Energy recovery device

Abstract

This invention provides an energy recovery device that prevents malfunctions due to reduced low-pressure brine flow during the filling process. The energy recovery device includes: first and second cylinder devices 9A and 9B, connected to a concentrated water pipe 4 via first and second pipe switching mechanisms 6A and 6B; a control unit C that controls the inflow and outflow of concentrated brine into these devices; a pipe control mechanism 11 for filling the first and second cylinder devices with low-pressure brine and sending the extruded high-pressure brine back to the membrane separation device via a booster pump 10; and a first flow meter 18a connected to the concentrated water pipe, measuring the flow rate of the concentrated brine and transmitting the measured first flow signal to the control unit, wherein the control unit controls the booster pump based on the first flow signal to adjust the flow rate of the concentrated brine flowing to the cylinder devices during the pressurized water supply process.

Images