WO2003070382A1

WO2003070382A1 - Method and device for producing an aerosol

Info

Publication number: WO2003070382A1
Application number: PCT/EP2003/000561
Authority: WO
Inventors: Götz SPIESS
Original assignee: Willy Vogel Ag
Priority date: 2002-02-21
Filing date: 2003-01-21
Publication date: 2003-08-28
Also published as: AU2003212222A1; DE10207435A1

Abstract

The invention relates to a method and device (1) for producing aerosol, particularly for an aerosol (4) used for lubricating tools, machines and parts thereof. The device comprises a mixing chamber (14) inside of which a liquid and a gaseous substance are mixed to form an aerosol. The volume flows (12, 13) of the liquid and/or of the gas flow that are to be mixed to form the aerosol are regulated by at least one dosing device (16, 19). The aerosol produced inside the mixing chamber is lead to aerosol consumers (5) via an aerosol line (21). The aim of the invention is to produce an aerosol of a uniform quality regardless of the aerosol consumers used and of whether the device has been subjected to wear. To this end, a control device (3) is provided that has an aerosol sensor (23) and a signal-transmitting connection to the at least one dosing device. The aerosol sensor detects a state quantity representing the aerosol volume flow that is lead through the aerosol line to the aerosol consumer. The volume flow of the liquid and/or of the gaseous substance is regulated by the control device on the basis of this state quantity.

Description

Method and device for producing an aerosol

The invention relates to a device for aerosol production, in particular for an aerosol for lubricating tools, machines and their parts, comprising at least one mixing chamber in which at least one liquid and at least one gas can be mixed to form an aerosol during operation, and with at least one metering device, by which during operation the volume flow of the at least one liquid and / or at least one gas stream mixed to the aerosol can be adjusted, and comprising at least one aerosol line through which the aerosol generated in the mixing chamber is passed to at least one aerosol consumer during operation, and a method for Generation of an aerosol, in particular for the lubrication of tools, machines and their parts, in which a liquid and a gas are fed to at least one mixing chamber and mixed to form an aerosol, and the aerosol then from the mixing chamber through at least one aerosol line to at least one aero sol consumer is managed.

Devices and methods for aerosol generation are used in a large number of areas of application, for example in spray systems with which paints or adhesives are sprayed over spray heads as aerosol consumers, or in modern minimal-quantity lubrication systems in which aerosol consumers such as tools, machines or machine parts by means of a spray of lubricant, for example an oil or an oil emulsion, lubricated and optionally cooled.

Apparatus and methods for aerosol generation with the features mentioned at the outset are known from the prior art.

DE 196 54321 A1 describes a device for aerosol production in which the aerosol is used for the cooling lubrication of tools. The device of DE 196 54 321 A1 comprises a mixing chamber designed as an injector device and an impact body. The oil atomized in the injector device is metered via an adjusting device, the compressed air supplied to the injector device is metered via a control valve. The aerosol generated in the injector device is directed to the aerosol consumers via an aerosol line. Another device for aerosol generation is described in DE 19721 650 A1, which represents a further development of the device of DE 196 54 321 A1. The device of DE 19721 650 A1 has a second injector device for generating a second aerosol. The composition of the aerosols can be influenced as desired by the user by setting flow control valves, one flow control valve being arranged in each case in a liquid line to the injector device and another flow control valve in a gas line to the injector device.

Another aerosol device is described in EP 0 941 769 A1, in which a liquid and a gas are likewise mixed to form an aerosol in a mixing chamber. In the device of EP 0 941 769 A1, a control valve is only provided for the compressed air line.

EP 0 943 861 B1 describes a device for supplying lubrication points with fluid lubricant, in which the amount of oil entering the air flow at the injector is scanned by means of a light barrier before the oil enters the air flow, which is only imprecise Determination of the amount of oil actually sent to a lubrication point.

WO 00/58016 relates to a device with which pharmaceutical aerosols are released in a controlled manner, with a predetermined dose of the aerosol being temporarily stored in an intermediate container. First an aerosol is generated and then the aerosol mass is then stored in a delivery area. The mass concentration in front of and behind the deposition area is measured using electro-optical sensors.

When operating these systems known from the prior art, it has been shown that the properties of the aerosol can change from system to system and also in a system depending on the aerosol consumer. This is undesirable since under these conditions no consistent properties of the aerosol are produced and under certain circumstances there is poor lubrication or paint application. This can ultimately damage the tool or the Machines or an insufficient coating of a workpiece with adhesive or paint and thus lead to rejects.

The cause of the fluctuations in the aerosol properties seem to be manufacturing and aging-related deviations of the device and the process management from the desired state as well as fluctuations in the flow resistance of the aerosol consumers.

