US1907940A - Boiler furnace - Google Patents

Description

May 9, 1933. s. w. ALLEN BOILER FURNACE Filed Oct. 8, 1950 16 .1. 132 .4. 0 12 .9 I 15 a2 ii Zg INVENTOR 1 W U1 A'ITORNEYS,

Patented May 9, 1933 UNITED STATES PATENT OFFICE s mmer w. ALLEN, ,or .waawrcx, mronn ISLAND, ASSIGNOR TO DRAKE NON:

CLINKERING FURNACE BLOGK COMPANY, 1110., ornnw YORK, N. Y., A coaroma;

TION OF NEW YORK BOILER FURNACE Lpjlieati on filed October 8, 1830. Serial No. 487,180.

This invention is a novel boiler furnace,

having especial reference'tothe water tube type of boiler having one or more baffles causing the products of combustion to travel successively through the passes of the boiler, and the furnace being fired in various ways for example by stoker or by the burning of injected or fluent fuel as a flame.

The general objects of the invention are to improve the operation and the efficiency of such a furnace and boiler and to reduce the maintenance cost thereof. A further object is to afford, in a practical manner, a bridge wall beneath the bafiie, which bridge Wall is water cooled, and to afford at the same time an effective slag screen between the combustion chamber and the boiler. Further and more specific objects and advantages of the invention will be pointed out in the hereinafter following description of an illustrative embodiment thereof or will be understood by those conversant with the subject.

To the attainment of such objects and advantages the invention consists in the novel boiler furnace and the novel features of operation, combination, arrangement and structure herein illustrated or described.

In the accompanying drawing Figure 1 is general side elevation of the elements of the boiler furnace of this invention, with the front wall, rear wall, bridge wall and baflles shown insection.

.Fig. 2 is a section taken on the inclined line 2--2 of Fig. 1 looking from the front and with certain parts broken away.

Fig. 3 is a vertical section taken on the line 33 of Fig. 2.

Fig. 4 is a view corresponding to a por- I tion of Fig. 1 but showing the combustion chamber fed with fuel by an injector or burner rather than by a stoker.

As will appear more in detail the present construct-ion comprises the water tube boiler with its higher header at what will be termed the front of the furnace and its lower header at the rear, with a baflie wall extending through the boiler, and a bridge wall below the baflle, the bridge wall comprising a system of ascending water tubes and means closing the spaces between the tubes, with downward tubes or connections bringing water to the lower ends of the bridge wall tubes and extension tubes connecting from the upper ends of the bridge wall tubes to the boiler.

The drawing indicates side walls 5, front wall 6 and rear wall 7 all supported on suitable foundations. As the indication is only illustrative, and to some extent diagrammatic, it'will be understood that the sizes, proportions and illustrated arrangements may be varied indefinitely in accordance with the type of boiler and furnace to which the invention is applied.

In Fig. 1 the invention is shown applied to a stoker fired furnace. Exterior to the front wall 6 is a coal hopper 8 and therebelow coal infeeding means conventionally indicated at 9. The grate 10 may be of the retort type into the retorts of which the coal is underfed. The fuel bed for example may buildup along the dotted line 11 and as the bed travels progressively toward the rear the burned out fuel is dumped intermittently orcontinuously by a dumping grate 12 into an ash pit 13.

Instead of the stoker and coal feeding arrangements as shown in Fig. 1, the furnace maybe fired by pulverized coal, or other fluent fuel, such as oil or gas; and in Fig. 4: the front wall 6 is shown as provided with a series of apertures, each containingv an inecting means or burner 10 by which the fluent fuel is injected into the combustion space to produce flames, in a well known manner, to traverse the combustion space find thence travel through the passes of the o1 er.

The boiler is composed mainly of inclined.

. ond bafile 21, so that the boiler is divided into three passes, the products finally traveling upwardly and to the usual stack.

The bridge wall 22 is arranged below the main baffle and is shown composed of water tubes 23 adapted to absorb radiant heat and effect evaporation, and wall closing elements 24, which may be continued upwardly to meet the lowerend of the baffle as continued downwardly at ,25 beyondthecombustion chamber, these extensions being led out from the ash pocket through openings in the. rear wall thereof and connected up -to-=a common header 26 located at an exterior point protected from the heat ofv the furnace and ash pocket. From the lower end ofthe boiler header 19, and therefore fed by downtakes 18,. is a system of. down takesv 27, conducting water to the header. 26 and thereby supplying water for circulation through the bridge wall tubes 23.:

An advantageous structure is 7 shown wherein the header 26 between;:the tubes,

and; tubes 27 is supported in a stirrup 28' which in turnis suspended by a resilient device 29 having means 30 for adjusting the height of the header. By this arrangement the bridge wall isin a substantially floating condition at its: lower end, expansion and contraction being allowed for by theadjust-ablerand resilient mounting-of the low.- er header. The curvatures ofthe tubes. 23 and 27 cooperate in this yielding action of the bridge wall.

Preferably 'all of the bridge wall tubes 23. deliver into anupper header 31, which is shown alsoin Figs. 2 and 3, and may beef. squareform. A system of shielding menr, hers. or blocks 32 is shown at the fire side of; the-header 31, protecting it from excessiye heat, andjthis shielding meansmay be composed of cast iron with or without refractory inserts, or any other material giving adequate protection to the header and the connection of the tubes therewith. From the upper bridge wallheader 31 is shown a series of tubes 33 and 34: extending at a forward and upward slant to the front of the boiler, for example to the lower end. of the front boiler header'15.

An advantageous construction is shown wherein the upper header 31 is solidly mounted andmay'beconsidered as a. support from whichthe bridge wall depends andiupon. which the baflie may to some extent .be supported. This construction. is

The

shown in Figs. 1 to 3 and involves at each end of the header 31 a saddle or support 35 solidly mounted within a recess 36 in the side wall 5. By this arrangement the entire bridge wall is substantially hung or suspended from its upper end; Itis supported firmly at the top end and hangs down preferably into the ash pit in the case of a stokerfurnace.

The contour of 'thefbridge wall. of

special'desi'gn. It: extends upwardly from the lower end and then slants or curves rearwardly at a decided incline from the center of. combustion. This permits the upper header 31 to be located at a point far removedfrom thecenter of combustion. Additionally this" header is protected by an interior shield. In effect the tubes 23, 33 and 3% pass to an exterior orprotected; point where'they are connected by the header.

Thelower header 26 islikewise protected atan exterior location; The bridge wall tubes extending up from: the lower header arespaced fairly closely asindicated in Fig. 2, whereas the downcomers 27 are preferably spaced at least twice as widely and indeed there may be few downcomers, across the width of the furnace, so long astheir total capacity will conduct all water required for circulation throughth'e tubes23;

[Thebridg'e wall tubes 23' are shown bare, but they may have Ia facing or covering so long asit'i's of'a high heat conductive character. It isintended that the bridge wall shall absorb large quantities of radiant heat, which is carried off by evaporation in the tubes 23, thus both increasing evaporation and protecting the wall.

The spaces between the tubes 23 are closed in any suitable manner, for example-by refractory or metallic closing, members either at the front,.or as shown at the rear, of the tubes. The manner of. the closure of the bridgewall is a detail and it may. be by fins or. extensions of the tube. v

Thetubes 33 and 34 extending from the upper header 31 to the'frontof the boiler,

or to the boiler header 15, are preferably separated orv spaced. into two rows, as well shown in Figs. 1. and 2., These tubes areshorter than thefull lengthboiler tubes and they extend across the topof the combustion.

space- They are spaced from each other twice as widely as the; spacing of theboiler tubes, as seen.in Fig. 2'. 'Fhis arrangement gives the effect? of a slag screenwith; tworows of; widely spaced-tubes. Such slag screen protects the boiler from. slaggin'g. The tubes receive radiant heat so that m'oliten ash particles: are cooled andsolidified before passing; into the-boiler. The two rows of tubes may; enter-the front. boiler header. at

two levels, but preferably they are bent near eachx'end, as shown, so'that'both rows-1 enter.

the header at the same level, just as they enter the header 31 at the same level.

