Патент USA US2403787код для вставки
July 9, 1946. C. V. CARROLL 2,403,787 GRATE Filed Aug. '7, 1944 _"v, NN 2. N`«n E. Nm \ .VëNÓWL Patented July 9, i946VV 2,403,787 (STATES »omcß ` , 2,403,737 `~GRATE VV,Charles Carroll, -Minneapolis,A Minn., assigner to. Wm. Bros.l Boiler & Manufacturing Co., Minneapolis, Minn., a corporation of Minne Sota Application August‘7, 1944, SerialNo. 548,398 9 Claims. ' (Cl.V 1261-163) Y 1 , 2, 4This `invention relates to the design of lgrate Figure 3 isa topplan view of a grate element `and a portion of two Vadjacent grate elements, -surfaces'used for supporting and/or furnishing air to a solid fuel bed for combustion on the grate ` surface, the-grate surface design being applicable one on each side; _ f ~ i Figure ‘lis an enlarged fragmentary sectional View taken along the >lines 4-4 of Figure 2; Figure 5 lis an enlarged fragmentary isometric `to any type `of «grate structure such as a shaker grate, dumping grate, chain grate .or rotating grate. It is known that for efficient combustion View of a grate element of Figure 1'; and Figure 6 is a fragmentary sectional view of fof solid fuels without an undue excess air loss it ` is necessary to supply air uniformly to the under .adjacent portions »of two grate elements. side of the solid fuel bed. This function of »uni .l0 The- grate surface vof the present invent-ion'is ‘form air-supply has been accomplished in the illustrated -as applied to `a shaker .or dumping ` past, with. only partía-l success. It isan object ` type of grate but it will .be understood to be -ofvthis invention vto provide a more satisfactory applicable `to-‘other types of grates. .Referring design `-of gratesurface capable of delivering air to the drawing there is illustratedY a grate bar uniformly- to `the under sideof» a solid fuel bed. I generally designated I-IJl of the-type used in hand havefound- that foreflicient combustion of thin _or stoker fired, Vstationary or -movable lboilers wherein the grate `bars are mounting upon a -solidÃ fuel beds particularly, itis desirable tosupl- a îply the> air ina manner so as to produce. a swirl Ying action. and divergent air .flow so that the solid carrier bar generally designated-I I which is trun- ` `nioned about pivots t2 so 'as to allow the carrier fuel bed is vprovided with combustion air uni formly throughout'its, entire'Y area. 20 barY IIand _the Igratebar IU thereon toY be ro tated in the direction of arrow I3 for grate shak - » It. is an object -of ther vinvention Yto provide a ing anddumping operation. yThe ñre surface of grate surface of improved design capablerof ac the grate bar |70, to thedesign of `which the complishing these functions and yet of a design .invention is particularlyA directed, is illustrated such that grate elements may be replaced easily 25 generally at l5 and maybe considered as `con Without disturbing other elements. k'It is ak further 'objectv of the invention to provide an exceed sisting of a thickened head portion having a top surface I-S` and side surfaces I:8 and I9, the »side ingly rugged grate element capable of withstand surfaces being parallel with each other and ver ing rough‘usage and extreme temperature vari-~ Along the upper corner formed at the tical.` ations. It is a.v further and especial object of 30 `junction of the top surface IS- and the side sur the invention to provide an improved grate sur. face I9 there are provided a plurality of notches face capable Yof delivering air flow uniformly in> 2B of identical configuration and along the junc a plurality of divergent swirling paths to a solid [fuel bed without at ïthe same time presenting any tion ofthe top I6l and-side surface I8, there are a plurality of notches V2|, likewise identical with those at 29. The notchesk 20 on thefsidev surface I9 .are staggered with relation to the notches 2.I on -the side surface I8, as shown in the drawing. The intervening spaces between the notchesv 20 straight-through vertical passages over the grate , area, and to provide a grate lsurface wherein the combustionv air supply is .metered-through ori ñces and then expanded so as to reduce the air lvelocity and' thereby reduce fly-ash difliculties. and 2i are chamfered off slightly, as illustrated It is also> an object of the invention to provide> a 40 at 22 and 2.3, though the chamfering is not so grate surface of non-sifting character.U It is a extensive as to- reach the level of the notches 20 and 2|. The intervening spaces between the » 'further object of the invention to provide an improved design of grate surfaces capable of notches 20 and 2|y are approximately equal in being manufactured at 10W cost without the ne width to the width `of the notches and each inter cessity of coring or other expensive molding . vening space is providedl with an air chute in' procedures. >taglio- recess 24 formed into'the side Wall.