US2575181A - Precipitator collecting electrode - Google Patents

Description

Nov. 13, 1951 w. E. MACK PRECIPITATOR COLLECTING ELECTRODE Filed July 14, 1948 INVENTOR WAYNE E.MACK J Patented Nov. 13, 1951 PRECIPITATOR COLLECTING ELECTRODE Wayne E. Mack, Martins Ferry, Ohio, assignor to Wheeling Steel Corporation, Wheeling, W. Va., a corporation of Delaware Application July 14, 1948, Serial No. 38,597

6 Claims. 1

This invention relates to precipitator collecting electrodes. It has to do with electrodes for collecting solid particles removed from gases in electrical precipitators.

In copending application Serial No. 38,638, filed of even date herewith, the practical requirements of precipitator collecting electrodes and certain forms of precipitator collecting electrode constituting improvements over electrodes previously developed are explained. Precipitator collecting electrodes, which are of sheet form, should be rigid and flat and parallel to each other in order to permit of the employment of maximum voltage in the electrostatic field creating electrodes without arcing across to the collecting electrodes. In said copending application certain forms of improved electrode are disclosed but no electrodes or electrode units or sections designed to be interfitted are disclosed.

It is desirable in forming a precipitator collecting electrode of large area to make the electrode sectional, i. e., to assemble sections or units into a composite electrode. The present invention is an improvement under the invention of said copending application and is directed primarily to the provision of a precipitator collecting electrode adapted to be formed by assembling sections or units. At the same time the electrode and the sections or units comprising it conform to the requirements of a satisfactory electrode as above explained.

I provide a precipitator collecting electrode comprising a sheet of foraminous metal bent to provide a plurality of thicknesses disposed in substantial parallelism with space between adjacent thicknesses, the thicknesses being braced against one another to form a substantially rigid unit. I prefer to use expanded metal in the fabrication of my precipitator collecting electrode, flattened expanded metal being found ideal for the purpose.

Desirably a precipitator collecting electrode is formed by bending back upon itself a sheet of foraminous metal to provide two thicknesses disposed in substantial parallelism with space therebetween, the edges of the sheet opposite the bend being brought together and braced against one another to form a substantially rigid unit. The edges of the sheet opposite the bend are desirably welded together. The bent edge may have an outwardly open groove for receiving an edge of another sheet or section or unit.

I further provide a sectional precipitator collecting electrode comprising a plurality of sections each comprising a plurality of thicknesses of foraminous metal disposed in substantial par- 2 allelism with space between adjacent thicknesses, the sections being interfitted at adjacent edges thereof. Each section may have at one marginal portion a relatively thin edge and at an opposite marginal portion a relatively thick edge with an outwardly open groove, the relatively thin edge of one section being inserted into the groove of another section. The thicknesses of metal are preferably braced against one another to form a substantially rigid unit and' are desirably welded together at the relatively thin edge. That edge, since it comprises two thicknesses of metal, may be termed a double edge or a double thickness edge.

The sections or units are thus adapted to interfit to brace or reinforce one another and to cooperatively maintain the electrode as a whole fiat and rigid. Electrodes of very large size may be built up out of prefabricated sections made as will be explained below yet each section may be comparatively light in weight and easy to handle. The sections are very easily assembled and disassembled.

Other details, objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawings I have shown a present preferred embodiment of the invention in which Figure 1 is a fragmentary plan view of a precipitator collecting electrode made up of three sections or units; and

Figure 2 is an edge view of the electrode shown in Figure 1.

Referring now more particularly to the drawings, there is shown a precipitator collecting electrode designated generally by reference numeral 2 which comprises three sections each designated 3, each section comprising two thicknesses 4 of expanded metal. In the form shown, each section 3 is made out of a single sheet of expanded metal bent as shown in Figure 2. The thicknesses 4 are arranged in substantial parallelism.

In making one of the sections 3, a sheet of flattened expanded metal is bent over upon itself so that the two thicknesses 4 lie in parallelism and spaced apart and the edge at the bend is further formed to provide an outwardly open groove 5. At the edge of the section or unit opposite the groove 5 the metal is bent inwardly as shown at 6 and the sheet edges 1 are brought together and braced against each other so that a substantially rigid unit is formed. The edges 1 may be and preferably are welded together. When a complete electrode is to be formed, sections 3 are assembled by inserting the double edge portion 1 of one section into the groove of another section as shown in Figure 2.

