Patent · US Expired

Filter and method

US4082664A · kind A · utility

20Cited by
6References
57Claims
0Family size

Assignee

Inventor

Key dates

Filing dateJun 2, 1977
Grant dateApr 4, 1978
Priority date
Expiry dateJun 2, 1997

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D24/4884
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

The rotating backwash isolation hood of a multibed filter is raised and lowered by either hydraulic forces and gravity, or by an improved mechanism employing a pair of pistons and cylinders and a perforated indexing disc, or by both of these arrangements. The force required to lift the hood is reduced by eliminating the effect of the static head of the liquid above the hood. Leakage between the hood and the filter it covers is detected by a pressure differential indicating switch. A floculator may be combined with the multibed filter, and the dirty backwash liquid from the hood may be recirculated into the floculator.

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