US2287961A - Separately fired superheater arrangement - Google Patents

Description

June 1942- J. A. BARNES. 2,287,961 SEPARATELY FIRED SUPERBEATER ARRANGEMENT Filed Nov. 1, 1959 Patented June 30, 1942 &

SEPARATELY FIRED SUPERHEATER ARRANGEMENT John A. Barnes, Chappaqua, N. Y., assignor to The superheater Company, New York, N. Y.

Application November 1, 1939, Serial No. 302,326

1 Claim.

The present invention relates to improvements in boilers equipped with superheaters and particularly to an improved method and means for regulating the final temperature of superheated steam.

The invention is embodied in a boiler having two sets of fuel feeding burners to be employed in regulating the final temperature of superheated steam as set forth in the following detailed description of an illustrative embodiment of the invention as shown in the accompanying drawing in which;

Fig. 1 is a diagrammatic elevational View, partly in section, of a boiler embodying the present invention; and

Fig. 2 is a sectional view on the line 2-2 of Fig. 1.

The boiler shown in the drawing has a steam and water drum I!) connected to a water drum therebelow by a substantially vertical bank [2 of generating tubes.- The furnace space at the side of the bank opposite the boiler offtake H3 is divided to form a superheater furnace chamber 14 and a boiler furnace chamber l5 provided with individual fuel feeding means l6, l7, respectively. This division is effected by several rows of tubes l8 connected at their lower ends to a header l9 spaced laterally from the drum II and having substantially vertical por tions extending transversely of the furnace space to form the chambers l4 and I5, the upper portions of the tubes extending parallel to the roof of the furnace and being connected at their upper ends to the steam and water drum I0. Baiile means are provided to prevent the flow of gases from boiler furnace chamber l5 into superheater chamber I4, for example, as by arranging a row of tubes 20 connected to drum I and header I9 so that portions of adjacent tubes are in contact from the header to a point near the drum H! where they are fanned out to permit the gases to flow from chamber to the upper portion of bank l2.

A superheater 2| is associated with bank l2 and is shielded from furnace chamber l5 by several rows of tubes 22; these may be considered part of the bank I2 but arranged in spaced relat-ion to the row 23 thereof. The bafile tubes 20 are also spaced from the rows of tubes l8 to provide a space in which a second superheater 24 is mounted. superheater 2| receives steam from the drum Ill and is connected by pipe 25 to the inlet of superheater 24. Valves 26 and 21 may be provided so that steam may be taken either solely from superheater 2| or from both superheaters.

The superheater 2| preferably has a greater superheating effect than superheater 24, for example by providing it with a greater amount of surface. There may also be a greater amount of generating surface between superheater 24 and furnace l4 than between furnace I5 and superheater 2|.

With the arrangement described above the greater part of the superheating effect is obtained in the superheater 2|. In the operation, the greater part of the total amount of fuel re-.- quired to maintain a determined load is burned in the boiler furnace l5 and the greater part of the superheating effect is obtained by gases passing therefrom over the superheater 2|. The remainder of the fuel needed to generate the amount of steam required and to raise the steam to a final desired temperature, or, in other words, to complete the superheating is burned in the furnace l4. If the superheat temperature exceeds the desired amount the proportionate amount of fuel burned in furnace I5 is decreased while that burned in furnace I4 is increased. The reverse procedure is followed. if the temperature of superheater steam falls below the desired point. It will be seen that when the proportionate amounts of fuel burned in furnaces l4 and I5 are varied in this way to maintain a predeterminedsuperheater temperature at a determined load, the superheating effect is varied because additional fuel burned in furnace l4 does not offset the reduction in superheating effect of gases from furnace l5 since the superheater 2| has the greater superheating effect and the increased amount of gases passing over the smaller superheater 24 does not result in an increase in the final steam temperature.

What I claim is:

In a boiler having upper and lower drums interconnected by a bank of generating tubes,-

means defining a furnace space at one side of said bank, other generating tubes having substantially vertical portions arranged in a row extending transversely of said space for dividing it into a boiler furnace chamber and an auxiliary furnace chamber, individual fuel feeding means for said chambers, and a superheater positioned to be heated by fuel burned in said auxiliary furnace chamber; a convection superheater having tubular elements located in the lower part of said bank and spaced from said upper drum; and bafile means on said tubes extending upwardly from the bottom of said furnace space to a point above said superheater and adjacent said drum for precluding the flow of gases from said auxiliary furnace chamber over said convection superheater and directing gases from said auxiliary furnace chamber into the part of said generating bank above said convection superheater.

JOHN A. BARNES.

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