Scale and corrosion control in flowing waters
Abstract
Abstract Disclosed is a method of conditioning water, particularly flowing or circulating water streams (e.g., as used in cooling water systems), to reduce the corrosive attack and/or scale accumulation on metal surfaces which the water contacts. The method includes introducing into the water a water soluble cationic polymer and a polyphosphate. The cationic polymer is a polyamide containing quaternary ammonium groups or a polyureylene containing quaternary ammonium groups. The polyphosphate is an inorganic polyphosphate or a polyfunctional acid phosphate ester of a polyhydric alcohol (i.e., a phosphorylated polyol). The cationic polymers synergistically increase the effectiveness of the polyphosphate as corrosion and scale inhibitors in certain waters. A typical inorganic polyphosphate is sodium tripolyphosphate. A typical phosphorylated polyol is phosphorylated pentaerythritol.
Inventors
- 👤 D Zecher
Bibliographic Details
Claims Analysis
Total Claims: 2References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1977-02-18 | 1977-08-20 | 1978-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-18 | 1981-08-20 | 1982-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-18 | 1985-08-20 | 1986-02-19 | $7700.00 | Window Closed / Lapsed |