasonably suppose, electric current will flow through the zone of the width (that is, 1 inch) that width is approximately equal to high resistivity part 1403.Therefore, foreign matter can cause maximum current I _max, it equals

I _max＝V _out/R _total＝13,064V/12*10 ⁶Ω＝1.2mA

It is just slightly greater than nominal operation electric current 1.12mA.Such one little electric current increase should not cause the dangerous of any electric shock or produce any offending noise (for example, electric arc and sonic boom).At this moment, all the maximum operating currenbt of EFA is restricted to:

I _max＝13,064V/0.5MΩ＝26mA

This value is enough to produce a large Fluid Flow in A, for example, and 100ft at least ³/ min.If accelerating electrode is by metal or have relatively low resistivity (for example, ρ≤10 ⁴Ω cm, preferably, ρ≤1 Ω cm, and ρ≤10 more preferably ^-1Ω cm,) other material make, short circuit current will only be subject to the maximum current (that is, maximum current capability) of HVPS1401, and/or be subject to and (for example be stored in its output filter, filtering capacitor) on any energy in, thus, provide a significant shock hazard to the user, offending " click is rattled away " or " sonic boom " sound that generation one is caused by spark, and/or generation electromagnetic distu (for example, radio frequency interference or radio frequency interference).In general, select Resistivity Characteristics and how much (length is to the width ratio) in high resistivity zone 103, in order to unobstructive work is provided, simultaneously, the limit value of electric current is given in work to EFA.This can be by realizing at the following relatively large ratio (if preferably being at least 10) that provides between the two: (i) total length of accelerating electrode (transverse to the size of fluid main flow direction) and (ii) to the accelerating electrode (along the size of fluid flow direction) of its width.In general, the length of electrode should be greater than the width of electrode.Optimum can realize by a plurality of accelerating electrodes are provided, and preferably, a plurality of accelerating electrodes equal number of corona and add 1 or subtract in 1 scope, depending on electrode position and structure.It should be noted that, although for illustrated purpose Figure 14, two accelerating electrodes and three corona electrodes are shown, but other electrode structure also can comprise three in four accelerating electrodes of identical three corona electrodes, perhaps, comprises other quantity and the structure of another kind of electrode structure.

Also should be taken into account, the local excessive electric current can cause high resistivity material to become bad.If a foreign matter was stationed between electrode within the time period of certain prolongation (for example, more than the several milliseconds before cleaning), this situation is especially true.For the relevant failure that prevents electrode damage and cause because of overcurrent situations, HVPS can be equipped with a current sensor or other device, its can survey such overcurrent event and promptly interrupt power produce or other method stops current flowing.One predetermined reset or quiescent time T _offAfterwards, generation can recover to continue certain minimum scheduled time T _on, this time is enough to survey any that stay or remaining short circuit condition.If short circuit condition continues, HVPS can close or alternate manner stops, and again continues time period T at least _offTherefore, if overcurrent problem exists, in order to ensure life-span of trouble free service and the electrode of EFA, HVPS1401 can continue this on-off periodic duty for several times (for example, ten times or more) makes T _offBe enough to greater than T _onIt should be noted that, in some cases, circulation will have the effect of removing some short circuit condition, and need not manual intervention.

Figure 15 illustrates another embodiment of EFA, and it is with the accelerating electrode with high resistivity part.The main distinction of EFA1400 shown in Figure 14 and EFA1500 is, in the latter, low-resistivity part 1505 fully be included in the high resistivity part 1503 of accelerating electrode 1509 (that is, fully by around the high resistivity material encapsulation).This remodeling provides at least two advantages to this embodiment of the present invention.The first, low-resistivity part 1508 fully is encapsulated in high resistivity part 1503, because can prevent by mistake or directly contact with high voltage " heat " terminals of HVPS 1501 by accident, and improve the EFA fail safe.The second, the configuration forces corona current flows through larger part or the volume of high resistivity part 1503, rather than surf zone only.Although to most of high resistivity material (for example, plastics or rubber) surface conductivity and volume are (namely, inside) conductance is identical magnitude, but because the surface is little by little polluted and becomes bad, surface conductivity is different (for example, may increase several orders of magnitude) over time greatly.