` Thus, as shown in Figure 5, the side wall I9 is pro vided with air chutes 24 having parallel walls 24a and 24h and a uniform intaglio depth illustrated Other and further objects of the inventionare those inherent in the apparatus herein illus trated, described` and claimed. ' y The -invention is illustrated. with reference to the drawing whereinV „ by the bracket 24e. Figure 1 is a top plan view of ka single grate elemente; - ` i Figure 2 is a side elevational view of a element illustrated in .Figure l; _ . The air chutes 24 terminate at the level of line . grate - .5.5 25-25, illustrated by the dimension Aof Figures 2 and 5, it being-noted that the air chute is tapered out as illustrated at :24e so as to causethe air moving upwardly in the-air chute to be forced out 2,403,787 3 -4 more uniform distribution of combustion air in accordance with the design here presented. In the grate design of the present invention the side of each grate lies in contact with the side of the adjacent grates, the air passage portion ex in the direction of the side wall I9; The notches 20 and 2| terminate at the level of line 28-2B, Figure 2, which is lower than the line 2li-_25, as illustrated by the dimension B. The notches 20 and 2| are of gradually increasing width from bottom to top, as illustrated by the dimension C cepted. No space is therefore available` through which sifting may occur, ¿forïtheupward draft and at the bottom of the notch, and the dimension D bent configuration of the air passages (see Figure .4) serves to prevent downward movement of ash walls 2 la and 2 Ib of the notches 2| are preferably'l 104 at these places. Sifting is therefore substantially at the top of the notch, Figure`2. The walls 20a and 20D of the notches 20 and the corresponding not quite vertical and are filleted into the surfaces 20c and 2 Ic of their corresponding notches. Referring to Figure 1, it will be observed that the notches 20 terminate at a line 30-30 sepa rated by the dimension E from the centerline of- ' i eliminated. As there are no interior areas in the grate de ' sign the entire grate surface may be cast by ordinary green sand molding and does not re 15 the grate bar, the notches 2| being similarly ter minated at the line 3|--3|, likewise separated quire any coring. ` It is to be understood that the grate surface of the present invention is applicable to grate bars, chain grates, dumping or rocker grates and other from the center line by the dimension F. Dimen forms of grates wherein air is delivered to the sions E and F are preferably equal. Referring to Figure 3 the grate bar 10 is 20 solid fuel bed. The form of support for the grate bar is adapted to the mechanical under-construc mounted with its side surf aces in contact with the tion of the grate, and to the fuel and air feeding side surfaces of grate bars Illf and I0". Thus systems> employed.Y the surface I8 of grate bar IU is in contact with As many apparently widely different embodi the surface I9' of grate bar Ill’ and the surface |,9 of grate bar l0 is in contact with Ythe surface 25 ments of this invention may be made withoutïde parting from the spirit and scope thereof, it is to I8" of grate bar I0”. Since the air chutes 24 be lunderstood that I do not limit myself to the and the notches 20 and 2| on opposite sides of specific embodiments herein except as defined each grate bar are staggered with respect to each by the appended claims. other, the mounting of a plurality of grate bars ' I0, l0’ and l0” side by side serves to locate the 30 `Whatl I claim is: 1. A grate bar having a head portion composed notches 20 and 2| of one grate bar, for exampler of topl and bottomY surfaces and parallel flat side I0, opposite the air chute of the adjacent grate surfacesv forming the extreme lateral surfaces of bars I0’ and I0". Referring to Figure 6 it will the bar, said surfaces being spaced apart a dis be observed that the air chute 24 of grate bar IB is thus adjacent the notch 2|" of the grate bar 35 tance at least equal to the width dimensionof the bar, the edges at the junction of the top land side surfaces being inwardly notched at evenly spaced intervals along each side, air-passage grooves in said sides, said grooves extending only part way