Granted Patent
Utility
US 6,030,538 · App. 09/229,279
Method and apparatus for dewatering previously-dewatered municipal waste-water sludges using high electrical voltages
Inventor:
Jeffery S. Held
Patented Case
View Patent ↗
Granted: Feb 29, 2000
Filed: Jan 13, 1999
Inventor
Jeffery S. Held
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.