Method for making a liquid heat exchanger coating

• US 4,093,755 A
• Filed: 07/26/1976
• Issued: 06/06/1978
• Est. Priority Date: 01/31/1975
• Status: Expired due to Term

• Current Assignee: Gates Corporation (Gates Industrial Corp. Plc)
• Original Assignee: Gates Rubber Company (Gates Industrial Corp. Plc)
• Inventors: Erb, Lester D., Dahl, Michael M.
• Primary Examiner(s): Smith, Ronald H.
• Assistant Examiner(s): Beck, Shrive P.
• Application Number:
  US05/708,960
• Time in Patent Office: 680 Days
• Field of Search: 427/191, 427/192, 427/422, 427/423, 427/299, 165/133, 165/183, 165/105, 29/191.2 R, 428/304, 428/308
• US Class Current: 427/451
• CPC Class Codes: F28F 13/187 especially adapted for evaporator surfaces or condenser surfaces, e.g. with nucleation sites
• CPC Class Codes: Y10T 428/12042 Porous component
• CPC Class Codes: Y10T 428/12118 Nonparticulate component has Ni-, Cu-, or Zn-base
• CPC Class Codes: Y10T 428/12125 Nonparticulate component has Fe-base
• CPC Class Codes: Y10T 428/12153 Interconnected void structure [e.g., permeable, etc.]
• CPC Class Codes: Y10T 428/12292 Workpiece with longitudinal passageway or stopweld material [e.g., for tubular stock, etc.]
• CPC Class Codes: Y10T 428/12299 Workpiece mimicking finished stock having nonrectangular or noncircular cross section
• CPC Class Codes: Y10T 428/12472 Microscopic interfacial wave or roughness
• CPC Class Codes: Y10T 428/12479 Porous [e.g., foamed, spongy, cracked, etc.]
• CPC Class Codes: Y10T 428/24413 Metal or metal compound
• CPC Class Codes: Y10T 428/24997 Of metal-containing material
• CPC Class Codes: Y10T 428/24999 Inorganic

Abstract

Flame spraying a plurality of particles of oxide film forming metal on a substrate and randomly attaching a plurality of particles to a substrate and to portions of each other, the unconnected portions between particles forming porously interconnected open cell nucleation sites capable of aiding change of state from a liquid to a gas.

Claims

1. A method for making a liquid heat exchanger coating comprising the steps of:

heating a plurality of powder particles of oxide film forming metal in an oxygen rich atmosphere and forming a metallic oxide film on the particles;

moving the particles with a stream of oxygen rich gas while simultaneously heating a plurality of the particles to at least a plastic state and some of the particles to a molten state;

impacting a plurality of the particles against a metallic substrate and against themselves partially deforming, securing and mechanically interlocking a plurality of the particles to the substrate and to portions of each other, breaking the oxide film and fusing some of the molten particles to portions of each other and forming unconnected portions between a plurality of particles that define a plurality of open nucleation cells and the unconnected portions also forming porous interconnections between nucleation cells.

2. The method of claim 1 comprising burning generally 17 cubic feet per hour of acetylene with generally 38.5 cubic feet per hour of oxygen with air aspiration to constitute the steps of heating the particles and forming an oxide film.

3. The method of claim 1 and further including the step of roughening the substrate prior to the step of heating the particles.

4. The method of claim 2 wherein during the step of moving, the particles travel generally 12 inches before impacting.

5. The method of claim 2 wherein the particles are aluminum of about -170 to +325 mesh.

6. The method of claim 5 which further comprises during the step of moving, the step of flowing the powder at a rate of about 3.75 pound per hour.

7. The process as set forth in claim 1 wherein during the step of heating, the powdered metal particles are exposed to an oxygen-rich atmosphere in which carbon is present.