In order to intercept at least the grossest deviations from the desired state, pressure-controlled systems have been developed in the prior art which are based on the conventional devices described above.

For example, WO 98/10217 describes a cooling lubrication device for applying cooling lubricant to a tool and / or a workpiece, which provides a control device for adapting to different lubrication and cooling requirements. The aerosol and / or the liquid cooling lubricant is transferred to a nozzle via the control device! and / or a gas is supplied via a line arrangement. The control device is used to adjust the greasiness of the aerosols, i.e. the proportion of the liquid cooling lubricant in the gas. In WO 98/10217, compressed air is present on the control device, on the one hand, and on the other hand, aerosol can be drawn in from the air space of an aerosol container. In addition, the control device can remove oil from an oil supply via a riser. The control device in WO 98/10217 is therefore a purely mechanical control which determines the greasiness of the aerosol according to values specified by the user.

Another device for producing aerosol is known from EP 1 106902 A1. In this device, the pressure prevailing in a reservoir for the aerosol can be adjusted by a pressure control valve depending on the flow resistance of the consumer. In the case of an aerosol consumer with a high flow resistance, less aerosol is consumed, so that the pressure inside the aerosol container increases and aerosol can no longer be generated. This pressure rise is prevented by the pressure control valve in the device of EP 1 106 902 A1. Finally, DE 101 04 012 A1 describes a quantity-controlled supply of carrier gas and / or liquid via a throttle system to an injector device. The throttle system is controlled via a control unit, the differential pressure between a supply pressure with which the carrier gas is supplied and the pressure in an aerosol container serving as the input variable for the control unit.

With the pressure-controlled devices and methods for aerosol generation, only rough fluctuations in aerosol generation can be compensated for; A fine adjustment of the aerosol properties as a function of the operating state of the device, especially an equalization of the aerosol quality regardless of the aerosol consumer is still not possible.

In view of the disadvantages of the devices and methods for aerosol generation known from the prior art, the object of the invention is to create a device and a method in which the properties of the aerosol can be better adapted to the respective requirements of the aerosol consumers which can achieve a constant aerosol quality regardless of the operating condition and application.

This object is achieved for a device or a method of the type mentioned at the outset in that a control device with an aerosol sensor, by means of which at least one state variable representative of the aerosol volume flow directed to the at least one aerosol consumer can be detected, and with one by at least one Signal-transmitting connection to the metering device connected controller is provided, by means of which the aerosol volume flow can be regulated to a desired value by changing the volume flow of the liquid and / or the gaseous substance depending on the state variable.

This solution is simple and, by means of the construction of a control loop, in contrast to the conventional controls, it is possible to obtain a constant aerosol quality and a constant aerosol volume flow. By measuring the size representative of the aerosol volume flow from the mixing chamber through the aerosol line, exactly the amount of aerosol delivered to the aerosol consumer is determined certainly. This is not possible with the above-described apparatus and methods known from the prior art, since it has been found that the pressure differences measured in the prior art do not allow a quantity representative of the aerosol volume flow and no conclusion to be drawn about the aerosol volume flow directed to the aerosol consumer. The aerosol volume flow is the amount of aerosol passed through the at least one aerosol line per unit of time. Deviations or changes in this quantity from a target quantity are corrected by changes in the volume flows of the gas volume flow and / or liquid volume flow directed into the mixing chamber or by changes in this or these volume flows in the mixing chamber itself.

It should be noted here that the volume flow of liquid supplied to the mixing chamber in conventional aerosol generators, such as that of DE 196 54321 A1, is not the same as the volume flow of liquid contained in the aerosol volume flow: in a conventional aerosol generator there are normally devices which only have one Let certain droplet size pass through and filter droplets that are too small or too large from the aerosol. Depending on the operating state of the aerosol generator, more or fewer droplets can be filtered out. This filtered out liquid volume flow leads to a difference between the liquid volume flow supplied to the mixing chamber and the liquid volume flow conducted through the aerosol line. However, this difference is taken into account in the regulation according to the invention.

In addition to the direct measurement of the aerosol volume flow, there are representative state variables of the aerosol volume flow that can serve as input variables for regulating the gas and / or liquid volume flow to the mixing chamber, for example the number of droplets dissolved in the gas stream per unit of time, their speed and / or the density of the aerosol - the number of droplets per unit volume - or a representative speed and composition of the aerosol at one point on the aerosol line, with the help of which the empirically determined and stored characteristics and / or equations then the entire aerosol volume flow passed through the aerosol line with the help of flow models how a Hagen-Poiseuille flow or a turbulent pipe flow can at least be approximately calculated or looked up. Various embodiments can be used for the aerosol sensor for detecting the state variable representing the aerosol volume flow. Sensors are known from the prior art, for example, with which individual aerosol properties can be detected capacitively.

