US1764173A - Furnace wall - Google Patents

Description

w. F. KEENAN, JR 1,764,173'

FURNACE WALL Filed May 27, 1926 2 Sheets-Sheet 1 2 llllllllllll |I.|1| H .l l I HHHI 5 J H June 17, 1 930.

June 17, 1930. w. F. KEE'NAN, JR

FURNACE WALL,

Filed May 27, '1926 2 Sheets-Sheet 2 ATTORNEY Patented June 17, 1930 UNITED STATES PATENT OFFICE WALTER F. KEEN-AN, JR, OF PELHAM, NEW YORK, ASSIGNOR TO FOSTER WHEELER CORPORATION, OF NEW YORK, N. Y., A. CORPORATION OF NEW YORK rumucn WALL Applicatipn filed. May 27, 1926, Serial 1T0. 111,908, and in Great Britain April 10, 1926.

My present invention relates .to fluid cooled.

furnace walls, and the general objectpf the invention is to provide improvements 1n con- -struction and arrangement especially devised and adapted for use under the severe conditions to which the so-called water back or water cooled wall at the clinker discharge end of a stoker gate are subjected. More specific objects of the invention are to provide improved means for supporting water back conduit elements and for providing the necessary heat insulating effect, and preventing gas leakage adjacent the elbow portions of said .elements when the later are the type comprising bare tubes having furnace wall lining portions surrounded by sectional cast iron casings, and having transverse end portions which extend through the outer portion of the furnace wall and are connected to external headers.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, however, its advantages and specific objects attained with its use, reference should be had to the accompanying drawings and descrip-- tive matter in which I have illustrated and described preferred embodiments of the invention. Y Of the drawings:

Fig. 1 is a diagrammatic sectional elevation of a boiler furnace;

Fig. 2 is a horizontal section the upper portion being taken on the line 22 and the lower portion of which is taken on the line 2A-2A of Fig. 1;

Fig. 3 is an enlarged section taken similarly toFig. 1;

Fig. 4 is section on the line 4 4= of Fig. 3, with parts broken away and removed;

Fig. 5 is a partial section on the line 55 of Fig. 3;

Fig. 6 is a front elevation of a portion of the apparatus shown in Figs. 2, 3, and 4;

Fig. 7 is a sectional elevation illustrating a modified form of water back construction;

Fig. 8 is a view taken similarly to Fig. 7 illustrating a second modification;

Fig. 9 is a horizontal section on the line 9-9 of Fig. 8'; Fig. 1O is a view taken similarly to Fig.

'7 illustrating another form of the invention;

and

-Fig. 11 is a partial section on the line 11-11 of Fig. 10.

In Figs. 1 to 6 of the drawings I have illustrated a preferred form of water back construction employed in a boiler A conventionally illustrated as of the verticaltube or Stirling type. The boiler A, as shown, comprises water tubes B connecting a lower Water drum B to upper steam and Water drums B the Water tubes being traversed by products of combustion coming to them from a. combustion chamber A at the bottom of which is located a stoker grate C. C represents the clinker discharge passage, the upper portion of the front wall of which is formed by the tions andtransverse end portions connecting the body portions to the external water back inlet and outlet headers E and E respec tively. The water back is connected into the boiler water circulating system by means of downcomer piping E connecting header E to the drum B, and riser piping E connect ing the header E to the front drum B The body portion of each tube e is surrounded by a sectional casing formed of perforated cast iron blocks E and end sections E and E which are advantageously iron bodies cast in ly bent. The body portions of the elements E ordinarily are vertically disposed, though in many installations they are advantageously not exactly vertical, but inclined slightly to the vertical as shown in Fig. 1. When the body portions of the elements are of any considerable length the tendency of the elements the bridge wall.

to warp or become deformed under the conditionsof use is advantageously restrained by stiffening bars F suitably connected to the elements. As shown in Figs. 1 and 3, the stiffening bars F are connected by bolts to lugs secured on the back sides of some of the sections E". 1

