IP Library Granted Patent US 4,325,921
Granted Patent Utility
US 4,325,921 · App. 06/147,459

Waste gas purification systems and methods

Inventors: John Edward Aiken, William J. Didycz
Patented Case View Patent ↗
Granted: Apr 20, 1982 Filed: May 7, 1980
Inventors
John Edward Aiken
William J. Didycz
Assignee (at issue)
United States Steel Corporation

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Quick Facts
Patent No.
US 4,325,921
App. No.
06/147,459
Filed
1980-05-07
Granted
1982-04-20
Kind
A