Issued Patents 1997
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5649823 | Apparatus for improved manufacture of cement in long kilns | — | 1997-07-22 |
| 5632616 | Method and apparatus for injecting air into long cement kilns | Eric R. Hansen, Michael P. Heap | 1997-05-27 |