US1165793A - Non-sifting grate for furnaces. - Google Patents

Description

W. II/ICCIAVE.

NON-SIFTING GRATE FOR FUBNACES. APPLICATION FILED 150.16. I9Is.-

l, 165,793. Patented Dec. 28, 1915.

3 SHEETS-SHEET l.

A W. McCLAV.

NoN-SIFTING GRATE FOR F'uRNAcEs. Y

APPLICATION FILED DEC. 16| 19|3- 1,165,793.. Patented Dec. 28, 1915.

3 SHEETS-SHEET 2.

rrnn srarns ra'rnivfr orbit.

VVILLIAIVI MGCLAVE, OF SCBANTON, PENNSYLVANIA, ASSIGNOB TO MoCLAVE-BROOKS COMPANY, OF SCRANTON, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

NON-SIFTING GRATE FOR FURNACES.

Application led December 16, 1913.

To all whom t may concern:

Be it known that l, WILLIAM MoCLAvE, a citizen of the United States, residing at Scranton, in the county of Lackawanna and State of Pennsylvania, have invented certain new and useful Improvements in Non- Sifting Gratos for Furnaces;v and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, and to the figures and letters of reference marked thereon.

ln the burning of fine fuel, modern developments have shown that a large percentage of the waste which occurs is due to the sifting of the fuel through the fuel supporting surface whereby it is deposited in the ash pit and lost. Another development is the fact that in the burning of such fuels ordinary practice results in the admission of far too large a percentage of air, and in the unequal distribution of the air through the fuel owing to the inequality of the size and distribution of the air admission openings. All fuels of this character should be burned in practically unbroken beds of relatively shallow depth and the air supplied thereto under forced pressure, under which conditions it is apparent that the resistance to the passage of air through the fuel and grate must be uniform throughout the whole body of fuel, if uniform conditions of combustion are to be maintained throughout.

The grate of the present invention is designed to accomplish all of the desirable ends herein above indicated; that is to say, to support the fuel throughout the whole grate area, leaving no opportunity fo-r it to sift through into the ash pit; to support the fuel in a uniform layer; and to supply the proper percentage of air thereto so distributed that each and every portion of the body of fuel will receive itsproper percentage of air so as to effect the most eco-- nomical and uniform combustion, with a minimum liability of incompletely consumed fuel escaping from the combustion area.

Referring to the accompanying drawings, Figure l is a section from front to rear through a furnace grate and some of the associated parts embodying the present invention, a portion of the grate being broken away in order to show the parts on a largerl Specification of Letters Patent.

Patented Dec. 28, i915.

Serial No. 807,079.

scale. Fig. 2 is a detail section of a portion of the grate shown in Fig. l, but on a very much enlarged scale. Fig. 3 is a section transversely of the grate shown in Fig. 1, substantially on the line 3-3 but with parts broken away. Fig. 4: is a top plan view of a portion of the grate shown in Figs. 1, 2 and 3. Fig. 5 is a front elevation of a portion of the grate shown in the preceding figures. Fig. 6 is a perspective view of one side of one of the removable tops or sections forming the fuel supporting surface. Fig. 7 is a similar view of a form of a top or section which is adapted to cooperate with that shown in Fig. G.

Fig. 8 is a detail sectional view showing a. modified section of the side wall top or bar sho-wn in Fig. 3. Figs. 9 and l0 are views corresponding to Figs. G and 7, showing a modified arrangement of the adjacent latl eral edges of adjacent tops or sections. Fig. 11 is a detail section showing a modified arrangement of the supporting connection for the tops or sections. Fig. l2 is a view corresponding to Fig. 2, but showing the L portion of the fuel supporting tops or sections adjacent the side walls.

Like letters of reference in the several figures indicate the same parts.

The grate embodying the present invention is as a whole designed to be set in an inclined position in the furnace; that is to say, it is 'inclined downwardly from the front' of the furnace and is adapted to receive the fuel at its upper front end, said fuel traveling down over the fuel supporting surface to the lower edge of the grate where it is discharged through the action of a dumping section or sections, the design of the grate being such that during its I" passage over the same there will be no sift ing of the fuel or ashes through the grate into the ash pit.

