US2979158A - Electrostatic particle separating apparatus - Google Patents

Description

April 11, 1961 B. H. VLIER, JR 2,979,158

ELECTROSTATIC PARTICLE SEPARATING APPARATUS Filed Oct. 17, 1958 2 Sheets-Sheet 1 BM/A/E 1/1 lER, JR,

INVENTOR.

WHAN/V 8 MMA/V/GAL A/I'omeys for li i/kafi/ b A Ar/ A ril 11, 1961 B. H. VLIER, JR 2,979,158

ELECTROSTATIC PARTICLE SEPARATING AP1 ARATUS Filed Oct. 17, 1958- 2 Sheets-Sheet 2 l6 /8 4 49 7 /8 9 2 2/ F g. 49 Q9 Z Z0 Z5 25 24 m 2 w 7 Z 5 w i, 22 #T g. 4.

BAA/NE H l/Z/E/Z JR.

INVENTOR.

Unite States Patent ELECTROSTATIC PARTICLE SEPARATING APPARATUS Blaine H. Vlier, Jr., Compton, Calif., assignor of sixty percent to Gordon M. Genge & Company, Inc., Los Angeles, Calif., a corporation of California Filed Oct. 17, 1958, Ser. No. 767,890

3 Claims. (Cl. 183-7) The present invention relates generally to electrical precipitation apparatus, particularly of the electrostatic type, for removing dust, smoke, fumes, mist, pollen and other foreign particles from gaseous fluids, such as air, and the like.

Heretofore, electrostatic preoipitators have been in the main of ponderous size and necessitating special constructions for installation. Such apparatus, due to the rather extremely high voltage required for operation and installation requirements, have for the most part been limited to industrial applications. Moreover, these devices were not economically and physically designed in such a way that they could be adapted for use in the treatment of air in such volume as would enable their use in domestic and relatively small, limited, industrial spaces.

Having the foregoing in mind, it is one object of the present invention to provide a precipitator of the above type, which is capable of being economically embodied in a relatively small, self-contained, portable unit for domestic and industrial use, thereby avoiding the necessity of especially designed constructions for installation.

A further object is to provide a precipitator of the electrostatic type, wherein the electrodes are so proportioned and designed that the generation of ozone will be maintained at a comparatively low value.

It is also a further object of the herein described invention to provide an electric precipitator which will operate efiiciently with respect to removal of large as well as fine particles from the circulated air.

Another object is to provide a device of the above character wherein the particle collector may be easily cleaned, or may be constructed as a throwaway structure.

Still another object is to provide a device for electrostatically cleaning air in a space, which utilizes relatively high DC. potential having a low ripple factor, thereby preventing undesirable back ionization and reducing generation of ozone therein.

Still another object is to provide an electric precipi tator which utilizes a small ionizing surface and a large, smooth collector surface so that all particles will be charged to the same sign at the ionizing electrode and not recharged to opposite sign at the collector electrode.

Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.

Referring to the accompanying drawings, which are IQC 2 v the housing wall being cut away to show the internal arrangement of parts;

Fig. 4 is a transverse section through the apparatus, taken substantially on line -4-4 of Fig. 3;

Fig. 5 is an enlarged fragmentaryv sectional view showing the interrelationship between the ionizing electrode and the collector electrode, taken substantially on line 5-5 of Fig. 3; and i Fig. 6 is a schematic wiring diagram of the electrical circuitry and interconnection of the component parts of the apparatus' Referring more specifically to the drawings, for illustrative purposes, a portable precipitator unit embodying the features of the present invention is disclosed in Fig. 1 as comprising a substantially rectangular casing or housing 10 which is arranged in this case with transversely extending Z-rails 11-11 which permit the apparatus to be suspended from wooden frame members 12, as shown in Fig. 2, which may comprise the ceiling joist of a room, or members forming a part of a supporting frame work. While the apparatus is shown as being adapted for mounting in an elevated position in a room or other area, the housing may, if desired, be supported on the floor of the area.-

The housing ltl is o-f box-like construction, and is fitted with hinged end frames 13 and 14 positioned at the opposite ends of the housing, each of these end frames lacing provided with a grille or screening 15 to permit passage of air or other gaseous fluid which is to be circulated through the apparatus.

Within the housing 10, as perhaps best shown in Figures 3 and 4, a tubular honeycomb structure, as generally indicated by the numeral 16, is removably .mount ed adjacent to the end frame 14,-and arranged to be withdrawn for replenishment or cleaning, when the hinged end 14 is opened. I

The structure 16 is composed of sheet material which is deformed so as to provide a plurality of parallel hexagonal tubes 17 which are secured together by any conventional means to provde the honeycomb structure and effect a plurality of parallel tubular flow channels 18 respectively through the tubes. At the periphery of the structure 16, suitable baflle fins 19 are provided between the tubes and the adjacent walls of the housing, while baflle fins 20 are similarly provided between the tubes and other walls of the housing.