An aerosol sensor based on such a capacitance measurement is described, for example, in DE 3049 035 A1. This document describes a capacitive sensor for aerosol flow characteristics and a device for the remote measurement of such values, which can be used for the contactless measurement of aerosol mass concentrations and of throughput quantities. However, this encoder has a complex structure and is only suitable for a solid, dispersed phase. Optical sensors for detecting a solid dispersed phase are also known, for example, from use in smoke detectors. However, the use of these devices for the devices for aerosol generation according to the invention does not seem to be known, since the signal evaluations that are required to do this require considerable adjustments and changes.

The disadvantages of the aerosol sensors known from the prior art can be avoided according to an advantageous embodiment if the aerosol sensor works on an optical basis according to an advantageous embodiment.

The aerosol sensor can include a light sensor by means of which scattered light, that is to say refracted or scattered light reflected by the aerosol, can be detected during operation. With such a sensor, the amount of scattered light can be used to reliably detect the aerosol density as a representative state variable of the aerosol volume flow. In a further development, the aerosol sensor can comprise a light source through which a preferably narrowly limited light beam is directed onto the aerosol during operation, the light of which is then scattered.

The light source can in particular have a specific spectrum limited to a few light wavelengths, as is the case, for example, with sodium vapor lamps or with lasers. Such a spectrum can be used to determine the speeds of the aerosol particles and thus the aerosol volume via light frequency shifts due to the Doppler effect, ie the speed-dependent frequency change in the scattered, refracted or reflected scattered light scattered by aerosol particles. Record flow efficiently. It is also advantageous if the light sensor is arranged outside the direct light beam of the direct light source, so that its sensitivity can be made larger. In this context, it can make sense to absorb the direct light beam after crossing the aerosol or the aerosol line, which can happen, for example, in a light trap. Instead of an optical sensor, an ultrasonic sensor with a corresponding ultrasonic source can also be used. In order to record the aerosol flow actually delivered to the aerosol consumer as precisely as possible, it is advantageous if the aerosol sensor is placed as close as possible to the aerosol consumer. When using several aerosol consumers that are supplied with aerosol via parallel branch lines of the aerosol line, an aerosol sensor can also be provided in each branch line. The total production of aerosol can then be recorded by adding up the individual measured values of the individual aerosol sensors.

The aerosol sensor can advantageously also be arranged directly in the aerosol consumer, it being possible for the aerosol consumer to be designed as a tool holder and / or tool. If cutting tools, such as drills or milling cutters, are used as aerosol consumers, which rotate during operation, then in a further advantageous development, contactless data transmission to the control unit and wireless energy supply can be provided, in particular via magnetic fields and coils of the aerosol sensor rotating in the magnetic field ,

The volume flow of the liquid and / or the gaseous substance to the mixing chamber or in the mixing chamber is adjusted in one advantageous development by a metering device. The metering devices can each be arranged in the liquid and / or gas lines or else in the mixing chamber itself. The metering device can each be designed as a valve which can be switched between a completely closed and fully open switching state in several switching stages, in particular as a proportional valve. This valve can be converted into a switching state by the control device as a function of the detected aerosol volume flow or the state variable representative thereof, by means of which the deviation of the detected aerosol volume flow from the target volume flow is reduced. Depending on the switching status of the valve and the switching status assigned to this ordered flow resistance of the valve, the volume flow of the liquid and / or the gas can be adjusted accordingly.

In addition to or instead of such proportional valves, the metering device for metering the bulk liquid and / or the metering device for adjusting the volume flow of the gas can also comprise an orifice arrangement. Such an arrangement has a predetermined number of orifices, which preferably have different diameters and ensure a well-defined volume flow. A switching valve is assigned to each orifice. The volume flows to the mixing chamber can be adjusted by combining the various orifices

According to a further advantageous embodiment, not only the aerosol volume flow is regulated to a desired value by the device for aerosol generation according to the invention, but also the average droplet size of the aerosol. This can be done, for example, by providing an adjusting device or an actuator in a mixing chamber designed as a nozzle, by means of which the geometry of the nozzle can be changed under the influence of the control device. The actuators can be designed, for example, as micromotors or stepper motors or piezo actuators or electromagnetic or pneumatic or hydraulic adjusting devices, which can change the narrowest cross section and / or the curvature and cross section ratios of the nozzle. In this embodiment, the aerosol sensor also detects a state variable representative of the mean droplet size of the aerosol and, in a further development, also the scatter of the droplet size by the mean droplet size and the deviation from a desired droplet size or target scatter is determined in the control device , This deviation then serves as a manipulated variable for regulating the geometry of the mixing chamber.

