DUCT FOR MAGNETOHYDRODYNAMIC THERMAL TO ELECTRICAL ENERGY CONVERSION APPARATUS

• US 3,621,310 A
• Filed: 06/01/1970
• Issued: 11/16/1971
• Est. Priority Date: 05/30/1969
• Status: Expired due to Term

• Current Assignee: Eiichi Ishibashi, Hisasuke Takeuchi, Humio Hataya, Ryo Hiraga, Ryoichi Sasaki, Takao Koyama
• Original Assignee: Eiichi Ishibashi, Hisasuke Takeuchi, Humio Hataya, Ryo Hiraga, Ryoichi Sasaki, Takao Koyama
• Inventors: Sasaki, Ryoichi, Takeuchi, Hisasuke, Hataya, Humio, Hiraga, Ryo, Ishibashi, Eiichi, Koyama, Takao
• Primary Examiner(s): D. X. Sliney
• Application Number:
  US05/042,291
• Time in Patent Office: 533 Days
• Field of Search: 310/11 313/311
• US Class Current: 310/11
• CPC Class Codes: H02K 44/12 Constructional details of fluid channels

Abstract

A duct for magnetohydrodynamic thermal-to-electrical energy conversion apparatus, which is provided with at least a pair of anode electrodes and cathode electrodes, the cathode possessing excellent erosion or corrosion resistance characteristics being made of an alloy consisting of a refractory metal and an adhesive metal, the fine grains of the refractory metal being bonded through the adhesive metal.

Claims

1. In a magnetohydrodynamic thermal-to-electrical energy conversion apparatus, a duct provided with a working fluid containing conductive gas products, at least a pair of anode and cathode electrodes disposed in the duct adjacent to the fluid and cooling means provided in the duct for cooling the anode and cathode electrodes to temperatures lower than about 1,500* C., the improvement being characterized in that said cathode electrode is made of an alloy consisting of a refractory metal having a melting point of about 300* C. higher than the surface temperature of the cathode and an adhesive metal having a melting point higher than the surface temperature of the cathode, a specific resistance smaller than about 10 X 10 6 Omega -cm at 20* C. and a thermal conductivity larger than about 0.16 cal. cm. 1sec 1deg 1 at 20* C., each of the metals having a sufficiently small mutual solubility, whereby the grains of said refractory metal are dispersed in a matrix of said adhesive metal.

2. A duct according to claim 1, in which the alloy comprises a refractory metal selected from the group consisting of tungsten, molybdenum, tantalum, niobium and iron and an adhesive metal selected from the group consisting of silver, copper, cobalt, and nickel.

3. A duct according to claim 2, in which the alloy contains 20 to 80 percent by weight of the refractory metal.

4. A duct according to claim 2, in which each of the metals forming said alloy are selected so that the mutual solubility thereof is negligibly small.

5. A duct according to claim 2, in which the refractory metal is selected from the group consisting of tungsten, molybdenum and a combination thereof and the adhesive metal is selected from the group consisting of silver, copper and a combination thereof.

6. A duct according to claim 1, wherein said refractory metal forming part of said alloy is tungsten and said adhesive metal forming the other part of said alloy is selected from a group consisting of gold, silver and copper.

7. A duct according to claim 1, wherein said refractory metal forming part of said alloy is molybdenum and said adhesive metal forming the other part of said alloy is selected from a group consisting of gold, silver, copper and cobalt.

8. A duct according to claim 1, wherein said refractory metal forming part of said alloy is tantalum and said adhesive metal forming the other part of said alloy is selected from a group consisting of gold, silver and copper.

9. A duct according to claim 1, wherein said refractory metal forming part of said alloy is niobium and said adhesive metal forming the other part of said alloy is selected from a group consisting of gold, silver, copper and nickel.

10. A duct according to claim 1, wherein said anode electrode is made of a chromium alloy containing more than 20 percent by weight of chromium.

11. A duct according to claim 10, wherein the alloy forming said cathode comprises a refractory metal selected from the group consisting of tungsten, molybdenum, tantalum and niobium, and an adhesive metal selected from the group consisting of silver, copper, cobalt and nickel.

12. A duct according to claim 1, wherein said cathode is made of an alloy comprising 60 parts by weight of tungsten and 40 parts by weight of silver, and said cathode is made of a high chromium stainless steel containing more than 20 percent by weight of chromium.