Heat exchanger

• US 7,901,617 B2
• Filed: 05/16/2005
• Issued: 03/08/2011
• Est. Priority Date: 05/18/2004
• Status: Active Grant

• Current Assignee: Enpot Holdings Limited
• Original Assignee: Auckland UniServices Limited (Auckland University)
• Inventors: Farid, Mohamed, Taylor, Mark P., Wallace, Robert John, Chen, John J J
• Primary Examiner(s): KASTLER, SCOTT R
• Application Number:
  US11/568,966
• Publication Number:
  US 20080047691A1
• Time in Patent Office: 2,122 Days
• Field of Search: 266/193, 266/194, 266/241, 266/46
• US Class Current: 266/194
• CPC Class Codes: C21B 7/106 Cooling of the furnace bottom
• CPC Class Codes: C21C 5/4646 Cooling arrangements
• CPC Class Codes: C25C 3/085 characterised by its non electrically conducting heat insulating parts
• CPC Class Codes: F27D 2009/0005 the cooling medium being a gas
• CPC Class Codes: F27D 2009/0013 the fluid being water
• CPC Class Codes: F27D 9/00 Cooling of furnaces or of charges therein F27D1/00, F27D3/00 take precedence
• CPC Class Codes: Y02P 10/134 by avoiding CO2, e.g. using hydrogen
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A heat exchanger 10 includes a conduit 12 for conveying cooling fluid relative to a body to be cooled. A heat transfer arrangement 62 is arranged in communication with an interior of the conduit 12, the heat transfer arrangement 62 and the conduit 12 together defining an assembly that is mountable adjacent the body to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the body and the heat transfer arrangement 62 of the assembly and radiant heat exchange occurring between the body and at least part of the heat transfer arrangement 62 of the assembly.

Claims

1. A smelting furnace heat exchanger which includes:

a conduit for conveying cooling fluid relative to a furnace to be cooled; and

a heat transfer arrangement in communication with an interior of the conduit, the heat transfer arrangement and the conduit together defining an assembly that is mountable adjacent to, and externally of, the furnace to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the furnace and to the heat transfer arrangement of the assembly and radiant heat exchange occurring between the furnace and at least part of the heat transfer arrangement of the assembly, the heat transfer arrangement further comprising heat transfer enhancing parts and in which the heat transfer enhancing parts of the heat transfer arrangement comprises a plurality of fins arranged on an outer surface of the conduit.

3. The heat exchanger of claim 1 in which at least the heat transfer arrangement is of a heat absorption material.

4. The heat exchanger of claim 1 in which an operatively inner region of the conduit contains heat exchange elements.

5. The heat exchanger of claim 4 in which the heat exchange elements are in the form of heat transfer media to effect increased convective heat exchange between the conduit and the cooling fluid within the conduit.

6. The heat exchanger of claim 1 in which control of fluid flow through the conduit is effected by means of control elements arranged in the conduit.

7. The heat exchanger of claim 1 which includes a deflector arranged, in use, operatively below the assembly for deflecting the cooling fluid into contact with the furnace to be cooled.

8. The heat exchanger of claim 1 which includes a fluid entrapment element arranged operatively above the conduit for inhibiting escape or by-passing of heated air.

9. The heat exchanger of claim 1 in which a downstream end of the conduit is connected to a fluid extraction arrangement.

10. The heat exchanger of claim 1 in which a heat absorbing accessory is mounted to the conduit.

11. The heat exchanger of claims 1 in which the heat transfer arrangement comprises a plurality of spaced ducts, connected by a manifold, to the conduit, the ducts being arranged at spaced intervals along each manifold.

12. The heat exchanger of claim 11 in which each duct is in the form of a substantially channel-shaped section which, in use, is positioned adjacent a wall of the furnace to form a passage through which the cooling fluid can pass.

13. The heat exchanger of claim 11 in which an entry opening of each duct is shaped to reduce a pressure drop associated with entry of the cooling fluid into the duct.

