US2922404A - Steam generators - Google Patents

Description

S. KOPP ET AL STEAM GENERATORS Filed Nov. 9, 1956 Jan. 26, 1960 F l G. 2

SIGMUND KOPP ARTHUR s. DENTON INVENTQR. WM o'qml ATTORNEY Fl G.

All

STEAM GENERATORS Sigmund 'Kopp, Fredonia, and Arthur S. l )enton, l larpursville, N .Y., assignors to Alco Products, Inc., New York, N.Y., a corporation of New York Application November 9, 1956, Serial No. 621,344

1 Claim. (Cl. 122-34) This invention relates to steam generators and particularly to steam generators having superheating apparatus associated therewith.

Steam generators of the class described herein are used primarily to supply superheated steam to drive turbines. One purpose of superheating such steam is to provide more available energy for the turbine thus to increase its output. Another purpose is to lower the moisture content of the steam. It has been found that if superheating is provided in steam generators of the class described, moisture content in the steam will be reduced from approximately 12% to 8% and this is sufficient to eliminate the installation of moisture drawoif means.

In common practice, the steam from a steam generator is passed through a separate superheater. Considerable heat loss occurs between the vaporizing section of the steam generator and the superheater and consequently the arrangement is expensive to operate. The present invention improves on such a construction by disposing the superheater inside the shell of the steam generator in a novel arrangement in relation to the generator. By such a construction, the feedwater is vaporized into steam and the steam is dried and superheated within a single unit. Only one system of heating fluid is utilized for both the vaporizing and superheating operations and no heat loss occurs between the vaporizing section of the generator and the superheater.

In the construction of the present invention, a plurality of heating tubes are separated from the remaining tubes by a partition thus forming a superheating section within the steam generator. Steam generated in the vaporizing section is passed over the tubes in the superheating section with resulting increase in temperature and decrease in moisture content of the steam.

The principal object of the present invention, therefore, is to provide an improved steam generator which has a novel superheating section integrated therewith.

Another object is to provide a shell and tube type steam generator having a vaporizing section to generate steam which is supplied in a novel manner to a superheating section built in to the shell.

Still another object is to provide a shell and tube type heat exchanger having a plurality of U-tubes extending upwardly from a tube sheet, the interior of the shell being divided into two sections with U-tubes in each section, one section serving as a vaporizing section to generate steam and the other section serving as a superheater for steam.

In the drawings:

Fig. 1 is a partial sectional view showing a vertically disposed steam generator having an integral superheating section.

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

Referring now to the drawings there is shown a vertical shell and tube type heat exchanger which functions as a steam generator. The shell 10 is cylindrical and is closed at its top end by a spherical end wall 11. The bottom end of the shell is closed by an end wall 12 and spaced upwardly therefrom .and extending across the shell 10 is a tube-sheet .13. Tube sheet 13, end .Wall 12, and the shell 1!) define a channel which is divided into inlet and outletcompartments 14 and 15 hy-xpartition 16. Inlet nozzle 17 supplies heating fluid toinlet compartment 14 and,.o.utlet nozzle .18 discharges the heating fluid from outlet compartment 15. The tube sheet 13 supports a plurality of U-tubes 19 and 20 (only one of each being illustrated), the inlet end of each U-tube being in communication with the inlet compartment and the outlet end of each tube being in communication with the outlet compartment. Feed water to be converted to steam is supplied to the shell 10 through inlet 21. Steam generated from the feed water by the action of the heat emanating from U-tubes 19 passes out of the shell through outlet nozzle 22 in the manner hereinafter described.

Supported by the tube sheet 13 and extending across the interior of the shell is a vertical partition 23 the sides of which are welded to the shell wall. Partition 23, which extends upwardly through the shell to terminate short of the top end wall, divides the interior of the shell into a vaporizing section 24 and a superheating section 25. A diaphragm 26 is arranged transversely across the top of the vaporizing section and supports a separator 2'7. The U-tubes 19 in the vaporizing section, it will be observed, extend upwardly only about half the length of the shell. The level L of the feed water is normally maintained just above the top bend of the U-tubes 19 so the latter are at all times submerged when the apparatus is in operation. This level is maintained automatically by a conventional control device which forms no part of the invention and is consequently not illustrated. A shroud 28, which is arcuate in cross section, is welded to partition 23 to enclose tubes 19 for a greater part of their length. Shroud 28 and partition 23 define a vertical channel 29 which is open at its top and bottom so that a thermosyphon cycle is established to promote effective water circulation.

In operation, the upward flow of steam from the vaporizing section is guided by diaphragm 26 through the separator 27 whence it is collected in the top end chamber 30 and then passes downwardly through the superheating section 25 and superheated by tubes 26. Bafiles 31 are provided in the superheating section to achieve optimum transfer.

A shield 32, arcuate in cross section, is welded to the vertical partition 23 and is spaced from the shell Wall. This shield extends from a line just below the steam nozzle 22 upwardly almost to the top of the cylindrical body of the shell. It is closed at its top by an arcuate end plate 33. An arcuate chamber 34, open at its bottom end, is thus defined by the shell Wall, the shield, and the arcuate end plate 33. This chamber fills with superheated steam during the operation of the apparatus to decrease the loss of heat from the superheating section.

While there has been hereinbefore described an approved embodiment of this invention, it will be understood that many and various changes and modifications in form, arrangement of parts and details of construction thereof may be made without departing from the spirit of the invention, and that all such changes and modifications as fall within the scope of the appended claims are contemplated as a part of this invention.

What we claim is:

A steam generator comprising a shell; a channel having inlet and outlet compartments to receive and discharge a heating fluid; a tube sheet; a partition secured to the tube sheet and extending across the shell to divide the latter into first and second chambers, the end of the partition remote from the tube sheet being spaced from the shell to provide for communication between said chambers; means to supply feedwater to the first chamber; a first set of U-tubes to conduct heating fluid through the feedwater 3 in the first chamber to vaporize such water into steam, the inlet ends of each of such tubes being in communication with said inlet compartment and the outlet end of each of such tubes being. in communication with said outlet compartment; a second set of U-tubes to-conduct heating fluid through the second chamber tosupeih'eat the steam passing from the first chamber into the second chamber, the inlet ends of eachjof said second set of tubes being in communication with said channel inlet 'compart ment and the outlet ends thereof being in communication with said channel outlet compartment; and steam outlet) means in the shell.

References Cited in the file of this patent UNITED STATES PATENTS 2,302,993 j Nov. 24, 1942 2 3 3,8 32 Badenha usen Dec. 14, 1943

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