US2521605A - Electrostatic precipitator - Google Patents

Description

Sept. 5, 195o E. L. RICHARDSON ELECTROSTATIC PRECIPITATOR Filed sept. 28, 1946 INVENTOR.

Ear L Fic/varas of? BY v M @im Patented Sept. 5, 1950 UNITED .STATES PATENT OFFICE (Cl. '18S-47) 8 Claims.

This invention relates to electrostatic precipitators for removing ydust and other ioleign particles from gases such as air.

The conventional 'electrostatic prec'ipitator for removing dust from air, includes an ionizing chamber in which the dust particles are given a charge, and includes yin 'a collection chamber down-stream of the ionizing chamber, 'a plurality yof grounded metal plates and insu-lated metal plates, the grounded plates serving as collector electrodes to which the charged dust particles are attracted. The insulated plates are charged to a high voltage, and it has been necessaryT not only to support them `from large insulators which extend into the air stream, but it has been necessary to use large numbers o spacer insulators between 'the plates rfor supporting ther-n in alignment and for insulating them electrically.

This invention provides Velectrode plates coin' pr'ising electric insulating material lia-ving layers of electric conductive material on their Afaces, the plates being supported upon metall rods and spaced apart by metal spacers, the conductive material being omitted lfrom the pla-tes it is 'desired to insulate from the yrods and spacers. Advantages of this construction are 'that'external supporting insulators Yare not necessary; Ithe metal spacers are much less expensive than the insulating spacers; the metal spacers are -cylindrical and do not trap the liquid used to flush the plates for cleaning, as the insulating spacers which have vraised surfaces, do, and the electric connections between the electrodes can be provided by the supporting vrods and the metal spacers.

Objects of the invention are to improve the eiciency nf, and to reduce the costei, electrostatic precipitators.

The invention will now be described with reference vto the drawing, of which:

Fig. 1 is a side elevation in cross-section, of an electrostatic precipitator embodying this invention, with the section .taken along .the lines .I--l of Fig. 2;

Fig. 2 is an end elevation partially in section, the section being taken along the lines 2-2 of Fig. l;

Fig. 3 is an enlarged view in section, of a portion of one of the collector plates of the pren cipitator, and

Fig. 4 is an exploded view illustrating the relations of portions of three of the collector plates to their supporting rods and spacers, and illustrating the absence of conducting surfaces on the plates where insulation from the spacers and rods is desired.

In the embodiment of the invention illustrated by the drawing, air to be treated is drawn in through the grille 5 inthe ltopcof the precipi-tatoi' cabinet 6, and passes downwardly through lthe ionizing `chamber l, and then through ythe precipitating chamber 8, thebot-tom -o-i which may be connected to a conventional blower.

The ionizing chamber 'l is similar to that disclosed in the G. W. Penney 'Paten-t No. 2,131,767 and contains the ionizing Wires S disposed bev- 'tween the tubular electrodes it, and which are `connected to the positive terminal I+ of the high voltage, ydirect current supply lsou-roe which is not illustrated. The electrodes Il! are grounded to the cabinet The ionizing wires il are suspended between the rigid end supports `I I carried by the skeleton framework I2 which is supported by the insulators 13. The wires *9 are supported at an intermediate point by the sup port Il! valso carried by the framework I2.

The electrodes in the precipitating cham-ber '8 are, as illustrated by Fig. 3, iormed as plates' -I' of `electric insulating vmaterial such as nbre glass or Micarta which is a synthetic plastic having suitable electric insulation characteristics, coa-ted or plated with a metallic, electric conductive coating I6.

AThe grounded precipitating electrodes Iii and the insulated electrodes lIl are supported 'onthe rods It from the walls of the cabinet the ends of the rods being threaded with the nuts Zil thereon .drawn up against the cabinet wal-ls. the rods I9 pass through the electrodes Il, the Vmetallic coating thereon is removed at '2l on'Fig. 4. The cylindrical 4vmetal spacers 22 :extend around the rods vI 8 and space the elec trodes I1 from the `electrodes 13, and space the outer electrodes I1 Yfrom the adjacent cabinet walls as illustrated by Fig. 1.

