US1476337A - Furnace grate - Google Patents

Description

Dec. 4, 1923. 1,476,337 H. B. HOLT FURNACE GRATE Filed July 14 1922 6 5 l I 30D 'I2 I ,f

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Patented ec. 4, 1923.

unirse STATES Pariiznry orricn.

HARES B. HOLT, 0F DOR-MONT, PENNSYLVANIA, ASSIGNOR T0 ROSEDALE FOUNDRY t :MACHINE COIJPANY, F ETTSBURGH, PENNSYLVANIA, .A CORPGRATON OF PENNSYLVANIA.

FURNACE GRATE.

Application led July 14, 1922.

To all 'whom t may concern.'

Be it kno-wn that l, HARRIS B. Hoi-LT, residino' Dormont, .in the county oi Alle gheny and State of Pennsylvania., a citizen ot the United States, have invented or discovered certain new und use'tul improvements in vFurnace Gratos, of which improvements the following is a specification.

My invention relates to furnace mates, and particularly to travelling grates of the endless-chain type, which by their movement carry new supplies of fuel to the urnace and carry away vthe ashes remaining after combustion. The objects of invention are simplicity of structure, durability, tacility in replacement, and efficiency.

ln the accompanying drawings Fig. I isa -tragmentary view oi a grate as seen from above, in which m invention is embodied; Figs. il and ll are views in lon-k gitudinal and transverse section, on the planes respectively indicated by the lines l'I-ll and IH-HL Fig. l; Fig. TV is a fragmentary section on the vertical plane indicated at IV-IV, Fig. I.-

The grate is made up ot a large number ot pieces of two kinds: links and grate bars. The links are' of two particular shapes, indicated at l and l, They are elongate bodies, ordinarily iron castings, with provision for interpivoting, and to that end have in this instance transverse pivot holes 12 at opposite ends. They are ifurther provided with intermediate outstanding essentially T-shaped lugs i3. Practically, l make these links about seven and one quarter inches long and an inch and an eighth wide. The particular dimens sions are nnimpiiirtant beyond this: they indicate how relatively small is 'he link compared with the dimensions ot the grate as a whole. Wide departure is ot course permissible from the dimensions given above by way of example. The T-shaped lugs 18 are in links l about twice as wide as the body of the links-about two inches and a quarter wide, more or less. This greater width of the lugs 18 is clearly shown in Figs. l and lll. The modiiication in the lugs formed upon links l will presently be noted.

More minutely examined, these T-shaped lugs are transversely crooved or hollowed, as indicated at lll, and on either side verti- Serial N0. 575,059.

cally grooved, as indicated at l5. To these minutite of comforination attention will again be directed.

The multitude oi links is assembled and of adjacent rows are interlocked, and the pivot pins imite the links row with row through the so interconnected ends. Thus the successive rows of links stand in echelon formation row upon row, while the whole articulated link assembly has openings or meshes between the links, allowing passage of air through the grate to the bed of fuel above.

lt is usual with chain grates to make the chain structure endless and to mount it on opposite sprocket wheels, by the turning of which the desired grate ino-vement is attained. Such mounting and driving will ordinarily be resorted to in the use of the grate 0In my invention, but, since these matters are of common knowledge, it suilices to make mention of them, without illustration in the drawings.

l have Asaid that the T-shaped lugs 13 extending 'from the links are twice as wide as the links themselves, and l have said that in assembly the transversely aligned links stand the breadth of a link apart. The links are assembled with these lugs standing out all from the same side of the grate structure, the burden-sustaining side, and accordingly, when assembly has been made, the lugs of each row of links constitute in effect a substantially continuous support, extending transversely from side to side, across the articulated chain structure.

The marginal links are alternately of the forms l and la. Links l have already been described. Links la differ in this respect only, that their T-shaped lugs are built out laterally from the link bodies on one side only, as indicated at 13a, Figs. I and HT.

On the other side the lugs are ilush with the lateral face of the link body.

