US2070166A - Furnace tuyere - Google Patents

Description

Feb. 9, 1Q37. Q E HARRISON 2,070,166

FURNAGE TUYRE Filed June 10, 1952 5 Sheets-Sheet 1 Invnor CZ z'fforc E. Harrison www Feb. 9, 1937. c. E. HARRISON 2,070,166

FURNACE TUYRE Filed June l0, 1932 5 Sheets-Sheet 2 zziffrd EHczrrSon BY g4/@Mb Y Aiiorne/ Feb. 9, 1937. c. E. HARRISON FURNACE TUYRE Filed June lO, 1932 3 Sheets-Sheet 5 .Fly

Patented Feb. 9, 1937 NETE@ STATES PATENT OFFICE irUaNAcn TUYRE [application June 10, 1932, Serial No. 616,434

S Claims.

This invention relates to stoker fired furnaces, and more particularly to the tuyres employed in such devices.

rlhe tuyres employed in stoker furnaces, as is well known in the art, constitute the fuel supporting grates and are so constructed that draft air may pass therethrough from a pressure chamber to the fuel bed. These tuyres obviously are subjected to extremely high temperatures, especially when preheated draft air is employed. During operation of stokers of the underfeed type, While many of the tuyres may be protected to a certain extent by a layer of green fuel or fuel which has not yet reached the incandescent stage, it often happens that a thin fire develops in certain portions of the fuel bed with the result that incandescent fuel cornes into directcontact with the tuyres. The tuyres subjected to such conditions may become damaged to such an extent that replacement thereof by new ones is necessary. It has been found that in most instances the nose portion is substantially the only part of the tuyre that is damaged; nevertheless in the older constructions the entire tuyre must be removed and replaced with a new one.

It is an object of the present invention to construct a tuyre block having two or more removable parts so that in case one of these parts should become damaged it is only necessary to replace that part and not the entire tuyre block.

A further object is to provide a tuyre block having a body portion and a nose portion removably attached thereto, said portions being so connected that but little heat is conducted to said body portion through said nose portion.

A more specific object of the invention is to provide a sectional tuyre block having interlocking means between the sections thereof which effectively secures them intact and yet permits ready replacement of any of the sections should it become damaged.

A further object is to provide a tuyre block having a series of substantially hollow air cooled projections which define passages through which draft air may pass.

A further object is to provide a sectional tuyre block having novel means provided thereon for distributing the draft air to all portions thereof.

A still further object of the present invention is to' provide a tuyre block having means thereon defining passages through which air may pass which are so constructed and arranged that (Cl. 11G-44) clogging of the passages during operation of the stoker is prevented.

Other and further objects will become apparent as the description of the invention progresses.

Of the drawings:

Fig. 1 is a side elevational view taken through one of the retorts of a multiple retort underfeed Stoker, showing the arrangement of the tuyre blocks, extension grates, and the fuel feeding elements.

Fig. 2 is a plan view of one of the tuyre blocks comprising the present invention.

Fig. 3 is a side View of the tuyre block shown in Fig. 2.

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2.

Fig. 5 is a view taken on line 5 5 of Fig. 2.

Fig. 6 is a plan view of a modified form of tuyre block.

Fig. 7 is a side view of the tuyre block shown in Fig. 6.

Fig. 8 is a sectional view taken on line 8-8 of Fig. 6.

Fig. 9 is a view taken on line 9--9 of Fig. 6.

Fig. 101s a perspective view of the tuyre blocks shown in Figs. 2 to 5 inclusive, in inverted position, and

Fig. 1l is a perspective view of the tuyre blocks shown in Figs. 6 to 9 inclusive, in inverted position.

Referring to the drawings, the numeral I indicates the front Wall of a furnace equipped with a multiple retort underfeed stoker 2, having alternately disposed retorts 3 and tuyre rows 4 extending lengthwise of the Stoker and inclining downwardly from front to rear thereof. Fuel is supplied to the Stoker from hoppers 5 which communicate with cylinders 6, each having a fuel feeding ram 1 provided therein. A series of pushers 8 are provided in the bottom of each retort 3 for underfeeding the fuel along said retorts. Extension grates 9 provided at the rear of the Stoker feed the residue into an ash pit I0. The fuel feeding rams are actuated by any suitable power mechanism indicated at II and at each reciprocation thereof predetermined quantities of fuel entering the cylinders 6 from hoppers 5 are fed to the retorts 3. The pushers and extension grates are also actuated by the power mechanism I I through the connections indicated generally as I2. Inasmuch as the specific construction of the operating mechanism for the rams, pushers and extension grates forms no part of the present invention, a detailed description thereof is unnecessary.

