Sewage treatment plants
Abstract
Abstract An automatically regulated plant for the treatment of sewage comprises a primary feeding tank for receiving liquid raw sewage, a pump immersed in said primary tank to feed the plant with the liquid discharged in the tank, means for controlling the operation of the pump, at least one digester with biologically active filter bed, means to convey a certain amount of the outflow of the treated effluent from said digester to the primary feeding tank, a valve for controlling the flow of the recirculated effluent, a program timer correlated with the means to control the operation of the pump and adapted to actuate the recirculation valve and to cause said valve to be drived into its open position after expiration of a delay period following the stopping of the pump.
Inventors
- 👤 Jean Joseph Regent
Bibliographic Details
Claims Analysis
Total Claims: 0References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |