LOWER HEAD OF DOWNHOLE HYDRAULIC MINING TOOL Russian patent published in 2006 - IPC E21C45/00 

FIELD: mineral field development by hydraulic mining methods, as well as borehole drilling and all-purpose underground cavities creation.

SUBSTANCE: device comprises connection pipe for pressure water. Connection pipe of slurry pipeline has conical constricted section, wear-resistant insert made as spaced rings of wear-resistant material installed downstream from the conical constricted section in slurry flow direction, and conical widening section arranged downstream from the rings. Connection pipe of slurry pipeline has orifices made in area of ring location and adapted to supply pressure water into connection pipe of slurry pipeline via gaps defined between the rings. Hydraulic elevator is arranged at end of connection pipe for pressure water. Connection pipe for pressure water and hydraulic elevator may have water-jet nozzles. Gaps between rings of wear-resistant insert are created due to ring end roughness. As pressure water is supplied part of flow moving via annular gap passes through annular hydraulic elevator and enters into connection pipe of slurry pipeline to create ascending flow. Due to created vacuum washed mineral is sucked into connection pipe of slurry pipeline in slurry form and then transported to surface.

EFFECT: reduced wear of inlet connection pipe part.

3 cl, 1 dwg