EFA has the intrinsic ability of the particle that exists in fluid is collected in the surface of accelerating electrode.When collecting a certain amount of particle or alternate manner and be accumulated on accelerating electrode, the surface of the pollutant solid layer that particle can adjoin (for example a, continuous film) coated electrode.The conductance of this layer of contaminants may be higher than the conductance of high resistivity material itself.In such situation, corona current can flow through this pollution layer, and diminishes the advantage that high resistivity material provides.By low-resistivity part 1508 fully is encapsulated in high resistivity part 1503, the EFA1500 of Figure 15 can avoid this problem.It should be noted that low-resistivity part 1508 need not be continuous, or have the wire 1505 that any point directly contacts the supply terminals of HVPS1501 or power is provided from HVPS1501.The major function that should be realized that these current-carrying parts is the length balance electromotive force along accelerating electrode 1509, that is, distributed current so that the high resistivity part 1503 of contact low-resistivity part 1508 remain on certain equipotential.In addition, if corona electrode 1502 (comprise and ionize edge 1510) ground connection, basically reduce or do not exist the chance of the current level that by mistake or by accident is exposed to danger, dangerous current level can cause injury and/or electrocute because of high working voltage, and this is because do not have " heat " electromotive force to contact whole structures.

Figure 16 is the schematic diagram of an EFA assembly 1600, it is with corona electrode 1602 (preferably forming the longitudinally Orientation Traverse with ionization edge 1610) and the accelerating electrode 1603 that is comprised of the bar of the stacking high resistivity of a plurality of levels, and all bars respectively reduce along the width of accelerating electrode with different resistance values.Accelerating electrode 1603 is made by several segmentations 1608 to 1612, and each its immediate contiguous segmentation closely contacts.Each these segmentations are made by a material, or otherwise elaborately planned and have different resistivity value ρ _nAlready determined, when connecing end closure towards HVPS1601 and little by little reduce (, successively decrease from segmentation 1608 to 1609,1611 and 1612), synthetic electric field becomes more even with respect to the principal direction of Fluid Flow in A aspect linear when resistivity.Notice, in Figure 14 and 16, be shown in the principal direction that electric field line between corona electrode 1402/1502 and accelerating electrode 1403/1503 preferably is not parallel to Fluid Flow in A, but arc.This curvature causes ions and other charged particle are accelerated on the scope of direction, thus, reduce the efficient of EFA.Go forward one by one gradually by the accelerating electrode resistance value, have found that the track of ion aligns with the principal direction of Fluid Flow in A when corona current reaches certain maximum.Should also be noted that the purpose for showing, comprise that a plurality of resistivity values are ρ although accelerating electrode 1603 is shown as _nDiscrete segmentation, resistivity value can be on the width of electrode changes continuously.The variation gradually of resistivity can reach by various procedures on width, for example, comprises the implanted ions of suitable impurity material on suitable varied concentration level, little by little increases or reduces in order to reach resistivity.

Figure 17 A and 17B are the schematic diagrames that also has another embodiment of EFA1700, and wherein, accelerating electrode 1703 is made by high resistivity material.Although for illustrated purpose, Figure 17 A and 17B distribute corona electrode 1702 and the accelerating electrode 1703 of a specific quantity are shown, and also can use quantity and the structure of other consistent with various embodiment of the present invention.

Accelerating electrode 1703 is made by faciola or the layer of one or more high resistivity materials.Corona electrode 1702 is made by the material of the low-resistivity such as metal or conductivity ceramics.HVPS1701 is connected to corona electrode 1702 and accelerating electrode 1703 by wire 1704 and 1705.The geometric form of corona electrode 1702 forms the geometric form of pin or fine rule in comparison with electrode, described pin or pin are hard to keep inherently and install, and is easy to damage in the course of normal operation of EFA.The downstream edge of each corona electrode 1702 comprises that one ionizes edge 1710.As other small articles, the fine rule that is typically used as corona electrode is frangible, therefore seems unreliable.On the contrary, be shown in the corona electrode that Figure 17 A and the present embodiment in 17B provide the shape that is relative wide metal tape.And these metal tapes must be thin in corona discharge end, so that easily along its " downstream " edge generation corona discharge, but is with relatively wider (along airflow direction), and thus, its fine rule than correspondence is difficult for broken.

