Underdrain for granular medium filter
US5089147A · kind A · utility
13Cited by
20References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 1, 1991 |
| Grant date | Feb 18, 1992 |
| Priority date | — |
| Expiry date | May 1, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D24/4869
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved apparatus and method for operating a granular medium filter is disclosed. The apparatus comprises an improved underdrain structure made up of a plurality of rectangular compartments which allows the filter bed to be "air pulsed" as well as backwashed for thorough cleaning of the bed. Nozzles are positioned within the rectangular compartments and directed vertically into the filter bed. Fluid from the nozzles helps to break up the bed during backwashing as well as countereact size classification of the medium during this process. The method of operating a filter with the improved underdrain structure is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.