US1912886A - Furnace grate construction - Google Patents

Description

June 6, 1933. J. J. BUCKLEY 1,912,886

FURNACE GRATE CONSTRUCTION Filed March 1, 1930 2 Sheets-Sheet l i ITZNTOR ATTORNEYS June 6, 1933; J B 1,912,886

FURNACE GRATE CONSTRUCTION Filed March 1, 1930 2 Sheets-Sheet 2 ATTORNEYS Patented June 6, 1933 UNITED STATES,

PATENT OFFICE JOHN J. BUGKLEY, 025 BOSTON, MASSACHUSETTS, ASSIGNOR T FIREIBVAR COR-PORA- TION, OF CLEVELAND, OHIO,

A CORPORATION OF DELAWARE FURNACE GBATE cons'muc'rion Application filed March 1, 1930. Serial-No. 432,476. 7 I

This invention relates to fuel grates and is concerned more particularly with a grate made up of grate bars of novel construction, whereby the grate is especially adapted for use in boiler furnaces, locomotive fire boxes and thelike. The grate bar of the present invention is an improvement on that described and claimed in my co-pending application, Serial No. 338,352, filed February 8, 1929, now Patent No. 1,884,557, Oct. 25, 1932, and differs therefrom in certain features which insure a better distribution of air for combustion throughout the fuel bed.

The grate bar of the prior application includes a longitudinal member and a plurality of cross-bars projectingbeyond the sides thereof. Each cross-bar has a plurality of spaced lugs on each lateral face and projections extend upwardly from the tops of the cross-bars and the lugs, the tops "of the pro-' jectlions forming the fuel-supporting surface. The cross-bars are disposed with the lugs on their opposed faces in alignment, and air flows up to the fuel through passages defined by pairs of lugs on one cross-bar and opposed pairs of lugs on the adjacent crossbar. As there is a space between the ends of the lugs on one cross-bar and those on the next cross-bar, it follows that in a grate made up of these grate bars mounted side by side with their cross-bars in registry, the spaces between lugs on adjacent cross-bars are in alignment throughoutthe grate. Air may flow through the grate to the fuel through these aligned spaces as well as through the passages with which the spaces connect, so that although air may flow to the fuel around and betweenthe upward projections, the fuel directly above the series of spaces and passages is likelyto receive more air than that above the middle of a cross-bar.

In order to obtain good combustion, there is a certain theoretical minimum amount 0 air that must'be supplied to the fuel, and it is common practise to supply an excess amount.

I have found, however, that proper distribution of the air is highly important and if such distribution is obtained with the air passing through the grate and entering the fuel bed at a great many points, it is not necessary to supply such excessive amounts of air as heretofore. In the grate of my prior application, a highly efficient combustion is obtained by means of the lug and projection construction used, but in the present grate,

even better results are obtained by elimination of the long narrow air spaces extending across the bars from one end of the grate to a the other. I

In the new grate bar, there area plurality of cross-bars havingspaced lugs on'their opposite faces, the lugs on one'face of the crossbar being staggered with relation to those on the other face and mating with lugs on an adjacent cross-bar. With this arrangement, there is no continuous air space between adjacent cross-bars from one side of the grate bar to the other, and consequently no long, narrow air space throughout the grate, defined by adjacent series of aligned cross-bars.

The new grate and the bars of which it is made up include numerous other features of novelty which will be explained in detail in the description to follow.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which Fig. 1 is a view in transverse section of one of the new bars;

Fig. 2 is a planview ofa portion of the bar with parts shown in section; i

Fig. 3 is 'a sectional view on the line of Fig. 1-; v v

Fig. 4 is a view partly in section and partly in elevation taken on the line H of Fig. 2-

construction showing apart of the support,

and a v j Ff g. 6 is a view in side elevation of a crossbar taken on the line 6-6 of Fig; '5.

