Functionality test of an innovative single-cylinder energy recovery device for SWRO desalination system

• An innovative single-cylinder energy recovery device is introduced and developed.
• Two new plates greatly improve power consumption and flow continuity of the device.
• Functionality and reliability of the SC-ERD are well verified through experiments.

Energy recovery devices (ERDs) are widely used in seawater reverse osmosis (SWRO) desalination systems, and have become a vital facility of the system due to their great contribution for significant reductions of the power consumption. The innovative single-cylinder ERD (SC-ERD) technology is an improved pressure exchanger concept which follows the principle of positive displacement, and provides more advantages than the current devices, including the simple installation, flexible operation and stable performance. This paper focuses on verifying the functionality of the SC-ERD and evaluating its operating performance based on the industrial conditions. Experiments are carried out by using two sets of SC-ERD working in parallel and the performance of the devices are evaluated by employing an inhouse emulational SWRO system with the flow rate of 30 m3/h and the operating pressure of 6.5 MPa. The experimental results show that two SC-ERDs in parallel have reached the basic function of the double-cylinders ERD (DC-ERD). The pressure fluctuation of the SC-ERD has been reduced about 80% compared with the DC-ERD under the same operating conditions and the energy recovery efficiency could still be remained as high as 98%.