Double balanced rotary pump for reverse osmosis water purification comprises two rotating cylinders containing axial pistons having specified displacement in the barrels

摘要

A double balanced rotary pump (2) has two rotating cylinders (20a, 20b) containing axial pistons (27a, 27b). The pistons in each cylinder operate alternately, one set discharging while the other draws in liquid. The displacement of the pistons in the first barrel is greater than in the second, by a similar ratio to the ratio of liquid fed to, and recycled from, the membrane filter (1).