To the marginal links are bolted, midway of their length, blocks 5; these blocks form stops, to secure the grate bars when strung in line upon the T-shaped cross rails, in the manner presently to be described. The marginal links 1fL are builtout with bosses 16 upon which block 5 may be bolted. This last mentioned detail, shown in Fig. I, is more clearly illustrated in `Fig. IV. y

The second component of the grate structure is theV grate bar. rhere is a large num ber of them, and they, but for the exception presently to be noted, are identicallyV alike.k They are essentially fuel-supporting plates 3, formed preferably iron castings, each provided underneath with two transversely extending convergent lugs 3l, defining and forming a seat for the Tshaped lugs 18 formed upon the links l.

The indi i lual grate bars may be of any desired width; conveniently they are of equal width with the chain links, that is to say about an inch and an Dighth wide, and in assembly they are strung, one after another upon the transverse rails formed by the T-shaped lugs of the links, after the links themselves have been assembled. in the manner already described.

The blocks 5 bolted to place secure the lines of grate bars when applied. The grate bars, then, like the links, are assembled, in transverse rows, but ordinarily they stand in'close succession, touching one another, or substantially in contact. It is not important that the grate bars of successive rows be aligned or be out of alignment; ordina.- rily -they will stand in alignment, or nearly so.

The drawings show certain more minute features of structure of these grate bar and these features I shall briefly note. These plate like grate bars'are so formed that when assembled they overlap, in testudo formation, both transversely and longitudinally of the grate. The transverse Overlapping is illustrated in Fig. III, the longitudinal, in FII. This renement of shape will be understood without further elaboration; the reason for it is, while permittingthe passage of air, to prevent the sifting through of fuel and ashes, and also to screen the chain from the heat of the fire.

The noticeable convex arching of the up perk surfaces of the grate bars is afeature which makes for the easy discharge of the ashes. And this last mentioned feature, t0- gether with the transverse corrugating of the burden-sustaining surfaces of the grate bars, facilitates the aeration of the bed of fuel, and aeration is of course essential to combustion. The features also aid in the feed of fuel and of ashes. n

I have said of the grate bars that they may be of any desired width. Ifig. III shows marginal bars 3a of greater width than the medial bars of the 'transverse row. The reason for providing such wider niarginal bars is that a tendency to freer aeration of the bed of fuel along the margins is corrected anda more even burning achieved. Another reason is that with wider marginal bars the whole grate moves more evenly. This provision of wider marginal bars is not, however, a limiting feature, of` my invention as here embodied.

.Jair in suticient quantities for combustion has free access, through the interstices in the chai tliroughithe spaces e defined y and between the grooved T-shaped extensions 13 formed on the links, and between the overlapped'grate bars to the bed of fuel above. Aeration is facilitated by the hollow spaces l), formed by and between the grooved tops of the T-shaped lugs 13 and the oppositel recessed under surfaces of the grate bars and by the spaces c between the grate bars, and aeration is further facilitated by the arching of and the transverse corrugating of the coal-sustaining upper surfaces of the grate bars.

The sifting through of dust and ashes which tends to foul such a mechanism is by the testudo formation of the assembled grate bars prevented. The structure has a minimum number of parts and is .very simple. The chain support is by the overlapped grate bars completely screened and protected from the heat of the nre. When a grate bar requiresrto be replaced, it may readily be slipped olf laterally and a new bar applied in place, without any greater disturbance of the organized structure.

I claim as my invention:

l. In a chain grate structure a chain made up of rows of interpivoted links, the links being provided with lugs which in assembly combine and constitute grate bar supports extending transversely across the structure.

and a plurality of grate bars borne by said' supports in transverse rows, the bars of each row standing in closed rank side by side.

2. In a grate structure al chain made up of rows of interpivoted links, the links being provided with lugs which in the assembly combine and constitute grate bar supports extending transversely across the structure, and a plurality of grate bars borne by said supports and each grate bar mounted upon and borne by one only of said supports.

In testimony whereof I have hereunto set my hand.

HARRIS B. HOLT.

Witnesses:

Fammi E. VVOLFF, PERGY A. ENGLrsH.

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