Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5675977 | Cryogenic rectification system with kettle liquid column | — | 1997-10-14 |
| 5600970 | Cryogenic rectification system with nitrogen turboexpander heat pump | Raymond Francis Drnevich | 1997-02-11 |