US2248890A - Boiler - Google Patents

Description

T. E. MURRAY July 8, 1941.

BOILER Filed May 20, 1927 1N VENfo/e.

PatentedJuly 8,1941

, iJNi'niD Asm'rlazs 4 PATENT oFFIcE l Thomas E. Murray, Brooklyn. N. Y.; Joseph Brad- I ley Murray, Thomas E. Murray, Jr., and John F. Murray. executors of said Thomas E. Mur- Tay deceased signora to Metropolitan Enrineering Company, a corporation of New York Application my zo, 1921. serial No. 192,836

` i claims. (ci. 122-235) ,f

In certain previous applications Nos. 177,533 and 177,534 dated March 23, 1927, I have described certain boiler constructions involving a wall or a lining of water tubes exposed'to the direct radiant heat ofthe fire in the furnace tion of this ash is irregular and not dependable.

The present invention provides means for holding the ash on the exposed surfaces and maintaining it reasonably well distributed over such The accompanying drawings illustrate an embodiment of the invention- Fig. 1 is a perspective view of -a pair of tubes;

Fig. 2 is a plan of the same;

Fig. 3 is a horizontal section of the combustion chamber of a boiler;

Fig. 4 is a vertical sectional view ,of the same', ontheline4-4ofF-ig3. l f Fig. 1 shows the surface which is exposed to the heat and on which the ash ,deposit is to be caught and retained. Each of the tubes I is provided with lateral flanges 2 extending in the direction of the length of the wall and preferably located in the spaces between the tubes and constituting additional heating surfaces for securing rapid generation of steam. It is desired to secure the ash on the surfaces of the tubes, the :Ilns and any similar parts which may be exposed. For this Purpose I propose to provide projections on the exposed surfaces.

In the case illustrated such projections are secured by means of lwires 3 lying against the of the upper end short period of use will be that o-f a red hot or white hot refractory surface.

Fig. 3 shows a combustion chamber enclosed on its four sides by walls of tubes I of the type shown in detail in Figs. 1 and 2. At intervals in the length of the end walls, there are nozzle burners B which project into the combustion chamber a' mixture of air and powdered coal. Such burners will be varied in number Iand location according to the particular capacity and design of boiler.

It ls with such, nozzle burners that the present invention is particularly useful. They project a flame of extremely high temperature against the tubular water walls so that the protection of the ash is particularly important; and at the same time they project the verynne ash also against the tubular water walls and thus in a very short period build up the desired protective coating. As soon as the deposit of ash has accumulated, it presents the appearance of a white hot wall of refractory material which serves to aid in the rapid combustion of the fuel which is supplied in large volume by the burners. At the same time, it shields the tubes and iins from excessive temperature and rapid burning out. The ash will .de-

y posit only on a comparatively cool surface and surfaces to be protected and extending sinuously in the vertical direction. They may be fastened by welding at the points where the wire bends such a's 4 and 5. Ihe deposit of ash. is loose and can be largely removed by shaking or brushing.

and where the surfaces are smooth there is no certainty that the ash will be retained. But by I providing a certain degree of roughness over the will build up only to a thickness balanced by the cooling effect of the circulating water and the heating eect of the name.

Fig. iillustrates one of the tubes I between upper and lower headers -'I and -8. The upper horizontal header 'I communicates at intervals with vertical headers 9 at the upper ends `of the inclined tubes I0 which extend across above the combustion chamber.

The construction above described is' covered in my previous application No. 642,725, filed June 1, 1923, now Reissue No. 18,748, and is described here merely by way of fuller illustration of the present invention.

Various other ways may be adopted of securing the desired projections.' such as the application of wire mesh and various other forms ofprojection or by suitably roughenlng the surfaces oi' the tubes and the iins themselves.

The invention is applicable not only to water tubes such as are illustrated, but to various other parts of a boiler which are subject to exposure to excessive heat such for example as steam drums, headers, etc.

Various other modliications may be made by those sinned in the sit without departing from 1. A boiler having a wall of water tubes spaced apart and having heat conducting extensions from said tubes into the spaces between said tubes to form a substantially continuous wall and heat conducting elements to retain heat refractory material comprising rod-like elements secured to said tubes by weldingland each said rod-like element extending transversely of the length of said tube and close to the surface-thereof.

2. A boiler having a wall ofwater tubes spaced apart and having heat conducting extensions from said tubes into the spaces between said tubes to form a. substantially continuous wall and heat conducting elements to retain refractory material on said surface comprising rod-like elements secured on the face'v of 'said individual tubes each said rod-like element extending at angles transverse to the length of said tube and in close proximity to the surface thereof.

3. A boiler having a wall of water tubes spaced apart and having heat conducting extensions from said tubes into the spaces between said tubes to form a substantially continuous'wall of independent tubes each said tube having an individual means on its face to retain refractory material and comprising a vertical sinuous rod welded to said tube and said extensions and lying flat against the surfaces of said tube and extensions.

4. A boiler having a wall of water tubes spaced apart and having heat conducting extensions from said tubes into the spaces between said tubes to form a substantially continuous wall of independent tubes and meanson a face of said tubes to retain heat refractory material each comprising a vertical sinuous rodsecured to said tubes l and to said extensions and lying fiat against the surfaces of said tubes and extensions.

5. The boiler of claimA 3 in which said sinuous rods are welded to said tube and extensions at the bends of said rod.

6. A heat transfer element for boilers and the like which comprises a tubular element having sidewise heat conducting extensions and rod-like elements welded to the surface of said tu-be and extensions and each said rod-like element extending transversely to the length of said tube.

7. A heat transfer element for boilers and the like which comprises a tubular element having sidewise heat conducting extensions and a sinuous rod extending longitudinallyl and flatly against said tube and extensions to provide transversely extending rod-like elements on the face of said tube. l

. THOMAS E. MURRAY.

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