US1997656A - Boiler construction - Google Patents

Description

. Filed May '7; 1932 Patented Apr. 16, 1935 UNITED STATES PATENT OFFICE Application May 7, 1

'7 Claims.

This invention relates to a boiler construction and has special reference to the formation of a combustion arch for a boiler construction.

More particularly this invention has reference 5 to a fire-brick tile so constructed as to form a combustion arch when a plurality thereof are arranged in order, each of the tiles comprising preferably a bodyv portion lying in a plane inclined with respect to an upper surface thereof.

Combustion arches have been employed in many boilers for the purpose of obtaining more complete combustion of the fuel and the volatile products of combustion thereof as a measure of economy and to prevent the issuance of an undue amount of smoke to pollute the air. A combustion arch is located substantially centrally of the masonry housing supporting the boiler and depends from the boiler in a spaced relation to the floor and to a bridge wall adjacent the fire box. Generally the volatile products of combustion circulate through the boiler construction by passing rearwardly from the fire box over the bridge wall and thence under the combustion arch and upwardly and forwardly through the ilues of the boiler to the stack.

In my copending application Serial Number 596,261, filed March 2, 1932, a combustion arch is shown which is constructed in a manner to retard the flow of the volatile products of combustion given off from the fuel and to provide in effect a trap therefor. By retarding these products, ample opportunity is afforded for the burning thereof in the fire box. The copending application shows a combustion arch built up of a plurality of the usual fire-brick courses having a facing of the usual nre-brick masonry to provide a pocket inclined in the direction of the bridge Wall.

vIn the usualvboiler constructions the combustion arches, when used, are built up in courses of the usual re brick although the inclined surfaces extend in a direction away from the bridge walls and fire boxes.

The present invention contemplates the provision of a combustion arch from a plurality of tile preformed to meet either of the above requirements. The tile may be formed of the usual rebrick ingredients with a. body portion inclined with respect to the upper surface thereof. Tongues and grooves are preferably provided on opposite sides thereof for assisting in locking adjacent blocks together, the sides converging when a continuous arcuate top surface is desired across a course of tile.

It may be readily seen that the tile may ac- 932, Serial N0. 609,856

comxnodate a condition wherein the arch extends in a direction toward the fire box and, by reversing the tile, may also accommodate a condition wherein the arch extends in a direction away from the fire box. The tiles being preformed in the manner above described permit of a very simple and inexpensive installation thereof in a boiler construction.

One of the objects of this invention is to provide a combustion arch which is comparatively inexpensive to install.

Another object of this invention is to provide a combustion arch which is simple and durable.

A further object of this invention is to provide a tile for use in the formation of a combustion arch having a face surface inclined with respect to an upper substantially nat surface.

Other objects and advantages will hereinafter be more fully pointed out and for a more cornplete understanding of the characteristic features of this invention reference may be had to the following description when read together with the accompanying drawing, in which latter:

Figure 1 is a central vertical longitudinal sectional view showing a boiler construction incorporating the features of this invention;

Fig. 2 is an enlarged transverse sectional View taken on the line 2-2 of Fig. 1;

Fig. 3 is a perspective view of a side skew or one of the end tile members incorporated in the above construction; and

Fig. 4 is a perspective View of one of the intermediate tile members.

Referring now more particularly to the drawing, the construction therein shown comprises a housing formed preferably of masonry of the usual type for supporting a steam boiler II),4 the forward end of the boiler resting on the front end of the housing and the rear end being supported by a central post IIla of a comparatively small diameter to not materially interfere with the flow of gases through the combustion charnber. The front end II of the housing has the usual fire box opening I2 and the ash pit opening I3 for permitting access, respectively, to the fire box and ash pit.

A bridge wall I4, preferably of the same material as that of the housing, is disposed within the housing and extends preferably upwardly from the base thereof to a spaced distance from the boiler Ill for subdividing the housing into a fire box portion I5 and a combustion chamber I6, the fire box and combustion chamber having communication therebetween by reason of the spaced relation between the top of the bridge wall and the lower periphery of the boiler.

A combustion arch I'I is disposed in the combustion chamber adjacent the lower periphery of the boiler and extends downwardly therefrom to terminate in a spaced relation with the floor of the housing. The combustion arch of the form illustrated particularly in the drawing is so designed as to provide a pocket for trapping a portion of the volatile products of combustion given off from the fuel in the nre box and for retarding the flow of such products in the circulation thereof from the fuel box to the combustion chamber.

The volatile products of combustion are preferably circulated through the housing from the re box over the top of the bridge wall I4 and under the combustion arch Il to the rear of the combustion chamber, whereafter they are directed upwardly by reason of their striking the end wall I8 of the housing to be directed through the iues of the boiler I0 to the stack I9. In this manner of circulation an effective transfer of heat is obtained to the water in the boiler. Unburned volatile products of combustion are insured ample opportunity to be burned, the passage of the products of combustion being somewhat retarded in their flow by the peculiar shape given to the combustion arch. In order to prevent any undue pressure being built up in the pocket formed by the arch, suitable vents 20 are provided adjacent the upper end thereof to permit of the escape of some of the products therethrough.

