Water treatment method
US5310488A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 1, 1991 |
| Grant date | May 10, 1994 |
| Priority date | — |
| Expiry date | Mar 1, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F2303/16
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A water treatment apparatus and method for softening "problem water". The apparatus includes a pair of treatment tank assemblies, each tank including serially connected filter and ion exchange beds. When a tank assembly requires regeneration, the tank assembly is taken off line and is regenerated using a regenerating apparatus that communicates a mixture of citric acid and brine solution to the ion exchange bed, followed by brine solution alone to form a barrier. A mixture of sodium carbonate and brine solution is then communicated to the ion exchange bed followed by a backwashing step which conveys treated water through both the ion exchange bed and the filter media in a counter flow direction. The regeneration apparatus includes a brine venturi and a chemical draw venturi connected in a parallel flow relationship and solenoid control valves for selectively communicating either a citric acid reservoir or a sodium carbonate reservoir to the chemical draw venturi. A timer or sequencer sequentially activates the control valves for predetermined time intervals. A heater and insulation is provided for the sodium carbonate reservoir to inhibit precipitation of the sodium carbonate out o…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.