US2454757A

US2454757A - Electric space-charge device

Info

Publication number: US2454757A
Application number: US504531A
Authority: US
Inventors: Lester H Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-10-01
Filing date: 1943-10-01
Publication date: 1948-11-23
Anticipated expiration: 1965-11-23

Description

Nov. 23, 1948.. H. SMITH 2,454,757

' ELECTRIC SPACE CHARGE DEVICE Filed Opt. 1Q 1945 2 Sheets-Sheet 1 FIG. 1

'IIIIIIIIIIIIIIIIIIILQIIII FIG. 2 I J INVE OR.

L. H. SMITH ELECTRIC SPACE CHARGE DEVICE Nov. 23, .194;&

2 Sheets-Sheet 2 Filed 001;, 1, 1943 FIG.4

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FIG.5

INVENTOR.

Patented Nov. 23, 1948 mural) STATES PATENT OFFICE LesterH. Smith, Maplewood, N. J. Application October 1, 1943, Serial No. 504,531

I 1 This invention relates vices for creating an electric space charge within a volume of gas or vapor or within a suspension of liquid or solid particlesin a gas. In particular this invention is concerned with the use of high frequency fields for increasing the .eifect oisuch electric space charges on thegases or suspended materials being processed.

to improvements in de- The improvements proposedare particularly concerned with themethods of mechanically pro jecting electrically charged physical particles from'emittingjelectrodes such as have been described in my copending applications No. 481,767 and No. 504,532 both-now abandoned, and the combination of high frequency electrostatic and electromagnetic fields with the space charges so produced, I Q I 1- Considerable experimental work has been done in the treatment of various gases with high frequency electrostatic and electromagnetic fieldsn chanicallyfprojected from the emitting electrode,

aswell as increased ionization' and local electrolytic action throughout. the gas or the suspension in agas. Other objects of this invention will be apparent from the drawings and the following description of the features of the invention and in themevision of apparatus and methods c of operation for accomplishing the foregoing object.

In accordance withone modification of my invention, electrically chargedphysical particles are mechanically projected from an emitting .electrodewhich may be a nozzle, a vibratory plate, or a rotating surface. Necessary electrostatic fields toinduce' the'fiow of electric charges on the i projected particles are set up by a wide spaced grid electrode in close proximity to .the emitting electrode and a collecting electrode located at a proper distance from the emitting electrode and maintained at such a direct current potential as 1 to cause a drift of the charged particles toward the collecting electrode which also provides an external electrical return circuit to the emitting electrode. At thesame time al fiow'. of gas or of a gas containing a suspension isrnaintained through i Claims. (Cl. 204-312) tentials, a high frequency potential source is connected between the emitting electrode or grid electrode and the collecting electrode, using these same electrodes to produce a high frequency electrostatic field. The design of the electrodes, the path of the drifting space charge and the circulation of the gas or suspension in a. gas are such as to obtain'maximum processing effect.

In accordance with a second modification of my invention, electrodes for producing a high frequency electrostatic field which are separate from the electrodes used to produce the direct current electrostatic fields are used. This will be made clear in the discussion of the drawings. In accordance with a third modification of my invention, a space charge is produced in the same manner as described in connection with the first modification by the projecting of electrically charged physical particles from an emittingelectrode in combination with a grid electrode and a collecting electrode. This space charge is passed through or in close proximity to a high frequency winding which generates a, high frequency magnetic field. At the same time a flow of gas or of a gas containing a. suspension is maintained through the same path traveled by the drifting space charge. I

The circulation of the gas or suspension tolbe processed should preferably be parallel to the path of the space charge between the emitting and collecting electrodes. It may be counter-current with proper proportioning of direct current potentials and gas velocities.

It'may be desirable to have the electrically charged physical particles projected from the emitting electrode, consumed or evaporated upon mixing with the gas or suspension to be processed, leaving the electric space charge available in a free state throughout the gas or suspension.

