Patent · US Expired

Sewage treatment system

US5653255A · kind A · utility

10Cited by
27References
11Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 7, 1995
Grant dateAug 5, 1997
Priority date
Expiry dateSep 7, 2015

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T137/87161
  • WIPO fieldEnvironmental technology
  • WIPO sectorChemistry

Abstract

A sewage treatment system includes a pair of substantially identical unitary fluid treatment modules, each module having a central sedimentation tank surrounded by a peripheral wetland. The sedimentation tanks are coupled through a dosing device to an input source of sewage and, as an outlet, to a leaching field. The dosing device includes a switching mechanism isolated from the fluids, which mechanism provides in one cycle for one treatment module to be filled with the incoming sewage while maintaining its outlet closed. When the liquid level in the sedimentation tank in the first treatment module reaches a predetermined level the dosing device switches the sewage input to the other treatment module, while opening the outlet from the first treatment module to the leaching field. The dosing device switching mechanism employs pinch valves arranged so that when the inlet on one treatment module is closed, the inlet on the other treatment module is substantially simultaneously opened. Similarly, when one sedimentation tank outlet module is opened, the outlet module from the sedimentation tank in the other treatment is substantially simultaneously closed. The switching mechanism is act…

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