The furnace wall A in front of which the water back is located, lies beneath the bridge wall A and supports the latter through iron Work. This iron work as shown in Figs. 1 to 5, comprises a steel beam G and transverse beams H shown as of I-beam cross section and spaced apart to provide openings in the wall through which the upper transverse end portions of the tubes e extend. The lower end portions of the elements extend through openings in the furnace wall formed by incorporating therein elements it generally similar to the elements H. Ordinarily a water back of the character shown in Fig.3, is suspended by supporting means engaging the elements at their upper ends, and suitable clearance provisions must be made to permit the lower ends of the elements to rise and fall as the elements elongate and contract in response to temperature changes.

In the construction shown in Figs. 1 to 6, the

elements E are supported by fins or platelike iron or steel ribs I which are welded to the under sides of the horizontal upper end portions of the tubes E and which rest on the top of the I-beam G.

With thetype of water back construction and mounting in the furnace wall shown in Figs. 1-6, it is necessary to protect the I-beam G and beams H against exposure to furnace temperatures, and 1t 1s, of course. necessary to prevent air and gas leakage t-hrough. the, openings in the furnace wall proper formed to receive the end portions of the tubes 6. To this end ribs or fins K formed by suitably shaped pieces of metal plate are welded to the convex side of the upper elbow portion of each tube 6. Advantageously, as shown in Fig. 3, these ribs K are shaped to have vertical front edges in substantial alignment with the heat absorbing face of the water back, and to have top edges which abut against the portion of the underside of the bridge wall A in front of the beams G and H which are overhung by Advantageously, and as shown, the ribs K are formed with registering apertures receiving horizontal reinforcing bars L. The spaces between the adjacent fins K and between the adjacent portions of the tubes 6 are filled with refractory material M which might be formed of fire brick or tile, but advantageously is a known kind of refractory cement or plastic fire brick which can be put into place while in an initial putty-like condition and which when sub- 'ected to the heat of the combustion chameslze r A in the regular operation of the boiler brick, and a clay binder. This material when heated becomes hard and strong enough to aid materially in supporting the overhanging portion ofthe bridge wall particularly' when, as in the construction shown in Fig.

6, the material M is worked snugly into place between the portion of the underside of the bridge wall in front ofthe beams G and H and the inner base flange of the beam G. The material assists in supporting the bridgewall not only directly but indirectly through the lateral support and rigidity which it gives to the fins K which bear at their upper sides direcltlly against the underside of the bridge wa In putting the material M into place it is tamped or hammered with a mallet to eliminate voids and to insure full contact with the surfaces engaged, and particularly with the sides of the fins K and the portions of the tubes (2 surrounded by the material. The strength and effectiveness of the material M in use is maintained by the cooling action of thefins K and elements E on the material M which prevents the latter from being heated to an injuriously high temperature. The effectiveness of the cooling action on the material M of the contacting portions of the elements E and fins K is enhanced, of course, by the closeness of the contact. The material M protects the upper elbow portions of the tubes 0 against flame impingement and prevents leakage through the furnace wall adjacent the top of the water back and effectuallyproteets the iron work G and H against overheating;

The lower cast-011 casing sections E, and the subjacent portion A of the wall A, may be shaped to provide only the necessary mechanical clearance to accommodate mal expansion and contraction between the lower ends of the blocks E .and the wall portion A. Gas leakage through the spaces ther-' between the transverse beams it may be pre- The modified water back construct on shown in Fig. 7, is practically, identical with that shown in Figs. 1 to 6, except that in Fig. 7 the water back is suspended through an angle bar P bolted to the upper cast arm casing blocks E The bottom flange of the channel bar P rests on a metal plate Q incorported in the wall A", which, as shown, in

this construction, comprises a masonry portion A at the outer side of the bar P which replaces the .beam G of the construction first described and supports the beams H. 1

