US2126260A - Superheater boiler - Google Patents

Description

Aug. 9, "mm. 7 G. P. JACKSON" 2,325,26Q

SUPERHEATER BOILER! Filed Nov. 20, 1935 INVENTOR G'fO/PGE E JAG/(SON ATTORNEY Patented Aug. 9, 1938 lE s Tar zsztzet SUPERHEATER BOILER George P. Jackson, Flushing, N. Y assignor to Combustion Engineering Company, Inc., New

York, N. Y.

Application November 20, 1935, Serial No. 50,642 In Great Britain December 10, 1934 2 Claims.

This invention relates to improvements in boilers of the kind wherein a furnace chamber with steam generating tubes on its walls is surmounted by an up-pass in which there is a superheater shielded by a bank of convectionheated boiler tubes. The improvements have for their main object to prevent over-superheating and to produce a maximum of superheat with a minimum of boiler heating surface preceding the superheater.

In carrying out the invention this main object is attained by providing a by-pass around the said up-pass in which the superheater is located, which by-pass contains some of the convectionheated boiler surface. Preferably the bank of tubes constituting the convection-heated boiler surface extends from a lower header first in a more or less inclined direction across the furnace chamber and then substantially vertically to an upper header connected with the steam and water drum. The by-pass encompasses the vertical portion of the convection-heated boiler surface and has at its upper part a damper-controlled communication with the up-pass, preferably above the level of the superheater. The setting of the damper controlling this communication determines the proportion of the heating gases which flow by way of the by-pass and above the superheater to the off-take.

The accompanying drawing represents a vertical section through the upper part of a boiler constructed in accordance with the invention.

The furnace chamber 5 is of well-known construction adapted for firing by turbulent combustion and having walls protected by steam generating tubes 2 connected to the steam and water drum 3 by downcomers t and risers 5. The convection-heated surface of the boiler comprises a bank of generating tubes 6 extending from a lower header l at slight upward inclination across the greater part of the width of the chamber l and then vertically to an upper header 8. One side of this upper header is turned upwardly as at 8, thus facilitating the provision of the tubes it connecting this header with the drum 3. The circulatory system is completed by the downcomers ii and I2 between the drum 3 and the lower header 1.

The by-pass it, which is a feature of the invention, is formed by a partition M extending through the upper part of the chamber I in front of the Vertical portion of the tubes 6. The upper portion of the partition constitutes a damper E5. The downcomers l2 are protected from heat by refractory tiles Mi which form another partition in the chamber; the space between the partitions is an. up-pass ll for the products of combustion which flow thence through the down-pass Hi to the off-take 20.

Tiles 2 i, in part supported by the tubes l, form a wall of the down-pass it in which an economizer 22 of any known kind is accommodated; for this may be substituted a primary stage superheater or a reheater and in either case by-pass dampers may be provided.

In the up-pass ll is placed the superheater 23 and it will be seen that when the damper I5 is closed the whole of the products of com bustion flow over the inclined portions of the convection tubes 6 and the superheater and that when the damper i5 is more or less open more or less of the said products flow through the bypass IB and across the top of the up-pass ll substantially without imparting heat to the superheater. Preferably, the ratio of heat absorbing surface comprised by the vertical parts of the tubes 6 to that of the parts thereof below the superheater and the surface of the latter is such that the gases flowing through the by-pass l3 are cooled by the vertical portion of tubes 6 so that their temperature is approximately the same as that of the products which have passed over the superheater;

What I claim is:

1. In a boiler; a furnace chamber; a superheater positioned above said chamber in a path of gases flowing therefrom; baffle means disposed substantially vertically at one side of said superheater and spaced from one side of the boiler setting to form a by-pass for gases to flow from said chamber to the boiler off-take without contact with the superheater; a steam generating bank comprising rows of tubes extending across the furnace chamber below said superheater with portions of the tubes in all rows of the bank extending substantially vertically through said by-pass, the heat absorbing capacity of said vertical tube portions being substantially equal to that of said superheater together with the tube portions below the latter; and damper means at the upper end of said Icy-pass for controlling the flow of gases through said by-pass.

2. In a boiler; a furnace chamber; a superheater above said chamber; bafiie means disposed substantially vertically at one side of said superheater and spaced from one side of the boiler to form a b-y-pass for gases to flow from said chamber to the boiler ofitake without contacting the superheater; rows of generating tubes extending across the furnace chamber below said superheater and having portions thereof extending upwardly through said by-pass and the heat-absorbing surfaces of which are so related to the heat absorbing surfaces of the superheater and of the tube portions below the latter that gases flowing through the by-pass are cooled to substantially the same extent as those flowing over the superheater.

GEORGE P. JACKSON.

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