Fail safe heat exchanger

• US 4,246,960 A
• Filed: 03/26/1979
• Issued: 01/27/1981
• Est. Priority Date: 03/26/1979
• Status: Expired due to Term

• Current Assignee: OLIN Corporation
• Original Assignee: OLIN Corporation
• Inventors: Popplewell, James M., Butt, Sheldon H.
• Primary Examiner(s): Richter, Sheldon J.
• Application Number:
  US06/023,631
• Time in Patent Office: 673 Days
• Field of Search: 165/134, 165/164, 165/133, 165/165, 165/DIG. 8, 165/180, 165/170, 165/171, 428/933
• US Class Current: 165/134.1
• CPC Class Codes: F28F 19/004 by using protective electric currents, voltages, cathodes, anodes, electric short-circuits
• CPC Class Codes: F28F 3/14 by separating portions of a pair of joined sheets to form channels, e.g. by inflation manufacture thereof B23P
• CPC Class Codes: Y10S 165/905 Materials of manufacture
• CPC Class Codes: Y10S 428/933 Sacrificial component

Abstract

A multiple passage metal heat exchanger is disclosed which contains a metal barrier between sets of passageways. The barrier is cathodic to the metal of the heat exchanger and prevents intermixing of different heat transfer fluids due to corrosion.

Claims

1. A fail safe metal heat exchanger comprising copper or a copper alloy, said heat exchanger comprising juxtaposed primary and secondary fluid passageways integral with and separated by a corrosion barrier comprising nickel or a nickel alloy which is noble to said copper or copper alloy of the remainder of said heat exchanger;

whereby said corrosion barrier is adapted to prevent intermixing between a fluid in said primary passageway and a fluid in said secondary passageway.

2. The heat exchanger of claim 1 wherein said corrosion barrier comprises a metallic foil.

3. The heat exchanger of claim 1 wherein said corrosion barrier comprises a nickel sheet.

4. A composite fail safe metal heat exchanger comprising:

a first metal panel comprising copper or a copper alloy having at least one fluid passageway;

a second metal panel comprising copper or a copper alloy having at least one fluid passageway;

said first and second metal panels being arranged in juxtaposition;

a substantially continuous corrosion barrier;

said corrosion barrier comprising nickel or a nickel alloy which is noble to the metal of said first and second panels; and

said corrosion barrier being located between and in intimate contact with said first and second panels;

whereby said corrosion barrier is adapted to prevent intermixing between a fluid in said passageway of said first metal panel and a fluid in said passageway of said second metal panel.

5. The heat exchanger of claim 4 wherein said first and second metal panels are of the tube in sheet type.

6. The heat exchanger of claim 4 wherein said first and second panels and said corrosion barrier are metallurgically bonded together to form said composite heat exchanger.

7. The heat exchanger of claim 4 wherein said first and second panels are diffusion bonded to said corrosion barrier whereby a diffusion zone exists at the interface of each said panel and said corrosion barrier.

8. The heat exchanger of claim 7 wherein said diffusion zone comprises copper nickel alloy.

9. The heat exchanger of claim 4 wherein said first and second panels and said corrosion barrier are mechanically fastened together to form said composite heat exchanger.

10. The heat exchanger of claim 4 wherein said corrosion barrier comprises a metallic sheet.

11. The heat exchanger of claim 4 wherein said corrosion barrier comprises a nickel foil.