' Referring now to the drawings, the grate Fig. 5 is a plan view of one type of grate is illustrated as made up of a plurality of grate bars 10, each of which is shown as including a longitudinal supporting member 11 in the form of a horizontally disposed web from which a flange 12 extends upwardly. From the under surface of the web a strengthening rib 13 extends downwardly and near one end'the supporting member is provided lug 18 also carries a pair of with the usual shaker arm 14. The supporting member terminates at its ends in trunnions 15 mounted for rocking movement in a supporting frame 16. The shaker arms 14 of plurality of grate bars are connected together so that these bars may be rocked in unison.

The supporting member carries a plurality of cross-ha rs 17, the main body of each crossbar having the form of a plate from the opposite faces of which extend lugs 18. These lugs are disposed near the top of the plate and project downwardly therefrom. The lugs on opposite faces are disposed in staggeredrelation and the lugs on one cross-bar mate with those on the adjacent cross-bars. The end cross-bars, such as that designated 19 (Fig. 2) may be made with lugs on one face only, in which event the smooth face of the cross-bar is placed adjacent the trunnion of the supporting member, so as to lie close to the face of the supporting frame 16. There is a small space indicated at 20 between adjacent cross-bars and a similar space between the face of the end cross-bar and the supporting frame. The space 20 between adjacent cross-bars is secured by the use of spacing lugs 21 formed as projections from certain lugs 18 on opposite faces of the cross-bars. convenient construction involves providing lugs 18 one near each end of each crossbar on each face thereof with a spacing lug 21. The lugs 21 on one cross-bar are engaged by those on the adjacent cross-bars so as to separate the cross-bars to the desired extent.

Extending upwardly from the tops of the cross-bars are projections 22, preferably of truncated pyramid form and having flat tops 23 which provide support for the fuel. The form and distribution of the projections may be varied to a considerable extent but I prefer to employ the arrangement shown in Figs. 1 to 3 of the drawings. In this construction, there are groups of four projections disposed along the top of each cross-bar, one group near each lug, the projections of each group being separated by intersecting channels 24 and 25. The bottoms of these channels are inclined downwardly as at 26 from the median line of each channel, so that ash dropping into any channel. may move downwardly toward the outer end of the channel and pass through the space 21 into the ash pit. Each v projections 22 separated from each other by an extension of the channel 25 and separated from adjacent projections of a group of four on the top of the cross-bar by a channel 27. With this arrangement, groups of six projections are dis posed from one end of the crossbar to the other, four projections of each group lying above the top of the cross-bar with the other two lying above the top of a lug.

The fuel supported on the tops of the proj ections is supplied with air which passes up through the spaces 20* between adjacent crossbars and also between the end of each cross-- bar on one supporting member and the aligned cross-bar on the next supporting member. This space is indicated (Fig. 1) at 28. In the construction shown in my co-pending application previously identified, each cross-bar has a plurality of lugs on each face and the cross-bars are so disposed that the lugs on adjacent cross-bars lie aligned instead of in mated relation. As a consequence there are formed a plurality of air passages leading upwardly through the grate to the fuel anddefined by a pair of lugs on one cross-bar a part of the cross-bar lying be tween the lugs and similar parts on the adjacent cross-bar. These air passages are of substantial size and are connected by spaces, so that throughout a grate formed of such grate bars there are rows of air passages connected by spaces and defined by adjacent rows of aligned cross-bars. The amount of air which flows through these air spaces and passages is likely to be in excess of the actual amount of air required for combustion. In the present construction. the mating of the lugs on adjaient bars practically eliminates the air passages defined in part by aligned lugs in the earlier construction, and causes the air to How through the grate in a plurality of spaces 20 between cross-bars. A part of each space 20, designated 206, (Fig. 2) is offset from the space 20?) and connected with space 201) by a space 200, and with this arrangement there are no long narrow air spaces from one end of the grate to the other. A better of the excess above that actually required for combustion are thus secured, and this results in a more efficient combustion, since the air approaches the theoreti al amount required for combustion and it is distributed more widely throughout the fuel bed than is possible with the prior arrangement.

Instead of making the end cross-bars of the series with a plain face, the desired result of eliminating large a r passages through the grate near the support may be obtained by the construction shown in Figs. 5 and 6. As here illustrated, the support 16 is provided with a plurality of projecting lugs 29 arranged to mate with lugs on the outer face of the end cross-bar. These lugs 18a are formed in such manner as to permit the rocking of the supporting member and its crossbars without interference.

