US3017953A - Electrostatic precipitators - Google Patents

Description

Jafi. 23, 1962 R. D. RIVERS 3,017,953

ELECTROSTATIC PRECIPITATORS Filed March 3, 1958 ll lr-6 I I II If FIG. l3

2 Sheets-Sheet 1 FIG.6 H65 ,4

FIGJZ INVENTOR. RICHARD D. RIVERS ATTORNEY i Tum! Jan. 23, 1962 R. o. RIVERS 3,017,953

ELECTROSTATIC PRECIPITATORS Filed March 3, 1958 2 Sheets-Sheet 2 FIG. l5

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RICHARD D. RIVERS QM Q. 624% ATTORNEY United States Patent ores Efil'ifiEB Faterrted Jan. 23, 1962 3,017,953 ELECTRUSTATIC PREGIPITA'IORS Richard D. Rivers, Louisville, Ky, assignor to American Air Filter Company, Inc, Louisville, Ky, 21 corporation of Delaware Filed Mar. 3, 1958, Ser. No. 718,647 4 Claims. (Cl. 183-7) This invention relates to electrostatic precipitators and more particularly to an improved plate electrode assembly for electrostatic precipitators.

In electrostatic precipitators of the type wherein electrostatically charged dust particles are passed into collector plates, such as is done in Dahlman Patent No. 2,486,521, it has been the practice to arrange the collector plates into plate electrode assemblies with the plates of the assemblies being spaced from each other by a number of individual tubular spacer segments positioned between the plates and supported on rods which pass through openings in the plates.

The present invention provides an improved plate electrode assembly which includes all of the desirable features of past electrode assemblies, and which, in addition, can be manufactured and assembled more economically, rapidly and efficiently with a minimum of operating steps and with fewer materials. Further, the electrode assembly of the present invention is of such construction as to insure effective electrical contact between the several parts of the assembly and to lend itself to ready removal and replacement for cleaning and servicing whenever necessary.

Various other features of the present invention will become obvious to one skilled in the art upon reading the disclosure set forth hereinafter.

More particularly the present invention provides a plate electrode assembly for an electrostatic precipitator comprising a plurality of plates, the plates having openings therein, spacer bars extending through the openings, the spacer bars having transverse slots therein into which the plates extend, and key bars extending through the openings to hold the plates in the transverse slots of the spacer bars and lock the plate assembly into desired position.

It is to be understood that various changes can be made in the arrangement, form and construction of the apparatus set forth herein without departing from the scope or spirit of the present invention.

Referring to the drawings:

FIGURE 1 is a partial face elevation of a plate electrode assembly arrangement which embodies the present invention;

FIGURE 2 is a partial side elevation taken in a plane passing through line 2-2 of FIGURE 1;

FIGURE 3 is a face elevationof a portion of a spacer bar, disclosing the transverse slots therein for spacing the plates of an assembly;

FIGURE 4 is a side elevation of the spacer bar of FIG- URE 3;

FIGURE 5 is a face elevation of a portion of 'a key bar which cooperates with the spacer bar of FIGURES 3 and 4;

FIGURE 6 is a side elevation of the key bar of FIG- URE 5;

FIGURE 7 is an enlarged side elevation of a portion of a plate assembly, disclosing a spacer bar inserted into the plate openings;

FIGURES 8 through 12 are a series of schematic, partial face elevations, disclosing the progressive steps involved in assembling the plates, spacer bar and key of the electrode assembly;

FIGURE 13 is an enlarged side elevation, similar to that of FIGURE 7, of a portion of a plate assembly, disclosing both key and spacer bars inserted and the plate assembly locked;

FIGURE 14 is an enlarged face elevation of a portion of the assembly of FIGURE 1, disclosing an arrangement for fastening the key bars to the side plates of an assembly;

FIGURE 15 is a side view of the key bar of FIGURE 14;

FIGURE 16 is a schematic, partial face view of a modified arrangement of the present invention;

FIGURE 17 is a schematic, partial side view of the arrangement of FIGURE 16;

FIGURE 18 is a schematic, partial side view of a further modification to that of FIGURES l6 and 17; and,

FIGURE 19 is a schematic, partial side view of still another modification to that of FIGURES 16 and 17.

