Granted Patent
Utility
US 4,278,621 · App. 06/149,729
Vapor-liquid contacting system
Inventors:
Paul W. Sigmund, Kenneth F. Butwell
Patented Case
View Patent ↗
Granted: Jul 14, 1981
Filed: May 14, 1980
Inventors
Paul W. Sigmund
Kenneth F. Butwell
Assignee (at issue)
Union Carbide Corporation
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.