As shown in l, a fuel supply hopper A is provided at the front or upper end of 3.

the grate, from which the fuel is discharged, past a swinging gate or valve B onto afeeding plate C, and a dead plate C. Suitable means, such, for example, as a reciprocatory pusher D may be provided for advancing the fuel down over the dead plate onto the grate proper, and in this connection it may be remarked that the inclination of the grate is such that the fuel is supported at .all Bugle slightly within its angle of rest,

whereby it may be advanced over the grate` in a comparatively simple manner by the application of pressure to its upper portion or by the introduction of suitable implements which are passed down into the layer of fuel through the opening provided for that purpose immediately above the pusher, or in case no pusher is provided, then the implements may be introduced through an opening at the point now occupied by the pusher.

It will be readily understood from the foregoing that the angle of the grate should be arranged to suit the particular fuel for which the grate is designed, and that such angle should never exceed an angle which will support the fuel without causing the same to slide down to the lower edge by gravity alone, unless provision is made for checking the tendency of the fuel to slide on the grate, such, for example, as the dumping sections which might be turnedy to form an obstruction adapted to hold the whole body of fuel against sliding.

The fuel supporting surface of the grate is formed by a series of removable tops or sections which underlap and overlap each other in a manner to be presently described, so as to facilitate their ready removal or renewal, and these removable tops or sections are supported by a framework, as it were, which is located a considerable distance away from the fuel supporting surface and is composed essentially of carrier bars and cross bars. rlChe carrier bars are indicated in the drawings by the letter E, and from Fig. l it will be seen that at their rear lower ends they are supported by a bridge wall rest F, and at their front or upper ends they are supported on brackets g on a dead plate support G. The dead plate C is held in place on the dead plate support G by an anchor bolt or bolts c, and at its lower edge projects downwardly in an inclined position which corresponds to the general inclination of the grate. Bridged between the carrier bars E are a series of cross bars E preferably dovetailed into suitable sockets in the sides of the carrier bars E, and one of said carrier bars is located adjacent to each side wall of the furnace, as shown in Fig. 3, there being as many intermediate carrier bars as is necessary for the width of the furnace, the design being to make the cross bars relatively short or adapted to support only a few ofthe removable tops.

The cross bars E are provided with upwardly extending webs or heads which conveniently take the form of jaws e or supporting eyes c2, both the jaws and the eyes being adapted for the reception of trans-l verse supporting pins or bolts H. Where the projections take the form of supporting eyes the bolts are passed through the same from side to side, but where they take the form of jaws, such as e', the bolts may rest in open bearings formed in the jaws, whereby they may be more readily removed and applied, as will be readily understood. The form of the structure is such that the making of the molds and the withdrawing of the patterns is easily accomplished. The upwardly extending supports are adapted for the cooperation of downwardly extending webs z' on the removable tops or sections I, and said downwardly extending webs are preferably, as shown in Figs. 3, 6, 7, etc., provided with open slots or bearings for cooperation with the'pins H before re ferred to. ln some instances, however, both the webs and the projections may be provided with eyes for the accommodation of transverse pins, as shown at 2 in Fig. 1l, but in this instance the pins or bolts must invariably be withdrawn before the tops can be removed.

In the preferred construction a web t' is provided near the center and other webs corresponding thereto near the side edges of each removable top I. The central web i is adapted to be held in its supporting jaw or projection e with rather a close fit, so as to center or position the removable top transversely, but a considerable space is provided between the edge webs and the supporting projections, all as shown'in Fig. 3, whereby lateral expansion and contraction is permitted, without causing any-binding between the parts or deformation by resistance to expansion or growth.