Referring to FIGURES 1 and 2 of the drawings, plate assembly 2, which embodies the present invention, includes charged end plates 3 from which are supported, intermediate thereto, charged plates 4. The charged plates 4 are arranged in spaced, parallel relationship to each other and have positioned in alternate arrangement therewith spaced, parallel grounded electrode plates 5. The plates 5 are supported from grounded end plates 6 which, in turn, are attached to the housing of the precipitator (not shown) and which support end plates 3 by means of insulators 7.

One of the principle features of the present invention is the structure used for supporting the intermediate electrode plate arrangements from their respective end plates. Referring to FIGURES 3 through 13, details of one advantageous embodiment of such structure are disclosed. As can be seen particularly in FIGURES 1, 2, 7 and 13, each electrode plate 4 is provide with rectangular support openings 8 therein. It is to be understood that in one advantageous embodiment of the invention, four such openings can be provided in each plate. Plates 4 are loaded in a jig for proper parallel spacing and for proper alignment of corresponding support openings. When the plates are properly set in the jig, spacer bars 9 are inserted into aligned sets of openings. As can be seen in FIG- URES 3, 4 and 7 of the drawings, spacer bars 9 are of a cross sectional contour similar to the contour of support openings 8 to snugly fit therethrough. Spacer bars 9, which can be die cast, are each provided with a plurality of spaced, transverse slots 11 on one side thereof into which plates 4 extend, as will be seen hereinafter. On the sides opposite the transversely slotted sides of the spacer bars 9 are provided longitudinally extending grooves 12. Designed to cooperate with each spacer bar R is a key bar 14 (FIGURE 5 and 6). Each key bar 14 is provided with a tongue 16 which is contoured to slidably engage with a groove 12 of a spacer bar 9, as will be seen hereinafter. It is to be noted that the cross-sectional depth of each key bar 14, including tongue portion 16, is substantially equal to the depth of transverse slot 11 plus groove 12 in spacer bar 9.

With such an arrangement abovedescribed, it is possible to hold the electrode plates of an assembly firmly in the slots and lock the plate assembly into desired position. It is to be understood that both the spacer bar and key bar can be cast, rolled or press formed and, in some instances, even can be extruded from aluminum.

Referring to FIGURES 8 through 12 of the drawings which disclose the steps involved in assembling the plates, spacer and key bars, plates 4 are supported in a jig (not shown) in spaced relationship with support openings 8 in alignment, the spacing between plates being equal to the spacing of the transverse slots 11 in the spacer bar 9. Bar 9 then is inserted through the openings 8 until each slot 11 in the bar is opposite its matching plate 4 (FIG- URE 9). At this point, bar 9 is lifted to engage plates 4 into slots 11 and to leave room for key bar 14. Key bar 14 then is inserted with tongue 16 slidably engaging groove 12 of spacer bar 9.

To fasten the spacer and key bar assembly to end plates 3, an arrangement can be provided wherein the ends of key bar 14 are tapped and single sheet metal screws 15 cooperate with such tapped ends to hold the key bar to plates 3 (FIGURES 14 and 15). With the key and spacer bars properly in position in the assembly, the assembly is tightly locked in place (FIGURE 13) to insure proper electrical contact throughout and, as in a Chinese puzzle, the assembly cannot be moved until the key bars are removed.

It is to be noted that in inserting spacer bars 9 and key bars 11 into openings 8 of plates 4, provision is made in the form of cut aways 1.6 in grounded plates and 6 (FIGURES 1 and 2) to permit such assembly and to provide proper electrical clearance where necessary. It further is to be noted that grounded plates 5 and 6 can be provided with spacer and key bar arrangements like that provided for charged plates 3 and 4 and that charged plates 3 and 4 can, in turn, be provided with cut aways to permit proper insertion and clearance of the spacer and key bars for the grounded plates.