14. The heat exchanger of claims 11 in which the duct connects to the manifold via an exit opening.

25. The heat exchanger of claims 11 in which the heat transfer enhancing parts are in the form of surface area increasing components carried in an interior of each duct to enhance at least one of convective heat transfer rates and radiant heat transfer rates.

26. The heat exchanger of claim 25 in which the components are selected from the group consisting of fins, vortex inducing elements and combinations of the foregoing.

27. The heat exchanger of claim 25 in which the components include foraminous elements.

47. The heat exchanger of claim 1 in which the cooling fluid is air.

2. A smelting furnace heat exchanger which includes:

a conduit for conveying cooling fluid relative to a furnace to be cooled; and

a heat transfer arrangement in communication with an interior of the conduit, the heat transfer arrangement and the conduit together defining an assembly that is mountable adjacent to, and externally of, the furnace to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the furnace and to the heat transfer arrangement of the assembly and radiant heat exchange occurring between the furnace and at least part of the heat transfer arrangement of the assembly, the heat transfer arrangement further comprising heat transfer enhancing parts, the assembly being formed in sections which can be arranged in end-to-end relationship with the conduit forming a passage through which the cooling fluid flows and in which each section of the assembly is mounted on rollers.

15. A smelting furnace heat exchanger which includes:

a conduit for conveying cooling fluid relative to a furnace to be cooled; and

a heat transfer arrangement in communication with an interior of the conduit, the heat transfer arrangement and the conduit together defining an assembly that is mountable adjacent to, and externally of, the furnace to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the furnace and to the heat transfer arrangement of the assembly and radiant heat exchange occurring between the furnace and at least part of the heat transfer arrangement of the assembly, the heat transfer arrangement comprising a plurality of spaced ducts, connected by a manifold, to the conduit, the ducts each containing heat transfer enhancing parts and the ducts being arranged at spaced intervals along each manifold, each duct connecting to the manifold via an exit opening and

in which each duct defines a secondary exit opening to allow escape of some of the cooling fluid to atmosphere to provide natural convective flow when no assisted flow is present.

16. The heat exchanger of claim 15 in which each duct is in the form of a tube to be arranged adjacent the wall of the furnace to be cooled.

17. The heat exchanger of claim 16 in which each tube is substantially rectangular in cross-section having a high depth to width aspect ratio.

18. A smelting furnace heat exchanger which includes:

a conduit for conveying cooling fluid relative to a furnace to be cooled; and

a heat transfer arrangement in communication with an interior of the conduit, the heat transfer arrangement and the conduit together defining an assembly that is mountable adjacent to, and externally of, the furnace to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the furnace and to the heat transfer arrangement of the assembly and radiant heat exchange occurring between the furnace and at least part of the heat transfer arrangement of the assembly, the heat transfer arrangement comprising a plurality of spaced ducts, connected by a manifold, to the conduit, the ducts each containing heat transfer enhancing parts and the ducts being arranged at spaced intervals along each manifold, each duct being in the form of a tube to be arranged adjacent the wall of the furnace to be cooled and

a part of each tube in proximity to the furnace defining at least one aperture to enhance heat transfer between the tube and the furnace due to reduced thermal boundary layers.

19. A smelting furnace heat exchanger which includes:

a conduit for conveying cooling fluid relative to a furnace to be cooled;

a heat transfer arrangement in communication with an interior of the conduit, the heat transfer arrangement and the conduit together defining an assembly that is mountable adjacent to, and externally of, the furnace to be cooled, convective heat exchange occurring, in use, due to movement of the cooling fluid relative to the furnace and to the heat transfer arrangement of the assembly and radiant heat exchange occurring between the furnace and at least part of the heat transfer arrangement of the assembly, the heat transfer arrangement comprising a plurality of spaced ducts, connected by a manifold, to the conduit, the ducts each containing heat transfer enhancing parts and the ducts being arranged at spaced intervals along each manifold; and

a shielding element for shielding those parts of a structure in which the furnace to be cooled is located, arranged on an opposite side of the shielding element from the furnace, from radiation heat transfer from the furnace.