Throughout this specification and the accompanying claims I have used the expression-wide spaced or intermediate gridto describe one of the electrodes involved in this invention. By this expression I mean any arrangement of Wires, rods or plates which in combination with an emitting electrode and a collecting electrode may be used to produce unobstructed electrostatic flux lines directed from the emitting electrode toward the collecting electrode. Obviously, the wires or plates must have open spaces between them. For purpose of illustration, I have shown in the drawings wide spaced mesh grids constructedoi parallel wires orplates. I

Referring to the drawings,

Fig. 1 illustrates a, preferred form of space charge device in which the same electrodes are used for setting up both the direct current electrostatic fields and the high frequency electrostatic fields.

Fig. 2 shows a modification of Fig. l in which the entering gas to be processed passes through the emitting electrode. Furthermore, separate electrodes are provided for setting up the high frequency electrostatic field.

In Fig. 3 is shown a. preferred form of space charge device in which the drifting space charge and the gas or suspension circulating through the the device of Fig. 3.

cycles per second is connected to a primary coupling coil 2I. A secondary winding 22 coupled with coil 2I introduces a. high frequency potential in series between collecting electrode I3 and direct current potential source I8.

Operation of the device shown in Fig. l is as follows: a gas to be processed, such as propane, for example, enters through raw gas inlet 2, passes downward through collecting screen electrode I3 and leaves through processed gas outlet 3. The emitting electrode 5 projects a cloud of liquid particles, of liquid butane, for example, downward during periods of vertical vibration. These liquid butane particles carry an electric charge .due to. the direct current potentials of grid electrode I2 and collecting electrode I3. After passing "downward through the wide spaced grid In Fig. 5 is illustrated an alternative arrange I ment of the high frequency electromagnetic winding of Fig. 3. 7 I t Figure 6 shows a form of rotating emitting electrode which can be utilized in either Fig. 1 or Fig. 3 in place of the vibratory emitting electrodes shown.

In Fig. l; the vessel I is constructed of a non conducting material such as glass sectioiis'or impregnated wood. The vessel I is provided with a raw gas inlet 2 and processed gas outlet" 3 and drain outlet I. A flexible circular plate electrode 5 in the upper portion of vessel l is supported from insulating collar 23 and is connected to the lower end of the shaft 6 which is in turn connected to -a source "I of intermittent vertical-vibratory motion of approximately 120 cycles per" second. The plate electrode 5 is the emitting electrode and is supplied with a fluid used to form charged particles through the tube 8. The'tube'il passes downward through the top of vessel I and makes a right angle bend and runs horizontally close" bration of emitting plate 5, additional'fluid is sup- F? plied through tube 8 and slots 9 and I0 and runs downhill on the lower surface of plate electrode 5 covering the lower surface of plate electrode 5 with a thin film of liquid. This thin film is .projected downward in the form of tiny droplets upon vibration of the plate electrode 5." .A gas. tight sleeve I I in the top of vessel I permits verticalniotion of the shaft 6. A wide spaced grid electrode I2 which is located close to the lower surface of emitting electrode 5 is provided,'a'lso' a-collecting' electrode I3 in the form of a screen Collecting electrode I3 is supported by an insulator I l and insulating bushing I5 which provides an external electrical connection to electrode I3. An external electrical connection to grid electrode I2 is provided through insulating bushing I6; .The emitting electrode 5 is connected to ground, as shown. The wide spaced grid electrode I2 is maintained at a. direct current potential of around 800 volts relative to ground by means of potential source I 'i. The collecting electrode I3 is maintained at a direct current'potential of around 1500 volts relative to grid electrode I2 by means of electric charges between emitting electrode 5 and :collecting electrode I3. Resistance 30 is for current limiting purposes in case of temporary'liq- .uid bridges grounding the'electrod'e I2." A source of high frequency currentat about 50,000

