Backwashing system for slurry pick-up used in hydraulic borehole mining devices
US4074779A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 1977 |
| Grant date | Feb 21, 1978 |
| Priority date | — |
| Expiry date | May 9, 1997 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B21/103
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A hydraulic borehole mining device is provided of the type wherein a pair of high pressure water jets located along the length of the device are used to cut the mineral to be mined and a slurry pick-up system used to transport the particles cut away by the jets back to the ground surface. The slurry pick-up may include a slurry jet pump which is also supplied with water under pressure. The jet pump includes a jet nozzle which is directed so as to draw particles through screens that cover inlets for the particles located about the circumference of the device, and which thus entrains the particles in a slurry with the water, this slurry of water and mineral particles being pumped back to the surface. To prevent clogging or blocking of the screens such as can occur when particles accumulate thereon, a backflush or backwash valve is provided which, when actuated, blocks and deflects the water from the jet nozzle and thus causes the water flow to reverse itself and pass out through the screens to thereby provide cleaning of the screens.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.