US3862826A

US3862826A - Aerodynamic/electrodynamic filter system

Info

Publication number: US3862826A
Application number: US303331A
Authority: US
Inventors: Hans O Haupt
Original assignee: Crs Industries Inc
Current assignee: Crs Industries Inc
Priority date: 1972-11-03
Filing date: 1972-11-03
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

A filter system for removing pollutant particles suspended in a fluid body comprising precharging means to electrically precharge the suspended particles, precipitator means to attract and collect the charged particles, fluid turbulator means disposed between the precharging means and precipitator means to alter the fluid flow to enhance the collection of the charged particles and neutralizing means to neutralize the fluid flow before exiting the filter system.

Description

United States Patent 1191 Haupt 1 11 Jan. 28, 1975 15 1 AERODYNAMlC/ELECTRODYNAMIC 2,634,818 4/1953 Wintermutc 55/136 x SY EM 3,633,337 l/l972 Walker ct a1. 165/186 X FILTER ST 3,718,029 2/1973 Gourdine etal..." 324/71 PC X Inventor: Hans Haupt, a p li nd. 3.740.927 6/1973 Vincent 55/154 x [73] Assignee: CRS Industries, Inc., Tampa, Fla. FOREIGN PATENTS OR APPLICATIONS 22] Filed; 3, 1972 444,333 3/1936 Great Britain .1 55/130 1,198,881 7/1970 Great Britainm. 55/138 1 1 pp Flo-1303,3311 421,151 11/1925 Germany 55/136 521 11.5. c1 55/112, 55/118, 55/138 "rimury Miles [51] Int. Cl. B03c 3/12 Agent awn-Stein and [58] Field of Search 55/138, 137, 136, I08,

55/118, 120, 122, 112 1 1 T CT A filter system for removing pollutant particles sus- 1 1 References cued pended in a fluid body comprising precharging means UNITED STATES PATENTS to electrically precharge the suspended particles, pre- 1,377,205 5/1921 Krause 55/138 Cipitator means to attract and Collect the Charged P 1,400,795 12/1921 Bradley.... 55/130 ticles, fluid turbulator means disposed between the 1,903,644 4/1933 Meston 55/119 X precharging means and precipitator means to alter the 2,1 2.129 9 HOSS Ct 111. 55/131 fluid flow to enhance the collection of the charged 2,318,093 5/1943 y 55/133 X particles and neutralizing means to neutralize the fluid 2,395,927 3/1946 White 55/137 X flow before exiting the filter System 2,579,441 12/1951 Palmer .1 55/138 X 2,610,699 9/1952 Penney et a1. 55/105 20 Claims, 5 Drawing Figures 9 |oo 92 l I sz h NEUTRALIZATION ZONE 1 PRECIPITATION ZONE FLUID TURBULATOR ZONE PRE. CHARGING ZONE loa :IIG: C :ll6: I20 llII IIB FIG. 4

FIG. 5

AERODYNAMIC/ELECTRODYNAMIC FILTER SYSTEM BACKGROUND OF THE INVENTION 1. Field of the Invention A filter system for removing pollutant particles suspended in a fluid body.

2. Description of the Prior Art Electrostatic air filter precipitators are well known. Such electrostatic precipitators are used for air pollution control, gas cleaning, separation and selective particle removal. Generally these air filters comprise a plurality of charged electrodes of opposite polarities arranged relative to one another to form an electrostatic field therebetween. Generally, the fluid containing the material to be precipitated flows, under positive or negative pressure, between the electrodes and the electrostatic field. Since high voltages are generated between the electrodes the separation therebetween must be sufficient to prevent breakdown of the medium which may cause shorting of the high voltage supply. Thus, the minimum size of such electrostatic precipitators is controlled by the voltage supply and spacing. Unfortunately the optimum flow velocity varies substantially from the velocities usually associated with the air flow within the air mass to be filtered. Thus the air flow must be reduced before entering the precipitator.

As a result these filters must necessary be extremely large to accommodate the air mass to be filtered. Thus a need exists to'control the aerodynamics of the air flow through the filter to optimize the filtering properties of the system.

SUMMARY OF THE INVENTION This invention relates to, an air filter system for filtering suspended pollutant particles from the air. More specifically, the air filter system comprises an aerodynamic/electrodynamic precipitator system.

