US1812966A - Coal dust furnace for high pressure boilers - Google Patents

Description

5 zfe oan We)" IN TDIT Filed Sept. 20, 1928 S LGFFLER COAL DUST FURNACE FOR HIGH PRESSURE BOILERS July 7, 1931.

1 Fig.1. The furnace gases-can,

' .45 horizontal or transverse tu Patented July 7, 1931 PATENT OFFICE s'rnzrmn 1611mm, OI. f-dnannor'rnmmno, NEAR BERLIN, GERMANY; JENNY EL- rnmnn Lori-LE2. sonn nm AND OF SAID STEPEAN IJi FFLEB, DECEASED GOAL DUST FURNACEFOR HIGH PRESSURE BOILERS Application filed September 20, 1928, Serial No. 307,289,, and in Germany September 26, 1927.

This invention relates to a coal dust furnace intended for use in connection with h1ghpressure boilers, especially such as shown and described in my U. S. A.- application Serial Number 701,855, filed March 25, 1924.

The chief characteristic feature of the present improved furnace resides therein that there are arranged in the furnace U-shaped superheating tubes branching oft from upper collecting tubes and forming with their vertical legs bounding walls for'and in the furnace space, the horizontal or transverse legs extending in several heights and affording free passages for the furnace gases on their way to flue or flues provided in the boiler.

The invention is illustrated diagrammatically and by way of example on the accompanying drawin s on which Figure 1 is a vertical section t rough a coal dust furnace designed according to this invention, and Figure 2 shows a detail, all as fully described hereinafter.

On the drawings, 1' (Fig; 1) denotes the 26 furnace space, and 2 are U- aped superheat- ..ing tubes arranged therein. The tubes 2 are branching off from upper collecting tubes 3 and 4, and their vertical legs are soarranged with respect to one another that they form a bounding wall or parts of such wall. That is to say: either said vertical tube legs zhemselves, i.e. solely these tube legs, for1 1 said wall, in that they are arranged 'sufiiciently closely to one another, or the said legs are provided with lateral ledgesj5 (Fig. 2), or'

instead of these ledgis br cks of refractory clay are arranged tween the said legs. These latter extend in any case down to about the depthar-a, below which the hori- 0 zontal or transverse connecting arts of thesuperheating legs 2 are locate in several 'helghts or depths, for instance in three, as in therefore,

aps between these ortions to the lines which form parts of t e furnace, as

shown.

There are two furnace-forming flues 15 and 16 in the example shown, and coiled pipes 6 D0 and 7 are arranged in these flues, of which "pass through the spaces or the flue 15 contains an aftersuperheater 6 and a feed-water heater 7, and the flue 16 contains a feed-water heater 7 which is connected up in series with the feed-water heater 7, as shown; the flue 16 contains, besides, an air preheater 12. The steam to be superheated is produced in the drum-shaped boiler 8 and conveyed to the superheatingtubes '2 by means of pipes 17 and 18, and by a pump 9 inserted between these pipes, as shown. There may be individual tubes 2 connected up in parallel, as in the drawing, but the tubes may be combined to a plurality of nests which in turn may be connected up also in parallel or in series or partly in parallel and partly in series, as most suited in the given case. The superheated steam flows through the pipes 4 andlO to the after-superheater 6 and finally through the pipe 11 to and into the boiler 8, as well as to a pipe D through which a part of the superheated steam is conducted to an engine, whereas the other part is used for the generation of live steam in the boiler 8.

The feed water is supplied at b and passes through the feed-water heaters 7' and 7 in the direction indicated by the arrows. The heated water then flows through the pipe 19 to and into the boiler 8, in which it is converted into steam bya part of the super-v heated steam arriving through the pipe 11, as already mentioned.

I- wish it to be understoodthat the feedwater heating coil 7 may be dispensed with, in which case the feed-water heating coil 7 is, however, correspondingly longer or larger. In either case an air heater 12 is preferably arranged in the flue 16, and the air which is supplied to this heater at A is used for operating the dust coal burner 13 which is connected at 14 by means of a pipe 20'(indicated only by dotted lines) with the air-heater 12, and receives'the dust coal through the pipe 1 21. 22 denotes the-waste gas flue.

-I claim: 1

1. A dust coal furnace of the Loflier type, comprising, in combination with the furnace parts forming the combustion space, and with the means for introducing the dust coal into said space, downwardly extending U- shaped superheating pipes arranged in said space and forming'with one half of their legs a bounding wall between the said space and a neighboring space in said furnace, the

5 transverse pipe parts connecting said wallforming regs with the opposite other legs being arranged in different heights so as to form passages between them, substantially and for the purpose set forth.

2. A dust-coal furnace, comprising, in combination, with the means for introducing the dust-coal into the combustion space, downwardly extending U-shaped super-heating pipes forming said space, the transverse pipe parts connecting one set of the legs of said pipes with-the opposite set thereof bein arranged in different heights so as to 1 orm passages between them, said transverse pipe "parts being freely arranged in the combus- 0 tion chamber to accommodate free expansion and contraction of the legs of th pipes.

' 3. A dust-coal furnace, comprising, in combination, with means for introducing the coal-dust into the combustion chamber, down- 5 wardly extending U-shaped super-heating pipes forming said space, each U-shaped pipe including opposed leg parts and a connecting part for'iningthe sole connection between the leg parts, said connecting parts being arranged at different heights to form passages I therebetween and being freely arranged in the combustion chamber to accommodate free expansion and contraction of the leg parts of the pipes.

In testimony whereof I aflix my signature.

ISTEPHAN LOFFLER.

Images