Each of the removable tops is .formed with a plurality of substantially horizontal fuel supporting surfaces l', said fuel supporting surfaces being substantially plane,

or smooth and each overlaps and under-laps the adjacent fuel supporting surfaces, leaving very narrow lateral oir-horizontal air admission openings between them. The webs which unite the horizontal. portions or fuel supporting surfaces of the tops extend downwardly a sufficient distance to afford the necessary strength and at the same time provide a relatively large radiating surface which will dissipate the heat transmitted thereto by conduction, so as to save disintegration of the metal and also heat the inflowing air. At each side of the removable tops adjacent tops are provided with. overlapping and underlapping projections bridging the spaces between the rows of removable tops and in order to give sufficient Vstrength to the parts the construction illustrated in ldetail in Fig. 6 is preferablyv adopted,`that is to say, each edgejofeach top is provided with a rounded molding or projection K and K, thev top having the underlapping portion being further provided with a projecting flange 7:," adapted t0 pass in ander the edge projection .K. on

the adjacent top. The flange 7c may be further provided with bearing lugs 702 of reduced area, thus permitting the more ready escape of any accumulations beneath the overlapping part and overcoming any tendency to bind during the expansion and contraction of the parts. By rounding the edges K and K it is obvious that any fuel or ashes resting on or between these portions of the grate will be squeezed out of the space between the sections and will not offer material resistance to the movements. At the same time there will be little or no liability of fuel becoming hung in the spaces.

Instead of the substantially straight edge projections K and K referred to, it is obvious that a stepped arrangement corresponding to the stepped arrangement of the fuel supporting surfaces may be employed, and this construction is illustrated in Figs. 9 and l0, where the overlapping edge is shown of a stepped formation at K2 and the flange projection of a corresponding stepped construction at K3. In both instances, however, the construction followed should be such that each removable top will have vcorresponding projections at its two lateral edges; that is to say, the edges are either both overlapping edgesor both underlapping edges, and the object of this arrangement is to permit of the tops being individually removed from the supporting frame without the necessity of taking down the whole grate. For example, an overlapping top may be withdrawn forwardly or horizontally from the top surface of the grate, while an underlapping top may be disengaged from its supporting projections by withdrawing the bolts, and removed toward the under side of the grate, leaving adjacent tops in practically their normal positions.

Each removable top is adapted to rest at the upper portion only on the support formed by the projections on the cross bars, and at the lower end each top overlaps and rests upo-n the upper portion of the next adjacent lower top. rlhis arrangement is well illustrated in Fig. 2 and by reason of it the tops being held at one edge only, are free to eXpand and contract or to grow if growth should take place, the effect being simply to move the lower edge slightly back and forth on the next adjacent lower top. The webs are extended below the lower fuel supporting surface I a distance which corresponds to the width of the spaces between the upper and lower fuel supporting surfaces so that the air admission openings are uniform, both between the fuel supporting surfaces of each top and between the fuel supporting surfaces of overlapping tops. lnasmuch as the openings between laterally adjacent tops at the upper edges might admit more air than would be desirable at this point, the tops are each provided with knife edge rojections L, Figs. 6, 7, 9 and 10, arrange in such wise as to be substantially opposite each other for reducing in a measure the size of the openings, and these projections, it will be understood., lie just beneath the overlapping edges of the neXt higher tops or beneath the projections thereon, which, in the construction shown in Fig. 10, constitute a part of the flange K3, and in the construct-ion shown in Figs. 6 and 7 constitute a horizontal foot K4 on the overlapping top, (Fig. 7), which is adapted to pass under the lower edge of the underlapping top (Fig. 6), this structure presenting the appearance in front elevation shown in Fig. 5 of the drawing.