HJ”, and since the air chute 24 extends upward to a dimension A, which is greater than the lower mostedge of the air chute 2|", the air chute and notch thus overlap slightly, and air may accordingly move- upwardly, as illustrated by the 40 up the side from the bottom of the side surfaces, each said air-passage groove being located in the arrows 32 of Figure 4. The air is deflected out wardly by the outwardly slanted surface at the side surface spaces between the notches, and a upper part of the air chute 24 and upon reaching downwardly extending support below said head the notch 2| which also converges upwardly, the portion. ' . air is distributed to a larger area of the grate than 45 2. A grate bar having a head portion composed is represented merely by the cross section of the of top and bottom surfaces and parallel flat side air chute 24. It will thus be observed that notches surfaces forming the extreme lateral surfaces of 24 and 24" serve as metering orifices through the bar, said surfaces being spaced apart a dis which the volume of combustion air may be care tance equal to the width dimension of the bar, fully'controlled by suitable regulation of the draft 5.o 'on the grate. At the same time, the expanding -notches 2Q and 2l reduce the velocity of the air before it reaches the fuel bed and consequently diminishes fly-ash trouble. Referring again to Figure 6, it will be observed that air chutes 24" of grate bar I0" lie opposite notches 2|-2I of grate bar l0, and Serve to deliver air to them in the same way as air chutes the edges at the junction of the top and side sur faces being inwardly notched atevenly spaced intervals along each side, the notches along one Iof the flat sides being staggered with respect to v55 the notches along the opposite side,_air-rpassage grooves in the sides, said grooves extending only part way up the side from the bottom of the side surfaces, each said air-passage groove being an indentation located in the side surface in the spaces between the notches, and a downwardly 24 delivei- air to notches 2|”. It may also be noted that there is no vertical passage through 60 extending support below said head portion. the grate assembly of` a plurality of grate bars. 3. A grate bar having a head portion bounded by a top surface and parallel nat side surfaces, The staggered 'relationship of the notches on said side surfaces forming the extreme lateral opposite sides of the grate cause a definite swirl surfaces of the bar, said surfaces being spaced ing action 0f the air, as illustrated by the arrows 65 apart a distance at least equal to the Width di rnension of the bar, the edges formed at the junc 35 in Figure 3, thus causing the «air to be distrib tion of the top and side surfaces being inwardly uted over a large portion of the solid fuel bed See Figure 4. immediately in contact with the grate surface. notched at regularly lspaced intervals along each side, the notches along one side being staggered It has been observed that with a grate surface of the design herein illustrated that there is a uni 70 with respect to the notches'on the other side, the surface of each said notch extending along an form distribution of air in a solid fuel bed, even angularly disposed plane from near its bottom at the junction with the side surface in which it is inch, whereas grate surfaces of prior design located to near the middle of the ‘top surface, showed definite points of intense burning with a fuel bed of corresponding depth.- This proves the 75 said notches'being of increased width from bot Where the fuel bed has a depth of as little as one 2,403,787 5 6 tom to top, and air passage grooves in the sides, tersection near but spaced above the lower edge said grooves being recessed into the side sur faces and reaching only part way up the side from the bottom of the side surfaces to a position above the bottom of the notch, each said air-passage ` of the side wall, said notches being of increas , ing width from bottom to top and terminated in line of intersection on `the top surface, said line of intersection being between the centerline of groove being located in the side surface between the grate bar and the side surface, air-chute re cesses indented into each of the side walls, each said recess extending only part way up the side the notches., 4. The apparatus of claim 3 further charac wall from the lower edge of the side Wall and width in the direction along the side of the grate 10 tapered out and terminated at a level above the line of intersection of the notch near the lower