Method for producing improved heat transfer surface

• US 4,136,428 A
• Filed: 01/09/1978
• Issued: 01/30/1979
• Est. Priority Date: 02/16/1977
• Status: Expired due to Term

• Current Assignee: Wolverine Tube Incorporated
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Janowski, Kenneth R., Godsey, Randall D., Crawford, James V., Svacha, Roy E.
• Primary Examiner(s): Lanham, C. W.
• Assistant Examiner(s): Rising, V. K.
• Application Number:
  US05/867,858
• Time in Patent Office: 386 Days
• Field of Search: 29/458, 29/459, 29/460, 29/157.4, 165/133, 138/144, 138/145, 138/146, 138/DIG. 9, 427/243, 427/244, 427/247, 427/373, 427/178, 427/227, 427/228, 427/202, 427/276, 427/257
• US Class Current: 29/890.045
• CPC Class Codes: B21C 37/154 Making multi-wall tubes
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 3/1137 by coating porous removable preforms
• CPC Class Codes: B22F 7/006 the porous part being obtained by foaming
• CPC Class Codes: B23P 15/26 heat exchangers or the like making heat exchangers by methods covered by other subclasses B21D53/02
• CPC Class Codes: B29K 2105/04 cellular or porous
• CPC Class Codes: B29K 2705/10 Copper
• CPC Class Codes: B29L 2009/003 comprising a metal layer
• CPC Class Codes: C25D 7/00 Electroplating characterised by the article coated
• CPC Class Codes: F28F 13/187 especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
• CPC Class Codes: Y10S 138/09 Cellular
• CPC Class Codes: Y10T 29/49377 Tube with heat transfer means
• CPC Class Codes: Y10T 29/49886 to roughen surface
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

The invention relates to a method of improving the heat transfer properties in boiling liquids of tubes and other surfaces by applying a very porous reticulated organic foam layer which has been precoated with graphite in contact with the tube surface, and then plating a thin metal coating on the foam substrate. Preferably, the tube is copper and the plating consists of an electroplated layer of copper which is applied over the conductive graphite coated foam. the foam is preferably in the form of a thin tape which is spirally wound about the tube. Pyrolyzation of the foam after plating improves the heat transfer performance of the tube. A method for applying the graphite to the foam is also disclosed.

Claims

1. A method of providing a metal heat transfer member with a porous nucleate boiling surface comprising the steps of applying a layer of open cell reticulated organic foam material having an adherent coating of conductive graphite to the surface of the metal member and electroplating the exposed graphite coated surfaces of the reticulated foam material and the exposed surfaces of the metal member which underlie the foam material with a metal so as to form a reticulated metal surface having open cells which overlies the surface of the metal member and is firmly adhered thereto.

2. The method of claim 1 wherein said graphite coating is applied to said layer of foam material by a shear mill.

3. The method of claim 1 wherein said metal heat transfer member is cleaned before it is plated.

4. The method of claim 1 wherein said metal heat transfer member is heated after it is plated to pyrolyze the organic foam material.

5. The method of claim 1 wherein said heat transfer member is a tube and said layer of graphite coated foam material is applied by spirally wrapping a strip of said foam material about said tube.

6. The method of claim 1 wherein said plating has a thickness in the range of about 0.0004-0.0006 inches.

7. The method of claim 4 wherein said metal plating is made sufficiently thin that portions of it will be fractured by gases developed during pyrolyzation to produce pore openings therein.

8. The method of claim 4 wherein said heating takes place at a temperature of less than about 900°

F.