| 摘要 |
PURPOSE:To perform concentration of the titled solution at high filtration rate without any mesh clogging or damage of a filter membrane by adjusting the gas pressure of a solution residence zone, a liquid feed pressure for circulation of a solution and a gas pressure in a gas/liquid separation process, so as to maintain the pressure of a filter membrane surface at constant level. CONSTITUTION:In a batch device which concentrates a solution containing an organic matter, valves 18, 22 are opened, the inner pressure of a container body 2 is restored to a normal level, and a raw liquid is supplied by a pump 6 until its described level. Next, valves 18, 2 are closed, and a compressor 8 is actuated to inject air into the container body 2 to maintain the inner pressure at a described level P1 and membrane surface pressure to a filter membrane 4 is kept high. When a pressure control switch 15 has reached a set value, a liquid flow pump 7 is actuated and maintained the pressure of the pump 7 at a described value P2 by a throttle of a control valve 27. Furthermore, the inner gas pressure P3 of a gas-liquid separator 10 for a filtrate is controlled by a pressure control valve 23, so that the membrane surface pressure is controlled to P1+P2-P3. As a result, a powder required for the liquid flow pump 7 can be reduced.
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