The precipitator system comprises a housing including a precharging means, fluid turbulator means, precipitator means and neutralizing means as more fully described hereinafter.

The precharging means comprises a plurality of negatively charged electrodes arranged in the forward portion of the housing to precharge the pollutants particles. The fluid turbulator means is disposed downstream of the precharging means. The fluid turbulator means comprises a plurality of positively charged electrodes configured to alter the flow of the airstream. The precipitator means which comprises a plurality of positively charged electrodes is disposed toward the rear portion of the housing. The precipitator means further includes a shaker means and fluid jet generating means to remove the particles as they accumulate on the positively charged electrodes. The neutralizing means comprises a plurality of positively charged electrodes disposed in the rear portion of the housing rearward from the precipitator means.

In operation an airstream is normally generated by a blower or fan device arranged in communication with the filter system. Of course the airflow may be generated by a draft within a stack wherein temperature differential generates the flow. As the suspended particles enter the filter system they are negatively precharged by the precharging means. The negatively charged particles are then accelerated through the filter by the positive attraction of the fluid tubulator means and collected on the precipitator means. As the air flow accelerates toward the fluid turbulator means the flow is aggitated by the plurality of electrodes spaced across the air flow.

Since the precipitator means has a substantially higher positive charge the flow continues past the turbulator means toward the precipitator means. As the air passes the turbulator electrodes the flow becomes turbulant and decreases relative to the precipitator means thereby increasing the precipatation or collection of the negatively charged particle by the positive precipitation zone. These charged particles are loosened by an electromagnetic shaker system and drawn off by a vacuum and water jet pump assembly. As the clean air passes the neutralizing means the suspended particles are neutralized by the low voltage electrodes.

This combination of aerodynamic and electrodynamic principals drastically reduces the total amount of pollutants filtered by the system. Thus the speed of the air flow can be increased creating a higher efficiency and quality in air cleaning.

This invention accordingly comprises the features of construction, combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter wet forth and the scope of the invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description, taken in connection with accompanying drawings in which:

FIG. 1 is a cross-sectional side view of the filter system.

FIG. 2 is a partial detailed top view of the filter system.

FIG. 3 is a top view of the filter system.

FIG. 4 is a detailed top view of an alternate embodiment of the neutralizing zone.

FIGS. 5a through 5e are a family of waveforms of the filter system operation.

Similar reference characters refer to similar parts throughout the several views of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIGS. 1 and 3, the present invention is a fluid filter system generally indicated as 10 comprising a aerodynamic/electrodynamic precipitator system. The filter system comprises frame 12 housing precharging means 14, fluid turbulator means 16, precipitator means 18 and neutralizing means 20 as move fully described hereinafter.

Frame 12 comprises side panels 22/24, top and bot tom panels, 26/28 respectively, and front and rear filter screens, 30/32 respectively. As shown in FIG. 3 filter screen 30 is connected through conductor 34 to ground 36.

Precharging means 14 comprises a plurality of finlike precharging electrodes 38 connected to negative voltage source 40 through conductor 42. Typically the power supply may be 5000 volts direct current. Electrodes 38 are attached to panel 28 by

support members

44 and 46. As more fully described hereinafter negatively charged electrodes 38 and filter screeen 30, coupled to ground, cooperatively form a negative precharging zone 48.

As best shown in FIG. 1, fluid turbulator means 16 comprises a plurality turbulator electrodes in the form of aerodynamic foils 50 specifically configured to alter the flow of fluid through frame 12. The convex forward portion 52 and concave rearward portion 54 changes the laminar flow to turbulent flow as more fully described hereinafter. Aerodynamic foils 50 connected to low positive voltage source 56 through conductor 58 comprise charged electrodes. Typically the power supply may be 5000 volts direct current. Electrodes 50 are affixed to panel 28 by support members 60.

