Vapor generating system utilizing integral separators and angularly arranged furnace boundary wall fluid flow tubes having rifled bores

• US 4,344,388 A
• Filed: 12/28/1979
• Issued: 08/17/1982
• Est. Priority Date: 11/07/1977
• Status: Expired due to Term

• Current Assignee: Foster Wheeler Energy Limited (John Wood Group PLC)
• Original Assignee: Foster Wheeler Energy Limited (John Wood Group PLC)
• Inventors: Stevens, William D.
• Primary Examiner(s): Favors, Edward G.
• Application Number:
  US06/108,054
• Time in Patent Office: 963 Days
• Field of Search: 122/6 A, 122/235 R, 122/406 R, 122/406 S, 122/512, 165/133, 165/179
• US Class Current: 122/235.11
• CPC Class Codes: F22B 29/065 involving upper vertically disposed water tubes and lower horizontally- or helically disposed water tubes
• CPC Class Codes: F22B 37/103 Internally ribbed tubes
• CPC Class Codes: F28F 1/40 the means being only inside the tubular element

Abstract

A vapor generating system in which a vapor generating section and a superheating section are connected in a series flow relationship. The vapor generating section includes an upright furnace section formed by a plurality of tubes, a portion of which extend at an angle with respect to the horizontal plane for passing fluid through the length of the furnace section to convert a portion of the fluid to vapor or to heat the fluid. The angularly extending portion of each tube has a rifled bore.

Claims

1. A vapor generating system comprising an upright furnace section the boundary walls of which are formed by a plurality of tubes having fins extending outwardly from diametrically opposed portions thereof, with the fins of adjacent tubes being welded together to form a gas-tight structure, burner means associated with said furnace section, said tubes extending vertically in the plane of each boundary wall in the upper portion of said furnace section walls and extending at an acute angle with respect to a horizontal plane in at least a portion of said boundary walls extending below said upper portion, means for simultaneously passing water through the tubes of all said boundary walls to add heat from said burner means to said water to convert said water to steam, and a rifled bore formed in said acute-angularly extending tubes.

2. The system of claim 1 wherein the configuration of said rifled bores is such that nucleate boiling is maintained and separation of steam and water is avoided during the flow of water through said acute-angularly extending tubes at relatively high and relatively low flow rates.

3. The system of claim 1 further comprising a fluid separating section, a superheating section and fluid flow circuitry connecting said sections in a series flow relationship.

4. The system of claim 3 wherein said fluid separating section receives fluid from said vapor generating section during start-up and full load operation of said system and separates said fluid into water and steam.

5. The system of claim 1 wherein said tubes extend vertically in the lower and upper portions of said furnace section and extend at an acute angle with respect to a horizontal plane in an intermediate portion of said furnace section extending between said upper and lower portions.

6. The system of claim 1 wherein there are more vertically extending tubes in the walls in said upper portion of said furnace section than acute-angularly extending tubes in said portion of said walls extending below said upper portion.

7. The system of claim 6 wherein each of said acute-angularly extending tubes bifurcates into at least two of said vertically extending tubes.

8. The system of claim 1 wherein said furnace section has a rectangular horizontal cross-section.

9. The system of claim 1 wherein said acute-angularly extending tubes wrap around the furnace for at least one revolution.

10. The system of claim 1 wherein said tubes are directly exposed to the heat from said burner means for the entire height of the furnace boundary walls.

11. The system of claim 1 wherein said rifled bores are formed by a plurality of ribs and grooves formed in the inner wall of each of said acute-angularly extending tubes, with the height of each rib being 0.05 to 0.06 inches and the width of each rib being 0.25 to 0.3 inches.

12. The system of claim 1 or 11 wherein said rifled bores are formed by a plurality of ribs and grooves formed in the inner wall of said acute-angularly extending tubes, with the pitch of said ribs being 0.75 inches to 1.25 inches and the minor tube diameter being 0.85 to 1.25 inches.

13. A vapor generating system comprising an upright furnace section the boundary walls of which are formed by a plurality of tubes having fins extending outwardly from diametrically opposed portions thereof, with the fins of adjacent tubes being welded together to form a gas-tight structure, burner means associated with said furnace section, said tubes extending vertically in the plane of each boundary wall in the upper portion of said furnace section walls and extending at an acute angle with respect to a horizontal plane in at least a portion of said boundary walls extending below said upper portion, and a plurality of ribs and grooves formed in the inner walls of said acute-angularly extending tubes, with the height of each rib being 0.05 to 0.06 inches and the width of each rib being 0.25 to 0.3 inches.

14. The system of claim 13 wherein the pitch of said ribs is 0.75 inches to 1.25 inches and the minor tube diameter is 0.85 to 1.25 inches.

15. The system of claim 13 wherein the configuration of said rifled bores is such that nucleate boiling is maintained and separation of steam and water is avoided during the flow of water through said acute-angularly extending tubes at relatively high and relatively low flow rates.