In order to provide additional input variables for the control of aerosol production, sensors can be provided in a further embodiment, which detect the volume flow of the gas to or into the mixing chamber or in the aerosol line and / or the volume flow of the liquid to or into the mixing chamber. These can be designed as vane anemometers or hot wire anemometers, hot film sensors or laser anemometers and ultrasound Doppler knives. Differential pressure measurement ser can be used to determine the volume flow of each liquid and / or gas.

The gas flow through the aerosol line can also be recorded in a similar manner. A differential pressure meter can also be used here, in an advantageous embodiment, the pressure within the mixing chamber by one pressure sensor and the pressure at any point along the aerosol line, but preferably at the end of the aerosol line, and the pressure difference between the two by the other pressure sensor Press can be determined.

With the aid of the measured volume flow of the gaseous substance through the aerosol line and with the aid of the aerosol density detected by the aerosol sensor as representative state variables for the aerosol volume flow, the actual aerosol volume flow can be calculated by the control device.

One way of calculating the aerosol volume flow q _A from the gas volume flow q _G and the aerosol density p _A is via the formula q _A = A xq _G x P _A. where A is a constant value.

Instead of this formula, however, certain characteristic fields with the at least one state variable measured by the aerosol sensor can also be used as a variable by means of test series and stored in the control device, so that for a determined representative state variable the aerosol volume flow associated with this state variable by looking up the stored characteristics (for example in the form a look-up table) or can be determined directly using a stored equation that is adapted to empirical test series.

According to a further advantageous embodiment, the operating state of the device is monitored to determine whether there are faulty or atypical combinations of the detected parameters that indicate a malfunction, faulty operation or a poor quality of the aerosol generation. This can be done, for example, by the control device comparing the currently detected state variables with reference values and, in the event of large deviations or certain combinations, emitting error or alarm signals. are given. The reference values can be stored in the control device and previously determined by tests. According to another variant, a learning algorithm can be implemented in the control device, which dynamically adapts the reference values to the operating states that have been run without errors to date. With these designs, system errors or incorrect user settings can be recorded and rejects avoided.

According to an advantageous embodiment, the aerosol sensor can be designed as a Doppler anemometer and simultaneously detect the particle speed, number of particles and particle size of the liquid dissolved in the gas as particles. The Dpppler anemometers can work on a laser basis or on an ultrasound basis.

The invention is described below by way of example using exemplary embodiments with reference to the accompanying drawings.

Show it:

Figure 1 is a perspective and schematic representation of an apparatus for aerosol generation according to the invention.

2 shows a cross section through an aerosol line;

3 shows a schematic block diagram of an apparatus for aerosol generation according to the invention in accordance with a first exemplary embodiment;

Fig. 4 is a schematic block diagram of an inventive device for aerosol generation according to a second embodiment.

First, the structure of a device 1 for aerosol generation is described with reference to FIG. 1. The device 1 can be functionally divided into an aerosol generator 2, in which aerosol is generated, and a control device 3 under whose control the aerosol generator 2 generates the aerosol. In the exemplary embodiment shown in FIG. 1, the aerosol is schematically represented by points 4, which is directed to aerosol consumers 5, the device 1 being used as a cooling-lubricating device for cutting tools as an aerosol consumer 5. Other types of aerosol consumers 5 include spray heads for, for example, paints or adhesives.

In the embodiment of FIG. 1, 5 drills 6 are used as aerosol consumers, which are attached to machine tool spindles 7. The aerosol consumers 5 themselves are not part of the device 1 for aerosol generation.

The aerosol generator 2 has a liquid container 8 which contains a reservoir 9 of the liquid. Depending on the application, the liquid can be a dye, varnish, adhesive or a cooling lubricant or lubricant, such as an oil or an oil emulsion. The liquid is dissolved in aerosol 4 as a sol in the form of droplets.

The container 8 is closed in a pressure-tight manner by a cover 10 and is designed as a pressure container in which there is a pressure which is different from the environment of the aerosol generator 2, preferably an overpressure.

The space 11 above the liquid supply 9 in the container 8 contains aerosol 4, which is generated in a mixing chamber 14 by mixing a gas volume flow, shown schematically by arrow 12, and a liquid volume flow, shown schematically by arrow 13.

Inert gases, for example noble gases, or gas mixtures such as air, for example compressed air, can be used as the gas.

