US2575628A - Water-cooled furnace wall - Google Patents

Description

NM. 2& 119511 o. A. JOHNSON 2575528 WATER COOLD FURNACE WALL Filed Oct. 2, 1946 2 SI-lEETS--SHEET 1 o. A. JOHNSON WATER COOLED FURNACE WALL 2 SHEETS-SHEET 2 New. 20), 511

Filed Oct. 2, 1946 05691? doHNso/v Patented Nov. 20, 1951 WATER-COOLED FURNACE WALL Oscar A. Johnson, Worcester, Mass., assignor to Riley Stoker Corporation, Worcester, Mass., a. corporation of Massachusetts Application October 2, 1946, Serial No. 700,'746

4 Claims.

This invention relates to water cooled furnace walls, and more particularly to an improved structure for supporting a substantially horizontal header located adjacent a mel-supporting grate and arranged to supply water to the lower ends of water Wall tubes.

In wall constructions of this type as heretofore employed difilculties have been encountered in providing adequate lateral support for the fuel bed and in preventing excessive air leakage into the furnace at the sides of the grate. Further more, the outer surface of the header has in some instances become cracked because of overheating, this trouble being especially pronounced in the case of headers with thick walls, as required to withstand high internal pressures. In certain prior arrangements, clinkers from the fuel bed have adhered to the wall and interfered with combustion. such clinkers prevent the proper movement of the fuel bed on progressive feed grates, and the walls have often been damaged by attempts at clinker removal.

It is accordingly one object of the invention to provide a header supporting structure which will furnish adequate lateral support for the fuel bed and prevent excessive leakage of air between the grate and the wall.

It is a further object of the invention to provide a header supporting structure arranged to be located adjacent one side of a fuel bed, and so constructed as to protect the header from overheating and abrasion.

It is a further object of the invention to provide a header supporting structure adapted to provide lateral support for a fuel bed and so constructed that clinkers will not readily adhere thereto.

It is a further object of the invention to provide a header supporting structure having parts arranged to support a fuel bed laterally and so constructed that they can be readily replaced if necessary.

With these and other objects in View, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specication and covered by the claims appended hereto.

Referring to the drawings illustrating one embodiment of the invention, and in which like reference num'erals indicate like parts, v

Fig. 1 is a longitudinal section through a stoke fired furnace having a water cooled side wall;

Fig. 2 is an enlarged View in section on the line 2-2 of Fig. l;

Flg. 3 is a perspective view of a block forming a portion of the Wall;

Fig. 4 is a perspectfve View of a different block forming a portion of the wall; and

Fig. 5 is a perspective view of the block shown in Fig. 4, taken from a different angle.

The embodiment illustrated comprises an end less grate o of well-known construction which is supplied with fuel at its front end by means of the usualhopper l i. The upper run of the grate travels rearwardly in known manner to support a bed of burning fuel, the ash being deposted in a pit !2 at the rear. Air for combustion is sup-*- plied beneath the fuel bed., preferably by forced draft, through the usual openings l4 at the sides. The grate is installed within a furnace having a side Wall l 5, a rear Wall !6, a front arch l8, and a rear arch [9. The rear arch |9 includes a row of water tubes 20 which extend forwardly from a transverse rear header ZI. The side wall 15 includes a row of upright water tubes 23 which are connected at their lower ends to a longitudinally extending header 24. As shown in Fig. 2, this header is of circular cross-section, this construction being less expensive to manufacture than other shapes and best adapted to withstand high internal pressures. On the outer side of the header there are provided an upper horizontal flange 26 and a lower horizontal fiange 21. The flange 26 provides a support for the refractory portion of the wall !5 thereabove, and the fiange 21 is bolted to the flanged upper edge of a verti-' cal plate 28.

` At the side of the grate IE] and beneath the side wall 15 there is provided a longitudinally extending girder 30 having a flat horizontal top plate 3 I. In known manner, this girder may form a portion of the supporting framework for the grate. The header 24 is located directly above the plate 3 l and slightly spaced therefrom.

