Patent · US Active

Maintaining wastewater-treatment sand filters

US7744759B1 · kind B1 · utility

14Cited by
8References
18Claims
0Family size

Inventor

Key dates

Filing dateJul 29, 2009
Grant dateJun 29, 2010
Priority date—
Expiry dateJul 29, 2029

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC02F2303/16
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

A downflow sand filter used for treating wastewater which has degraded in function from its original design is at least in part rejuvenated by flowing air downwardly through the bed during time when flow of wastewater is ceased. The low velocity air flow helps dewater the bed and leads to the removal of accumulated organic material which has clogged the pores of the bed. In accord with different embodiments, air flow is alternated with water flow in particular ways, for instance, so the water flow is sufficient to create ponding or is sufficient to maintain moisture content within the bed.

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