Another advantage of EFA1700 as shown in Figure 17 A comprises: the electrode that accelerating electrode 1703 uses than the system of prior art basically is for thin.That is, existing accelerating electrode far is thicker than relevant corona electrode usually, to avoid producing an electric field around the edge of accelerating electrode and accelerating electrode.By the opposite or edge of placing corona electrode 1702 facing to the flat surface of accelerating electrode 1703 (in the present note, edge, the right side of corona electrode " decline "), the structure shown in Figure 17 A farthest reduces or eliminates any electric field that is produced by accelerating electrode 1703.Namely, at least a portion of the main body of corona electrode 1702 is extended along the preceding limb of the fluid flow direction that requires by accelerating electrode 1703 with descending, thus, a working portion of corona electrode 1702 produces a corona discharge along its tail edge between the plane surface of the extension of accelerating electrode 1703 and near this surface.This orientation and structure provide an electric field strength near such plane surface, it is basically lower than the electric field strength of the correspondence that forms around the tail edge of corona electrode 1702.Therefore, a corona discharge is formed near the tail edge of corona electrode 1702, and not in the surface of accelerating electrode 1703.

Just when corona discharge is initial, generation by ion in fluid and charged particle, and such electric charge is delivered to HVPS1701 by wire 1705 along accelerating electrode 1703, corona current flows through the accelerated fluid (for example, air, iknsulating liquid etc.) between corona electrode 1702 and accelerating electrode 1703.Owing to not having electric current to flow along relative direction (that is, from accelerating electrode 1703 by fluid to corona electrode 1702), so do not produce back of the body corona.Have been found that also this structure causes electric field (by line 1706 expressions), its direction with respect to the Fluid Flow in A that requires (illustrating with arrow 1707) is more linear than the electric field that alternate manner provides.The linearity of the raising of electric field is caused by the voltage drop of traversing accelerating electrode 1703, and this accelerating electrode produces the equipotential line transverse to the electric field of the principal direction of Fluid Flow in A.Because electric field line is orthogonal to such equipotential line, so electric field line is parallel to the principal direction of Fluid Flow in A more.

The advantage of another of the EFA1700 as shown in Figure 17 A is by inserting the structure of accelerating electrode 1703, provided by each other movable part of isolated corona electrode 1702 (that is, as shown in the figure right hand edge).Therefore, corona electrode " be can not see " each other, therefore, compares with existing system, and corona electrode 1702 can be located (that is, along the vertical direction as shown in Figure 17 A) with coming in close proximity to each other.By using the design feature as shown in Figure 17 A, can avoid two major obstacles of sizable Fluid Flow in A of occurring.The first obstacle in these obstacles is, the high air drag that cause the relatively thick front portion of common accelerating electrode.The corona electrode that this structure provides and accelerating electrode all have low drag geometries,, are formed on the shape of " close friend " in aerodynamics that is.For example, these geometric forms provide a resistance coefficient Cd who is used for air to be not more than 1 preferably less than 0.1, more preferably less than 0.01.The viscosity of the fluid that flows and be accelerated of the fluid that actual geometric form or shape must depend on requirement, these factors are different between each design.

The second obstacle that is overcome by the present embodiment of the present invention is, due to traditional interpolar spacing requirement necessary according to existing structure and that observed by existing structure, synthetic low-density electrode is possible.For example, US patent No.4,812,711 illustrate four corona electrodes of the 50mm distance that is spaced apart from each other, and this paper quotes this full patent texts for your guidance.Not having beat all is that this relative low-density and electrode in a small amount only can hold low-down power level, with a synthetic low level Fluid Flow in A.On the contrary, the present embodiment holds corona electrode to the spacing between attractor electrode less than 10mm, preferably less than 1mm.

Another structure that also has of electrode is shown in the EFA1700 of Figure 17 B.In this case, corona electrode 1702 is placed on from the predetermined distance of accelerating electrode 1,703 one along the fluid flow direction of the requirement as shown in arrow 1707.Moreover it is linear, shown in dotted line that synthetic electric field is basically, from corona electrode 1702s towards accelerating electrode 1703.Yet, it should be noted that, the fluid flow direction of relevant requirements, corona electrode 1702 are not placed on accelerating electrode 1703 " wherein ".

The purpose of various embodiment of the present invention as shown in Figure 17 A is, and is possible with other or compared by the technology that other EFA device is implemented, and realizes the corona electrode (that is, the electrode of higher density) with the more close space length that manufacturing technology is consistent now.That is, extremely thin and short electrode can easily be made, and it is by single manufacture process or a step, and for example, described process or step and modern micro-electro-mechanical systems (MEMS) and relevant semiconductor technology and ability are consistent.Referring again to Figure 17 A, as seen from the figure, adjacent corona electrode 1702 can vertically be spaced apart from each other less than the distance of 1mm, or several μ m only even each other.The increase of the electrode density that causes at last provides acceleration and the flow rate of the fluid that improves.For example, U.S. Patent No. 4,812,711 have described one can produce air velocity and only be the device of per second 0.5 meter (m/sec).On the contrary, if electrode spacing is 1mm, can reach the electrode density of 50 times of increases and the current capacity of raising, so that the corresponding air velocity that increases to be provided, that is, reach approximately 25m/sec or 5,000ft/min.In addition, some EFA levels are placed serially, or place in tandem along the horizontal direction of the Fluid Flow in A that requires, when excessively continuous multistage of flow, and the accelerating fluids of going back at different levels.The predetermined distances of level one of leaving nearby that are positioned at different levels, this distance is determined by the maximum voltage that is applied to comparative electrode at different levels.Especially, when the corona discharge electrode of certain one-level and accelerating electrode closely put together, require lower voltage to start and keep corona discharge.Therefore, in view of low operating voltage be used for should be at different levels within, all EFA of level closely placements each other similarly.This relation causes the density of the level of along continuous straight runs to be proportional to approx the interior electrode density (for example, vertically) of level.Therefore, can expect that the increase of electrode " vertically " density will provide similar increase on " level " density so that the Fluid Flow in A acceleration be inversely proportional to anode-cathode distance square.

The all advantages that obtained by various embodiment of the present invention give the credit to use one high resistivity material at least in part as the part of accelerating electrode.High resistivity material can comprise relatively high-resistance material, for example, and the plastics of filling carbon dust or rubber, silicon, germanium, tin, GaAs, indium phosphide, boron nitride, carborundum, cadmium selenide etc.The resistivity that these materials have should be 10 ¹To 10 ¹⁰In Ω cm scope, preferably should be 10 ⁴To 10 ⁹Between Ω cm, more preferably should be 10 ⁶To 10 ⁷Between Ω cm.Use the raising of the material supporting electrode density of high resistivity.For example, the metal accelerating electrode of close space length demonstrates the unsettled operating characteristic that produces the high-frequency spark event.By contrast, the electrode of high resistivity produces a more linearizing electric field according to an embodiment of the invention, thus, farthest reduces the generation of spark and reduce to send back of the body corona from the cusp edge of accelerating electrode.Be appreciated that with reference to Figure 17 a and eliminate back of the body corona.

