REVERSE OSMOSIS MEMBRANE-TYPE CONCENTRATING APPARATUS

摘要

PROBLEM TO BE SOLVED: To reliably change a switching valve to control the operation of a reverse osmosis membrane-type concentrating apparatus provided with an energy recovering function by a simple mechanism and provide a highly reliable and efficient reverse osmosis membrane-type concentrating apparatus. SOLUTION: An inlet port and an outlet port of a check valve 41 are connected respectively with a tank 1 for a liquid to be concentrated and a cylinder chamber 28 in a cap side of a double acting pump 21. A switch valve 61 has three pairs of inlet and outlet ports and these parts are connected with the cylinder chamber 28 in the cap side and a cylinder chamber 29 in a head side of the double acting pump 21 as well as with a reverse osmosis membrane tank 11. A spool 75 of the switch valve 61 is driven by a coil spring 79 and pressure of the liquid to be concentrated and a concentrated liquid. The pressure energy of the concentrated liquid which flows in the cylinder chamber 29 in the bend side is recovered as the driving energy for the double acting pump 21.