Apparatus for sewer treatment to kill tree roots and other organic growth therewithin
Abstract
Abstract A composition for killing plant roots inside sewers, comprises an alkali metal alkyl dithiocarbamate in an amount of about 30%, a biodegradable liquid nonionic surfactant in an amount of about 12%, and water making up the remainder. One method for treating the sewer pipes comprises coating the inside wall of the pipe and any roots or other growth inside the pipe with the composition in the form of a foamy film by spraying it thereon or on the upper portion thereof, as from a continuously moving device. Preferred apparatus for so treating the sewer pipes comprises a sled having bottom skid means, a low center of gravity and a spray system mounted on said sled having generally upwardly directed nozzles, and means for pulling the sled through a pipe while supplying it with the composition under pressure. Another method comprises soaking with the solution diluted to about 2% of the methyldithiocarbamate, this being done by plugging the pipe and filling the pipe above the plug with the diluted solution. Special plugging apparatus is described.
Inventors
- 👤 Frederick F Horne
Bibliographic Details
Claims Analysis
Total Claims: 10References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-28 | 1978-10-28 | 1979-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-28 | 1982-10-28 | 1983-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-28 | 1986-10-28 | 1987-04-29 | $7700.00 | Window Closed / Lapsed |