The tuyre blocks 4 are supported upon the upper edges of the walls I3 of adjacent retorts and span the space therebetween, as shown in Fig. 1. The chamber beneath the tuyre blocks defined by adjacent walls i3 communicates with a pressure chamber ii common to the series of tuyres and into which draft air is supplied by any suitable blower apparatus (not shown) For the purpose of illustration but one retort 3 and row of tuyre blocks 4 is shown, it being obvious that any number may be employed.

The terms front and rear hereinafter employed in the description of the various elements comprising the present invention, it is to be understood, indicate those portions of the elements disposed towards the front and rear respectively of the furnace.

Referring to Figs. 2 to 5, it is seen that each tuyre block d comprises a substantially rectangular body portion i6 and a substantially triangular nose portion i?. The body portion I 6 of each tuyre block comprises a relatively thin flat portion I8 which is defined by side edges I9 and 2U and front and rear edges 22 and 2i, respectively. The side edges IS and 2li terminate near the rearwardly disposed end thereof in converging portions 23 and 24 which extend to the rear edge 2i. The front end of body portion I 6 is provided with a reduced portion 25, having side edges 26 and E?, which, when the tuyre blocks are assembled in the stoker, lie in close juxtaposition to the inner surfaces of side plates I3. Depending from the lower surface of portion I8 are a pair of elongated projections 28 and 2S having substantially flat lower surfaces 3G and 3|, which in assembly rest upon the upper surface of the next lower tuyre block of the series. Projections 2B and 29 are also provided with inclined surfaces 32 and 33, the inclination of which corresponding with that of side plates i3, and which when the tuyre blocks are assembled in the stoker, rest upon the upper edges of said side plates i3. Also depending from the lower surface of body portion i ii is a stud Sli which engages into an aperture 35 of the next lower tuyre block of the series when the tuyres are assembled on the stoker. It will be noted that projections 34 and apertures 35 are in longitudinal alignment and are positioned substantially midway between side edges i9 and 2i) of the tuyre block. A substantially U shaped slot 36 is provided at the rearwardly disposed end of portion I6 midway between the converging portions 23 and 2li. The walls of slot 36 converge as shown in Fig. 2, into a rounded neck portion 31 near the rear edge 2l of body portion I6. This slot receives a correspondingly shaped locking lug 38 extending forwardly of nose portion I'l. The rear edge 2| of body portion IB is also provided with an eX- tension 3B with which an extension 4d provided along the forward edge ii of nose portion Il overlaps.

Nose portion I'I also comprises a relatively thin portion C32 having side edges d3 and 44 which converge, as shown in Fig. 2, and lie in substantially the same vertical plane as the converging edges '23 and 25., respectively, of body portion I6. Side edges d3 and fifi terminate in a substantially arcuate portion fiii. Ihe upper surface of nose portion il is substantially flat and in assembly lies in the same horizontal plane as the upper surface of portion I6, as shown in Figs. 2 to 5. Depending from the lower surface of nose portion I'l is a series of projections 46, 41, and 48, which define passages lit and 50 through which drft air may pass. The forwardly disposed sides and 52 of projections fil and 43 also form, with the rounded rearwardly disposed ends 53 and 54, respectively, of projections i@ and 25, passages 55 and 5t through which draft air may also pass. The sides 56 and Ei of projection 6, and the arcuate portion 62 thereof, terminate inwardly of the outer edges of nose portion Il, and incline downwardly and inwardly as shown in Figs. 3 to 5. Projection 45 is formed with a flat base G3 which rests upon the next lower tuyre block of the series when the tuyre blocks are assembled on the stoker.

As shown more particularly in Figs. 2 and 4, an aperture 65 is provided in nose portion I7 near the rearwardly disposed end thereof through which some of the air entering the interior of projection 4E is discharged to the fuel bed.

The outer sides El and t8 of projections 4'! and 43, respectively, also terminate inwardly of side edges 43 and tf:- of nose portion il, and incline downwardly and inwardly therefrom. These projections are also provided with base portions 63 and i8, respectively, which rest upon the upper surface of the next lower tuyre block of the series when the tuyre blocks are assembled on the stoker. By constructing projections 66, i7

and i8 in this manner, substantially the entire n lower surface of each nose portion il is cooled by the incoming draft air. The heat transfer between the nose portions of adjacent tuyre blocks is also relatively small owing to the reduced areas of the base portions of said projections.

