US1387871A - Grate - Google Patents

Description

L. A. STATES.

GRATE.

APPLICATION FlLED AUG. 11. 1911.

Patented Aug. 16, 1921.

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GBATE.

' This invention has reierence to grates andit has for one of its chief objects lthfe provision of an improved form of grate which is simple and economical in construction and I which providesa maximum air i ion space and provides better combustion and more economical consumption of fuel,- thus increasing general ,elficiency. Another object ofthe invention resides in .theprovision of a grate of the character. specified in which the necessity for shaking-the grate is eliminated, and in which .theformation of slag,

even with relatively poor fuel, hardly. ever takes place.

My invention. also contemplates .the previsionof a grate of such character thatlburn- .ing, buckling, sagging, and other d stortions caused by over-heating are prevented.

In addition myinventi'on .makesit possible to have all of the grate bar units counterparts, any one ,ofwhioh can {be readily replaced.

The foregoing, v together .with such other objects. as may hereinafter appear, I obtain by means of a construction which I have illustrated in preferred form .inlthe .accojgep'anying drawings, whereine Figure 1 is a plan' view ofaportionof a grate embodying'myinvention Fig. .2 is a side elevation of one.of:the,grate bar units; Fig. 3 is asectiontaken on ,theline 3 3 of .Fig. 1;.and Fig. 4 is a sefctiontaken on the line 44 of Fig. 1.

In carrying out my .invention 1 .build up the grate Ifroma plurality ofgratebarnnits A, preferably arranged ;in groups ofthree, secured together in a manner to be described.

Each grate bar unit comprises a supporting truss member 7Ywhich isprovided at each end with i a .flatted ,end portion .8, adapted .to rest npon some .suitable support in the fire box or furnace. A plurality of fire sup porting stools or fingers?) are cast integral with the truss member 7 and project above the top edge thereof in such manneras to suppornthe fire bedout of contact with the truss member. These fingers are oblong in shape and extend transversely of thetruss Specification of Letters Patent. Pat g ntgd A 16\ 1921 Applieation filed August 11, 1917. Serial No. 185,644.

member, and in length are about three times the width of the truss member. The fingers are wedge-shaped with the small ends down so as to provide jet-like vertical circulation spaces abetween the fingers, the fingers being spaced ape-rt a distance approximately equalto half theirthickness. The end portions 8 are provided with laterally extending fingers 8 which are slightly longer than the fingers 9 and act as spacing members.

bar will come opposite the spaces between the fingers of the adjacent grate bar, and

so on. By this arrangement the transverse clrculat ngchannels 0 extending transversely of the grate, above the tops of the truss members, will be sinuous in character. This arrangement has many advantages, for it not'only provides adequate circulat ontrans- .versely of the grate but also prevents the formation of large gaps which would permit fuel to fall through thegrate, such as would be the case if the fingers were arranged in allnementtransversely of the grate as well as longitudinally. l

Aboutmidway of the truss members and at otherintervals on long grates are cast laterally extending projections 7, the upper ends of which are pointed, and the angle ofinclination being greater than theangle of rest soth atany ash which will work down past the fingers will bedepOsited inthe ash pit. These extensions 7 have the same length as the fingers S and serve to space apart-the truss members. Between the extensionsieach'truss member is apertured to receive a bolt 10,'by means of which the rooms of three grate-bars are held together. imilar bolts are used at the ends as Wlll )be seen from inspection of Figs. 1 and 2. lfiythis general; arrangement the truss members. are securely "supported and will not Warp or bend, as a result of which the fingers are always maintained in proper spaced relation to provide the longitudinal air circulation channels 6.

From inspection of the drawings it will be noted that the tops of the truss members which extend between the fingers 9 are pointed so that ash will be freely discharged into the ash pit. It will also be noted that the truss member, in alternate. spaces, is carried nearer to the top of the fingers but not to such an extent as to completely interrupt the transverse air circulating channels a. By this arrangement the fingers are reinforced, which is of vital importance to the life of the grates, while at the same time adequate provision is made to accommodate the expansion of the metal contained in the stools under the head of the fire bed and to permit of what is technically termed the growth, of the iron under the action of the continued heating and cooling effects in the regular service of a grate, and this without placing strain on the truss member proper.

It will also be noted that the truss members intermediate the top and bottom, and intermediate the fingers, are reinforced .by diamond-shaped projections 7 which in addition to reinforcing the truss members act in the nature of air diffusion nozzles. Stated in other words, the vertical space between the truss members is contracted and then expanded, which assists in diffusing or spreading the. air equally through all of the air passages at the sides and ends of the stools or fingers.

To further increase the stiflness of the truss members I provide each of them with a rib-like portion 7* at the lower edge thereof, and to further assist in setting up free air circulation, I provide in each of them a plurality of openings 11 at points which are substantially intermediate the lower edges of the fingers and the lower edge of the truss member.

By the foregoing improvements I am enabled to construct a grate which is very economical in the consumption of fuel, is productive of far more nearly perfect combustion, and which it is not necessary to shake, as I have found by actual experience. In this connection it is also to be observed that even with poor fuel the formation of clinkers hardly ever occurs. At the same time I have found that a grate of this construction, in comparison to standard grates now being used, lasts considerably longer. I have removed grates of this type which have been in service over ten thousand consecutive working hours, and found them in substantially the same condition as when installed, without appreciable loss of metal and with no bending or distortion. Furthermore, I have also found that a far greater percentage of ash sifts through naturally, so that it is only necessary to use a fire hoe to clean the fire.

I attribute the foregoing advantages in great part to the arrangementwhereby I secure such a large percentage of air space. Thus, for example, in the general construction shown, if I were to use fire supporting stools or fingers 5% x 1%, with a a" air space between fingers,'I obtain a total percentage of air space of 50% of the grate area. If x 1% stools, with a air space, be utilized, I obtain 56% air space; and if 4 x 13 stools, with 1} air space, be utilized, I obtain 6.25 air space. Notwithstanding that I secure such a large percentage of air space,the grates are amply strong and rugged, as is evidenced by the long life of the grates. It will be obvious that with such increased air space more nearly perfect combustion will be obtained while at the same time the metal will be relatively cooled, and warping and distortion prevented. It is also to be observed that even with this large air space, at no point is there formed any opening of such size as will permit live or unconsumed fuel to fall through the grate.

As previously pointed out, ample provision is made for reinforcing the stools and also for accommodating the expansion of the metal contained in the stools when they are heated, and to permit of the growth of the iron under the continued heating and cooling effects in service, without strain on the truss member proper, and this without diminution of the air space.

In addition to the foregoing, it is to be noted that the grate is simple and economical, in that each grate member is a counterpart of the other, which simplifies and cheapens manufacture, as well as maintenance, for new elements can be readily inserted to replace worn ones.

I claim:

1. A grate comprising a plurality of grate bar members each comprising a truss provided with a plurality of stools spaced apart and projecting thereabove, the truss member extending more nearly to the top in the spaces between certain of the stools than between others whereby to reinforce the stools.

2. A grate bar comprising a truss provided with a plurality of stools spaced apart and projecting thereabove, the truss member extending more nearly to the top in alternate spaces between the stools whereby to reinforce the stools,

In testimony whereof I have hereunto signed my name.

, LOUIS A. STATES.

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