Hitachi Plant Engineering & Construction Co., Ltd.
61Patents
3Active
61Granted
39Portfolio score
Filing activity: Dec 20, 1976 → May 3, 2006 · 3 expiring within 5 years
Most-cited patents
| Patent | Title | Area | Cited by | Status |
|---|---|---|---|---|
| US6732540B2 | Air conditioning plant and control method thereof | Mechanical Engineering; Lighting; Heating | 146 | Expired |
| US4549472A | Rearrangeable partial environmental control device | Mechanical Engineering; Lighting; Heating | 80 | Expired |
| US5018202A | Electronic noise attenuation system | Physics | 79 | Expired |
| US4783817A | Electronic noise attenuation system | Physics | 54 | Expired |
| US4667481A | Method of and apparatus for emitting light in ice | Emerging Cross-Sectional Technologies | 50 | Expired |
| US4791061A | Immobilization of microorganisms by entrapment | Emerging Cross-Sectional Technologies | 30 | Expired |
| US4440552A | Electrostatic particle precipitator | Performing Operations; Transporting | 27 | Expired |
| US4693173A | Clean room | Mechanical Engineering; Lighting; Heating | 25 | Expired |
| US4976815A | Draft chamber | Electricity | 17 | Expired |
| US4412930A | Heat-storing composition | Emerging Cross-Sectional Technologies | 16 | Expired |
| US4117255A | Insulator bushing for high voltage input | Electricity | 16 | Expired |
| US4198293A | Tubular membrane separation process and apparatus therefor | Performing Operations; Transporting | 16 | Expired |
| US5558763A | Sewage treatment system with air jetting means | Emerging Cross-Sectional Technologies | 16 | Expired |
| US4160713A | Process for electro-dialysis | Emerging Cross-Sectional Technologies | 14 | Expired |
| US5295192A | Electronic noise attenuation method and apparatus for use in effecting such method | Physics | 13 | Expired |
| US4130268A | Rotary valve for powdery and granular materials | Emerging Cross-Sectional Technologies | 12 | Expired |
| US6572468B1 | Clean room device | Mechanical Engineering; Lighting; Heating | 12 | Expired |
| US5849180A | Method of biologically removing nitrogen and system therefor | Emerging Cross-Sectional Technologies | 10 | Expired |
| US5976378A | Method and system for removing nitrogen and immobilized microorganisms | Emerging Cross-Sectional Technologies | 10 | Expired |
| US4245998A | Method and apparatus for crystallization of solution containing salts | Performing Operations; Transporting | 9 | Expired |
| US5061368A | System for treating waste water by nitrification | Emerging Cross-Sectional Technologies | 8 | Expired |
| US5997736A | Method of biologically removing nitrogen and system therefor | Emerging Cross-Sectional Technologies | 8 | Expired |
| US4255255A | Tubular membrane separation process and apparatus therefor | Emerging Cross-Sectional Technologies | 8 | Expired |
| US5578200A | Sewage treatment system | Emerging Cross-Sectional Technologies | 7 | Expired |
| US4415465A | Heat-storing composition | Emerging Cross-Sectional Technologies | 7 | Expired |
Source: USPTO / EPO open patent data. Counts and citation impact are objective bibliographic measures.