Immediately downstream of fluid turbulator means 16 is precipitator means 18. Precipitator means 18 comprises a plurality of spiral precipitator electrodes 62 wound around porous sleeve 63. Electrodes 62 are coupled to voltage source 64 through conductor 66. Typically power source 64 may be 20,000 volts direct current. The lower portion of each electrode 62 is coupled to nozzle means 68 through funnel means 70. Precipitator means 18 further includes electrode cleaning means comprising fluid jet generating means generally indicated as 72 and shaker means generally indicated as 74. Fluid jet generating means 72 comprises bellows 76 and manifold means 78 which is coupled to a water source (not shown). Fluid jet generator means 72 is attached to the upper end of sleeve 63 to create a downward flow of air stream to generate a vacuum therein Shaker means 74 comprises an electromagnetic shaker including coil/conductor 80 connected between voltage source at 82 and ground at 84 and electromagnet 86. Shaker 74 is insulated from panel 26 by insulator 88.

Disposed between precipitator means 18 and filter screen 32 is neutralizing means 20. Neutralizing means 18 comprises a plurality of fin-like electrodes generally indicated as 90. As best shown in FIG. 3, a portion of the electrodes 92 are connected to voltage source 94 through conductor 96. Typically power source 94 comprises 5000 volts alternating voltage superimposed on 2500. of course power source 94 may comprise or DC. signal (FIGS. b and 5d respectively), A.C. signal (FIG. 5c) or negative pulsed direct current (PDC) with superimposed A.C. (FIG. 5e). Electrodes 98, alternately disposed between electrodes 92, are connected through conductors 100 and filter screen 32 to ground. As more fully described hereinafter

electrodes

92 and 94 cooperatively form a postive charging neutralizing zone 102.

Alternately as shown in FIG. 4, neutralizing means 18 may comprise a plurality of spaced, parallel charged first, second and third electrode means 104, 106 and 108 respectively extending across the airstream. As shown in FIG. 4, first electrode means 104 comprises a plurality of spaced electrodes 110 coupled to power source 112 through conductor 114. Typically power source 112 comprises a P.D.C. voltage with an A.C. voltage superimposed thereon (FIGS. 5a and 5e). Disposed downstream of first electrode means 104 are second and third electrode means 106 and 108 respectively. Second electrode means comprises a plurality of space electrodes 116 coupled to ground 118 through conductor 120. Third electrode means 108 comprises a third plurality of spaced electrodes 122 that are coupled to power source 124 through conductor 126. Typically power source 124 comprises an A.C. voltage (FIG. 50). As more fully described hereinafter, electrode means 104 and 106 cooperatively form first neutralizing field 128 while electrode means 106 and 108 cooperatively form second neutralizing field 130.

In operation, a contaminated airstream is normally generated by a blower or fan disposed in front or rearward of the filter system. This contaminated air enters the filter system by passing through negative precharging zone 48 generated by filter screen 30 are precharging electrodes 38. These negatively charged particles are carried in the airstream toward positive attraction zone 51 formed by positively charged aerodynamic foil electrodes 50. Due to the compression of the airstream through the narrow spacing between electrodes 50 the speed of the air flow increases substantially. As the high speed air passes the trailing edge 54 the laminar air flow is perturbed greatly reducing the rearward linear flow rate of the air flow relative to electrodes 62, thereby permitting the negatively precharged particles to be precipitated at the high positively charged electrodes 62. It should be noted that electrodes 62 are disposed at the focal point or geometric center of the air disturbance such that the charged particles are attracted toward electrodes 62 from 360 degree arc. Particles are then loosened by the electromagnetic shaking system 74 and removed by the vacuum generated airstream and water jet. The cleaned air continues rearwardly through positively charged neutralizing zone 102. Any suspended particles remaining in the air stream receive a low positive precharge. The air is then returned to the filtered area or enclosure where affinites may be attracted to these charged suspended particles. When the air is released into the atmosphere, no positive precharge will be applied so all particles leave the system neutralized.

In the alternate embodiment of FIG. 4, the cleaned air flows through first neutralizing field 128 where particle compounds are separated under the influence of the P.D.C. voltage signal. As the air flow continues through second neutralizing field 130, the separated particles are precharged by the A.C. voltage signal.