Referring again to Figure 17 A, the event of corona discharge shown in figure is in the afterbody of corona electrode 1702 or right edge or occur along its afterbody or right hand edge, but does not occur along the leading or left hand edge of accelerating electrode 1703.This is the distribution that has produced voltage and electric field because of by corona discharge process.For example, the left hand edge of accelerating electrode 1703 is thicker than the right hand edge of corona electrode 1702 at least slightly, and the right hand edge of corona electrode 1702 is both carefully sharp-pointed.Because be proportional to approx the thickness of electrode near the electric field of an electrode, so corona discharge begins the tail edge place at corona electrode 1702.Then, synthetic corona current flows to the high voltage link end of HVPS1701 from the tail edge of corona electrode 1702 by two paths.The first path is the ionization part of the fluid that passes through of the electric field shown in along the line 1706.The second path is the body by accelerating electrode 1703.The corona current that flows through the body of accelerating electrode 1703 causes the voltage drop along this body.This voltage drop is advanced towards the left hand edge of electrode from the high voltage link end of the right hand edge that is applied to accelerating electrode 1703.Along with corona current increases, corresponding increase is presented in this voltage drop.When the output voltage of HVPS1701dd reach one be enough to along the left hand edge starting corona discharge of accelerating electrode 1703 level the time, slow down the increase of any voltage at the enough height of voltage drop of these edges, and prevent the edge electric corona along accelerating electrode.

Other embodiment of the present invention can be reduced to the interpolar spacing magnitude of several microns.Under such spacing, the voltage starting that a corona discharge condition can be relatively low, the formation of corona discharge is not to be caused by voltage itself, but the high field that is produced by voltage causes.This electric field strength is proportional to the voltage that applies approx, and is inversely proportional to the distance between comparative electrode.For example, approximately the voltage of 8kV is enough to start corona discharge being approximately under the interpolar spacing of 1cm.The interpolar spacing reduces 1/10th to 1mm, corona discharge can be started desired lower voltage to being approximately 800V.The interpolar spacing further is reduced to 0.1mm can drop to 80V with the corona starting voltage that requires, and the spacing of 10 microns only needs 8V to start corona discharge.These low-voltages provide the more close spacing of interpolar and at different levels between nearer spacing, thus, increase several times of total fluid acceleration.As mentioned above, this recruitment be inversely proportional to approx distance between all utmost points square, compare with the 1cm spacing, cause total increase of 100,10000 and 1000000 in air stream.

Use the benefit of a high resistivity electrode structure, can be further explained with reference to Figure 18 A and 18B.With reference to Figure 18 A, EFA1800 comprises corona electrode 1802 and accelerating electrode 1803.Accelerating electrode 1803 comprises again a low-resistivity part 1804 and a high resistivity part 1806.One corona current is on the current path shown in arrow 1805, flow through be present in the ionization between corona electrode 1802 and accelerating electrode 503 fluid (namely, pass through interelectrode space), the high resistivity part 1806 of accelerating electrode 1803 is as shown by arrows continued to pass through in this path.Local disturbance one occurs, a spark event for example, and synthetic discharging current guides to by by the narrow path shown in the arrow 1807 of Figure 18 B.Then, electric current advances along a wider path 1808 of traversing high resistivity part 1806.Because the electric current of the increase of sending from a zonule of accelerating electrode 1803, only on path 1808 little by little to external expansion, on path 1808, synthetic resistance is basically high on whole high resistivity parts 1806 time than such CURRENT DISTRIBUTION.Therefore, be that event is subject to along the path 1808 resistance limits before the spark of signal or spark by the current flowing that increases, thus, limit electric current.Have a resistivity and width if select high resistivity part 1806 to the ratio of length, the increase that can avoid or slow down any significant electric current.Such electric current increase can be caused by a plurality of events, comprise above-mentioned discharge or spark, have foreign matter (for example, dust, insect etc.) screwdriver on electrode or between electrode, or even finger is placed between electrode and with electrode and comes in contact.

Another embodiment of the present invention is shown in Figure 19.As shown in the figure, EFA1900 comprises the high resistivity part 1906 of a comb shape of accelerating electrode 1903.The event of any part such as spark obviously is constrained on the sub-fraction that attracts electrode 1903 and flows, for example, and on the tooth of single or minority close event.The corona current relevant to normal running conditions shows with arrow 1905.For example, the event such as a spark that is presented at arrow 1907 and 1908 places is limited in flowing along finger or tooth 1906.The enough height of resistance on this path are modulated the increase of any electric current that is caused by event.It should be noted that, the raising of performance is by the increase number of teeth, rather than selects width to length ratio.One is that the typical width of 1 pair 0.1 can be suitable to length ratio, is preferably the ratio of 0.05 pair 1 or less.

