US2372260A - Grate bar - Google Patents

Description

Mmzv, 1945. w. am. 2,312,260

GRATE BAR Filed Jx me 9, 1942 ATTORNEY;

8nd spaces.

Patented Mar. '27, 1945 OFFICE GR'ATE BAR Walter C. ii iariaral 72m, n.1, semis to Waugh Equipment ooh Maine a corporation of pal y, N w raft, n. 2.,

/ Application June 9, 1942; serial not 416,384

- This, invention relates to grate bars for heavy duty purpose as, for example, in locomotive fire boxes and boiler furnaces, and i'sconcerne'd more particularly with a novel grate bar which is superlor to prior grate bars of the same general 1 type,- in that it provides for more nearly uniform distribution of combustion air throughout the fuel bed and also reduces the liability of blow holes being formed through the fuel bed by the action of the draft. The new grate bar resemtiles in somerespects that describedand claimed in Thompson Patent No. 1;s03,-152, issued April 28,1931; but is an improvement on the patented bar by reason of the inclusion of novel features, the use of which produces the better results mm tl'on'ed:

The Thompson grate bar includes fuel-supportins units which are preferably mounted detachably on a carrier bar provided with trunnions by which it is supported on a grate frame.-. Each such unit comprises a plate-like body having spaced vertical lugs projecting from its opposite faces and defining passages through whicho'ombustlonair flows upwardly from the ash pit. The top of each lug and the top of the body between aligned lugs on its opposite faces are subdivided into small fuel-supporting areas separated by air channels; some of which openinto the passages between adjacent lugs and others bf Which.- lead to the outer faces of the lugs. Adjacent fuelsupporting units are kept at asuitable close spacingon the carrier bar by stop lugs on opposed races or the units, and adjacent carrier bars are so mounted on'the frame that the opposed ends or the iuel su'pporting units on adjacntbars lie close together. I

. When fuel is burned on a; grate formed of bars "of the Thompson type, combustion air flows up from the ash pit to the fuel bed through the passages between adjacent lugs on each fuel-supporting unit, the spaces between aligned lugs on 8 Claims. toiiz islp 1;

that combustion ofthe fuel may be as nearly unliorrhandicomplete as possible.

' In the Thompson bar, the plate or body of veach Mel-supporting unit isvof increasing thickness throughout the length of the passages and the lugs are or substantial length and also of in creasing width upwardly. The passages are thus of decreasing cross section upwardly and the air flowlng through the passages under the pull or the dr'aft attains substantial velocity by the time it: reachesathe fuel bed, so that there is less tend e'ncyfor the air to flow laterally in the channels adjacent units on the same carrier bar, and the spaces between the opposed ends of units on adja'eent carrier bar's. some of the air flowing upwardly from the ash-pit to the fuel bedenters the channels and flows horizontal-1y thereinto parts of the fuel not directly over the passages The air so supplied to the fuel through the channels thus changes direction in itshow from the ash pit to the fuel bed and may be termed indirect airs The remainder or the air flowing directly u wardly to the fuel may be termed direct air andit is desirable that a; sun "stal'i'tial proportion of the air supplied for combustioiiabe in the term or indirect air in order than is'desirable. Also; when sudden heavy drafts and applied, as occurs frequently in locomotive operation, the air flowing upward through the unobstructed passages may produce blow holes through the fuel bed.

'Thepresent grate bar is so constructed as to provide improved combustion by reason of the fuel being supplied with an increased amount of air in indirect form and, with the new bar,- the liability of blow holes being formed by the application of sudden heavy drafts to the fuel bed is lessenedi These results are obtained by the provls'loh of mean's which intercept the air streams flowing upwardly to-the fuel and cause mingling and turbulence or the streams with resultant reduction in velocity and increased lateral flow. F!o'ra better understanding of the invention, reference may be had to the accompanying drawing-ih which q 1 FIE 1 is a view showing a carrier bar in crosssect on and one of the fuel supporting units [thereon in rront elevation; 1

