US 1938362 A
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Description (OCR text may contain errors)
08 5, 1933. R, WAT ON 1,938,362
GRATE FRAME Filed Feb. 25. 1930 I I fifmv E ATTORNEY;
Patented Dec. 5, 1933 UNITED STATES GRATE FRAME Robert Watson, Cleveland, Ohio, assignor, by mesne assignments, to Waugh Equipment Company, New York, N. Y., a corporation of Maine Application February 25, 1930. Serial No. 431,267
The present invention is concerned with grates of the type used in locomotives, marine boiler furnaces, and for other similar heavy duty purposes. More specifically, the invention comprises a novel grate construction consisting of a grate frame, and grate bars supported therein, the frame being so formed that fuel supported on it receives the proper amount of air for combustion so that the fuel is thoroughly consumed.
In the co-pending application of Thompson, Serial No. 431,282, filed February 25, 1930, there are set forth the difliculties involved in the burning of fuel on grates as at present constructed, and these diflicultieshave been explained as arising from the failure of the grate builders to appreciate that the top of the grate frame serves as a fuel-supporting surface equally with the grate bars. As a result, the grate frames now in common use are so constructed that air can reach the fuel carried. thereon only with great difficulty, and those parts of the fuel bed which lie over the frame burn sluggishly and with improper combustion. In certain present grates, the top of the grate frame which represents dead area through which no air can pass may amount to as much as 15% of the total cross-sectional area of the fire box, and it will be apparent that so large an amount of dead area beneath the fuel bed in the fire box seriously impairs the combustion of the fuel and greatly reduces the combustion efficiency.
In the Thompson application there is described a grate construction in which the difficulties mentioned are overcome. The grate of the present invention represents a departure from the Thompson idea in numerous respects, the differences residing in constructional features by which the strength and ruggedness of the frame are increased without reducing the desired access of air to the fuel supported on the frame.
In the present grate, the grate frame consists of frame members provided with fuel-supporting units which are removable therefrom. The frame members consist of a web with flanges at top and bottom and the fuel-supporting units are mounted on these flanges and held securely in place thereon by readily removable means. Mounted in the frame are the usual grate bars which are preferably of the type disclosed in Buckley application, Serial No. 328,352, filed February 8, 1929, although standard grate bars may be used if desired. The grate bars to be adopted are of the type which have trunnions at their ends and the fuel-supporting units on the frame are provided with sockets in which the trunnions are received. 0 For a better understanding of the invention,
reference may be had to the accompanying drawing, in which Fig. l is a View in side elevation of a grate frame with a few fuel-supporting units mounted thereon:
Fig. 2 is a fragmentary plan view of a portion of the new grate;
Fig. 3 is a view in side elevation on an enlarged scale of a part of the frame with fuel-supporting units in place;
Fig. 4 is a sectional view on the line 4-4 of Fig. 3;
Fig. 5 is a partial plan View of the parts shown in Fig. 4; and
Fig. 6 is a plan View of a part of a side frame member.
The grate illustrated in the drawing comprises a pair of side frame members of which only one designated 10 is shown, a center frame member 11, and grate bars 12 extending between the frame members and having trunnions 13 received in sockets, one in each member. Each center frame member comprises a Web 14 with a bottom flange 15 and a top flange 16. The top of the frame, if desired, may be serrated with upstanding projections 17 as shown in Fig. 1. If the frame has a serrated top edge, its lower edge is preferably straight although the top edge may be straight upstanding lugs 18 having openings 19 therethrough, and mounted on the top flange 16 on opposite sides of each lug are fuel-supporting units 20.
Each unit comprises a plate 21 having a flat lower end 22 adapted to rest on top of the top flange 16. On opposite sides of this plate and extending downwardly from the top thereof are lugs 23 spaced apart to define passages 24 for the upward flow of air. Each lug terminates at its top in a projection 25, the top of which is subdivided by intersecting air channels 26 into a plurality of fuel-supporting surfaces. In the construction illustrated there are four such surfaces at the top of each projection and there is an air channel 27 extending along the top of the plate between groups of projections which lie above lugs on opposite sides of the plate. At the middle of the top of the plate there is a depression 28 forming a socket for the trunnion 13 of a grate bar, this socket being outlined by a strengthening rib '30. On the center bar there are two fuelsupporting units on opposite sides of each lug and these units have an opening 31 therethrough which lies in alignment with the opening 19 through the lug when the units are in proper position. The units may be held in place against the faces of the lug by a suitable securing means such as a bolt 32 passing through the two units and lug and provided with a cotter pin 33.
At the ends of the frame member there may be a socket 28' formed in the frame member itself. At this point the member is relatively narrow and it is preferable to have the gratebar mounted directly in the frame member rather than in a fuel-supporting unit. If the unit were used, it would have to be narrower than those used elsewhere or else the frame member itself would have to be quite narrow, since otherwise the unit would extend upwardly beyond the level of the other units on the frame.
Each side frame is similar in construction to the center frame and it is provided with lugs 34 which lie along one side of the top flange. A single fuel-supporting unit is mounted opposite each lug of the side frame member and is secured in place thereto, for instance, by means of a bolt similar to the bolt 32.
With the construction described, it will be apparent that the weight of the main frame members may be reduced to a substantial degree below that of a similar frame member of the construction heretofore used. Consequently these frame members may be handled and installed with much more facility than ordinary frame members and after the frame members are in position, the units may be readily mounted thereon and secured in place against the lugs. Each 35 j unit extends up above the top of the frame memter is, therefore, protected against injury and kept cool by air which flows from the ash pan and through the air passages defined by the lugs 23 to the fuel supported on top of the units. The air is distributed around the sides of the projections 25 through the channels 26 and these projections are thus kept cool and prevented from burning out. After the grate frame members with the fuel-supporting units have been placed in position, the grate bars are mounted therein in the ordinary manner and when the shaker arms of the grates are connected to the usual shaker rods, the grate is complete and ready for use.
In the new grate, fuel supported above the grate frame on the fuel-supporting units receives air suflicient for its combustion and the fuel burns as satisfactorily as the fuel on the bars. Accordingly, there is no dead space in the fire box such as occurs when frames of ordinary construction are employed and the effective area of the grate is thus increased by the area of the top of the frame. As the top of the frame is of substantial width, this increase is considerable and the new construction therefore increases the combustion emciency to an important extent. At the same time the frame is easier to handle and install and 7 since the main frame members are lighter than is ordinarily the case, they are not as subject to injury during handling and shipment as frames now in use.
What I claim:
In a grate construction, a grate frame comprising a web having a top flange, and lugs extending upwardly from said flange, a pair of fuelsupporting units mounted on said flange on opposite sides of each lug and secured thereto, each of said units being provided with an opening for receiving the end of a grate bar and having a flat bottom resting directly on top of said flange.