Helmold von Plessen
14Patents
4h-index
18Co-inventors
57Inventor score
Filing activity: Jun 12, 1974 → Oct 4, 1994
Most-cited inventions
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US3972987A | Process for regenerating sulfuric acid | Chemistry; Metallurgy | 9 | Expired |
| US4010240A | Process for the regeneration of sulfuric acid | Chemistry; Metallurgy | 7 | Expired |
| US4479924A | Process for the separation of heavy metal compounds from phosphoric acid | Emerging Cross-Sectional Technologies | 7 | Expired |
| US5464876A | Process for the recovery of valuable materials during the work-up of polyvinyl chloride | Emerging Cross-Sectional Technologies | 4 | Expired |
| US4194952A | Process for regenerating waste sulfuric acid | Chemistry; Metallurgy | 3 | Expired |
| US4794204A | Process for the removal of dimethyl ether in methyl chloride | Chemistry; Metallurgy | 3 | Expired |
| US4032622A | Method of concentrating sulfuric acid using a boiler of improved cast iron | Chemistry; Metallurgy | 2 | Expired |
| US4916257A | Process for the purification of 2-hydroxynaphthalene-6-carboxylic acid | Chemistry; Metallurgy | 2 | Expired |
| US5308600A | Process for conditioning waste sulfuric acid | Emerging Cross-Sectional Technologies | 1 | Expired |
| US4145393A | Process for the protection against corrosion of cast iron in boiling concentrated sulfuric acid | Chemistry; Metallurgy | 1 | Expired |
| US4925959A | Dioxane adduct of 2-hydroxynaphthalene-6-carboxylic acid and process for the preparation thereof | Chemistry; Metallurgy | 0 | Expired |
| US4148858A | Process for the protection against corrosion of cast iron boilers | Chemistry; Metallurgy | 0 | Expired |
| US5047558A | Process for the preparation of a dioxane adduct of 2-hydroxynaphthalene-6-carboxylic acid | Chemistry; Metallurgy | 0 | Expired |
| US4150103A | Foam prevention during the regeneration of waste sulfuric acid with aromatic nitro compounds | Chemistry; Metallurgy | 0 | Expired |
Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.