Extraction of water from mines etc.

摘要

The water pump (1) is hydraulically driven using clean water supplied under pressure from the surface. The pump consists of a cylinder (2) with flat closure plates at the ends and a central wall (3) with a bore which has a watertight seal (6) engaging a piston rod (5). There are pistons (4a,b) on either side of the rod. Clean high-pressure water is admitted to the inner chambers (7a,b) formed between the pistons and the central wall to make the piston assembly reciprocate in the housing. Water to be pumped out of the mine is admitted to the outer chambers (8a,b) between the ends of the pistons and the end covers. There are control valves (10) for the inner chambers and (12) for the outer chambers.