The gas volume flow 12 is conducted under pressure through a gas line 15 via a metering device 16 and a further gas line 17 to the mixing chamber 14.

A negative pressure is generated in the mixing chamber 14 by the gas flow, through which liquid from the liquid supply 9 via a liquid line 18 siereinrichtung 19 and a further line 20 is sucked into the mixing chamber.

In the mixing chamber 14, the liquid in the gas stream 12 is dissolved in drops and, while still under pressure, is passed onto an impact body 21. The mechanical interaction between the impact body 21 and the aerosol flow can produce finer droplets of constant size. For example, the step pyramid-shaped impact body described in DE 196 54 321 A1 can be used as the impact body. Drops that are too large fall back into the liquid reservoir 9.

The aerosol 4 collects in the room 11 and is conducted out of the aerosol generator 2 via an aerosol line 21. The aerosol can be conveyed through the aerosol line 21 by the internal pressure prevailing in the container 8. Alternatively, delivery devices such as pumps can also be provided in the aerosol line 21.

In addition, the aerosol line 21 can have a suction nozzle (not shown) in the region of its inlet opening 22, with which aerosol is actively sucked into the aerosol line 21 from the space 11 via compressed air.

Arranged in the area of the aerosol line 21 is an aerosol sensor 23, by which at least one variable representative of the aerosol volume flow through the aerosol line is detected, for example the aerosol density and the aerosol speed, which corresponds approximately to the speed of the gas phase of the aerosol.

The aerosol sensor 23 is attached as close as possible to the aerosol consumers 5 and is preferably arranged in the aerosol consumers 5 themselves. In the embodiment of FIG. 1, for example, an aerosol sensor can preferably be interchangeably integrated in each tool such as the drill 6 or in each tool holder such as the spindle 7. With this arrangement, the aerosol sensor can directly detect the aerosol flow at the aerosol consumer. Due to the rotating tool spindle, contactless energy transfer to the aerosol sensor can take place, for example, via a magnetic field prevailing in the spindle, in which a coil of the aerosol sensor rotates and thus generates electricity, by means of an energy transmission device (not shown). To ensure the longest possible lifespan In this embodiment, the data transmission is likewise carried out in a contactless manner by optical or radio technology by means of a data transmission unit not shown in FIG. 1.

From the aerosol line 21, the aerosol volume flow 24 passed through the aerosol line 21 is distributed to branch lines 25, which lead to the aerosol consumers 5. Any number of aerosol consumers 5 can be connected to a device 1 for aerosol generation, as long as the amount of aerosol generated by the device 1 is sufficient to supply the aerosol consumers 5.

In the embodiment of FIG. 1, the aerosol flows distributed on the branch lines 25 are guided through a line (not shown) in the rotating machine tool spindle 7 to the drills 6 up to the cutting edges or the location of the chip removal.

The control device 3 regulates the function of the aerosol generator 2. It comprises an input device 26a and an output device 26b, for example a conventional computer 26 with a screen and keyboard, and data readers such as CD-ROMs, flops, removable disks, tapes and the like. Like. Via the input and output device 26a, 26b, a user can interact with the device 1 and set the parameters and setpoints important for aerosol generation. Such parameters are, for example, the aerosol volume flow 24 required by the aerosol consumers 5, the average droplet size of the aerosol and the greasiness of the aerosol, i.e. the proportion of the liquid phase in the aerosol. Further parameters or state variables that can be entered by operating personnel through the input / output device are, for example, the aerosol temperature and the substance variables, such as the viscosity, of the starting materials used to generate the aerosol. Depending on these substance sizes, the mixing process to be set in the mixing chamber 14 is determined, i.e. the volume flows to be fed to the mixing chamber, the speeds of the volume flows and the temperatures of the volume flows.

The state of the aerosol generator 2 as well as deviations from the desired state and operational disturbances are displayed to the operator via the input / output device 26b. The regulation of the aerosol generation itself takes place in a controller 27, which is shown schematically in FIG. 1. The controller 27 can comprise a microprocessor, which can be designed as part of a conventional computer or else as an electronic circuit specially designed for control tasks.

The controller 27 is connected via a first signal path 28 to the metering device 16 for the gas volume flow 12. The controller 27 is connected to the metering device 19 for the liquid volume flow 13 via a second signal path 29. Via a third signal path 30, the controller 27 is connected to an adjusting device 31, via which it is possible to intervene directly in the aerosol generation process in the mixing chamber 14. For example, the adjusting device 31 comprises a motor, by means of which the geometry of an atomizing nozzle (not shown) can be changed.

Finally, the controller 27 is connected to the aerosol 23 via a fourth signal path 32.

