Method for membrane backwashing and backwashing apparatus
US8641904B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 13, 2005 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Nov 6, 2027 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D2321/185
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A backwashing method incorporating a membrane filtration apparatus in which a ceramic filtration membrane including a substrate layer 11b having an extremely large number of filtration pores and a separating layer 11a having filtration pores smaller than those of the substrate layer is accommodated in a casing. Air controlled to a pressure p1 is supplied to the secondary side of the filtration membrane so as to drain the filtrated water in the membrane filtration apparatus gradually toward the primary side. After that, air pressure is increased to p3 so as to push the water in the filtration membrane toward the primary side together with the air, thereby peeling off any fouling substances. Unlike in conventional cases, a large amount of backwashing drain water is at no time drained at any one time, and thus, without reducing the effectiveness of backwashing, a backwashing drain pipe can be designed to have a small diameter. As a result, equipment can be reduced in size and the flexibility of equipment can be enhanced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.