The cross-bars of the new grate involve an other feature of importance in that the crossbars are so formed that the grate bars must be rocked through a substantial angle before openings are formed in the grate through which fire can be dumped. This feature is illustrated in Fig. 1, where it will be observed that the cross-bar 17 has its greatest width distribution of'air and a reductionsliding off and into above the axis of rocking passingthrou h the trunnions 15. Each end of the cross M is then cut back, as shown at 30, so that as the I ported on one grate bar is prevented from of the cross-bars -on the adjacent grate bar. After this movement has exceeded the desired angle, further tilting of the bars results in a space being formed between the ends of cross-bars on adjacent grate bars through which ash may pass into the ash pit.

This arrangement is desirable for manyreasons. With the present type of grate, the better distribution of air throughout the fuel bed causes the fuel to be consumedwith the formation of only a fine ash, practically no clinkers occurring. Little shaking is therefore required in order to maintain a clean fire and there is little occasion to dump the A careless fireman, however, is likely to shake the grate vigorously to clean the fire and if the spaces through the grate bars are opened up as soon as the bars begin to tilt, burning coals will be dropped into the ash pit with a loss in economy. With the present construction, dumping cannot occur except by extreme rocking of the grate bars.

The cross-bars are illustrated as mounted to rest loosely on the flange 12 on the supportsomewhat the same in shape as the crosssectional shape of the supporting member. At the end of the recess, the cross-bar has oppositely'disposed lugs 82 and when the supporting member is rocked, it first swings relative to the cross-bars which are held stationary by the weight of the fuel upon them, and thereafter shifts laterally slightly with 1 the flange moving relatively to the cross-bars in a direction opposite to that in which the tilting force is applied. One edge of the web 11 of the supporting member is thus permitted to pass behind the lugs 32 at one side of the member, and all the cross-bars are thereupon. locked to the member. I

The cross-bars have the limited freedom of movement indicated with reference to the supporting member and these cross-bars tend.

to adjust themselves as the fire settles. The movement of the cross-bars results in the bars are employed in a locomotive where the structure is sub ected to incessant jarring.

the horizontal. During this angular movement, the fuel suptheash pit by the ends mg member, each cross-bar having a recess b -entering new grate construction as involving the use of cross-bars detachably mounted on a supporting bar, it is tobe understood that the advantages of the new construction may be obtained in a bar in which the cross-bars and longitudinal member 11 are formed integral. For many reasons, I prefer to employ crossbars separate from the supporting member, since that reduces the cost of repairs and re placement, as explained in the prior application.

lVhat I claim is:

1. A grate bar which comprises a longitudi nal supporting member and a plurality of removable cross-bars mounted thereon and extending beyond the side edges of said member, each cross-bar having spaced lugs on its the top thereof, the lugs on oppofaces near site faces of the cross-bar being staggered and the lugs on one cross-bar entering the spaces between lugs on the adjacent cross-bars, and spaced fuel-supporting projections extending upward from each cross-bar and itslugs, said projections being arranged in groups with a pair of projections of each group lying above a lug and the remainder of the projections of said group lying above a portion of the cross-bar adjacentto said lug, said projections in said group being separated by air channels, certain of which lead to the spaces between said lug and those adjacent thereto.

2. A grate bar which comprises a longitudinal supporting member and a plurality of removable cross-bars mounted thereon and extending beyond the side edges of said member, each crosssbar having spaced lugs on its faces extending down from the top thereof, the lugs on opposite faces of the cross-bar being staggeredwith the lugs on one crossthe spaces between the lugs on the adjacent cross-bars, and fuel-supporting projections extending up from the top of each cross-bar and its lugs, said projections being arranged in groups of six, with the adjacent projections in said group separated by air channels and adjacent groups separated by air channels extending across the cross-bar, two projections in each group lying above a lug and the remainder above the cross-bar.

In testimony whereof I affix my signature.

, JOHN J. BUCKLEY.

grate cleaning itself to a marked degree and While I have illustrated and described the v

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