The signal paths 28, 29, 30, 32 can be designed as an electrical signal line, light-conducting fibers or radio transmission paths for unidirectional and / or bidirectional data transmission.

Furthermore, volume flow measuring devices can be provided in the area of the metering devices 16 and 19, by means of which the volume flows 12, 13 through the lines 15, 17 and 18, 20 can be set. Such volume flow measuring devices can include vane radonemometers, hot film or hot wire probes, laser or ultrasonic double sensors or differential pressure sensors.

2 schematically shows the structure of an embodiment of the aerosol sensor 23, by means of which a state variable representative of the aerosol volume flow 24 through the aerosol line 21 can be detected.

The aerosol sensor 23 of FIG. 2 operates on an optical basis and takes advantage of the fact that the liquid drops dissolved in the gas scatter light. The amount of light scattered is representative of the aerosol density p _A), ie the number of droplets per volume: the more droplets dissolved in the aerosol, the more light is scattered. The aerosol line 21 has at least one transparent section 33, which transmits the light from a light source 34, or is designed to be completely transparent.

The light source 34 generates a light beam 35 that is bundled as possible and preferably extends over the entire cross section of the aerosol line 21, which crosses the transparent area 33 of the aerosol line 21 and is absorbed in a light trap 36.

In a region outside the direct light beam 35, a scattered light sensor 37 is arranged, the measuring region of which is directed towards the flow cross section of the aerosol line 21 through which the light beam 35 passes.

The scattered light sensor 37 is connected to the controller 27 via the data line 32; it is preferably adjusted so that the output signal, for example in the form of an analog voltage, is proportional to the aerosol density.

The light source 34 preferably generates light that only contains wavelengths of certain frequencies and is designed, for example, as a sodium vapor lamp or laser. The liquid drops dispersed in the aerosol 4 scatter the light 35 and the speed of the scattered light can be used to determine the speed of the liquid particles in the aerosol 4. This speed determination can be carried out point by point on a small measurement volume within the flow cross-section of the aerosol line 21 or simultaneously across the entire cross-section. If the flow velocities are recorded only point by point, fluidic models of the aerosol tube flow can be used to infer from a representative measurement volume the entire aerosol volume flow through the aerosol line, or else the flow cross section and is sampled sequentially.

Instead of a light beam 35, an ultrasound beam can also be used and evaluated analogously. 3 shows a schematic block diagram of the construction of the device 1. The function of the control device 3, in particular the controller 27, is to be explained with the aid of FIG. 3.

The aerosol volume flow 24 is to be regulated to a constant value by the control device 3 or the regulator 27.

For this purpose, a state variable representing the aerosol volume flow 24, for example the aerosol density p _A , is first output by the aerosol sensor 23 via the signal path 32 and sent to a flow calculation module 39 of the controller 27.

A quantity representative of the gas flow throughput q _G is also detected via a flow sensor 40 and is likewise passed on to the flow calculation module 39 of the controller 27. The flow calculation module determines the volume flow q _{F of} the dispersed liquid in the aerosol line 21 from the state variables q _G and ρ _A using the following equation:

q = A xp _A xq _G ,

where A is a proportionality constant.

The measured or calculated volume flow quantities q _G and q _F are output by controller 27 via output lines 41 to other devices, for example to output device 26b (cf. FIG. 1).

A memory unit 42 is also provided in the controller 27, in which controlled variables, in particular target variables, are stored. The storage unit 42 is connected via a signal line 41 to external devices, for example the input device 26a, by means of which the sizes stored in the storage unit 42 can be changed by a user. The target gas volume flow q _GR and a target liquid volume flow q _F, for example, are stored in the storage unit 42 as target values. The target volume flow quantities q _GR and q _FF <are sent to a calculation module 43 of the controller 27, where the difference to the actual volume flows q _G and q _F in the aerosol line 21 is calculated and as manipulated variables U _G and U _F to an output unit 44 to get redirected. The output unit 44 converts the manipulated variables into signals which are forwarded to the metering devices 16 and 19. For this purpose, the output unit 44 converts the manipulated variables into a suitable format, for example an analog voltage signal or a digital signal in accordance with a data exchange protocol, which can be specified directly to the metering devices.

The metering devices 16, 19 can each be designed as proportional valves, the degree of opening of which is proportional to an analog voltage output via the signal paths 28, 29. In this case, the output unit 44 generates a signal that adjusts a flow resistance at the proportional valve 16, 19 in such a way that the deviation between the respective actual volume flow and the desired volume flow is reduced or regulated to zero.