It is also seen, that by this construction clog- 3' ging of the passages by slag or other formations which occur during furnace operation is prevented. The inclined sides of each projection, which are set back from the outer edges of the tuyre block, form in effect channeis around the outer surfaces thereof which permit air to flow therethrough in case an obstruction is encountered adjacent one of the passages.

In order to assemble each tuyre block it is only necessary to bring the locking lug 3S into registering position with slot 3% and to then lower the nose portion I'l until the overlapping extensions 39 and Il@ are brought into engagement.

It will be noted that the forwardly disposed side 5l' of each locking lug i3 extends downwardly a considerable distance below the lower surfaces of portions I3 and Q2 of the tuyre block, and that the lower edges 5t of the sides thereof incline upwardly and rearwardly as shown in Figs.

3 and fi. By this construction the sections I 6 and il of each tuyre block 4 are effectively locked, and will remain intact even in case the parts thereof become distorted during operation of the furnace.

When the tuyre blocks are assembled on the Stoker, the portions i5 and I1 thereof are secured against relative vertical movement by the overlapping arrangement of the superimposed tuyre blocks. The weight of the fuel supported by the tuyre blocks also has a tendency to maintain the parts in locked relation.

The modified tuyre blocks 4 shown in Figs. 6 to 9 are similar in general construction to the tuyre blocks f1 just described. These tuyre blocks also comprise a substantially rectangular body portion Iii and a substantially triangular nose portion I1', the former also having a substantially U shaped slot 36 which receives the correspondingly shaped locking lug 38' extending forwardly from the latter. Each tuyre block 4 is also provided with depending projections I9 and 28', and a locking lug 34 which engages in a substantially circular aperture 35' of the next lower tuyre block of the series. Extending rearwardly from locking lug 34 are a pair of spaced ribs 'H' and 'l2' which extend substantially to the rear edge 2l of portion I6'. The lower edges 'd3' and 14 of ribs il and 12', respectively, lie in a plane slightly above the plane in which the lowersurfaces 3D and 3| of projections 28 and 29' lie so that air may enter the chamber defined by said ribs. A pair of spaced ribs l5 and 'i6' are also provided on the lower surface of nose portion il and extend substantially the entire length thereof. These ribs are in alignment withribs 'Il' and 12', respectively, and the lower edges 1l and 1S thereof lie in substantially the same horizontal plane as the lower edges 13 and 14 of ribs 1l and 12', respectively. The lower edges 19 and 88 of the rearwardly disposed portion of ribs l5 and 16 extend downwardly from edges 'll' and 18, and in assembly rest upon the upper surface of the next lower tuyre block of the series. An aperture 8l is provided at the rearwardly disposed end of nose portion I'lso that the air entering the chamber defined by the ribs just described may be discharged into the fuel bed.

Spaced from ribs 'l5' and 'i6' are a pair of substantially triangular shaped ribs 82' and 83 which extend inwardly from side edges 43' and 44', respectively, of nose portion l1. The forwardly disposed sides 84 and 85 of projections 82 and 83 are curved and form with the rounded forward ends 53 and 5d of projections I9 and 20', passages 86 and 81 through which draft air may pass.

The sides 88' and 89' of ribs 82 and 83 and the outer sides S and 9| of ribs l5 and 16 incline outwardly and inwardly, respectively, as shown in Fig. 9, thus forming triangular shaped passages 92 and 93 through which the draft air passes. The lower surfaces of ribs 82 and 83 lie in the same horizontal plane as the lower edges of ribs l and 76 and projections I8' and 20', and in assembly also rest upon the upper surface of the next lower tuyre of the series.

From the foregoing description, it is seen that draft air owing through the tuyres comes into contact with substantially the entire lower surface thereof. The body portion I6 of each tuyre block is not only eifectively cooled by the incorning draft air but is somewhat removed from the burning fuel so that but little damage occurs thereto during operation of the furnace. The nose portions Il of the tuyre blocks, however, are subjected to higher temperatures and under certain conditions may become damaged from time to time and require replacement by new ones. This portion of the tuyre block, however, constitutes but a small part of the entire tuyre block and thus the cost of maintenance is very small. It is also seen that but little of the heat absorbed by nose portion l1 is conducted to body portion IE because of the joint therebetween and thus damage to the latter is further prevented. By the novel interlocking means between the nose and body portions of the tuyre block, bolt, rivet, key, or other troublesome forms of fastening means are entirely dispensed with, and replacement of damaged parts may be readily made.

