This paper shows that the combination of a water hydraulic vane
pump and a vane hydraulic motor is a feasible approach for small
driven membrane system. The prototype pump was investigated
under pressure conditions of membrane module. The energy
reduction percentage was about 20% at the maximum operation
pressure. From the experiment results, volumetric efficiencies of the
pump and motor elements mainly affect hydraulic performance and
energy consumption of the prototype pump. Compared with other
ERDs, the prototype pump is easier to operate and maintain. The
cartridge design of the prototype pump is simply to replace the pump
or hydraulic motor element to change displacement, which adapt the
recovery ratio of membrane module. Like Danfoss APP–APM system,
two elements in the prototype pump are fixed displacement and
connected by a shaft with the same rotation speed, so the membrane
system has constant recovery ratio and less flexibility. When the performance of the membrane module and the pump/motor element
are accurately designed, the membrane separation system can reach
optimized operation conditions.