Spiral wound membrane element, spiral wound membrane module and treatment system employing the same as well as running method and washing method therefor
US6733675B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2001 |
| Grant date | May 11, 2004 |
| Priority date | — |
| Expiry date | Apr 20, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2325/24
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A spiral wound membrane module comprises a spiral wound membrane element including a separation membrane having high back pressure strength. In filtration running, raw water introduced from a raw water inlet of a pressure vessel is subjected to dead end filtration, and permeate is taken out from a permeate outlet. In washing, wash water containing a chemical having a contaminant separating function is introduced from an end of a water collection pipe through the permeate outlet for performing back wash reverse filtration with a back pressure of 0.05 to 0.3 MPa. The filtration running is temporarily stopped for maintaining the pressure vessel in a state sealed with the raw water and the permeate for a prescribed time. Thus, contaminants adhering to the membrane surface of the spiral wound membrane element are separated. A treatment system is formed by connecting units comprising spiral wound membrane modules in parallel with each other. In the treatment system, one of the units is subjected to filtration running when another one of the units is washed. In washing, back wash reverse filtration and chemical soaking are performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.