As mentioned above, various feature of the present invention makes the present invention can produce with the material outside solid corona discharge or an emission of ions.In general, solid material is only to emit " limpingly ", and produces ion, and thus, the EFA of limit fluid accelerates.At this moment, if location and shaping produce corona discharge, the many fluids such as water can discharge more ion.For example, use a conductor fluid as the description in the visible U.S. Patent No. 3,751,715 of corona emission material.Wherein, a lachrymal container is described as the groove that holds conductor fluid.For example, conductor fluid can be running water, is preferably an aqueous solution that comprises strong electrolyte, for example, and NaCl, HNO3, NaOH etc.Figure 20 illustrates the work according to an EFA of one embodiment of the invention, and wherein, EFA2000 comprises five accelerating electrodes 2003 and four corona electrodes 2002.All these electrodes are shown as sectional view.Corona electrode respectively comprises the non-conductive shell 2009 of the narrow elongate of being made by the insulation such as plastics or silicon, and the slit 2011 at 2010 places, ionization edge that are formed in housing tail edge or right side is arranged.The housing 2009 of corona electrode 2002 is connected to a conductor fluid source of supply or container (not shown) by a suitable supply pipe.The slit 2011 that is formed in the tail edge of corona electrode 2002 is sufficiently narrow, so that within fluid is included in housing 2009 by fluid molecule tension force.Slit 2011 can be equipped with spongiform " obstruction " or nozzle segment, in order to a constant conductor fluid that discharges by groove lentamente is provided.HVPS 2001 produces voltages is enough to occur corona discharge, like this, 2008 conductors of making sharp edges of conductor fluid, and from the tail edge of the corona electrode 2002 of groove 2011 in groove 2011 place's emitting ions.The ion that conductor fluid 2008 generates moves towards the electrode 2003 of the high resistivity that accelerates along the electric field by line 2006 representatives from groove 2001.Along with fluid is consumed in the corona discharge that produces, fluid replenishes from suitable fluid source or container (not shown) by housing 2009.

Should be noted that and be understood that, all publications, patent and the patent application of mentioning in this specification is to show technical merit in the art involved in the present invention.This paper quotes all publications, patent and patent application for your guidance, and its degree of quoting duplicates and indicated particularly and individually in extenso for your guidance degree in each publication, patent and patent application.

Claims

1. an electrostatic fluid accelerator comprises:

The corona electrode with corresponding ionization edge of one first quantity;

The accelerating electrode interval of one second quantity and that have the corresponding edge, corresponding edge are arranged essentially parallel to the Close edge edge in the described ionization edge of described corona electrode; And

Power supply is connected to described corona electrode and described accelerating electrode with operating voltage, with formation one high-intensity electric field in the interelectrode space between described corona electrode and described accelerating electrode,

Described accelerating electrode is made by the material of high resistivity, and the resistivity that the material of described high resistivity has is 10 ¹To 10 ¹⁰Ω cm scope, the width dimensions that each described accelerating electrode has and orthogonal length and height dimension directed transverse to the fluid flow direction that requires and is parallel to the fluid flow direction orientation of described requirement, along transverse to the length of the described accelerating electrode of the direction of the fluid flow direction that the requires width greater than the described accelerating electrode that is parallel to described fluid flow direction, and the described width of described accelerating electrode is along 10 times transverse to the height of the described accelerating electrode of the direction of the fluid flow direction of described requirement and described length at least.

2. electrostatic fluid accelerator as claimed in claim 1, is characterized in that, the voltage drop Vd that crosses described accelerating electrode is not more than by 50% of the described operating voltage of described power supply supply.

3. electrostatic fluid accelerator as claimed in claim 1, is characterized in that, the voltage drop Vd that crosses described accelerating electrode is not more than by 10% of the described operating voltage of described power supply supply.

4. electrostatic fluid accelerator as claimed in claim 1, it is characterized in that, each described accelerating electrode comprises a plurality of segmentations, each described segmentation of one of described accelerating electrode has the different resistivity of all the other segmentations in the described segmentation of described from described accelerating electrode, and each described segmentation is oriented the described ionization edge that is arranged essentially parallel to corona electrode.