electrode I2, the charged butane particles mix withthe propane gas entering through inlet connection 2. At the same time the electric charges carried on the particles are subjected to the high frequency electrostatic field set up between grid I; and collecting electrode I3. Ionization and inter electrolytic action take place throughout the circulating gas. Polymerization products result- 'ing may be collected as condensate in the bottom of vessel I or they may be separated from the processed gas bymeans that do not form a part of this invention. Between periods of vibration of the emitting electrode '5, the lower surface of dis rewet with fluid fed through the tube 8. Residual electric charges are collectedby electrode I3 and returned through the external ciruit to emitting electrode 5.

In'Fig." 2, the vessel I is also constructed of electrically"non conducting material as in Fig.

-l of intermittent vibratory motion. The emitting electrode 5- is acircular flexible plate provided with perforations and is rigidly supported at the edges by the solid insulating collar 23. Theemitti'ng electrode 5 is [supplied with fluid used to form charged particles through the tube, 8 which-makes a right angle {bend and extends "horizontally across the top of emitting electrode 5. Aslot' 9' is provided in the horizontal portion of tube 8 close toth'e surface of emitting electrode 5. In between periods of vibration of electrode 5 the fluid supplied through tubes and slot 9 runs. down over the front surface of emitting electrode 5. The wide spaced grid electrode I2 and collecting screen electrode I3 are similar to "those in Fig. Land function in the same manner except that'they do not set up any high frequency electrostatic field. The parallel plate electrodes 29 and Z5.. are connected through insulating bushings '26 and 21 to the high frequency secondary windingjlz. The source 20' of high frequency. current and primary winding 2I are the same asin Fig. 1. The emitting electrode 5 lis connected'to ground. Direct current potentials' IT and I 8 andlelectric'al condenser I9 and resistance 36 arethe same as in Fig. 1. The high frequency electrodes 24 and 25 are maintained at a'negative direct current potential of about volts relative to ground by potential source 39. I

" Operation of' thefdevice shownin Fig. 2 is very "similar toft'hat .of Fig.. 1. The gas or suspension of' rnaterial jin agasto be processed enters throughinlet 2;"pas'se's through the perforations in emitting electrode 5 toward the grid electrode l2 and collecting screen .electrode l3 and out through the processed gas outlet 3. At the same time, charged particles 'of"the fluid supplied through tube 8 are projected from emitting electrode 5 through widespaced grid electrode I2 and toward the collecting screen electrode l3. Circulating currents and electrolytic action in the mixture of charged particles and gas or the suspension to be processed is promoted by the high frequency electrostatic fields set up between electrodes 24 and 25.

In Fig. 3 the vessel l is constructed. of electrically non conducting material as in Figures 1 and 2. Likewise, a raw gas inlet 2, processed gas outlet 3 and drain outlet 4 are provided. The arrangement of the emitting electrode 5, methods for supplying fluid to electrode 5 from which charged particles are to be formed and for vibrating the emitting electrode are identical with those used in Fig. l. The wide spaced grid electrode I2 is also identical with that of Fig. 1 and serves the same purpose. In order to have the high frequency winding 28 at a proper distance from the emitting electrode and to avoid excessive circulating currents in the emitting electrode, it is necessary to make use of several

intermediate grid electrodes

29 and 30. These intermediate grid electrodes as well as the collecting screen electrode 13 are shaped as shown in Fig. 4 so as to discourage circulating currents. The direct' current potentials 3|, 32 and 33 which are used between the various grid electrodes and the collecting screenelectrode l3 are dependent upon the dimensions of the apparatus and gas velocities through the device. The high frequency winding 28 passes completely around the vessel I, as shown, and is supplied with high frequency cur-'- rent from the source 20 at a frequency of about 50,000 cycles per second. Items l5, l6, 3'! and 3,8 are insulating bushings.

