Rise-rate control of pulsed-bed granular medium filters
US4693831A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 28, 1987 |
| Grant date | Sep 15, 1987 |
| Priority date | — |
| Expiry date | Jan 28, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D24/4869
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for controlling the pulsing of a granular medium filter, based on determination of the rise rate of liquid level above the filtration medium. A pulse system is activated whereby sub-fluidizing pulses of a fluid are directed upwardly through the filter medium from an array of orifices, and each pulse is initiated whenever the determined rise rate attains a predetermined value. The pulses dislodge solids from the upper surface of the bed and store a portion of the solids within the bed itself at particular loci, for decreasing the resistance of the bed and reducing the rise rate. The frequency of backwash is optimized over a wider range of solids load, liquid load and other factors affecting the filtration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.