| Number | Name | Date | Kind |
|---|---|---|---|
| D223701 | Lausch | May 1972 | |
| D245999 | Strigle | Oct 1977 | |
| D281308 | Bussey | Nov 1985 | |
| D337148 | Burens | Jul 1993 | |
| D344784 | Swingle | Mar 1994 | |
| 3481455 | Graham et al. | Dec 1969 | |
| 4333893 | Clyde | Jun 1982 | |
| 4425285 | Shimoi et al. | Jan 1984 | |
| 4575435 | Kuhl | Mar 1986 | |
| 5304423 | Niknafs et al. | Apr 1994 |
| Number | Date | Country |
|---|---|---|
| 316497 | Nov 1919 | DEX |
| 1945048 | Sep 1969 | DEX |
| Entry |
|---|
| Design Information for packed Towers, pp. 3-39 Norton Company's Engineering Laboratories, 1977, Akron, Ohio. |