Patent · US Expired

Slow sand filters

US4911831A · kind A · utility

10Cited by

11References

34Claims

0Family size

Assignee

Thames Water Authority · GB

Inventors

Roger C. Davison · Wichita Falls, US
Michael Bauer · Unterföhring, DE

Key dates

Filing date	Sep 28, 1988
Grant date	Mar 27, 1990
Priority date	—
Expiry date	Sep 28, 2008

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB01D24/48
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

The invention relates to an apparatus for cleaning a slow sand filter for a body of liquid while the liquid is in situ, in which there is a carrier adapted to traverse the body of liquid, and a device carried by the carrier and adapted to skim successive layers of sand from the filter. The carrier is a floatable vessel and the skimmer device is an auger. The skimmer device is controlled by depth control means which are automatically adjusted in response to the contour of the filter.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.