Issued Patents All Time
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 7322317 | Heat-recovery boiler | Walter Boll, Christoph Erdmann, Ulrich Wagner, Thomas Wurzel | 2008-01-29 |
| D479030 | Crystal shaped stone monument | — | 2003-08-26 |
| D478402 | Circular shaped stone monument | — | 2003-08-12 |
| 5935517 | Method of preventing metal dusting corrosion of ducts which conduct hot gas mixtures containing carbon monoxide | Friedrich Hohmann | 1999-08-10 |
| 5490974 | Tubular heater for preparing carbon monoxide-containing gas mixtures | Friedrich Hohmann, Hans G. Mortel | 1996-02-13 |
| 4411152 | Method and apparatus for testing pipes | — | 1983-10-25 |