Alternatively, the metering devices 16, 19 can also each be designed as an orifice arrangement which comprises a plurality of orifices of different flow cross-section, each orifice being opened or closed by an upstream and downstream switching valve. In this case, the output unit 44 generates switching signals for the switching valves assigned to the different orifices in order to achieve a combination of open and closed orifices by means of which the deviation of the respective volume flow 12, 13 from the target value is reduced.

Finally, the controller 27 also includes an error monitoring module 45, by means of which the current state variables of aerosol generation, the actual volume flows and the target variables are monitored. These status variables are compared by the error monitoring module 45 with reference values which are stored in the storage unit 42. The state variables in the memory unit 42 are predetermined by the manufacturer and changed via the input unit 26a or else adapted to the current operating conditions by means of a learning algorithm. In the case of an atypical combination of the state variables, for example if the liquid volume flow 13 is in a specific ratio to the gas volume flow 12, the error monitoring module 45 issues an alarm signal via line 41, which can be output optically on the output unit 26b, for example, for the information of operating personnel. In addition, the fault monitoring module 45 can output a stop signal to the output unit 44 via a line 46, through which the Aerosol generation is interrupted by the aerosol generator 2 when an alarm signal is present.

4 shows a further exemplary embodiment of a control device 3, in particular of the controller 27. In the embodiment of FIG. 4, the same reference numerals as in FIGS. 1 to 3 are used for the same or similar components and elements. For the sake of simplicity, only the differences from the exemplary embodiment in FIG. 3 are discussed below.

The embodiment of FIG. 4 differs from the embodiment of FIG. 3 by the type of aerosol sensor 23 used. The aerosol sensor 23 of FIG. 4 simultaneously determines the particle speed v _F , the number of particles n _F and the average particle size d _A in the aerosol line 21 Such an aerosol sensor 23 can be, for example, a laser anemometer or laser Doppler anemometer or an ultrasound anemometer.

The calculation module 43 calculates from the number of particles n _F and the particle velocity v _F aerosol density p _A q the Aerosoivolumenstrom _A, the Gasstoff- flow q _G and the liquid flow rate q _F. The calculation module 43 also calculates the average particle diameter d _AV and the scatter of the particle diameters.

The manipulated variables U _G and U _F for the gas flow volume flow or liquid volume flow are calculated as in the exemplary embodiment in FIG. 3 and passed on to the metering devices 16, 19.

In addition, in the exemplary embodiment in FIG. 4, a manipulated variable U _{d is} calculated from the average particle diameter d _AV and the target value for the average particle diameter d _AR stored in the storage unit 42 and output to the mixing chamber 14 via the output unit 44. The manipulated variable U _d can represent, for example, the diameter to be set on an atomizer nozzle at one point. An actuator region 14 'of the mixing chamber 14 then changes the geometry of the mixing chamber as a function of the manipulated variable U _d such that the aerosol volume flow 24 has the desired average particle diameter d _AV R or the desired dispersion of the particle diameter. As in the exemplary embodiment in FIG. 3, an error monitoring module 45 is also provided in the exemplary embodiment in FIG. 4, via which the state variables of the aerosol generation are monitored and error messages or warnings are output in the case of atypical combinations of state variables.

Claims

claims

Device (1) for aerosol generation, in particular for an aerosol for lubricating tools, machines and their parts, comprising at least one mixing chamber (17) in which at least one liquid and one at least gas can be mixed to form an aerosol (4) during operation, and with at least one metering device (16, 19) by means of which the volume flow of the at least one liquid (13) and / or at least one gas stream (12) mixed to the aerosol can be adjusted, and comprising at least one aerosol line (21) through which in operation, the aerosol generated in the mixing chamber is directed to at least one aerosol consumer (5), characterized by a control device (3) with at least one aerosol sensor (23), through which at least one for the one directed to the at least one aerosol consumer (5) Aeroso volume flow (24) representative state variable (ρ _A) q _A , v _A , n _A ) can be detected, and with one by at least one signal Transmitting connection (26, 28) with the metering device (16, 19) connected controller (27), through which the aerosol volume flow by changing the volume flow of the liquid (13) and / or the gas (12) depending on the detected state variable to one Setpoint is adjustable.

Device (1) according to claim 1, characterized in that the aerosol sensor (23) comprises a light sensor (37), by means of which light which is reflected, refracted or scattered by the aerosol (4) can be detected during operation.

Device (1) according to claim 1 or 2, characterized in that the aerosol sensor (23) comprises a light source (34) through which a light beam (35) is directed onto the aerosol (4) during operation. Device (1) according to claim 2 and 3, characterized in that the light sensor (32) is arranged outside the direct light beam (35) of the light source (34).

