Double-acting Reciprocating Pump for Water Desalination with Reverse Osmosis

The present paper describes the work carried out in the development of a pump system for water desalination in a small reverse osmosis plant. The system must satisfy high pressure (4.8 MPa) and low flow rates (3.78 L/min) to operate the reverse osmosis membrane in its minimum energy consumption range. In order to achieve this objective, a positive displacement pump system (single action double effect) driven by a cyclo speed reduction was developed. The system was tested under laboratory conditions. The analysis of the results shows high energy conversion efficiencies throughout the pumping cycle. The equipment was validated based on the acceptable flow and permeates concentration results. This design is able of replacing actual pump systems that are technologically complex and at the same time more expensive.