The tubes of'the structure 16 may be constructed of a light metallic sheet metal, such as aluminum; or the structure 16 may be provided as a throwaway unit with the tubes constructed of cardboard or other suitable material, in which case the interior surfaces of the tubes would be lined with a metallic coating or foil. The tubes 17 may be constructed of cylindrical or other configuration. However, the hexagonal tube is preferred since it naturally permits the tubes to be assembled into a honeycomb construction so that a maximum flow channel area may be obtained in a minimum section of the housing.

Adjacent the innermost end of the structure 16, a pair of spaced straps 2121 of insulating material are secured at their opposite ends in each case to the adjacent opposite walls of the housing by means of suitable angle brackets 22 to provide an insulating support for a wire grid structure, as generally indicated at 23, this grid structure being composed of 'a plurality of parallel members 24 which are secured and held in parallel relation by means of transversely extending members 25 which are welded or otherwise secured to the members 24. The grid structure is secured to the straps 21 by means of appropriate clips 26. It will be observed that there are a similar number of members 24 and tube rows, and

that each of the members 24 extends along a row of tubes.

As shown in Fig. 5, the grid structure 23 supports a plurality of branch wires or conductors 27 which respectively extend into each of the tubes 17. The conductor 27 is preferably made of a wire size of sufliciently large diameter that it will not have an ionizing effect when a relatively high voltage, as hereinafter described, is connected thereto. As shown, the branch conductor 2-7 is offset intermediate its ends to provide. an inner leg portion 28 and an outer end portion 29, in each case, between which a relatively fine filamentary member 30, such as a wire, may be strung. The filamentary member 30 makes electrical contact at the end thereof which is connected with the leg portion 29, while the other end of the member is insulated with respect to the leg portion 28 by means of a suitable insulating covering 31 which is provided on the members 24 and 25 of the grid structure, as well as the adjacent inner end portions of the conductors 27, including the leg portions 28. It is desirable that the filamentary members shall be as small in diameter as possible, consistent with sufiicient strength to prevent breakage, and for this purpose wires of a diameter of the order of .008 inch have been utilized. The filamentary member in each case is positioned so as to extend substantially axially of the tube 17 with which it is associated. The member 30 forms an ionizing electrode while theinner surface of the tube 17 provides a collector electrode, and these electrodes cooperate when connected with a proper high voltage source to produce a substantially uniform electrostatic field throughout the length of each flow channel within each of the tubes 17, as will hereinafter be discussed in greater detail. By supporting the filamentary members adjacent the innermost ends of the tube 17, these members do not interfere with the removal of the honeycomb structure 16.

As shown in Figures 2 and 3, upper and lower rail members 32 and 33 are secured to the adjacent walls of the housing 10, these rail members having an elongate groove 34 respectively formed in their confronting edges for slidingly receiving opposite edge margins of a filter frame structure 35 which carries a filter panel '36 of close mesh metallic material, such as aluminum. The filter frame structure may be inserted and removed through a suitable slot in the housing wall, which may be normally closed by a removable closure member 37. This arrangement permits removal of the filter frame and the filter panel as a unit for cleaning and for replacement, when desired.

As shown primarily in Fig. 3, there is a compartment 38 formed within the housing between the mounting for the filter frame structure 35 and the end frame 13 within which a device is mounted for providing a movement of air through the apparatus. For purposes of illustration, this device is shown as comprising an electric motor 39 which is suspended from a wall of the housing by a suit able supporting bracket 40. This motor drives a multiblade fan 41 which is positioned in an opening 42 formed in a transversely supported bathe plate 43 positioned inwardly of the end frame 13. With the arrangement described above, it will be apparent that operation of the fan 41 will cause a circulation of air to flow into the apparatus through the grille 15, through the flow channels 18, the filter panel 36, to the opening 4 2 and thence out through the grille 15 associated with the end frame 13.

The compartment 38 further provides space for mounting of the voltage converting means whereby a domestic AC. electric potential is converted into a relatively high DC. potential having a low ripple factor to be utilized for creating an electrostatic field in the path of flow of the particle, laden air, whereby the particles are removed.

.The potential converting device is generally indicated by numeral 43, Fig. 2. As shown in Fig. 6, the potential converting device comprises a transformer 4- having a primary winding 45 which connects with a domestic A.C. electric source 46 through a primary control switch 47 4 and safety switches 48 and 49. The output side of the transformer is connected from a secondary winding 50 to a voltage tripler rectifying and filtering circuit as generally indicated by the numeral 51, which converts the alternating current into a DC. potential of the order of 14,000 volts, no load, which is reduced under load conditions to substantially 10,000 volts in the apparatus of the present invention. Moreover, the rectifying and filtering circuit is designed to produce an output potential having a low ripple factor, e.g., 3-5%. The positive side of the output potential is grounded, while the negative side is connected with the ionizing electrode filamentary member 30, the circuit being completed through the collector electrode tube 17 which is grounded. The safety switches 48 and 4-9, are shown in Fig. 3 as being associated with the hinged end frames 13 and 14 of the housing, and are so arranged that these end frames must be in closed position in order to energize the transformer by closure of the main switch 47. With the safety switches closed, closure of the main switch energizes the motor 39 to start movement of air circulating through the ap paratus. Energization of the transformer is indicated by an indicating lamp 52 connected across the primary winding 4-5 of the transformer, and the circuit is shown as including a protective fuse 53.

