Granted Patent
Utility
US 6,821,420 · App. 10/428,601
Apparatus and method for cleaning membrane filtration modules
Inventors:
Fufang Zha, Edward John Jordan
Patented Case
View Patent ↗
Granted: Nov 23, 2004
Filed: May 1, 2003
Inventors
Fufang Zha
Edward John Jordan
Assignee (at issue)
U.S. Filter Wastewater Group, Inc.
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.