Operation of the device shown in Fig. 3 isas follows: The gas to be processed, such as propane, for example, enters through the raw gas inlet 2 and mixes with the electrically charged particles, of liquidbutane, for example, which are pro- J'ected downward from the lower surface of electrode 5, as in Fig. 1. The mixture of charged butane particles and propane as travels downward through the intermediate grid electrodes 1' 29 and 30. As this mixturepasses through the high frequency electromagnetic field set up by the windin 28, circulating currents are produced throughout the mixture, resulting in incre aed ionization of the gas or suspension and local electrolytic action. Residual electric charges equal to those leaving the emitting electrode 5 are collected on the screen electrode I3 and are returned through the external circuit shown to the emitting electrode 5L Polymerization products resulting may be collected in the bottom of vessel l-or may be separated from the processed gas leaving through outlet 3 by a separate condenser not shown. c

The alternative arrangement shown in Fig; 5 of the high frequency winding used in Fig. 3 consists merely'of directing the electromagnetic field across the path of the charged particles and gas by splitting the winding into two halves 34 and 35. Other parts of the device remain the same as in Fig. 3.

In Fig. 6 is shown an alternative arrangement with a rotating emitting electrode which can be used in place of the vibratory emitting electrodes shown in Figures 1 and 3. A partial section only is shown in which item l is the wall of the vessel, H is a gas tight insulating bushing which allows rotation of a shaft 6 and a disc emitting electrode 5.' Item 40 is a motor which turns shaft 6 at approximately 200 R. P. M. Tube 8 feeds fluid material to the top surface of disc 5 which material is projected in the form of fine particles from the edge of disc 5 and falls through the openings in the wide spaced or intermediate grid electrode 12. Item 15 is an insulating bushing.-

In Figures 1 and 3, I have shown electrical connections for creating space charges of negative polarity. Reverse connections of the potential sources used will create positive space charges just as readily as negative ones. Also, the size of the potentials applied between the various electrodes and the rate of vibration or rotation of certain emitting electrodes are not criticalbut can be varied as desired.

Withregard to the electrical processing of suepensions ingases, it is contemplated that certain materials in a finely divided state may be suspended in a gas in order to be able to process them in this manner. The gas present may or may not enter into the reaction or change of state which it is desired to accomplish.

As mentioned in my copending applications it may be desirable to use insulating bushings and supports which are provided with internal heating coils so as to prevent wetting of the insulating surfaces exposed inside of the processing chamber.

Itis to be understood that wherethe term gaseous material is used in the appended claims, the term is to be construedas covering gaseous material, and gaseous material having liquid or solid particles suspended therein.

This invention has been illustrated only in a general preferred form throughout-and it should be'understood that it is capable of many and varied modifications without departing from its purpose and scope, and I therefore believe myself to be entitled to make and use any and all of these modifications such as suggest themselves to those skilled in the art to which the invention is directed, provided that such modifications fall fairly within the purpose and scope of the hereinafter appended claims.

c What is claimed is:

l. Gaseous phase electric space charge device comprising a perforated emitting electrode, means associated with said emitting electrode for mechanically projecting a stream of physical particles from the surface of said emitting electrode, a collecting electrode and an intermediategrid electrode provided with an opening for the passage of charged physical particles from said emitting electrode through said intermediate grid electrode to said collecting electrode, means for maintaining a rising potential gradient between the respective electrodes causing a drift of electrically charged physical particles from said emitting electrode to said collecting electrode,

, means for setting up a high frequency field with.-

in said electric space charge device and means for circulating gaseous material to be processed through the perforations in said emitting elec- 'trode and through said electric space charge device.