5. electrostatic fluid accelerator as claimed in claim 4, is characterized in that, in the described segmentation of described accelerating electrode, the resistivity of each segmentation, reduce with the distance from described corona electrode.

6. electrostatic fluid accelerator as claimed in claim 4, is characterized in that, have a lowest resistivity, away from one of described segmentation of described corona electrode, have the electrical contact that an output that is connected to described power supply connects end.

7. electrostatic fluid accelerator as claimed in claim 4, is characterized in that, all part each intervals of the segmentation of the vicinity of the described segmentation of described accelerating electrode, and close contact not each other.

8. electrostatic fluid accelerator as claimed in claim 1, is characterized in that, described accelerating electrode has a comb shaped structure, its with tooth towards corona electrode, and with a bottom away from corona electrode location.

9. electrostatic fluid accelerator as claimed in claim 1, is characterized in that, described corona electrode is operated in ground potential.

10. electrostatic fluid accelerator as claimed in claim 1, is characterized in that, the resistivity of described accelerating electrode changes on the width of described accelerating electrode.

11. electrostatic fluid accelerator as claimed in claim 1 is characterized in that, the resistivity that the material of described high resistivity has is 10 ⁴To 10 ⁹Ω cm scope.

12. electrostatic accelerator as claimed in claim 1 is characterized in that, the resistivity that the material of described high resistivity has is 10 ⁶To 10 ⁷Ω cm scope.

13. electrostatic fluid accelerator as claimed in claim 4 is characterized in that, the segmentation of the vicinity of described segmentation is close contact each other.

14. an electrostatic fluid accelerator comprises:

Corona electrode;

With the accelerating electrode at described corona electrode interval, each described accelerating electrode is made by the material of high resistivity and is comprised a laminal shape along a fluid flow direction elongation that requires, and the electricalresistivityρ that the material of described high resistivity has is 10 ¹To 10 ¹⁰Ω cm scope, each described accelerating electrode is arranged essentially parallel to described corona electrode, and described corona electrode is positioned between the adjacent electrode of accelerating electrode; And

Be connected to the power supply of described corona electrode and described accelerating electrode, to produce electric field at interelectrode space, thus along described direction accelerating fluid in described interelectrode space of the Fluid Flow in A of described requirement.

15. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, the electricalresistivityρ that the material of described high resistivity has is 10 ⁴To 10 ⁹Ω cm scope.

16. electrostatic accelerator as claimed in claim 14 is characterized in that, the electricalresistivityρ that the material of described high resistivity has is 10 ⁶To 10 ⁷Ω cm scope.

17. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, the voltage drop Vd that crosses described accelerating electrode is not more than by 50% of the output voltage of described power generation.

18. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, the voltage drop Vd that crosses described accelerating electrode is not more than by 10% of the output voltage of described power generation.

19. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, described accelerating electrode comprises a plurality of segmentations, and each described segmentation has different resistivity, and each described segmentation is arranged essentially parallel to described corona electrode.

20. electrostatic fluid accelerator as claimed in claim 19 is characterized in that, the resistivity of one of described segmentation of close described corona electrode has peak, and the resistivity of each described segmentation reduces along the direction away from described corona electrode gradually.

21. electrostatic fluid accelerator as claimed in claim 20 is characterized in that, has with the described segmentation of lowest resistivity the electrical contact that an output that is connected to described power supply connects end.

22. electrostatic fluid accelerator as claimed in claim 19 is characterized in that, all part each intervals of the segmentation of the vicinity of the described segmentation of described accelerating electrode, and close contact not each other.

23. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, described accelerating electrode has a comb shaped structure, its with tooth towards corona electrode, and with a bottom away from corona electrode location.

24. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, described corona electrode is operated in ground potential.

25. electrostatic fluid accelerator as claimed in claim 14 is characterized in that, the resistivity of described accelerating electrode changes on the width of described accelerating electrode.

26. electrostatic fluid accelerator as claimed in claim 19 is characterized in that, the segmentation of the vicinity of described segmentation is close contact each other.