Fig"; 2' is" a sectional view through a pair of addecent fuel-supporting units 2-2 of Fig. 3; v 1 Fig, 3 is s iiagme'ntary plan view of the units shown mile: 2 and Fig. 4 is a view of a carrier bar in side elevation and snows'the manner in which the units 'ihay be epplien thereto and removed therefrom. "Th gr st-spar in the term illustrated is of the thrill-l tilllioh includes a carrier bar and a number of oro ss bars or fuel-supporting units detachably mounted thereon; but it is to be understood that the lil'lit'sl'r'lay' be formed integrally with the Carneuter, if desired. The carrier includes a web fo and a longitudinal flange H extending upwardly therefrom-and the web is provided at its "ends with arms I! groin which project trun- "riions lm 'Mounted' detachably on the carrier are fuel-supporting units, each or which includes a plat-dikbody It which is formed at its lower end with an opening 15 of the same general shape as theorists-section ofthe carrier. vAt the lower ends of the opening are lugs l6 and to mount a unit on the carrier, the unit is placed in the inclined position shown at the left in Fig. 4 and lowered with the lugs passing on opposite sides of the trunnion arm, until the lugs pass beyond the end of the web It). To facilitate this operation, the web may be cut away as indicated at 11. When the lugs lie below 'the level of the web, the unit is'swung to upright position and moved alon the web. The unit then rests on the inclined upper surfaces l8 of the web on either side of the flange and the unit cannot be accidentally dislodged from the bar because the ends of the lugs underlie the lateral edges of the web.

Projecting outwardly from opposite faces of the body at its upper end are lugs 19, and the bottom of each lug slopes downwardly at an angle to the face of the body and is formed of a pair of surfaces 21 diverging upwardly from a median line 22. The top of each lug is subdivided into four small fuel-supporting areas 23 by air channels 24, 25, the channels 24 opening at the outer faces of the lugs and channels 25 leading to the passages defined byadjacent lugs. Between adjacent lugs, the top of the body is of decreasing thickness upwardly, as indicated at 26, so that the stream of air flowing through the passage between the lugs may flow over the top of the body to fuel lying directly over the body. The top of the body is also channeled, as indicated at 21, between aligned lugs on opposite faces of the body, so that air flowing up through the passages between adjacent lugs may enter channels 21 and reach fuel lying directly above the body.

Mounted on the faces of the body in alignment with and spaced downwardly from the lower ends of the passages between adjacent lugs are projections 28. The upper ends of the projections slope upwardly and inwardly toward the body and have surfaces 29 which converge upwardly to meet in a median line 30.

The end lug 3! on each face of the body has a portion 32 which extends down along the end of the body and has a flat bottom. The inward side of the extension 32 slopes upwardly and inwardly and leads to a surface 33 which inclines upwardly and inwardly and leads to the air passage between the end lug and that next to it.

At the middle of each face of the second supporting unit, there is a single double lug 34 employed to give the unit additional strength at the place where it would. otherwise be weakened by removal of the metal to form the opening in which the carrier is received. The lug 34 is provided on its sides with projections 35 which have inwardly sloping upper surfaces 36 lying directly beneath the passages 31 between lug 34 and the adjacent lugs outwardly therefrom.

The lugs 28 project outwardly from the face of the body a distance slightly greater than lugs l9 and, when a plurality of fuel-supporting units are mounted on a carrier, lugs 28 on adjacent units make contact and serve as means for keeping the adjacent units at the desired spacing.

In the combustion of fuel on a grate made up of the new bars, the fuel is supported on the top of the small areas 23 and part of, the air supplied by the fuel flows upwardly along the faces of the units in each passage between a pair of lugs 28. The air flowing through this space cannot flow directly to the fuel, however, but is intercepted by the under surface of a lug I9 above the space between adjacent lugs 28 and is subdivided into two streams by the inclined surfaces adjacent lugs I9 and of the decreasing thickness of the body at 26, the velocity of the air flow is reduced so that proper flow of air into the channels 25 and 21 is insured. Some air flows upward through the spaces 38 between the ends of the aligned lugs on adjacent units, but, as these passages are relatively narrow and of decreasing cross-section, as shown in Fig. 2, the

, tendency is for the greater proportion of the air to flow laterally along the surfaces 2! on lugs l9 and then upwardly through the passages between adjacent lugs l9. Additional air also flows upwardly through the spaces between the ends of aligned units o adjacent carrier bars, but ordinarily the carrier bars are mounted so that such aligned units lie relatively close together and the amount of air flowing through the spaces between such units is less than that flowing between adjacent units on the same carrier.

The formation of the units with portions 26 of tapering thickness between adjacent lugs i9 is advantageous not only in the distribution of air, as above pointed out, but also in preventing collection of ash. The sides of these portions are relatively steep and there is little likelihood that ash will accumulate thereon. Also, the tops of the lugs 28 slope downwardly at a relatively steep angle and that, together with the formation of the tops with the opposite sloping surfaces 29,

40 likewise tends to prevent ash accumulation.

