Issued Patents 1994
Showing 1–2 of 2 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 5362395 | Method and apparatus for biologically purifying sewage which is organically loaded with substances difficult to decompose biologically or not decomposable biologically | Wolfgang Dorau, Herbert Wienands, Robert Rautenbach, Rainer Mellis | 1994-11-08 |
| 5348042 | Ceramic-plate flow-control valve | Walter Grau | 1994-09-20 |