2. Gaseous phase electric space charge device comprising an emitting electrode, means asso ciated with said emitting electrode for projecting mechanically a stream of physical particles from the surface of said emitting electrode, an intermediate grid electrode formed to provide a Path for physical particles projected from said emitting electrode, means for maintaining said intermediate. grid electrode. at such an electrical potential; relative to said emitting electrode that certain of the particles leaving the. surface of said emitting electrode carry an electric charge and retain this charg in passing through said intermediate gridelectrode, a collecting electrode and means for maintaining said collecting electrode at such an electrical potential relative to said emitting electrode and said intermediate grid electrode as to cause a. drift of electrically charged particles toward said collecting electrode, said electric space charge device also comprising means for setting up a high frequency of the particles leaving the surface of said, emittin electrode carry an electric charge and retain this charge in passing through said intermediate grid electrode, a collecting electrode; and means for maintaining said collecting electrode at such an electrical potential relative to. said emitting electrode and said intermediate grid electrode as to cause a drifc of electrically charged particles toward said collecting electrode, said electric space charge device also comprising means for increasing circulatin currents originating in said electrically charged particles by the use of high frequency fields and means for introducing gaseous material to be processed into and for withdrawing processed material from said device.

4. Gaseous phase electric space charge device comprising a rotating electrode, means. associated with said rotating electrode for. proiecting mechanically a stream of physical particles from the surface of said rotating electrode, an intermediate grid electrode formed to provide. a path for physical particles projected from said rotating electrode, means for maintaining said intermediate grid electrode atv such an, electrical potential relative to said rotating electrode that certain of the particles. leaving the surface of said rotating electrode carry an electric charge and retain this charge in passing through said intermediate grid electrode, a collecting electrode and means for maintaining said collecting electrode at such an electrical potential relative to said emitting electrode and said intermediate grid electrode as to cause a drift of electrically charged particles toward said collecting electrode, said electric space charge device also comprising means for setting up a high frequency field within said electric space charge device and means for introducing gaseous material to be processed into and for withdrawing processed material from said device.

5. An apparatusv for effecting gaseous: phase chemical reactions com-prising an emitting, electrode, means associated, with said emitting elec trode for projecting mechanically a stream; of physical particles from. the surface of said emitting electrode, an' intermediate grid electrode formed to provide; a path for physical particles projected from said emitting electrode, means; for maintaining said intermediate grid electrode at such an electrical potential relative to said emitting electrode that certain of the particles leaving the surface of said emitting electrode carry an electric charge and retain this charge in passing through said intermediate grid electrode, a. collecting electrode and means for maintaining said collecting electrode at such an electrical potential relative to said emitting electrode and said intermediate grid electrode as to cause a drift of electrically charged particles toward said collecting electrode, said apparatus also comprising means for setting up a high frequency field within said apparatus and means for introducing gaseous material to. be processed into and for withdrawing processed material from. said apparatus.

6. Gaseous phase electric space discharge device com-prising: an emitting electrode, means Operatively associated with said emitting electrode for vibrating at least a portion thereof to mechani-cally project a stream of physical particles from the surface of said emitting electrode, a, collecting electrode and an, intermediate electrode, said intermediate electrode being provided with an opening for the passage of charged physical particles from said emitting electrode, through said intermediate grid electrode to said collecting electrode, means for maintaining a rising: potential gradient between. the respective electrodes causing a drift of electrically charged, physical particles from said, emitting electrode to said collectin electrode, means for setting up. a high frequency field within said electric space charge device and means for introducing gaseous. material to be processed into and for withdrawing processed material from said device.

LESTER H. SMITH..

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 965,060 Babcock July 19, 1910 1,035,684 Bunet Aug. 13, 19.12 1,440,775 Eddy Jan. 2, 1923 1,809,115 Goddard June 9, 1931 2,064,260 Herrmann Dec. 1'5,v 1.936 2,240,914 Schutze May 6, i941 2,272,374 Kallmann Feb. 10,. 1 .942 2,285,622. Slepian June 9,1942 2,334,377 Bennett Nov. 16., '1943 FOREIGN PATENTS Number Country Date 421,811 Great Britain Dec. 20, 193.4 502,063 Great Britain Mar. 10, 193.9