Referring to FIGURES 16 through 19 of the drawings, there is schematically disclosed three further modifications which embody the principle of the spacer and key bar arrangement of the present invention. In these figures, support openings 18 in the electrode plates are substantially circular in shape and the spacer bars 21 which extend through such openings each comprise a longitudinal segment of a cylinder, having an arc-like cross-sectional contour conforming to an outer portion of the circular opening with transverse slots 22 in the curved, outer side of the segment into which the electrode plates extend. The key bars which cooperate with spacer bars 21 to hold the plates in the transverse slots 22 of spacer bars 21 when the spacer bars have been inserted into the plate openings are curved to nest with the curved inner side of the spacer bars and are of a crosssection which insures a tightly locked final assembly. As can be seen in the drawings, these key bars can have various cross-sectional contours. In FIGURES 16 and 17, key bar 23 is shown to have a circular cross-sectional contour of a diameter less than the diameter of opening 18. In FIGURE 18, key bar 24 is shown to have an elliptical cross-sectional contour the length along the major axis of which is substantially equal to the diameter of opening 18, to insure more bearing surface between key, plate, and spacer bar. And, in FIGURE 19, key bar 26 is of substantially circular cross sectional contour of a diameter substantially equal to diameter of opening 18 and which is recessed or cut away to allow the key bar to conform with the inner surface of the spacer bar 21 to insure an almost complete bearing surface between plate, spacer and key bar.

It is to be understood that the spacer and key bar arrangements of FIGURES 16 through 19 can be roll formed or extruded with no sawing, the key bars serving to provide a ready orientation with the circular supports openings 18 through which they are inserted for spacing the electrode plates. In addition, electrical clearances can be easily provided with the arrangements of FIGURES 16 through 19 since there is no concentration of fields at the corners of the bars. As a result, the cut away portions in plates of opposite electrical sign need not be as large. Further, these circular type arrangements afford streamline surfaces to gas flowing through the precipitator to thus permit better flow characteristics.

The invention claimed is:

1. A plate electrode assembly for an electrostatic precipitator comprising a plurality of spaced plates, said plates having openings therein, a spacer bar extending through said openings, said spacer bar having a crosssectional contour peripherally conforming with said openings except for a groove on one side of said spacer bar extending parallel the longitudinal axis of said spacer bar, the opposite side of said spacer bar having spaced transverse slots therein engageable with said plates adjacent the edges of said openings upon lateral translational movement of said spacer bar, and a key bar extending in said groove of said spacer bar parallel thereto to hold said slots of said spacer bar in engagement with said plates after said spacer bar has been so laterally moved to lock the plate assembly into desired position.

2. A plate electrode assembly for an electrostatic precipitator comprising a plurality of spaced plates, said plates having substantially rectangular openings therein, spacer bars extending through said openings, each of said spacer bars having a cross-sectional contour peripherally conforming with said openings except for a groove on one side of said spacer bar extending parallel to the longitudinal axis of said spacer bar to fit therethrough upon initial insertion into said openings, said spacer bars further having transverse spaced slots on the sides opposite said grooves thereof engageable with said plates adjacent the edges of said openings upon lateral translational movement of said spacer bars, and key bars extending in said grooves of said spacer bars parallel thereto, said key bars having a cross-sectional depth at least equal to the depth of said transverse slots in said spacer bars to hold said slots of said spacer bars in engagement with said plates after said spacer bars have been so laterally moved to lock the plate assembly into desired position.

3. The apparatus of claim 1, wherein said plate electrode assembly includes end plates positioned in spaced relationship on either side of said plurality of spaced plates, and fastening means to fasten said key bar to said end plates.

4. The apparatus of claim 3, said fastening means including screw members passing through said end plates into the ends of said key bar.

References Cited in the file of this patent UNITED STATES PATENTS 469,519 Hale Feb. 23, 1892 856,131 Canda June 4, 1907 1,140,657 Benjamins May 25, 1915 1,697,316 Horny Jan. 1, 1929 2,542,262 Richardson Feb. 20, 1951 2,642,952 Landgraf June 23, 1953 FOREIGN PATENTS 385,508 Great Britain Dec. 29, 1932 749,290 France May 2, 1933 773,867 France Sept. 10, 1934 893,555 Germany Oct. 15, 1953

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