Claims
- 1. A steam generator, comprising:
- a plurality of heat exchange tubes through which a heated fluid flows;
- a tube bundle tube sheet through which said heat exchange tubes pass;
- a wrapper, having a lower free edge portion, disposed about said heat exchange tubes so as to define a heat exchange tube section interiorly of said wrapper;
- an outer shell disposed substantially concentrically about said heat exchange tube wrapper so as to define a downcomer region between said outer shell and said heat exchange tube wrapper;
- means for introducing water into said downcomer region of said steam generator for flow into into said heat exchange tube section so as to permit said water to undergo a heat exchange process with said heat exchange tubes and thereby be converted into steam; and
- means operatively associated with said heat exchange tube wrapper, interposed between the lower free edge portion of said wrapper and the upper surface of said tube bundle tube sheet, comprising a foraminous plate in the form of an annular ring having the configuration of a conical frustum for imparting to said water non-tubulent uniform flow conditions as said water flows from said downcomer region of said steam generator into said heat exchange tube section of said steam generator.
- 2. A steam generator as set forth in claim 1, wherein:
- said foraminous plate is operatively associated with the lower end of said heat exchange tube wrapper.
- 3. A steam generator as set forth in claim 1, wherein:
- said foraminous plate is in the form of a skirt operatively associated with the lower end of said heat exchange tube wrapper.
- 4. A steam generator as set forth in claim 1, wherein:
- the porosity factor of said foraminous plate is approximately fifty percent (50%).
- 5. A steam generator as set forth in claim 1, further comprising:
- a tubesheet within which the ends of said heat exchange tubes are disposed; and
- said foraminous plate is interposed between the lower end of said heat exchange tube wrapper and said tubesheet.
- 6. A steam generator as set forth in claim 1, wherein:
- the angle of inclination of the side wall of said conical frustum is approximately 80.degree. with respect to a horizontal plane.
- 7. A steam generator as set forth in claim 1, wherein:
- said foraminous plate comprises a plurality of arcuate plate segments secured together so as to form said annular ring.
- 8. A steam generator as set forth in claim 7, wherein:
- each of said foraminous plate segments is fabricated from INCONEL 600 nickel-chromium alloy.
- 9. A steam generator as set forth in claim 1, wherein:
- said foraminous plate comprises a one-piece annulus fixedly secured to the lower end of said heat exchange tube wrapper.
- 10. A steam generator as set forth in claim 9, wherein:
- said one-piece annulus is fabricated from INCONEL 600 nickel-chromium alloy.
- 11. A steam generator, as set forth in claim 1, wherein:
- the apertures comprising said foraminous plate have a predetermined size so as to prevent foreign particles having a size greater than said predetermined size from entering said tube bundle section of said steam generator.
- 12. A steam generator as set forth in claim 11, wherein:
- said predetermined size is approximately one-quarter inch (0.25") in diameter.
- 13. A steam generator, comprising:
- a plurality of heat exchange tubes through which a heated fluid flows;
- a tube bundle tube sheet through which said heat exchange tubes pass, a wrapper, having a lower free edge portion, disposed about said heat exchange tubes so as to define a heat exchange tube section interiorly of said wrapper;
- an outer shell disposed substantially concentrically about said heat exchange tube wrapper so as to define a downcomer region between said outer shell and said heat exchange tube wrapper;
- means for introducing water into said downcomer region of said steam generator for flow into said heat exchange tube section so as to permit said water to undergo a heat exchange process with said heat exchange tubes and thereby be converted into steam; and
- means operatively associated with said heat exchange tube wrapper, interposed between the lower free edge portion of said wrapper and the upper surface of said tube bundle tube sheet, comprising a foraminous plate in the form of an annular ring having the configuration of a conical frustrum, for preventing foreign particles of a predetermined size, and disposed within said water flowing through said downcomer region of said steam generator, from entering said heat exchange tube section of said steam generator.
- 14. A steam generator as set forth in claim 13, wherein:
- the apertures comprising said foraminous plate are approximately one quarter inch (0.25") in diameter.
- 15. A steam generator as set forth in claim 13, wherein:
- said foraminous plate comprises a plurality of arcuate segments secured together so as to form said annular ring.
- 16. A steam generator as set forth in claim 13, wherein:
- said foraminous plate comprises a one-piece annulus fixedly secured to the lower end of said heat exchange tube wrapper.
- 17. A steam generator as set forth in claim 13, further comprising:
- a tubesheet within which the ends of said heat exchange tubes are disposed; and
- said foraminous plate is interposed between the lower end of said heat exchange tube wrapper and said tubesheet.
Parent Case Info
This application is a continuation of application Ser. No. 671,822 filed Nov. 15, 1984 now abandoned.
US Referenced Citations (23)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0035450 |
Sep 1981 |
EPX |
2720812 |
Mar 1978 |
DEX |
2182119 |
Dec 1973 |
FRX |
2458781 |
Jan 1981 |
FRX |
1407137 |
Sep 1975 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
671822 |
Nov 1984 |
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