The described structureis a combination which gives the advantages of a water cooled bridge and of a slag screen between the combustion space and boiler. These results are obtained in a simple and practical way. The invention is well adapted to be introduced upon existing boilers since the connections to both the front and rear headers of the boiler are allowed for merely by omitting the usual lowest row of boiler tubes.

It will thus be seen that a boiler furnace has been described attaining the objects of this invention. Since many matters of operation, combination, arrangement and structure may be variously modified without departing from the principles of the invention, it is not intended to limit the inven tion to such matters except to the extent set forth in the appended claims.

What is claimed is:

1. In a boiler furnace, a water tube boiler having a higher front and a lower rear header, front, side and bridge walls enclosing the combustion chamber below the front portion of the boiler, an ash pit below the rear portion of the combustion chamber, a baille wall extending through the boiler above the bridge wall, a system of water tubes comprised in the bridge wall, upper and lower headers therefor, extension tubes from the upper header to the front of the boiler, and downtakes from the rear of the boiler to the lower header; the bridge wall being supported from above and hangs ing into the ash pit, and the tubes of the bridge wall being continued through and from the ash pit to an exterior point whereat is said lower header.

2. In a boiler furnace, a water tube boiler having a higher front and a. lower rear header, front, side and bridge walls enclosing the combustion chamber below the front portion of the boiler, an ash pit below the rear portion of the combustion chamber, a bafiie wall extending through the boiler above the bridge wall, a system of water tubes comprised in the bridge wall, upper and lower headers therefor, extension tubes from the upper header to the front of the boiler, and downtakes from the rear of the boiler to the lower header; the bridge wall being supported from above and hanging into the ash pit, and the tubes of the bridge wall being continued through and from the ash pit to an exterior point whereat is said lower header, and means for yieldingly supporting the lower header.

3. In a boiler furnace, a water tube boiler having a higher front and a lower rear header, front, side and bridge walls enclosing the combustion chamber below the front portion of the boiler, the bridge wall continued into the boiler as a baflle, fixed walls enclosing an ash pit below the rear portion of the combustion chamber, a system of uptake water tubes comprised in the bridge wall, an upper header therefor and extension tubes from the upper header to the front of the boiler; the bridge wall being supported from above and hanging into the ash pit, and its water tubes being extended slidingly through the rear fixed wall of the ash pit for downward expansion thereof, and having an exterior lower header, and downtakes from the boiler to said lower header.

4. In a boiler furnace, a water tube boiler having a higher front and a lower rear header, front, side and bridge walls enclosing the combustion chamber below the front portion of the boiler, the bridge wall continued into the boiler as a baffle, fixed walls enclosing an ash pit below the rear portion of the combustion chamber, a stoker delivering to the ash pit, a system of uptake water tubes comprised in the bridge wall, an upper header therefor and extension tubes from the upper header to the front of the boiler; the bridge wall being supported from above and hanging into the ash pit, in overlapping relation to the fixed rear wall of the ash pit, and the bridge wall water tubes being continued below such overlap and extended slidingly through the rear fixed wall of the ash pit in a downward direction, for expansion thereof through such wall, and such tubes having an exterior lower header, and downtakes from the boiler to said lower header.

5. In a boiler furnace, a Water tube boiler having a higher front and a lower rear header, front, side and bridge walls enclosing the combustion chamber below the front portion of the boiler, an ash pit below the rear portion of the combustion chamber, a system of water tubes comprised in the bridge wall, extension tubes from the upper ends of said tubes to the boiler, means supporting the bridge wall and its tubes from above to hang into the ash pit, and the lower ends of the tubes being connected by a header adapted to descend with expansion, and vice versa, a resilient means yieldingly positioning such lower header, and a downtake from the boiler to said lower header.

In testimony whereof, this specification has been duly signed by:

STUART W. ALLEN.

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