At the sides of the furnace, the tops adjacent the side walls are preferably always overlapping tops, as shown beyond the broken away portion in Fig. 3, and the side wall tops M under-lap, the same being preferably sectional tops formed on the upper edge of plates or bars M secured to the side wall and receiving their support from the carrier bars E before referred to. The preferred construction adjacent the side walls is shown in Figs. 3, a and 12, wherein it will be seen that the rounded edges or thickened portions of the tops have a substantially straight under surface indicated by the dotted line N in Fig. 12, and at the lower ends extend do-wn beyond the lower fuel supporting surfaces in the form of projections Nv, Fig. 4f, while the side wall tops M are formed with substantially straight surfaces on which the overlapping parts rest. ln this construction also the overlapping portions of the removable tops are strengthened so as to form bead-like enlargements which are thicker than those at the intermediate edges, for example, as shown at l 2 in Fig. 12, but it is obvious that the construction followed at the intermediate edges may be followed also along w the side walls, or the construction shown in Fig. 8 may be adopted. ln Fig. 8 the intermediate tops have underlapping projections O and the side wall tops have overlapping projections O', these overlapping projecportion of the grate may be overcome, such provision, as shown in Figs. 1 and 12, consisting in making the overlapping edges of the fuel supporting surfaces of a few of the removable tops near the upper portion of the grate slightly thicker than those at the lower portion of the grate, as shown at P,

.thereby reducing the vertical width of vthe spaces for the admission of air, and conseuuently effecting a more uniform' distribution of the air in accordance with the requirements of the fuel being consumed.

As compared with other grates, it will be noted that the percentage of the area of the air admission openingsto the total area of the grate is very small indeed, and may be as low as nine orten per cent. The air is admitted uniformly to practically every part of the body of fuel resting on the grate and it enters invariably through lateral openings through which, under normal conditions, there can be no reverse movement of the fine fuel or ashes, and consequently no sifting' action will take place. The underlapping surfaces both ofthe removable tops or sections as a whole and of the fuel supportinv surfaces of each top is sufficient to support any fine fuel or ashes which may ent-er the openings from the upper surface of the grate without permitting it to drop through, and while the extent of the overlap may be considered excessive from the proportion of the parts shown in Figs. 2 and l2, yet it is preferred to make it excessive, rather than too little, particularly as the construction provides an extra weight of metal for strength and a sufficient eXtension of the metal into the air space to provide a radiating surface whereby the heat of all of the metal parts will be distributed by conduction and dissipated by radiation and conduction to the entering air, to prevent burning or disintegration of the parts to a degree greater than is to be expected in this class of devices.

In use, the solid products which remain on the grate surface work down to the lower edge of the grate and onto a dumping section Q pivotally mounted on the lower portion of the carrier bars and adapted to be operated by a dumping rod or connection Q. rlhe particular construction of this dumping section or sections Q is not material to the present invention, save thatpit should be of such construction as to permit the ashes and other solid products to pass readily onto the same from the grate, and when turned into the dumping position to prevent the fuel from passing directly from the grate through the dumping section opening, this result being attained in the structure illustrated by the segmental ends Q2 of the dumping section.

To support the iowermost removable top at its lower edge, the bottom cross bar is formed .vith upwardly extending intermediate tops R, which in construction substantially conform to one of the fuel supporting surfaces of the removable tops, save that it is divided into sections by transverse cuts,

als is ordinarily practised4 in this art for overcoming the effects of growth or eXpansion. rlhe lowermost removable 'top I, therefore, rests on a lixedsupport R which constitutes an intermediate top over which the solid products pass to the dumping section, but it is obvious that any suitable form of support for the lower edge `of the lowermost removable top may be provided if the precaution is taken to have the air admission openings at this point conform to the areas adopted throughout the grate, and thereby prevent the flow of air from being concentrated at any particular point.

Having thus described my invention, what l claim as new and desire to secure by Letters Patent is,-

l. An inclined non sifting grate .for fine fuel embodying an inclined supporting frame and a series of removable tops mounted thereon, each top having a plurality of plane substantially horizontal fuel supporting faces arranged at diderent levels and one overlapping the other, longitudinally of the grate, said tops being disposed in lateral series and being provided with projections overlapping laterally so that the growth of the tops both longitudinally and laterally of the furnace is compensated.

