US1883303A

US1883303A - Steam boiler with superheater and reheater

Info

Publication number: US1883303A
Application number: US408702A
Authority: US
Inventors: Howard J Kerr
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1929-11-21
Filing date: 1929-11-21
Publication date: 1932-10-18
Anticipated expiration: 1949-10-18

Description

Oct. 18, 1932.

H. J. KERR STEAM BOILER WITH SUPERHEATER AND RBI-{EATER Filed Nbv. 21, 1929 Fi gr 1 L l L .4 2 6 I/T, ,2, 0 0 0 0 o M O O O O O 0 o 0 o O 2) O .20 Y; 1 z 10 v 1 V.

1 i j v INVENTORV Patented Oct. 18, 19 32 UNITED STATES PATENT; OFFICE HOWARD J. KERR, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO THE BABCOCK 82; WILOOX COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY STEAM BOILER WITH SUPERHEATER AND REHEATER Application filed November 21-, 1929. Serial No. 408,702.

This invention relates to a steam boiler having the steam generating surfaces, superheater surfaces and reheater surfaces so arranged that the gases for the reheater are i sufliciently hot. The superheater may also 0 companying drawing in which be heated in part by radiant heat from the furnace.

The invention will be understood from the description in connection with the "acig. 1 is a vertical section through an illustrative embodiment of the invention; Fig. 2 is a section along the line 22 of Fig. 1; and Fig. 3 is a front view of some of the headers.

In the drawing, reference character 1 indicates the upper portion of a boiler furnace above which a boiler of the Babcock & Wilcox type is located. The boiler comprises the usual steam and water drum 2 connected by nipples 3 to downtake headers 4:. A bank of inclined tubes 5 connects the downtake headers 4 to uptake headers 6. The bank of inclined tubes 5 differs from the usual bank of inclined tubes in boilers of this type by having alternate rows of tubes omitted for some distance from the lower portion of the bank as most clearly shown in Fig. 3. In the illustrative embodiment of the invention, the second, fourth and sixth rows of tubes from the bottom are omitted, thus leaving a smaller number of tubes spaced farther apart, which-will act as a slag screen and will also permit a certain amount of radiant heat from the furnace to pass through the bank of tubes.

The upper ends of the uptake headers 6 are connected by rows of circulating tubes-7 to'the steam and water drum 2. Straps 8 from supports 9 extend around the ends of the tubes 7 where they areconnected to the headers 6 for supporting the same. These ends of the tubes 7 are protected from direct contact with hot ases from the furnace by an arch 10 of re ractory material that extends from the upper portions of the headers 6 to the lower end of the outer wall of the gas flue 11. The arch 10 may be supported by a support 10'.

a A tube 12 extends from the steam space of the steam and water drum 2 to the inlet thereon.

header 13 of the superheater. The header 13 is supported from the bank of tubes 5 by means of supports 14. A bafie-15 extends from the headers 4 along the upper side of the upper row of tubes, 5 and thence across the superheater tubes 16 in front of the header 13. The superheater tubes 16 extend from the inlet header 13, to the outlet header 17. These tubes are inclined at a greater angle than the tubes 5 and are bent so that they can expand and contract. The

tubes in the bank nearest the gas stream are staggered and spaced farther apart than the others, as shown in Fig. 2, thereby assisting distribution of hot gases within the bank of superheater tubes. A bafiie 18 extends along the upper side of the superheater tubes 16 and a sliding gas seal 19 is provided between the superheater header 17 and the lower end of one wall 20 of the flue 11, which extends across the tubes 7 about midway between the ends of these tubes.

The upper end of the flue 11 is connected to the upper end of the down-flue 21 in which the reheater is located. 7

The reheater may be used for reheating steam between stages of a turbine. It comprises an inlet header 22 located along one side of the flue 21 and connected by rows of serpentine tubes 23 to the header 24:. The header 24: is connected by rows of U-tubes 25 to the outlet header 26. The U-tubes 25 extend beyond the wall 20 and are supported Cross supports 27 are provided for the

tubes

23 and 25 to keep them properly spaced. One of the rows of cross supports 27 rests upon brackets 28 that are supported by the su ports 29, which also support the wall 20. cross support 30 is also indicated for the other wall of the flue 11.

By having a small number of inclined tubes 5, the gases which pass from the furnace 1 across these tubes will retain a considerable amount of their heat. The superheater tubes 16 are not burned out as the gases do not pass directly across these tubes, but only the gases along one side of the gas path contact with these tubes and move along the same substantially parallel to them. The radiant heat from the furnace that reaches 7 primary superheater,

the superheater tubes 16 gives a more uniform superheat at various ratings. Also, the objection of the superheater giving higher superheats at higher loads is avo1ded, because of the fact that most of the gases are by-passed without contacting directly with the tubes of this superheater.

After the gases cross the tubes 5 and most of them have by-passed the superheater, they cross the tubes 7 and flow upwardly in the flue 11, thence downwardly in the flue 21 across the

reheater tubes

23 and 25 and again across the tubes 7 at another place. The gases then pass between the baflie 18 and drum 2 and out between the nipples 3 into the outlet 31 of the stack.

In the boiler illustrated in this application,

the steam generating surface 1s small compared to the reheater or secondary superheater surface. Therefore, the primary superheater is located at one side of the pat for the gases after they have passed across steam generating surface so that the primary superheater tubes will not be contacted by all of the ases that pass through the boiler setting. he quantity of steam that is generated in the boiler and passes through the primary superheater is comparatively small compared to the quantity of steam that passes through the reheater so that the degree of superheat in the primary superheater would be too great if all of the gases were to contact with the primary superheater. By this invention a proper balance can be maintained between the amount of heat absorbed by the steam generating surfaces of the boiler, the

and the reheater, re-

spectively.

I claim:

1. In a boiler, a bank of inclined steam generating tubes, a superheater located along one side of the gas path beyond said bank of tubes having its tubes inclined at a greater heater tubes adjacent the gas'path being spaced apart farther than those remote from said gas path. I

2. In a power steam installation, a steam boiler including a furnace, a bank of inclined steam generating tubes above said furnace, the ma]or1ty of said tubes being arranged in 'rows providing straight unobstructed gas lanes permitting the transmission of radiant heat from said furnace, a flue directing heating gases from said furnace between said rows of tubes, a steam retubes being more widely spaced on the side of the superheater nearest the center of the flue, said superheater being arranged to absorb heat both by radiation and convection, whereby the degree of superheat is not unduly increased at high ratings.

3. In a boiler, a bank of inclined steam generating tubes, and a superheater located out of the main path of the gases beyond said bank of tubes, the superheater tubes adjacent the gas path being spaced apart farther than those remote from said path.

4. In a boiler, a furnace, a gas pass leading from the furnace, a bank of inclined steam generating tubes of relatively low heat absorptive capacity extending across the gas pass above the furnace, the tubes of said bank being arranged to permit the transmission of radiant heat from the furnace to a portion of said gas pass above said bank, a bank of fluid heating tubes in said gas pass subsequent to said steam generating tube bank with respect to gas flow, said gas pass havin a wall section above said steam generating bank and ,in position to absorb heat radiantly transmitted from the furnace, and a superheater having tubes extending along and cooling said wall section and absorbing heat both by radiation and convection.

HOWARD J. KERR,

' angle than the tubes of said bank, the supera steam superheater comprising