Patent · US Expired

Method to protect the surface of metal in vertical melting furnaces

US4828609A · kind A · utility

20Cited by
1References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 1, 1988
Grant dateMay 9, 1989
Priority date
Expiry dateMar 1, 2008

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF27D99/0075
  • WIPO fieldThermal processes and apparatus
  • WIPO sectorMechanical engineering

Abstract

Inert liquid gas such as liquid nitrogen or liquid argon is used in vertical melting furnaces to prevent oxidation of the metal during holding periods. The method can be applied to any kind of metal. The use of inert liquid gas for the "blow-dow" of the furnace will flush art all existing furnace atmosphere and prevent oxidation. The casting recovery time may be reduced from about one hour to 15 minutes. Also the layers of oxide resulting from oxidation can be negated, allowing for fewer rejects, if any, during further surface treatment.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.