Granted Patent
Utility
US 4,806,132 · App. 07/065,482
Turndown control method for membrane separation systems
Inventor:
Michael J. Campbell
Patented Case
View Patent ↗
Granted: Feb 21, 1989
Filed: Jun 23, 1987
Inventor
Michael J. Campbell
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.