16. The system of claim 13 further comprising a fluid separating section, a superheating section and fluid flow circuitry connecting said sections in a series flow relationship.

17. The system of claim 16 wherein said fluid separating section receives fluid from said vapor generating section during start-up and full load operation of said system and separates said fluid into water and steam.

18. The system of claim 13 wherein said tubes extend vertically in the lower and upper portions of said furnace section and extend at an acute angle with respect to a horizontal plane in an intermediate portion of said furnace section extending between said upper and lower portions.

19. The system of claim 13 wherein there are more vertically extending tubes in the walls in said upper portion of said furnace section than acute-angularly extending tubes in said portion of said walls extending below said upper portion.

20. The system of claim 19 wherein each of said acute-angularly extending tubes bifurcates into at least two of said vertically extending tubes.

21. A vapor generating system comprising an upright furnace section the boundary walls of which are formed by a plurality of tubes having fins extending outwardly from diametrically opposed portions thereof, with the fins of adjacent tubes being welded together to form a gas-tight structure, burner means associated with said furnace section, said tubes extending vertically in the plane of each boundary wall in the upper portion of said furnace section walls and extending at an acute angle with respect to a horizontal plane in at least a portion of said boundary walls extending below said upper portion, and a plurality of ribs and grooves formed in the inner walls of said acute-angularly extending tubes, with the pitch of said ribs being 0.75 to 1.25 inches.

22. The system of claim 21 wherein the configuration of said rifled bores is such that nucleate boiling is maintained and separation of steam and water is avoided during the flow of water through said acute-angularly extending tubes at relatively high and relatively low flow rates.

23. The system of claim 21 further comprising a fluid separating section, a superheating section and fluid flow circuitry connecting said sections in a series flow relationship.

24. The system of claim 23 wherein said fluid separating section receives fluid from said vapor generating section during start-up and full load operation of said system and separates said fluid into water and steam.

25. The system of claim 21 wherein said tubes extend vertically in the lower and upper portions of said furnace section and extend at an acute angle with respect to a horizontal plane in an intermediate portion of said furnace section extending between said upper and lower portions.

26. The system of claim 21 wherein there are more vertically extending tubes in the walls in said upper portion of said furnace section than said acute-angularly extending tubes in said portion of said walls extending below said upper portion.

27. The system of claim 26 wherein each of said acute-angularly extending tubes bifurcates into at least two of said vertically extending tubes.

28. A vapor generating system comprising an upright furnace section the boundary walls of which are formed by a plurality of tubes having fins extending outwardly from diametrically opposed portions thereof, with the fins of adjacent tubes being welded together to form a gas-tight structure, burner means associated with said furnace section, said tubes extending vertically in the plane of each boundary wall in the upper portion of said furnace section walls and extending at an acute angle with respect to a horizontal plane in at least a portion of said boundary walls extending below said upper portion, each of said acute-angularly extending tubes bifurcating into two vertically extending tubes, and a rifled bore formed in said acute-angularly extending tubes.

29. The system of claim 28 wherein the configuration of said rifled bores is such that nucleate boiling is maintained and separation of steam and water is avoided during the flow of water through said acute-angularly extending tubes at relatively high and relatively low flow rates.

30. The system of claim 28 further comprising a fluid separating section, a superheating section and fluid flow circuitry connecting said sections in a series flow relationship.

31. The system of claim 30 wherein said fluid separating section receives fluid from said vapor generating section during start-up and full load operation of said system and separates said fluid into water and steam.

32. The system of claim 28 wherein said tubes extend vertically in the lower and upper portions of said furnace section and extend at an acute angle with respect to a horizontal plane in an intermediate portion of said furnace section extending between said upper and lower portions.

33. A vapor generating system comprising a fluid separating system, a superheating section, an upright furnace section, fluid flow circuitry connecting said sections in a series flow relationship, the boundary walls of said furnace section being formed by a plurality of tubes having fins extending outwardly from diametrically opposed portions thereof, with the fins of adjacent tubes being welded together to form a gas-tight structure, burner means associated with said furnace section, said tubes extending vertically in the plane of each boundary wall in the upper portion of said furnace section walls and extending at an acute angle with respect to a horizontal plane in at least a portion of said boundary walls extending below said upper portion, and a rifled bore formed in said acute-angularly extending tubes.

34. The system of claim 33 wherein said fluid separating section receives fluid from said vapor generating section during start-up and full load operation of said system and separates said fluid into water and steam.

35. The system of claim 33 wherein the configuration of said rifled bores is such that nucleate boiling is maintained and separation of steam and water is avoided during the flow of water through said acute-angularly extending tubes at relatively high and relatively low flow rates.

36. The system of claim 33 wherein said tubes extend vertically in the lower and upper portions of said furnace section and extend at an acute angle with respect to a horizontal plane in an intermediate portion of said furnace section extending between said upper and lower portions.

37. The system of claim 33 wherein each of said acute-angularly extending tubes bifurcates into at least two of said vertically extending tubes.