In the construction shown in Figs. 8 and 9, the portion of the furnace wall A above the water back is carried by beams GA which support metallic parts HA and HA replacing the beams H of the construction previously described. The parts HA are in the form of open cast iron boxes with a central web parallel to the length of the beams GA. The central webs and the end walls of the box-like parts HA are perforated for the passage of the of the out-turned end portions of the tubes 6. Suitable packing materlal O which may be like the material 0 previously referred to, is placed in each box at the outer side of its central web. The parts HA are cover plates resting on the parts HA and directly supporting the wall A The lower end portions of the tubes 6 pass through box-like parts ha similar to .the parts HA, and .supporting cover plates ha which in turn, support the portion of the wall A above them. In this construction, however, the wall A extends but a short distance above the cover plates ha. Gas leakage through the joints between the elements E,

and heat radiation losses from the outer sides of the elements are prevented by a facing of refractory cement R plastered on the outer sides of the elements. The facing B may be made of the same material as the cement packing material 0 previously referred to.

vThe facing R extends as shown, between the 'elbow'portions of the tubes 6 at the top and ,to the material M, and maybe reinforced when necessary as by means of a reinforcing bar S suspended from one of the bars L and centered by metal parts S positioned in turn by bars S in the facing R. In the construction shown in Figs. 8 and 9, the material MA replaces one element E omitted because the header E is divided into sections as indicaated at FF" so that it would not be readily possible to make header connections to an element in front of the abutting ends of the two header sections.

. Figs. 10 and 11 illustrate another modification in which the portion of the furnace wall above the water back is supported by a structural beam GB through transverse beams H as in the construction first described, and in which as in Figs. '8 and 9,

there is no brick wall at the outer side of j the water back. In this construction the water 'backinstead of being suspended is supported by the engagement of the lower casing blocks E with the subjacent portion ,A of the masonry wall A and the ribs KA welded to the convex sides of the upper e1- bow portions of the tubes 6, are on the furnace side of, and project above the lower edge of the wall A With this construction the upper portions of the water back move relative to the wall A as the result of thermal expansion and contraction, and to I prevent gas leakage-through the spaces be the rear sides of the elements E, and a metal sheathing at the outer side of the elements.

In a co-pending application, Serial No. 111,945, filed of even date herewith, I have disclosed and claimed a furnace wall in which the wall cooling body portions of the conduits arecovered at their furnace chamber sides by refractory material supported and cooled by longitudinal ribs like the ribs Kherein described but prolonged to extend along the body portions of the tubes.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made inthe form of the apparatus disclosed without departing from the spirit of my invention as set forth in the appended claims and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

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

1. In a fluid cooled furnace chamber wall, the combination with conduit elements each comprising a metal tube having a wall lining body portion and a transverse wall penetrating end portion having an integral fin at its furnace chamber side, and refractory material in the spaces between the fins of adjacent elements.

2. In a fluid cooled furnace wall, the combination with conduit elements each comprising a tube having a wall lining body portion and an end portion, a metallic casing for said body portion and a metal fin secured to the furnace'chamber side of said end portion, and refractory material placed between and supported and cooled by the fin portions of adjacent elements. 1

3. In a fluid cooled furnace chamber wall, the combination with wall coolin metal conduits, of means for restricting t e heat absorption by portions of said conduits con 1- prisingl re ractory material, and metal fins secure chamber side thereof supporting and cooling said refractory material placed between said fins.

4. In a fluid cooled furnace chamber wall, the combination with wall cooling metal conduits each having a portion exposed for a portion of its length at the furnace chamber side, refractory material covering the furnace chamber side of another portion of each conduit, and a metal projection carried by each last mentioned conduit portion at the furnace chamber side supporting and cooling said refractory material.