In order to assist in effecting a complete combustion within the boiler construction, incendiary means may be provided at one or more points in the housing for burning the unburned products of combustion during the circulation thereof. A plurality of nozzles 2I may be provided in the front end II of the housing for blowing a combustible steam mixture downwardly acrosss the flre box above the fuel therein in the direction of the bridge wall. 'I'he nozzle is connected by a suitable conduit to a source of supply of steam and fuel. As an auxiliary incendiary means, a plurality of nozzles 22 may be disposed in the housing for burning the volatile products of combustion in the combustion chamber and, as shown in the drawing, such a nozzle or nozzles are provided in the rear wall Il of the housing.

The nozzles 2 I and 22 are connected to a pipe line 23 for connection with a source of steam supply, preferably from the boiler I0 if it should happen to be a high preure boiler, or for connection with coils which are given to that specinc purpose coming into contact with the heat from the fire box. Some of the steam from the source of supply is by-passed into a tank containing a combustible compound, and by reason of the compression thus produced in the tank, some of the combustible mixture is forced back into the main supply line to become vaporized with the steam and emitted from the nozzles 2| and 22. Further, the pipe line 23 is enclosed by a conduit for directing pre-heated air to the nozzle from a point remote from the boiler. All of this latter construction is shown and described more particularly in my copending application above noted.

The combustion arch of the present invention contemplates the formation thereof from a plurality of tiles 25 preferably formed of the same ingredients as the usual fire-brick and arranged in a single course, each of the tiles having preferably a flat upper surface 2B for supporting the ordinary fire-brick 21. The front face 28 of the tile is inclined over a substantial distance thereof relatively to the flat upper surface thereof and, as shown in full lines in Fig. 1 of the drawing, the inclination extends in a direction toward the bridge wall I4. The rear surface 29 of the tile 25 is likewise preferably formed at an inclination and extends preferably parallel with the front surface 28.

A lower projecting portion 30 is preferably formed at the bottom of the inclination so as to permit of its being rested readily on a temporary support (not shown) which latter is removed after the arch is assembled. Also a ledge 3| is formed in the rear portion of the tile for the purpose of permitting the upper portion of the tile to rest on a temporary support during the installation of the arch, which support is also removed after the tiles are set. However, the formation of a projecting lug 30 and a ledge 3i are not necessary to the essential working of the construction, but are desirable when the tiles are assembled in the boiler construction.

The side edges of the tile preferably converge in order that the upper surfaces 26 thereof form a continuous arc. This construction is preferable for strength, although it is to be understood that the arch may be formed straight by the provision of substantially parallel sides, and whether straight or converged edges are employed it is preferable to provide an interlocking means in the form of ridges 32 on one edge and depressions 33 on the other edge for interlocking adjacent tiles when assembled. A suitable binder may be employed between the tiles although it is not deemed essential. Of course, the construction may be modified, if desired, by the provision of a. ridge and a groove on each side or by variations thereof.

For convenience in handling, a separate tile section or so-called side skew 34 is shown that may be set in the wall of the housing, the tile conforming more or less to the shape of the edge of the intermediate tile members, although having a square end portion for fitting vertically and horizontally in the wall of the housing in order to avoid fitting of portions of bricks in the housing wall. One of the side skews 34 is illustrated very clearly in Fig. 3 of the drawing and it is believed needs no further description, it being provided with either ridges or grooves to fit the adjacent intermediate tiles for the end support thereof.

The fire-brick 21 disposed above the combustion arch 25 are set in the usual manner by providing courses of the ordinary fire-brick to meet the lower periphery of the boiler I0.

In lieu of the inclined surface 28 extending in the direction of the bridge Wall I4, the same may be reversed and extended in a direction away from the bridge wall, since, in some instances, it is desirable to form a combustion arch of this character. Such a construction is shown in dotted lines in Fig. l oi' the drawing, the tiles being merely reversed in position.

As a result of this invention, the fabrication of the combustion arch is very much simplified and materially reduced in cost of materials and in cost of labor in that but a single course of fire brick tile may be employed to effect an inclined arch, whereas, in previous constructions, so far as applicant is aware, the inclination is had by the building up of courses of bricks at the desired inclination at a substantial increase in cost of labor and material.

While but a single embodiment of this invention is herein shown and described, it is to be understood that various modications thereof will be apparent to those skilled in the art without departing from the spirit and scope of this invention and, therefore, the same is to be limited only to the scope of the prior art and the appended claims.

I claim:

1. The combination with a boiler construction comprising a housing having a ilre box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles arranged in a single course, each of said tiles having an inclined surface extending in the direction of said fire box.

2. 'I'he combination with a boiler construction comprising a housing having a re box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles set side by side, the front faces of each of said tiles being inclined toward said fire box.

3. The combination with a boiler construction comprising a housing having a fire box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles set side by side, one side of each of said tiles having projecting portions fory engaging recessed portions on the other side of adjacent tiles, the front faces of each of said tiles being inclined in a direction toward said fire box.

4. The combination with a boiler construction comprising a housing having a re box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles set side by side in a single course, each of said tiles having a flat upper surface for supporting firebrick and a face surface inclined with respect to said upper surface.

5. The combination with a boiler construction comprising a housing having a fire box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles set side by side in a single course, each of said tiles having a flat upper surface for supporting rebrick and front and rear surfaces inclined With respect to said upper surface.

6. The combination with a boiler construction comprising a housing having a fire box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles set side by side in a single course, each of said tiles having a flat upper surface for supporting rebrick and a front face inclined in a direction toward said fire box.

7. The combination with a boiler construction comprising a housing having a nre box and a combustion chamber, of an arch in said combustion chamber formed of a plurality of tiles having front faces inclined in the direction of said fire box.

FREDERICK H. SCHALK.

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