Method for inhibiting corrosion in aqueous systems
US4237090A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1978 |
| Grant date | Dec 2, 1980 |
| Priority date | — |
| Expiry date | Nov 15, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F5/125
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
This invention is a method for inhibiting corrosion in aqueous systems containing components composed of aluminum, copper, iron, or alloys thereof. The method comprises (a) incorporating in the aqueous medium 2-10 ppm by weight of tolyltriazole; an effective amount of a biodegradable organic biocide; 500-1000 ppm by weight of sodium metasilicate; 500-2000 ppm by weight of sodium nitrite; and 500-2000 ppm by weight of sodium tetraborate, all of these concentrations being based on the weight of water in the system; and (b) maintaining the pH of the resulting system in the range of 7.5 to 8.0. The method permits longterm operation with very low corrosion rates and bacteria counts. All of the additives to the system are biodegradable, permitting the treated aqueous medium to be discharged to the environment without violating current regulations. The method has special application to solar systems in which an aqueous medium is circulated through aluminum-alloy heat exchangers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.