The illustrated embodiments show tuyre blocks made up of but two parts. It is obvious,

however, that further divisions may be made, and also that the interlocking connections between the parts may be reversed if it is deemed desirable, without departing from the present invention. It therefore is to be understood that the present invention is not to be limited to the specific constructions shown herein but only by the scope of the claims which follow.

What is claimed is:

l. A furnace tuyre block, adapted to conn prise one of a series arranged in superimposed stepped relation, said tuyre block having a relatively at body portion, and a series of projections provided thereon dening passages through which air may pass, said projections each having a side, end, and a bottom wall forming an open chamber into which air may enter, and the side walls of said projections inclining downwardly and inwardly, forming reduced bottom wall surfaces.

2. A nose piece adapted for assembly with the body portion of a furnace tuyre block adapted to comprise one of a series arranged in stepped relation, said nose piece having a substantially smooth upper surface and a series of projections provided on the under surface thereof defining passages for draft air, each ofr said projections having a side, end, and a bottom wall forming an open chamber into which air may enter, and the side walls of said projections inclining inwardly from the corresponding edges of said nose piece forming reduced base portions adapted to contact the next lower tuyre block of the series.

3. A nose piece adapted for assembly with the body portion of a furnace tuyre block, adapted to comprise one of a series arranged in stepped relation, said nose piece having a substantially smooth upper surface, a plurality of projections depending from the under side of said nose piece deflningpassages for draft air, certain of said projections extending longitudinally of the nose piece in spaced relation forming an air chamber, an outlet opening provided at the forward end of said chamber, and a locking lug for securing said nose piece in position projecting from one edge thereof. l

4. A tuyre block comprising a substantially rectangular body portion adapted for assembly with a nose portion, said body portion having a flange provided along one edge thereof, means provided adjacent said edge adapted to interlock with the securing means provided on an associated nose portion, a pair of ribs depending from the under side of said body portion and extending longitudinally thereof in spaced relation forming an air chamber, and additional means depending from the under side of said body portion for supporting the same, and forming with said ribs rst named, passages for draft air.

5. A furnace tuyre block adapted to comprise one of a series arranged in superimposed stepped relation, said tuyre block comprising a body portion, and a nose portion removably secured thereto, a series of projections provided on the under side of said nose portion defining passages for draft air, each of said projections having a side, end, and a bottom wall forming an open chamber into which air may enter, the side walls of said projections inclining inwardly from the corresponding edges of said nose piece forming reduced base portions adapted to Contact the next lower tuyre block of the series.

6. A furnace tuyre block, comprising a substantially fiat body portion having a locking slot provided at the rearwardly disposed end thereof,

and a nose portion extending rearwardly of said body portion, meansfor. securing said nose portion to said body portion forming in assembly a self contained tuyre unit, said securing means comprising a lug extending forwardly from said nose portion which engages in said slot provided in the rearwardly disposed end of ksaid body portion, and the vertical dimension of at least a portion of said lug being greater than that of the body portion bounding said slot whereby disengagement of said nose portion from said body portion may be effectedonly by relative vertical 'movement of said parts.

7. A furnace tuyre block comprising a substantially flat-body portion, and a substantially flat nose portion removably secured thereto, said nose portion extending rearwardly of said body lportion and forming therewith a self contained unit, means for attaching said nose and body portions comprising a lug extending from oneof said portions which engagesl into a slot provided in the other of said portions, the upper surfaces of said lug, and nose and body portions lying substantially in the same plane thereby providing a substantially smooth continuous surface, and means provided on at least one of said portions dening passages for draft air.

8. A furnace tuyre block adapted to comprise one of a series arranged in stepped relation, said tuyre block comprising a substantially flat body portion, and a nose portion arranged in abutting relation therewith and extending rearwardly thereof, overlapping means provided on said body and nose portions forming a seal along the abutting edges thereof, and means for attaching said nose and body portions comprising a locking lug extending from one of said portions which engages into a slot provided in the other of said portions, and means provided on the under side of said nose portion defining passages for draft air.

CLIFFORD E. HARRISON.

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