Multi-action internal curve piston pump with energy recovery function for desalination system.

The installed capacity of seawater reverse osmosis (SWRO) as the main means to solve the water resource crisis is increasing year by year. However, the current SWRO is mainly composed of membrane components, high pressure pumps, booster pumps and energy recovery devices. In this paper, a new multi-action internal curve seawater desalination high-pressure pump with energy recovery function was proposed, which can recover the pressure energy of concentrated seawater and pressurize the raw seawater at the same time. The working principle and internal structure of the pump were described in detail, and the design of a pulsation-free structure was illustrated. The operating pressure and specific energy consumption of the proposed system with different membrane component structures, feed water flow rate and recovery rate were analyzed. The final design of the membrane component structure had one segment for each stage with three containers in each segment and eight reverse osmosis membranes in each container. The recovery rate and the feedwater flow rate of the proposed system were 40% and 531 m³/d, respectively. The specific energy consumption of water production reached 1.65 kWh/m³ in a validation test. The water production cost and the system volume were both significantly reduced. [ABSTRACT FROM AUTHOR]