5. In a fluid cooled furnace chamber wall, metal wall cooling conduits each exposed for a portion of its length at the furnace chamber side, refractory material covering another portion of each tube and a metal fin welded to the furnace chamber side of the last mentioned portion of each tube and support- .a metallic casing surrounding the body portion of said tube, and metal fins welded to.

and projecting radially away from the convex sides of said elbow portions.

8. In a fluid cooled furnace wall, conduit elements each comprising a bare tube having a straight body portion and transverse end portions adapted to project outward from the wall, and metal fins welded to the convex sides of said elbow portions.

9. In a fluid cooled Iurnace'wall, conduit elements each comprising a bare tube having a straight body portion and transverse end portions adapted to project outward from the wall, and metal fins welded to the convex sides of said elbow portions, and refractory material in the spaces between said fins and in contact with'said end portions.

-10. In a fluid cooled furnace wall, conduit elements each comprising a bare tube having a straight body portion and transverse end portions adapted to project. outward from the wall, and metal fins welded to the convex sides of said elbow portions, and refractory material in the spaces between said fins and to said conduit portions at the furnace in contact with said end portions, and reinforcing bars connecting said fins.

11. A fluid cooled furnace wall compris-' ing tubes having vertically disposed body portions united to form a furnace wall lining, and tran sverse wall penetrating end portions, and means for supporting said tubes adjacent their upper ends, said means comprising metal fins welded to the undersides of the upper transverse end portions.

12. In a fluid cooled furnace wall, the combination with conduit elements each comprising a metal tube having a wall lining body portion and a transverse wall penetrating end portion of radial fins of metal welded to the furnace chamber sides of said end portions, and refractory material in the spaces between said fins and in contact with said end portions.

13. A fluid cooled furnace wall comprising a tube having a straight body portion, and transversely extending portions united to the body portion by curved elbow portions, metallic casing blocks shrunk in place on the body portion of said tube, and metallic casings for said elbow portions castin place thereon.

14. In a fluid cooled furnace wall, conduit elements each comprising a bare tube having a straight body portion and transverse end portions adapted to project outward from the wall and connected to the body portion by curved elbow portions, metal casing sections snugly secured to the body portion of each element and uniting to provide a smooth heat absorbing wall lining, and metal casing sections for said elbow portions cast in place upon the latter.

15. In a furnace chamber wall, the combination witha lower wall portion, a water back lining said wall portion, and a wall portion overhanging said lining, said water back comprising tubes each having a vertically disposed body portion and an out-turned upper end portion, of a metallic casing for the body portion of each tube, a plate-like fin welded to each of said end portions and having its upper edge extending into contact with said overhanging wall portion and having its front edge substantially flush with the heat absorbing Wall formed by the furnace chamber sides of said casing sections.

16. In a furnace chamber wall, the combination with a lower wall portion, a water back lining said wall portion, and a wall portion overhanging said lining, said water back comprising tubes each having a vertically disposed body portion and out-turned upper end portion, of a metallic casing for the body portion of each tube, an apertured plate-like fin welded to eachof said end portions and having its upper edge extending into contact with said overhanging Wall portion and having its front edge substantially flush with the heat absorbing wall formed by the furnace chamber sides of said casing sections, re-inforcing bars received in the apertures in ad- 'acent fins, and refractory material molded mto place between said fins and about said A re-enforcing bars and in contact with said end portions and the upper ends of said casmgs.

17. In a furnace chamber wall having an upper portion and a lower portion overhung by said upper portion, spaced metal conduits having vertically disposed body portions inw front of said lower wall portion and trans-. verse portions at their upper ends penetrating said lower wall portion, metal casings surrounding said body portions, metal fins welded to the furnace chamber sides of said end 7 portions adjacent the upper ends of said cas-' ings and projecting upward into contact with the overhanging upper" wall portion, and refractory material located in thespaces between said fins at the furnace chamber side of the wall.

Signed at New York city, in the county of New York and State of New York, this 18th day of May, A. D. 1926. WALTER F. KEENAN, J R.

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