In its broad concept, the present invention differs in a number of respects from previous approaches for devices and apparatus of this character. Heretofore, it was considered essential to utilize an ionizing electrode having sharp points or projections thereon, and in the main the arrangements produced a nonuniform electrostatic field so that in some embodiments the removed particles were merely arrested on the surface of the collector, and due to the presence of peak voltages, there was a tendency for back ionization and production of undesirable quantities of ozone which made the previous arrangements unsuitable for domestic installation.

According to the present invention, is has been determined that greater efficiency may be obtained by utilizing a small ionizing electrode surface in combination with a large collecting surface, and that by properly proportioning the spacing between these surfaces it is possible to increase the emeiency of the separation, particularly where the ionizing voltage has a low ripple factor.

By utilization of a small wire of the order of .008 inch diameter, it is possible to obtain a uniform or constant electrostatic field; and that by the use of a potential having a low ripple factor, the peaks are avoided so that there will be no back ionization, and all the particles in the fluid will be charged to the same sign at the ionizing electrode and not recharged to opposite sign at the collector electrode.

It has been further determined that by connecting the negative side of the high potential to the ionizing electrode, it is possible to utilize lower potentials of the order of 10,000 volts, thus making the device available for domestic operation. While the use of negative potential on the ionizing electrode produces greater ozone than in the case where the electrode is made positive, this is readily overcome by the use of a potential having a low ripple factor which prevents back ionization.

In the device of the present invention, as described above, both the large particles and fine particles are efficiently removed. The larger particles are rapidly deposited near the entrance to the tubes 17, while the tines tend to collect toward the rear end of the tubes. Due to the fact that the particles are held in the uniform electrostatic field for a longer period of time, the particles which are removed and deposited on the inner wall of the collector tubes are compacted rather than merely being arrested. These particles can only be removed by means of a detergent, or if the collector tube structure is made of the throw-away type, then, of course, it is only necessary to dispose of the collector unit and replace it with a clean unit.

In the event that some of the fine particles may not have been collected in the tubes, then these particles will be caught in the mesh of the filter panel 36 where they will become entrained and de-ionized, since this filter is grounded the same as the collector electrode.

From the foregoing description, it is believed clearly apparent that the apparatus of the present invention accomplishes the indicated objectives as stated above.

Various modifications may suggest themselves to those skilled in the art Without departing from the spirit of my invention, and, hence, I do not wish to be restricted to the specific form shown or uses mentioned, except to the extent indicated in the appended claims.

I claim:

1. Electrical precipitator apparatus, comprising: a housing open for the fiow of particle laden fluid there through; a plurality of hexagonal tubular members having uninterrupted inner exposed surfaces and secured together to form a unitary honeycomb structure; an insulating support carried by the housing at one end of said honeycomb structure, said honeycomb structure being removably carried in said housing whereby said structure may be removed as a unit in a direction away from said support; a plurality of support wires carried by said insulating support and respectively extending axially into each of said tubular members and offset from the axes thereof; a plurality of electrically interconnected filimentary members and each carried by a support Wire to extend lengthwise and centrally of a tubular member; a high D.C. potential source connected to said tubular members and said filimentary members for establishing an electrostatic field in each of said tubular members; and means for moving said particle laden fluid through said tubular members.

2. Electrical precipitator apparatus, comprising: a substantially rectangular housing having hinged grilled opposite ends; a collector electrode structure removably supported in said housing adjacent one of said grilled ends, and being replenishable through said one of said grilled ends when in opened position, said electrode structure including at least one tubular member forming an air flow channel; an ionizing electrode structure in said housing including at least one insulated support wire extending axially into said tubular member and offset from the axis thereof and one filamentary member carried by said support wire and extending centrally of said tubular member; means in said housing for circulating air through said grilled ends and said tubular member; and means in said housing for converting a relatively low input A.C. potential into a relatively high low ripple D.C. output potential connected to said ionizing electrode and said collector electrode.

3. Electrical precipitator apparatus, comprising: a substantially rectangular housing having grilled opposite ends, a collector electrode structure supported in said housing adjacent one of said grilled ends, said electrode structure including at least one tubular member forming an air flow channel having an uninterrupted inner surface; an ionizing electrode structure in said housing including an insulated support wire extending axially into said tubular member and olfset from the axis thereof and an extremely small filamentary member carried by said support and extending cent-rally of said tubular member; means in said housing for circulating air through said grilled ends and said tubular member; and means in said housing for converting a relatively low input A.C. potential into an output no load D.C. potential of the order of 14,000 volts, said output potential having a positive grounded side electrically connected with said collector electrode and a negative side connected with said ionizing electrode.

References Cited in the file of this patent UNITED STATES PATENTS 2,233,639 Pegg Mar. 4, 1941 2,422,564 Pegg June 17, 1947 2,443,780 Wintermute June 22, 1948 2,476,247 MacKenzie July 12, 1949 2,650,672 Barr et al. Sept. 1, 1953 2,672,207 Hedberg Mar. 16, 1954 FOREIGN PATENTS 682,588 Germany Oct. 18, 1939

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