It will thus be seen that the objects set forth above, among those made apparent from the preceeding description, are efficiently attained, and since certain changes may be made in carrying out the above method and article without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

What is claimed is:

l. A fluid filter system for filtering suspended polluted particles from a fluid stream, said filter system comprising a frame having a plurality of electrically charged zones operatively disposed therein, said plurality of electrically charged zones comprising a precharging zone defined by a plurality of precharging electrodes having a charge thereon of a first polarity; a precipitator zone including precipitator means defined by a plurality of precipitator electrodes, a fluid turbulator zone comprising a plurality of turbulator electrodes disposed between said precharging electrodes and said precipitator electrodes and adjacent said precipitator electrodes; said precipitator electrodes and said turbulator electrodes both having a charge of a second polarity thereon, said second polarity being opposite to said first polarity, said precipitator electrodes comprising a voltage field strength substantially greater than said voltage field strength of said turbulator electrodes, whereby said charged particles are accelerated through said precipitator zone to collect on said precipitator means; said fluid turbulator electrodes disposed in predetermined spaced relation to one another and relative to said precipitator electrodes so as to aerodynamically reduce the rate of fluid flow immediately forward of said precipitator means.

2. The filter system of claim 1 wherein said precipitator zone charged electrodes are coupled to a positive voltage source.

3. A fluid filter system as in claim 1 further comprising shaker means disposed in said precipitator zone and interconnected to said precipitator means, said shaker means comprising electromagnetic actuating means connected to said precipitator means, whereby energization of said electromagnetic actuating means causes movement of said precipitator means and dislodging of charged particles therefrom.

4. A filter means as in claim 1 wherein each of said precipitator electrodes is substantially enclosed within a substantially correspondingly configured sleeve means such that said charged particles are collected on said sleeve means.

5. A fluid filter system as in claim 1 further comprising fluid jet generating means connected in fluid communicating relation with said precipitator means, said fluid jet generator means defining a fluid flow about said precipitator electrodes, whereby charged particles are removed from said precipitator electrodes.

6. A fluid filter system as in claim 5 wherein said precipitator means comprises sleeve means disposed in substantially surrounding relation to at least one of said plurality of precipitator electrodes, said fluid generating means connected in fluid communicating relation with said sleeve means and, whereby charged particles are dislodged from said one electrode.

7. A filter systems as in claim 1 wherein said fluid jet generating means comprises bellow means to generate a vacuum within said sleeve means whereby said fluid flow is at least partially defined by said vacuum.

8. A fluid filter system as in claim 7 wherein said fluid jet generating means further comprises a liquid source coupled to said sleeve means such that liquid from said liquid source flows over said sleeve means to remove charged particlesfrom said precipitator electrodes.

9. The filter system of claim 1 wherein said turbulator zone comprises a plurality of aerodynamic foils, each of said aerodynamic foils comprising a convex leading edge and concave edge such that the rate of fluid flow relative to said precipitator means immediately adjacent thereto is substantially reduced.

10. A fluid filter system as in claim 9 wherein said aerodynamic foils comprise said turbulator electrodes. said aerodynamic foils designed and configured to at least partially define said turbulator zone.

11. The filter system ofclaim 10 wherein said aerodynamic foils are coupled to a positive voltage source.

12. The filter system of claim 1 further including neutralizing zone disposed in the rearward portion of said frame to neutralize said particles prior to exit or fluid flow from said frame.

13. The filter system of claim 12 wherein said neutralizing zone includes first and second plurality of electrodes, said first plurality of electrodes comprising a plurality of charged electrodes coupled to a voltage source, said second plurality of electrodes comprising a plurality of neutral electrodes, said charged and neutral electrodes being arranged in alternating fashion relative to each other such that adjacent charged and neutral electrodes cooperatively form a voltage gradicut to generate said neutralizing zone.

14. The filter system of claim 1.3 wherein said first plurality of electrodes voltage source includes an AC. voltage signal.

15. The filter system of claim 13 wherein said first plurality of electrodes voltage source includes a D.C. voltage signal.

16. The filter system of claim 15 wherein said voltage source further includes an AC. voltage signal superimposed on said D.C. voltage signal.

17. The filter system of claim 12 wherein said neutralizing zone comprises first and second electrode means disposed across the fluid flow, said first electrode means coupled to a first voltage potential, said second voltage source coupled toa second voltage potential, the relative magnitude of said first voltage potential relative to said second voltage potential such that said first and second electrode means cooperative form a first neutralize field.

18. The filter system of claim 17 wherein said first voltage potential comprises a pulse D.C. potential including a D.C. potential having an A.C. potential superimposed thereon and said second voltage potential is neutral.

