Method of back-washing submerged-type ceramic membrane separation apparatus
US5647988A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 2, 1994 |
| Grant date | Jul 15, 1997 |
| Priority date | — |
| Expiry date | Dec 2, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02A20/131
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for back-washing a submerged-type ceramic membrane separation apparatus is provided in which filtrate once removed from the apparatus and a chemical agent are forcibly supplied to filtrate passages in ceramic membrane filters to wash the ceramic membrane filters with the filtrate and with the chemical agent, wherein the water washing and chemical washing are carried out at a predetermined frequency ratio and for a predetermined time period, or wherein the frequency and time period of the chemical washing are determined on the basis of a transmembrane pressure difference, suction pressure or filtrate flux observed during a filtering operation performed by the membrane separation apparatus. This method makes it possible to avoid an excessive chemical washing, and to reduce the amounts of water and chemical agent and the time required for the chemical washing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.