The electrode shown in the drawings is frameless. Ordinarily it is not necessary to provide a frame around the electrode although it may be framed if desired. An advantage in not framing the electrode is that when it is unframed there is less horizontal surface area to catch solid particles falling therefrom. When the electrodes are shocked or vibrated to dislodge the particles adhering thereto it is desired that those particles drop free of the electrodes. I

While any suitable foraminousmetal may be employed in making the sections 3, I desirably employ flattened expanded metal. Flattened expanded metal i in efiect cold worked foraminous sheet metal having strands and bonds forming diamonds of the shapeof the characteristic diamonds of expanded metal. The expanded metal may be flattened by passing it through a stand of rolls of a .cold rolling mill. Thus the electrode is doubly strong and rigid first because the metal itself is of exceptional strength .and rigidity and second because the sections reinforce and strengthen each other and maintain the electrode very flat and rigid.

The sections v3 may be welded together if desired, in which case the electrode can be suspended without any support from beneath. However, if desired, the sections may be simply interfitted and not welded-to each other and the lower section may be supported in any-suitable way, the upper sections being carried by'the lower section and maintained in position by guides such as channels at their vertical edges. When an electrode is thus installed the grooves 5 extend horizontally. They may also bearranged vertically ing procedure such as resistance welding or spot welding. Since :both edges are of the same gage a sound Weld is easily formed without inducing substantial stresses in'any part of the section as i likely to occur when a thin metal member is welded to a comparatively heavy member.

While I have shown and described a-present preferred embodiment of the invention, .it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within thescope of thefollowing claims.

I claim:

1. A precipitator collecting electrode comprising a sheet of foraminous metal bent to provide a plurality of thicknesses disposed in substantial parallelism with space between adjacent thicknesses, the thicknesses respectively having parts removed from the bent portion of the electrode extending toward and abutting each other whereby the thicknesses are braced against one another-to form a substantially rigid unit.

Number 2. A precipitator collecting electrode comprising a sheet of expanded metal bent to provide a plurality of thicknesses disposed in substantial parallelism with space between adjacent thicknesses, the thicknesses respectively having generally parallel flanges lying against each other whereby the thicknesses are braced against one another to form .a substantiallyrigid unit.

3. A precipitator collecting electrode comprising a sheet of foraminous metal bent back upon itself .to provide two thicknesses disposed in substantial parallelism with space therebetwecn, the edges of the sheet opposite the bend being brought together and braced against one another to form a substantially rigid unit, the bent edge of the unit having an outwardly open groove for receiving an edge of another unit.

4. A sectional precipitator collecting electrode comprising a plurality of sections each comprising a plurality of thicknesses of foraminous metal disposed in substantial parallelism With space between adjacent thicknesses and having at one marginal portion a relatively thin edge and at an opposite marginal portion a relatively thick edge with an outwardly open groove, the relatively thin edge of one section being inserted into the groove of another section.

5. A sectional precipitator collecting electrode comprising a plurality of sections each comprising a sheet of foraminous metal bent back upon itself to provide two thicknesses disposed in substantial parallelism with spacetherebetween, the edges of the sheet opposite the bend being brought together and braced against one another to form a substantially rigid unit, the bent edge havin an outwardly open groove, the first mentioned edges of one section being inserted into the groove of another section.

6. A sectional precipitator collecting electrode comprising a plurality of sections each comprising a sheet of flattened expanded metal bent back upon itself to provide two thicknesses disposed in substantial parallelism with space therebetween, the edges of the sheet opposite the bend being brought together and welded together to form a double thickness edge, the bend edge having an outwardly open groove formed therein, the double thickness edge of one section being inserted into the groove of another section.

WAYNE E. MACK.

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

UNITED STATES PATENTS Name Date Arras June 24, 1930 Anderson Feb. 24., 1931 FOREIGN PATENTS Country Date Great Britain Apr. 30, 1931 Great Britain Feb. 6, 1939 Germany Dec. 20, 1928 Germany Sept. 26, 1931 France Dec. 23, 1930 Sweden Nov. 17,1924

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