US1762335A - Boiler furnace - Google Patents

Description

June 10, 1930. G, p JACKSON 1,762,335

BOILER FURNACE Filed Nov. 6. 1925 Patented June 10, 1930 PATENT OFFICE GEORGE P. JACKSON,

OF FLUSHING, NEW YORK, ASSIGNOR T0 INTERNATIONAL COM'.-

BUSTION ENGINEERING CORPORATION, OF NEW YORK, N. Y., A CORPORATION 0F DELAWARE IBOILER FURNAOE My invention relates to boiler-furnaces, and is particularly useful in the burning of pulverized fuel. Primarily it contemplates an arrangement of parts whereby 1t 1s possible to use pulverized fuel where heretofore it has not been possible.

Another object of the invention is to make it practically feasible to burn pulverized coal in a boiler setting with horizontal ad-Y mission of the fuel.

A further object of the invention is the provision of a novel arrangement of furnace and boiler construction having a very large proportion of the area of the evaporating surfaces exposed to radiant heat, with, at the same time, a comparatively short travel of the fuel and iiame stream.

Still another object of the invention is the provision of novel means for supplying highly preheated air to hasten ignition and support rapid combustion of the fuel.

How I obtain these advantages, and others which will occur to those skilled in the art, will clearly appear hereinafter and by reference to the accompanying drawings. Figure 1 is a vertical longitudinal section of a boiler-furnace embodying my improvements, certain of the associated parts being illustrated somewhat diagrammatically. Figure 2 is a fragmentary vertical cross section taken on the line 2--2 of Figure 1. The combustion chamber, designated by the reference character L, is substantially of L shape, and the fuel is admitted thereto substantially horizontally in the horizontal leg of the l. through rthe burner nozzle or nozzles 2, to which it is fed from the bin or hopper H, by the usual aerating feeder (shown diagrammatically at 3) and the conduit 4.

The front or upper, and back or lower, sides of the L-shaped combustion space are dened by rows of upcomer tubes 5 and 6 connected into the circulation of the boiler unit B, the tubes 5 being connected to the 'pass employed, as this section of 6, 1925. Serial No. 67,384.

drum 7 and the tubes 6 extending into and discharging near the top of drum 8, At their lower ends the tubes 5 are connected to a transverse header 9 and the tubes 6 to a similar header 10, the two headers being connected by suitable pipes 11. At each end of the header 10 is connected a large downcomer tube 12, these tubes being located outside the furnace walls and connected at their upper ends to the lower part of the drum 8. The tubes 5 and 6 are spaced laterally, and carry, at their adjacent sides,

ns 13 and 14 of the proper width to close the gaps between tubes. Along the lower portions of the tubes 5 and 6 however, the fins 13 and 14 are broken away 'at inter-v vals to leave air inlets or passages 15 and 16 between the tubes. The tubes 17, of the boiler unit B, may also be equipped with ins,

these fins 18 closing the gaps between tubes for a portion of the length of the tubes to provide baies around which the gases* of combustion must pass. However, these fins may be dispensed with entirely and a single the boiler is largely of the convection type, tions, with the exception of the lowermost row of tubes, somewhat after the nature of an economizer.

Located rearwardly of the boiler is an airpreheater P, through which the gases, while still at a high temperature, must pass on their way to the offtake 19 leading to'the usual stack (not shownb 'Air' for combustion, forced through the preheater by the fan F, is delivered through the conduits 2O and21 to the upper and lower air-spaces or and funcchambers 22 and 23, from which it enters the furnace chamber L through the passages 15, 16. The space 23 is of suticient vertical depth to permit of the accumulation of the solid refuse products of combustion on the floor 24, and in the front wall there is provided a convenient cleanout door 25 for such refuse. As some of the ash, however, will settle u on the tubes 6 and on the sections of the 14 between the openings or inlets 16, it will be necessary from time to time to clean od such ash deposit, and for this purpose there is provided a door 26 through which a steam or air lance may be directed to dislodge the deposit and precipitate it, through the openings 16, to thelloor 24.

In operation this boiler furnace is characterized by a short, hot flame, and by the exposure to its radiant heat of a large area of the evaporating surfaces. This arrangement produces enou h steam in the tubes 5 and 6 to permit o the employment of a relatively small boiler proper, the setting here shown utilizing only a single boiler unit B, the .tubes of which are very short, and few in number. ln consequence of the combination of violent combustion, short travel of the fuel and flame stream, and small size of the boiler proper, the waste gases pass to the air heater P at an unusually high temperature. The result is a very great degree of preheat. This highly preheated air, forced through the conduits 20 and 21 by the fan F, discharges from above and below the horizontal leg of the L-shaped fuel and llame stream through the ports or openingsl 15, 16, violently agitating the incoming stream of fuel and air as it enters the furnace, and initiating and supporting a very hot flame by reason of such agitation and consequent commingling of the fuel -with thehhighly heated air.