I claim:

1. A grate structure comprising a carrier bar and a plurality of cross bars mounted thereon and extending transversely thereof, each cross bar having a plurality of lugs extending from opposite faces at the top and spaced to provide air passages between them, the lugs on the opposite faces of each cross bar being in alignment and the 'cross bars being mounted on the carrier bar with the spaced lugs of one cross bar being in alignment with the spaced lugs of adjacent cross bars, and a plurality of projections from the opposite faces of the cross bars lying in alignment with and spaced from the lower ends of the air passages, the outer ends of the projections lying outwardly beyond the ends of the lugs and the outer ends of the projections of one cross bar engaging the outer ends of the corresponding projections of adjacent cross bars to space the outer ends of corresponding lugs of adjacent cross bars to provide air passages between them.

2. A grate structure comprising a carrier bar and a plurality of cross bars mounted thereon and extending transversely thereof, each cross bar having a plurality of lugs extending from opposite faces at the top and spaced to provide air passages between them, the lugs on the opposite faces of each cross bar being in alignment and the cross bars being mounted on the carrier bar with the spaced lugs of one cross bar being in alignment with the spaced lugs of adjacent cross bars, and a plurality of projections from the opposite faces of the cross bars lying in alignment with and spaced from the lower ends of the air passages, the outer ends of the projections lying of the projections and to enter those passages at a, converging angle. 7

3. A cross bar for a grate structure having a plurality of lugs extending from its opposite faces at its top and spaced along the-body to provide air passages between them, the lugs on opposite faces of the cross bar being in alignment transversely, the thickness of the body of the cross bar between the lugs decreasing upwardly to increase the cross-sectional area of the air passages between the lugs toward their upper ends, and a plurality of projections from the opposite faces of the cross bar lying in alignment with and spaced from the lower ends of the passages.

4. A cross bar for a grate structure having a plurality of lugs extending transversely therefrom at opposite faces at the top thereof, the lugs on opposite faces of the cross bar being in alignment, the tops of the lugs and the tops of the portions ofthe body of the cross bar between the aligned lugs being channeled to substantially divide the upper surface of the unit into'small fuel-supporting surfaces, the lugs on each-face of the body being spaced to provide air passages between them leading to the channels, and a projection from the face of the cross bar lying in alignment with and spaced from the lower end of each air passage, said projections being of a width not substantially less than the width of the lower end of the air passages so that most of the air to enter said passages from beneath the cross bar will be caused to flow around opposite sides of said projections and to enter the passages at a converging angle. I

5. A cross bar for a grate structure having a plurality of lugs extending transversely. therefrom at opposite faces at the top thereof and spaced to provide air passages between them, the

lugs on opposite faces of the cross bar being in alignment, and projection from the opposite faces of the cross bar lying in alignment with and spaced from the lower ends of the air passages, said projections being of a width not substantially less than the width of the lower ends of the air passages so that most of the air to enter said passages from beneath the cross bar will be caused to flow around opposite sides of said projections and to enter the passages at a converging angle.

6. A cross bar for a grate structure having a plurality of lugs extending transversely therefrom at opposite faces at the top thereof and spaced to provide air passages between them, the lugs on opposite faces of the cross bar being in alignment, and projections from the opposite faces of the cross bar lying in alignment with and spaced from the lower ends of the air passages, the projections having downwardly and outwardly sloping top surfaces, said projections being of a width not substantially less than the width of the lower ends of the air passages so that most of the air to enter said passages from beneath the cross bar will be caused to flow around opposite sides of said projections and to enter the passages at a converging angle.

'7. A cross bar for a grate structure havinga plurality of lugs extending transversely therefrom at opposite faces of the top thereof and spaced to provide air passages between them, the lugs on opposite faces of the cross bar being in alignment, the bottoms of the lugs sloping outwardly and upwardly and being provided with surfaces which diverge upwardly, and projections from the opposite faces of th cross bar lying in alignment with and spaced from the lower ends of the air passages,'the top of each projection sloping upwardly and inwardly and being provided with surfaces which converge upwardly,

said projections being of a width not substantially less than the width of the lower ends of the air passages so that most of the air to enter said passages from beneath the cross bar will be caused to flow around opposite sides of said projections and to enter the air passages at a converging angle.

8. A cross bar for a grate structure having a plurality of lugs extending transversely therefrom at opposite faces of the top thereof and spaced to provide air passages between them, the lugs on opposite faces of the cross bar being in alignment, the bottoms of the lugs sloping outwardly and upwardly and being provided with surfaces which diverge upwardly, and projections from the opposite faces of the cross bar lying in alignment with and spaced from the lower ends of the air passages, the top of each projection sloping upwardly and inwardly and being provided with surfaces which converge upwardly, the opposite faces of the cross bar between adjacent lugs sloping inwardly, said projections being of a width'not substantially less than the width of the lower ends of the air passage so that most of the air to enter said passages from beneath the cross bar will be caused to flow around opposite sides of said projections and to enter the air passages at a converging angle.

WALTER C. DILG.

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