Granted Patent
Utility
US 4,867,948 · App. 06/644,343
Fluidized bed reactor
Inventor:
Seppo Ruottu
Patented Case
View Patent ↗
Granted: Sep 19, 1989
Filed: Aug 27, 1984
Inventor
Seppo Ruottu
Assignee (at issue)
A. Ahlstrom Osakeyhtio
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.