The rods 25 extend through the electrodes I1 and t8, and where 4they `extend through the grounded electrodes I8, the metallic vcoasting thereon is removed as at '2B on Fig. 4. The rods 25 also have `the spacers 22 therearound for spacing `rthe electrodes Il and I8 apart 'and fior rnainu taining same parallel. The ends of the rods 25 are threaded and have the nuts 24 thereon which are drawn up against the outer electrodes I1 as illustrated by Fig. 1.

Where the rods I9 pass through the grounded electrodes I8, they and the spacers 22 therearound, Contact the metallic coatings on the electrodes I8 and electrically interconnect same, the rods I9 being connected to the minus terminal of the said high voltage, direct current supply source, and to ground.

Where the rods 25 pass through the insulated electrodes l1, they and the spacers 22 therearound, contact the metallic coatings on the electrodes I1 and electrically interconnect same. The cabinet walls have the circular openings 21 therein in axial alignment with the rods 25 whereby the outer ends of the rods 25 are insulated from the cabinet walls. The rods 25 are connected to the positive terminal P+ of the said high voltage supply source.

In operation, the air entering the top of the cabinet 6 as shown by the arrows indicating -air ilow, of Figs. l and 2, is rst ionized in the ionizing chamber 1 so as to charge the foreign particles entrained in the air. The air then passes into the precipitating chamber 8 where the charged particles are attracted to the oppositely charged precipitating plates I8, after which the purified air is drawn from the bottom of the cabinet.

Since the rods I9 support all of the electrodes I1 and I8 from the cabinet Walls the need for large supporting electrodes extending into the air stream, is eliminated and the electrodes are more securely held in alignment.

While one embodiment of the invention has been described for the purpose of illustration, it should be understood that the invention is not limited to the exact apparatus and arrangement of apparatus illustrated, as modification thereof may be suggested by those skilled in the art, without departure from the essence of the invention.

What is claimed is:

1. An electrostatic precipitator comprising a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface thereof, and metal supporting rods extending through perforations in said electrodes, alternate of said eleci trodes having the said conductive material omitted around the perforations therein said rods contacting only the insulating material of said alternate electrodes.

2. An electrostatic precipitator comprising a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface thereof, metal supporting rods extending through said electrodes, and metal spacers between said electrodes and around said rods, alternate of said electrodes having the said conductive material omitted where the spacers and rods contact same.

3. An electrostatic precipitator having a cabinet, a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface thereof, and means including metal rods extending through perforations in said electrodes for supporting said electrodes from the walls of said cabinet, alternate of said electrodes having the said conductive material omitted around the perforations therein, said rods contacting only the insulating material of said alternate electrodes.

4. An electrostatic precipitator having a cabinet with metal side walls, a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface thereof, metal supporting rods extending through said electrodes, metal spacers around said rods and between said electrodes, alternate of said electrodes having the said conductive material omitted where the spacers and rods contact the same, and means for attaching said rods to said walls.

5. An electrostatic precipitator comprising a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface. thereof, metal supporting rods extending through perforations in said electrodes, alternate of said electrodes having the said conductive material omitted around the perforations therein, and other metal supporting rods extending through perforations in said electrodes, the others of said electrodes having the said conductive material omitted around the perforations therein through which said other rods extend, said rods contacting only the insulating material of said electrodes.

6. An electrostatic precipitator comprising a plurality of electrodes formed as plates of electric insulating material with layers of electric conductive material on the surface thereof, metal supporting rods extending through said electrodes, metal spacers around said rods and between said electrodes, alternate of said electrodes having the said conductive material omitted where the spacers and rods contact same, other metal supporting rods extending through said electrodes, and metal spacers around said other rods and between said electrodes, the others of said electrodes having the said conductive material omitted Where said other rods and the spacers thereon contact same.

'7. An electrostatic precipitator according to claim 5 in which the electrodes are contained Within a cabinet having metal side walls, and the rst mentioned rods are attached to the said side walls.

8. An electrostatic precipitator according to claim 6 in which the electrodes are contained within a cabinet having metal side walls, and the rst mentioned rods are attached to said side walls.

EARL L. RICHARDSON.

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

UNITED STATES PATENTS Number Name Date 2,195,431 Shively et al. Apr. 2, 1940 FOREIGN PATENTS Number Country Date 551,358 Great Britain Feb. 18, 1943 675,300 France Oct. 29, 1929

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