bar, approximately equal to the bottom width of edge of the side wall, said air-chute recesses being the notches. ' . in the intervening spaces between the notches on 5. A grate bar of the type set forth in claim 3 further characterized in that the junction of the each side. 8. A grate bar of the type set forth in claim ’I top and side surfaces is slightly charnfered be further characterized in that the edges between tween notches. the notches, formed by the junction of the top 6. A grate surface comprising a carrier support and side surfaces, is chamfered slightly. and a plurality of grate bars, the fire element of 9. A grate surface comprising a carrier support each grate bar being composed of a solid member and a plurality of grate bars, the ñre element of having a flat top surface and parallel flat vertical each »grate bar being composed of a solid mem side surfaces, said side surfaces each including ber having a, flat top surface and parallel nat ñat continuous similarly shaped areas extending vertical side surfaces, said side surfaces each from one end of the grate bar to the other end, including flat continuous similarly shaped areas said areas each being a uniform distance from a vertical central -plane through the bar, the oppo 25 extending from lone end of the grate bar to the other end, said areas each being a uniform dis site edges formed by the junction of said top and tance from a vertical central plane through the both side surfaces being notched at regular in bar, the opposite edges formed by the junction tervals, the width of notches and intervening spaces being approximately equal, the notches of said top and both side surfaces being notched along one side being staggered so as to- be opposite 30 at regular intervals, «the width of notches and terized in that the air-passage grooves have Ya the spaces on the other side, air-chute recesses v indented into the side walls and extending only intervening spaces being approximately equal, each side, said grate bars being mounted side by notches being of increasing Width from bottom the notches along one side being staggered so as to be opposite the spaces on the other side, each lpart way up the sidewall from the lower edge of said notch being a ñat chamfered surface ex the side wall to a level above the lowermost part of the notches, said air-chute recesses being in 35 tending from a line of intersection near, but the intervening spaces between the notches on spaced above, the lower edge of the side wall, said side on the carrier support with the side surface to top and terminated in line of intersection on of adjacent bars in contact so as to locate the air the top surface, said line of intersection being chute recesses of one bar with the upper part of 40 between the center line of the grate bar and the each air chute overlapping the lower part of the side surface, air-chute recesses indented into the corresponding notchesof adj acent grate bars, and flat surface of each of the side walls, each said recess extending only part way up the sidewall with the flat continuous side area of one bar in-y contact with the similar area of the adjacent bar. from the lower edge of the side wall and up 45 wardly, being then tapered out and terminated 7. A grate bar wherein the fire element is com at a level above the line of intersection of the posed Of a solid member havin-g a iiat top sur face and parallel flat vertica1 side surfaces, said n notch near the lower edge of the side wall, said air-chute recesses being in the intervening spaces side surfaces each including ñat continuous simi larly shaped areas extending from one end of 50 between the notches on each side, said grate bars being mounted side by side on the carrier sup the grate bar to the other end, said areas each port with the side surfaces of adjacentbars in being a uniform distance from a vertical cen contact so as to locate the air-chute recesses at tral plane through the bar, the opposite edges one bar with rthe upper part of each air chute formed by the junction of said top and both side surfaces being notched at regular intervals, the 55 lapping the lower part. of the corresponding notches of adjacent grate bars, and with the flat width of notches and intervening spaces being continuous side area of one bar in contact with approximately equal, the notches along one side being staggered so as to be opposite the spaces the similar area of the adjacent bar. on the other side, each said notch being a ñat chamfered surface extending from a line ofin _ CHARLES V. CARROLL.