Pulsed backwash for immersed membranes
US6547968B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1999 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Oct 25, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02W10/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method and apparatus for chemical cleaning microfiltration and ultrafiltration membranes immersed in a tank involves backwashing a chemical cleaner through the membranes while the tank is empty of tank water. A backwash pump which drives the chemical cleaner is controlled by a speed controller which is in turn connected to a programmable logic control and, preferably pressure and flow indicators. The backwash pump is operated to supply the chemical cleaner to the membranes in pulses. The pressure of the pulses is high enough to reduce the relative size of pressure differentials between membranes or portions of membranes in varying places in the tank. The duration and frequency of the pulses is chosen to provide an appropriate contact time of the chemical, preferably without allowing the membranes to dry between pulses and without using excessive amounts of chemical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.