Means is provided to support the header 24, to protect the header from overheating and abrasion, and to confine the fuel bed laterally on the grate o. For this purpose there is mounted on the top of the'girder plate 31 a continuous row or series of wedge-shaped metal blocks 33 with comparatively thick inner portions which slightly overlap the adjacent edge of the grate. On the upper surface of each block there is formed a longitudinally extending rib 34 of substantial width and relatively slightelevation. This rib is spaced from the inner edge of the block, and its upper surface is concave to make contact with the lower surface of the header 24 somewhat inwardly of the axis of the header. At installation, a thin layer of heat-conductive cement 35 is laced in the gap or recess between the inner portion of each block 33 and the adjacent surface of the header. This cement may be of any suitable composition, for example, a mixture of iron powder and water glass. The outer portion of each block is somewhat less in thickness than the minimum distance between the plate 3! and the header and on the substantially fiat upper surface of this outer portion there are mounted three relatively small wedge-shaped metal blocks 31. These blocks have concave upper surfaces which make contact with the lower surface of the header 24 somewhat outwardly of the axis of the header. It will be noted that the bloeks 31 face oppositely to the blocks 33.

Releasable means is provided to connect the small wedge blocks 31 to the main blocks 33. As shown, each block 31 is constructed with a de-.

pending fiange 38 at its outer edge which overlaps the outer edge of the 'block 33, this flange having a hole 39 therethrough to receive a horizontal bolt 4! with a nut 42on its outer end. 'I'he outer portion of the block 33 is formed with three ?iF-.Slots 43 to receive the heads on the inner ends of the bolts 41.

It will now be apparent that the blocks 33 and 3.1 provide a supporting saddle for the header 24. 'Ifhe blocks 33 form a ledge along the marginal portion of the grate lil and support the fuel bed iaterally, while preventing excessive leakage of air between the grate and the header. Although the thicl inner portions of the blocks 33, are subjeeted to the heat of the fuel bed, they will nevertheless remain at a comparatively low temperature because of the rapid flow of heat therefrom through the cement 35 and the rib 34 to the metal wall of the header 24 and thence to the water within the header. Clinkers will not adhere to these relatively cool blocks. These blocks also protect the header 24 to a considerable extent from heat and abrasion. In case any of the blocks 33 become damaged after a long life of service, they may be easily replaced from the innerside of the wall 15 when the furnace is shut down. To permit replacement of the blocks, the nuts 42 should be removed, access being had thereto by removal of the plate 28. By replacing the blocks one at a time, the header 24 will remain supported in a proper manner.

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

1. As an article of manufacture, a. wedgeshaped block having a relatively thick inner por: tion adapted to provide lateral support for a fuel bed, the block having a slightly elevated rib of substantial width extending along its upper surface and spaced from the inner edge of the block, the rib having a concave upper surface for engagement with the lower surface of a water Wal header.

2. As an article of manufacture, a wedgeshaped block having a relatively thick inner portion adapted to provide lateral support for a fuel bed and a relatively thin outer portion. the inner portion of the block being shaped to provide -a concave upper surface for engagement with the lower surface of a water wall header. and the outer portion of the block having a T-slot therein.

3. A support for a substantially horizontal furnace water wall header comprising a wedgeshaped block having a relatively thick inner portion adapted to provide lateral support for a fuel bed, and a relatively small wedge-shaped block mounted on the outer portion of the firstmentioned block, the two blocks racing oppositely and forming a saddle adapted to engage the lower surface of the header on opposite sides of its axis, the first-mentioned block having a slightly elevated rib extending along its upper ur e a s ed from s nner ed e he' rib b n ad o gas th h a ern suc a wer as to leave a gap or recess between the inner por, tion of the first-mentioned block and the, header for the reception of heat conductive cement.

4. A support for a substantially horizontal jure nace water wall header comprising a Wedgeshaped block having a relatively thick inner por: tion adapted to provide lateral support for a fuel bed, and a relatively small wedge-shaped block mounted on the outer portion of the first: mentioned block, the two blocks facing oppositee ly and forming a saddle adapted to engage the lower surface of the header on opposite sides of its axis, the outer portion of the first-mentioned block being provided With a T-slot to receive the head of a. bolt, the relatively small block having a depending flange provided with an opening through which the bolt extends in the outward direction.

OSCAR, A. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,423,540 Poppenhusen July 25, 1922 1,466,930 Cipra Sept. 4, 1923 1,477,898 Poppenhusen et al. Dec. 18, 1923 1,485,952 Blunt Mar. 4, 1924 2241932 Rehm May 13, 1941 2375341 Foresman May 15, 1945 '2393,707 Rehm -v- Jan. 29, 1946 FORE'IGN PATENTS Number Country Date 405298 Great Britain Jan. 30, 1934:

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