20. The heat exchanger of claim 19 in which the shielding element is in the form of a shield plate which, together with the wall of the furnace, defines a channel through which the cooling fluid can pass to aid in natural convective heat transfer from the wall of the furnace to those parts of the heat transfer arrangement arranged within the channel.

21. The heat exchanger of claim 20 in which a rising part of each duct is arranged in the channel so that heat transfer from the furnace to the tubes occurs both by radiation and by convection.

22. The heat exchanger of claim 21 in which each duct has a vertical section entering its manifold via a cranked downstream region of the duct.

23. The heat exchanger of claim 21 in which each duct has a horizontal upstream portion leading to a vertical portion arranged between the shielding plate and the furnace.

24. The heat exchanger of claim 23 in which each section of the heat transfer arrangement comprises a plurality of units, each unit comprising a manifold with its associated ducts, with the manifolds being vertically stacked and the ducts of an upper unit being interleaved with the ducts of a subjacent unit providing lengths of vertical portions of the ducts facing the wall of the furnace to enhance heat transfer.

28. A method of cooling a smelting furnace which includes:

mounting a heat transfer arrangement of a heat exchanger assembly, the assembly including a conduit in proximity to, and externally of, the furnace so that radiant heat exchange between the smelting furnace and at least a part of the heat transfer arrangement occurs; and

directing cooling fluid past the furnace, into contact with the heat transfer arrangement and into the conduit so that convective heat exchange between the fluid, the furnace and the heat transfer arrangement occurs, the heat transfer arrangement comprising heat transfer enhancing parts for enhancing at least one of radiant heat exchange and convective heat exchange and in which the heat transfer enhancing parts of the heat transfer arrangement comprise a plurality of fins arranged on an outer surface of the conduit and the method includes passing the fluid through spaces between adjacent fins, the spaces serving as radiant heat traps to assist in radiant heat transfer between the furnace and the assembly.

29. The method of claim 28 which includes assisting convective flow of the fluid through the heat transfer arrangement and the conduit.

30. The method of claim 29 which includes effecting the assistance by creating a low pressure region in a passage of the conduit.

31. The method of claim 30 which includes forming the heat exchanger assembly in sections and arranging the sections in end-to-end relationship with the conduit forming the passage through which the fluid flows.

32. The method of claims 28 which includes controlling fluid flow through the conduit.

33. The method of claim 28 which includes mounting the assembly between a plurality of furnaces to be cooled and deflecting fluid into contact with walls of the furnaces and drawing the fluid into the interior of the conduit through apertures defined intermediate the fins in walls of the conduit.

34. The method of claim 28 which includes arranging a fluid entrapment element operatively above the conduit for inhibiting escape or by-passing of heated air.

35. The method of claims 28 which includes connecting a downstream end of the conduit to a fluid extraction arrangement.

36. The method of claim 28 which includes positioning the conduit in proximity to a floor of a structure in which the furnace is contained.

37. The method of claim 36 which includes mounting a heat absorbing accessory to the conduit.

38. The method of claims 28 which includes mounting a plurality of ducts of the heat transfer arrangement at spaced intervals along the furnace, adjacent a wall of the furnace, and connecting a plurality of the ducts to the conduit by at least one manifold.

39. The method of claim 38 which includes shaping an entry opening of each duct to reduce a pressure drop associated with entry of cooling fluid into the duct.

40. The method of claim 38 which includes connecting an exit opening of the duct to the manifold.

46. The method of claim 38 which includes enhancing at least one of convective heat transfer and radiant heat transfer by passing the fluid over surface increasing components arranged in an interior of each.