19. The filter system of claim 17 wherein said neutralizing zone further includes a third electrode means coupled to a third voltage potential, said third electrode means disposed relative to said second electrode means to cooperatively form a second neutralizing field therebetween.

20. The filter system of claim 19 wherein said third voltage potential comprises an AC. potential and said second voltage potential is neutral.

elmxee STATES PATENT owme QEETH MATEE @F CQREMWN Patent No. 3,862 ,826 D t January 28 1975 lnventofls) Hans O0 Haup't It is certified that error appears in the above--identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3 line 61 "space" should read spaced M Column 5 line 39 after "and" insert disposed to generate fluid flow within said sleeve means Signed and sealed this 15th day of July 1975" {SEAL} Attest:

Cw MARSHALL DANN RUTH Co MASON Commissioner of Patents Attesting Officer and Trademarks

Claims

1. A fluid filter system for filtering suspended polluted particles from a fluid stream, said filter system comprising a frame having a plurality of electrically charged zones operatively disposed therein, said plurality of electrically charged zones comprising a precharging zone defined by a plurality of precharging electrodes having a charge thereon of a first polarity; a precipitator zone including precipitator means defined by a plurality of precipitator electrodes, a fluid turbulator zone comprising a plurality of turbulator electrodes disposed between said precharging electrodes and said precipitator electrodes and adjacent said precipitator electrodes; said precipitator electrodes and said turbulator electrodes both having a charge of a second polarity thereon, said second polarity being opposite to said first polarity, said precipitator electrodes comprising a voltage field strength substantially greater than said voltage field strength of said turbulator electrodes, whereby said charged particles are accelerated through said precipitator zone to collect on said precipitator means; said fluid turbulator electrodes disposed in predetermined spaced relation to one another and relative to said precipitator electrodes so as to aerodynamically reduce the rate of fluid flow immediately forward of said precipitator means.

3. A fluid filter system as in claim 1 further comprising shaker means disposed in said precipitator zone and interconnected to said precipitator means, said shaker means comprising electromagnetic actuating means connected to said precipitator means, whereby energization of said electromagnetic actuating means causes movement of said precipitator means and dislodging of charged particles therefrom. 4. A filter means as in claim 1 wherein each of said pRecipitator electrodes is substantially enclosed within a substantially correspondingly configured sleeve means such that said charged particles are collected on said sleeve means.

6. A fluid filter system as in claim 5 wherein said precipitator means comprises sleeve means disposed in substantially surrounding relation to at least one of said plurality of precipitator electrodes, said fluid generating means connected in fluid communicating relation with said sleeve means and disposed to generate fluid flow within said sleeve means, whereby charged particles are dislodged from said one electrode.

8. A fluid filter system as in claim 7 wherein said fluid jet generating means further comprises a liquid source coupled to said sleeve means such that liquid from said liquid source flows over said sleeve means to remove charged particles from said precipitator electrodes.

10. A fluid filter system as in claim 9 wherein said aerodynamic foils comprise said turbulator electrodes, said aerodynamic foils designed and configured to at least partially define said turbulator zone.

11. The filter system of claim 10 wherein said aerodynamic foils are coupled to a positive voltage source.

13. The filter system of claim 12 wherein said neutralizing zone includes first and second plurality of electrodes, said first plurality of electrodes comprising a plurality of charged electrodes coupled to a voltage source, said second plurality of electrodes comprising a plurality of neutral electrodes, said charged and neutral electrodes being arranged in alternating fashion relative to each other such that adjacent charged and neutral electrodes cooperatively form a voltage gradient to generate said neutralizing zone.

14. The filter system of claim 13 wherein said first plurality of electrodes voltage source includes an A.C. voltage signal.

16. The filter system of claim 15 wherein said voltage source further includes an A.C. voltage signal superimposed on said D.C. voltage signal.

17. The filter system of claim 12 wherein said neutralizing zone comprises first and second electrode means disposed across the fluid flow, said first electrode means coupled to a first voltage potential, said second voltage source coupled to a second voltage potential, the relative magnitude of said first voltage potential relative to said second voltage potential such that said first and second electrode means cooperative form a first neutralize field.

20. The filter system of claim 19 wherein said third voltage potential comprises an A.C. potential and said second voltage potential is neutral.