System for maintaining a clean skein of hollow fibers while filtering suspended solids
US6193890A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 1999 |
| Grant date | Feb 27, 2001 |
| Priority date | — |
| Expiry date | Aug 30, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC02F1/444
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The outer surfaces of hollow fiber membranes in a skein, or a bank or cassette of stacked skeins, are kept essentially free of solids by maintaining a substantially uniform flow of a stream of coarse bubbles through each of plural orifices in an aerator disposed beneath the fibers. Aerators for skeins used in microfiltration of wastewater in a tank are periodically flushed when their air orifices are fouled, by injecting a flushing fluid into a fouled aerator. The flushing fluid may be a two-phase mixture of flushing liquid and air, or flushing liquid only. The flushing liquid may be permeate, clean water or wastewater (substrate). When air is injected into the flushing liquid flowed to an aerator for less than 5 min, preferably less than 20 sec, the flushing fluid produces discrete masses of liquid which are flowed laterally through the body of the aerator, cleaning its walls and maintaining the orifices essentially free from plugging. When only flushing liquid is flowed through the fouled aerator for less than 5 min, preferably less than 20 sec, the flushing liquid is highly effective to keep the air orifices clean.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.