41. A method of cooling a smelting furnace which includes:

mounting a heat transfer arrangement of a heat exchanger assembly, the assembly including a conduit, in proximity to, and externally of, the furnace by mounting a plurality of ducts of the heat transfer arrangement at spaced intervals along the furnace, adjacent a wall of the furnace, and connecting a plurality of the ducts to the conduit by at least one manifold and connecting an exit opening of each duct to the manifold so that radiant heat exchange between the smelting furnace and at least a part of the heat transfer arrangement occurs;

directing cooling fluid past the furnace, into contact with the heat transfer arrangement and into the conduit so that convective heat exchange between the fluid, the furnace and the heat transfer arrangement occurs, the heat transfer arrangement comprising heat transfer enhancing parts for enhancing at least one of radiant heat exchange and convective heat exchange; and

providing natural convective flow when no assisted flow is present by allowing escape of some of the cooling fluid to atmosphere through a secondary exit opening defined in each duct.

42. A method of cooling a smelting furnace which includes:

mounting a heat transfer arrangement of a heat exchanger assembly, the assembly including a conduit, in proximity to, and externally of, the furnace by mounting a plurality of ducts of the heat transfer arrangement at spaced intervals along the furnace, adjacent a wall of the furnace, and connecting a plurality of the ducts to the conduit by at least one manifold and connecting an exit opening of each duct to the manifold so that radiant heat exchange between the smelting furnace and at least a part of the heat transfer arrangement occurs;

directing cooling fluid past the furnace, into contact with the heat transfer arrangement and into the conduit so that convective heat exchange between the fluid, the furnace and the heat transfer arrangement occurs, the heat transfer arrangement comprising heat transfer enhancing parts for enhancing at least one of radiant heat exchange and convective heat exchange; and

enhancing heat transfer between the duct, which is in the form of a tube, and the furnace by passing the fluid through an aperture defined in a wall of the tube.

43. A method of cooling a smelting furnace which includes:

mounting a heat transfer arrangement of a heat exchanger assembly, the assembly including a conduit, in proximity to, and externally of, the furnace by mounting a plurality of ducts of the heat transfer arrangement at spaced intervals along the furnace, adjacent a wall of the furnace, and connecting a plurality of the ducts to the conduit by at least one manifold and connecting an exit opening of each duct to the manifold so that radiant heat exchange between the smelting furnace and at least a part of the heat transfer arrangement occurs;

directing cooling fluid past the furnace, into contact with the heat transfer arrangement and into the conduit so that convective heat exchange between the fluid, the furnace and the heat transfer arrangement occurs, the heat transfer arrangement comprising heat transfer enhancing parts for enhancing at least one of radiant heat exchange and convective heat exchange; and

mounting a shielding element in spaced relationship relative to a wall of the furnace for shielding those parts of a structure in which the furnace to be cooled is located, arranged on an opposite side of the shielding element from the furnace, from radiation heat transfer from the furnace.

44. The method of claim 43 which includes passing the fluid through a channel defined between the shielding element and the wall of the furnace to aid in natural convective heat transfer from the wall of the furnace to those parts of the heat transfer arrangement arranged within the channel.

45. The method of claim 44 which includes arranging a rising part of each duct in the channel so that heat transfer from the furnace to the ducts occurs both by radiation and by convection.

48. A method of cooling a smelting furnace which includes:

mounting a heat transfer arrangement of a heat exchanger assembly, the assembly including a conduit in proximity to, and externally of, the furnace so that radiant heat exchange between the smelting furnace and at least a part of the heat transfer arrangement occurs;

directing cooling fluid past the furnace, into contact with the heat transfer arrangement and into the conduit so that convective heat exchange between the fluid, the furnace and the heat transfer arrangement occurs, the heat transfer arrangement comprising heat transfer enhancing parts for enhancing at least one of radiant heat exchange and convective heat exchange; and

using air as the cooling fluid.

49. The method of claim 48 in which the heat transfer enhancing parts increase the surface area available for enhancing convective heat transfer between the air and the heat transfer arrangement.

50. The method of claim 48 in which the heat transfer enhancing parts include vortex inducing components carried on an interior of the heat transfer arrangement for enhancing convective heat transfer between the air and the heat transfer arrangement.