Device according to one of the above claims, characterized in that the aerosol sensor (23) is arranged in the aerosol consumer (5).

Apparatus according to claim 5, characterized in that the aerosol consumer (5) is designed as a tool holder (7) and / or tool (6) of a machine tool.

Apparatus according to claim 5 or 6, characterized in that the aerosol sensor (23) is integrated in a cutting tool (6).

Device according to one of the above claims, characterized in that the aerosol sensor (23) is provided with an energy transmission device, by means of which the aerosol sensor can be supplied with energy in a wireless manner during operation.

Device according to one of the above claims, characterized in that the aerosol sensor (23) is provided with a data transmission unit by means of which data can be transmitted wirelessly to the control device (3) during operation.

Device (1) according to one of the above claims, characterized in that the metering device (16, 19) comprises at least one valve, the switching state of which can be controlled by the control device (3) during operation. Device (1) according to claim 10, characterized in that the metering device (16, 19) comprises at least one valve, the flow cross section of which can be changed in several stages between a fully open and a fully closed state.

Device (1) according to claim 10 or 11, characterized in that the metering device (16, 19) comprises a plurality of diaphragm openings, each diaphragm opening being assigned a valve controlled by the control device (3).

Device (1) according to one of the above-mentioned claims, characterized in that the aerosol generator (2) has an aerosol generating nozzle which is provided with an actuator (14 ') which can be actuated by the control device (3) during operation Actuator (14 ') the geometry of the aerosol generating nozzle is changeable.

Device (1) according to one of the above claims, characterized in that a volume flow detection device (40) is provided, by means of which a state variable representing the volume flow of the gas flow (12) through the aerosol line (21) can be detected during operation.

Method for producing an aerosol, in particular for lubricating tools, machines and their parts, in which a liquid and a gas are fed to a mixing chamber (14) and mixed into an aerosol in the mixing chamber, and the aerosol is then removed from the mixing chamber by at least one Aerosol line (21) is directed to at least one aerosol consumer (5), characterized in that at least one state variable representing the aerosol volume flow (24) to the at least one aerosol consumer (5) is detected by an aerosol sensor (23) and the aerosol volume flow by changing the mixing chamber (14) supplied volume flow of liquid (13) and / or Gas (12) is regulated to a setpoint depending on this state variable.

Method according to claim 15, characterized in that a state variable representing the number (n _F ) of liquid drops per aerosol volume is detected by the aerosol sensor (23).

A method according to claim 15 or 16, characterized in that the aerosol sensor (23) detects the light scattered, refracted or reflected by the aerosol.

Method according to one of claims 15 to 17, characterized in that a light beam (35) is directed onto the aerosol in the region of the aerosol sensor (23).

Method according to claim 18, characterized in that the aerosol sensor (23) detects stray light components lying essentially outside the direct light beam (35).

Method according to one of claims 15 to 19, characterized in that the gas volume flow through the aerosol line (21) and the aerosol density are recorded as the state variables representing the aerosol volume flow in the aerosol line, and that the control device (3) from the recorded aerosol density (g _A ) and the detected gas volume flow (q _G ) the aerosol volume flow (q _A ) is calculated.

Method according to claim 20, characterized in that the aerosol volume flow q _{A is} calculated from the gas volume flow q _G and the aerosol density p _A according to the following formula:

where A is a constant value.

Method according to one of claims 15 to 1, characterized in that the volume flow of liquid (13) and / or gas (12) to the mixing chamber is controlled by at least one valve of a metering device which is actuated under the control of the control device.

A method according to claim 22, characterized in that the control device (3) controls a plurality of valves, each of which is assigned an orifice opening through which the liquid and / or gas stream is passed.

Method according to one of Claims 15 to 23, characterized in that the control device (3) uses the detected aerosol volume flow to determine deviations from target values and the at least one metering device is actuated in such a way that the deviations are reduced.

Method according to one of Claims 15 to 24, characterized in that the control device (3) compares the measured variables detected with reference variables and, depending on the result of this comparison, outputs a signal representative of a faulty state.

Method according to Claim 25, characterized in that the reference variables are determined automatically by the control device (3) using a learning algorithm. 03 00561

25

Method according to one of claims 15 to 26, characterized in that a state variable representative of the particle size is recorded in the aerosol line.

A method according to claim 27, characterized in that the geometry of at least sections of the mixing chamber is changed depending on the particle size.

A method according to claim 27 or 28, characterized in that the gas volume flow and / or the liquid volume flow to the mixing chamber is changed depending on the particle size.

Method according to one of claims 15 to 29, characterized in that the target value for the aerosol volume flow is predetermined depending on an aerosol consumer.