Ruhrgas Aktiengesellschaft
44Patents
0Active
44Granted
37Portfolio score
Filing activity: Apr 8, 1976 → Jun 13, 2000
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US4384792A | Process and apparatus for the combustionless measurement and/or control of the amount of heat fed to gas consumption devices | Physics | 28 | Expired |
| US5055032A | A burner with a flame retention device | Mechanical Engineering; Lighting; Heating | 26 | Expired |
| US4396371A | Device for controlling the air supply to a gas burner | Mechanical Engineering; Lighting; Heating | 24 | Expired |
| US4457704A | Method for the operation of a gas burner exposed to an air current as well as burners to implement the method | Mechanical Engineering; Lighting; Heating | 23 | Expired |
| US4541407A | Cooking station for gas ranges | Emerging Cross-Sectional Technologies | 23 | Expired |
| US6425942B1 | Method and device for drying a gas | Chemistry; Metallurgy | 16 | Expired |
| US4509913A | Device for controlling the air supply for a gas burner | Mechanical Engineering; Lighting; Heating | 16 | Expired |
| US4749002A | Shut-off device in the form of a ball valve | Emerging Cross-Sectional Technologies | 15 | Expired |
| US4960378A | Gas burner | Mechanical Engineering; Lighting; Heating | 14 | Expired |
| US5333591A | Device to control a gas-fired appliance | Emerging Cross-Sectional Technologies | 14 | Expired |
| US4941345A | Method and apparatus for the measurement of gas properties | Physics | 13 | Expired |
| US4689009A | Skid system for carrying a furnace charge | Mechanical Engineering; Lighting; Heating | 12 | Expired |
| US4569890A | Process for increasing the heating value of fuel gas mixtures containing hydrogen | Emerging Cross-Sectional Technologies | 12 | Expired |
| US4082520A | Process of producing gases having a high calorific value | Chemistry; Metallurgy | 12 | Expired |
| US4659306A | Method of and system for determining the ratio between the oxygen-carrying gas content and the fuel content of a mixture | Mechanical Engineering; Lighting; Heating | 12 | Expired |
| US4508501A | Method of monitoring furnace installations | Mechanical Engineering; Lighting; Heating | 10 | Expired |
| US4579523A | Method of operating a controlled atmosphere furnace | Mechanical Engineering; Lighting; Heating | 10 | Expired |
| US4859171A | Method and apparatus of operating pre-mixed burners | Mechanical Engineering; Lighting; Heating | 10 | Expired |
| US4723873A | Method and device for preparing an existing buried conduit for replacement by a new conduit | Emerging Cross-Sectional Technologies | 10 | Expired |
| US4585631A | Method for the conversion of nitrogen oxides contained in gaseous products of combustion | Performing Operations; Transporting | 9 | Expired |
| US6446487B1 | Method for measuring the quantity of heat present in fuel gas | Physics | 9 | Expired |
| US4501127A | Heating system incorporating an absorption-type heat pump and methods for the operation thereof | Emerging Cross-Sectional Technologies | 8 | Expired |
| US4738577A | Furnace for the heat treatment of work pieces | Mechanical Engineering; Lighting; Heating | 8 | Expired |
| US6244097A | Method for measuring without combustion the heat value of fuel gas | Physics | 8 | Expired |
| US4599092A | Process for the gasification of carbonaceous agglomerates in a fixed bed reactor | Chemistry; Metallurgy | 7 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.