2. An inclined'non-sifting grate for fine fuel embodying an inclined supporting frame, and a series of removable tops, each top having a plurality of plane substantially horizontal fuel supporting surfaces arranged at different levels, one overlapping the other and with air entrance openings therebetween, the lower fuel supporting surface of one top overlapping and being supported by the upper fuel supporting surface of the next top below the same, and lateral overlapping and `underlapping projections bridging the spaces between laterally adjacent tops, the horizontal faces of lateral adjacent tops all lying in thesame horizontal plane whereby the downward escape of fuel or ashes through the grate is prevented.

3. An inclined non-sifting grate for line fuel embodying an .inclined supporting frame and a series of removable tops, each top having a plurality of plane substantially horizontal fuel supporting surfaces arranged at different levels, one overlapping the other and with air openings therebetween, the lower fuelsupporting surface of one top overlapping the upper fuel supporting surface of the next lower top, and each top having its lateral edges provided with rounded projections, alternate tops being provided with flanges adapted to underlap the projections on the intermediate tops.

4f. An inclined non-sifting grate for iine fuel embodying v an inclined supporting frame and a series of removable tops mountedthereon, each top havinga plurality of plane substantially horizontal fuel supporting surfaces, arranged at different levels ics and one overlapping the other with an air entrance opening therebetween and with the lower fuel supporting surface of one top overlapping the upper fuel supporting surface of the adjacent lower top, the lateral adjacent tops being provided with projections one overlapping the other, said tops having rounded edges so that when in operative position the distance between the rounded portions is less at the bottom than at the top.

5. A n inclined non-sifting grate for ne fuel embodying an inclined supporting frame and a series of removable tops, each top having a plurality of plane substantially horizontal fuel supporting surfaces arranged at different j levels one overlapping the other and with air entrance openings therebetween, the lower fuel supporting surface of one top overlapping the upper fuel supporting surface of the next top below the same, the lateral alternate tops of the furnace being provided with overlapping edge projections bridgingthe space between adjacent tops, said lateral adjacent tops presenting in opposition curved edges forming a channel therebetween, said channel having upwardly and outwardly diverging walls, whereby when the tops grow the material within said channel is forced out of and up from said channel.

6. An inclined non-sifting grate for fine fuel embodying an inclined supporting frame formed by inclined carrying bars and transverse cross-bars, having upwardly extending projections thereon, and a series of removable tops, each top having a plurality of 'fuel supporting surfaces arranged at different levels and one overlapping the other, the lower fuel supporting surface of one top overlapping and resting on the upper fuel supporting surface of the next top below the same, downwardly extending webs on the tops having bearings at their upper end and transverse connecting pins intermediate the bars on the webs, and upwardly extending projections on the cross-bars of the supporting frame.

7. ln an inclined, non-sifting grate for fine fuel, the combination with a removable top embodying a plurality of substantially horizontal fuel supporting surfaces arranged at diierent levels one overlapping and resting on the other, and a plurality of downwardly extending webs connecting said able top having a plurality of fuel supporting surfaces arranged at different levels and one overlapping the other, with lateral air entrance openings therebetween, and also having a plurality of downwardly extending supporting webs, of a support having an upwardly extending projection coperating with one of said webs for retaining the top in position laterally and also having' upwardly extending projections cooperating with webs adjacent said first mentioned web for supporting the top with connections intermediate the projections and last named webs, spaced to permit of lateral expansion and contraction of the tops.

9. ln an inclined non-sifting grate for line fuel, the combination with a series of removable tops arranged in rows from top to bottom of the grate and each embodying a plurality of plane fuel supporting surfaces arranged at different levels and one overlapping the other, with air entrance openings therebetween, the lower fuel supporting surface of one top overlapping the upper fuel supporting surface of the next top below the same, said tops being provided with lateral overlapping and under lapping projections bridging the spaces between adjacent rows of tops, and projections extending into the spaces between the laterally adjacent tops for reducing the area of the openings therebetween through which air may enter.

WILLIAM MCCLAVE.

Witnesses:

CHAs. H. WELLns, Jr., Anonm THOMAS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, D. C.

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