By virtue of the fact that there is so much evaporating surface subject to radiant heat, heat is transmitted to the boiler at avery high rate and consequently, as before mentioned, for the same steaming capacity a very small boiler can be emloyed as compared to standard practice.

ecause of the turbulence of combustion and the short flame obtained, and since the rear wall and the arch are protected by the tubes 6 and 5, horizontal firing of the Vfuel may be employed, with, the fuel admitted well down toward the lower portion ofthe chamber. I am enabled to lower the arch 27 from a point usually near'the level of the upper boiler down to a point more than halfway down if desired. Thus it is possible to locate the bin H, of the indirect liring system employed, immediately above the arch and in front of the setting. F rom the standpoint both of horizontal area covered and vertical height required the whole installation is very compact and may be housed in a relatively small building, whereby the initial plant investment 1s greatly reduced.

I claim 1. A boiler-furnace for burning pulverized fuel comprising, in combination, an L-shaped combustion chamber having a relatively `horizontally shallow upright leg and evaporating tubesmarginal of the combustion spacev comprehended by the legs, an oftake at the upper portion of the combustion chamber for the products of combustion, a relatively short single bank of boiler tubes extending across said oEtake, and means for admitting fuel horizontally into the lower portion -of the combustion space to be burned in space therein.

2. A boiler-furnace for burning pulverized fuel comprising, in combination, an

L-shaped combustion chamber having a relatively horizontally shallow upright leg and evaporating tubes marginal of the combustion space comprehended by the legs, anv odtake at the upper portion of the combustion chamber for the products of combustion, av relatively short single bank of boiler tubes extending across said oi'take, interrupted longitudinal fins on tubes of said evaporating tubes providing openings for the admission of air into the lower part of said combustion chamber, and means for admitting fuel horizontally into the lower portion of the combustion space to be burned in space therein.

3. A boiler-furnace for burning pulverized fuel comprising, in combination, an yl.sh'aped combustion chamber having a relatively horizontally shallow upright leg, an odtake at the top for the gaseous products of combustion, a relatively short single bank of boiler tubes extending across said offtake, evaporating tubes marginally defining the front and rear of the upright portion of said combustion chamber and the top and bottom of the lower portion of said chamber, longitudinal fins on said tubes, said fins bein interrupted at intervals along those portions of the tubes which define said top and bottom to form openings for the admission of combustion air, and means for admitting fuel horizontally into the lower portion of the combustion space to be burned in space therein.

4. A boiler-furnace for burning pulver- .ized fuel, comprising, in combination, an L- shaped combustion chamber having a relatively horizontally yshallow upright leg, an oiftake at the top for the gaseous products of combustion, a relatively short single bank of boiler tubes extending across said olftake, evaporating tubes marginally defining the front and rear of the upri ht portion of said combustion chamber van the top and bottom` of the lower portion of said Achamber, longitudinal fins on said tubes, said fins bein interrupted at intervals along those portlons of the ,tubes which define said top and bottom to form openings for the admission of combustion air, refractory sheathing .providin an air chamber above the evaporating tu es which define the top of the lower portion of the combustion chamber and an air chamber below the evaporating tubes which dene the bottom of the lower portion -top of the chamber and two rows of L- shaped tubes connected into the circulation defining with the refractory side walls of the chamber an L-shaped combustion space, and air chamber below the horizontal leg of the combustion space, means for admitting preheated air into said air chamber, sai air being admitted to the combustion space between the L-shaped tubes, and means for admitting fuel at the foot of the combustion space.

1 6. A combustion chamber having spaced substantially horizontal tubesextending in the` lower portion and above the bottom thereof, horizontally extending ns on said tubes; the tubes being so spaced and the Ems being of such size that the fins of adjacent tubes substantially abut, said fins 'being interrupted to provide openings for the admission of combustion air between the tubes, and means for admitting fuel to be burned in space.

7. A combustion chamber having spacedy substantially horizontaltubes extending in the lower portion and above the bottom theerof, horizontally -eXtendin fins on said tubes, the tubes being so space and the fins being of such size that the fins of adjacent tubes substantially abut, said fins being interrupted to provide openings for the admission of air between the tubes, means for admitting preheated combustion air below the tubes and means for admitting pulverized f uel to be burned in space.

8. A boiler-furnace for burning pulverized fuel, comprising, in combination, an L- shaped combustion chamber, an oii'take in the upper part thereof for -the gaseous products of combustion, evaporating tubes marginally dening the top and bottom `of the horizontal leg of the combustion cham- `ber, said tubes being spaced 4apart for the .admission of combustion air, means providling anl air chamber above the evaporating tubes which define the-top of said leg, and an air chamber xbelow the evaporating tubes which define the bottom of said leg, means for admitting air lto said chambers, and means for admittingfuel horizontally into said leg to be burned' in space inthe combustion chamber.

9. A boiler-furnace for burning pulvervized fuel, comprising, in combination, a conibustion chamber having an arch-portion and an oiftake in the upper part thereof,

evaporating tubes at the arch, portion arranged and spaced therefrom to provide an air chamber, said tubes being spaced apart for the admission of combustion air, means for admitting air ,to said chamber, and

means for admitting pulverized fuel into.

the combustion chamber below the arch.

In testimony whereof, 1 have hereunto signed my name.

GEORGE P. JACKSON.

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