| 摘要 |
PURPOSE:To increase a liquid permeation rate without causing damage to a reverse-osmosis membrane, by providing a high-pressure pump with a speed-changing means, controlling the high-pressure pump after a measured liquid permeation rate is compared with a predetermined desirable rate, and decreasing the operation speed of the high pressure pump if a supplying pressure exceeds a tolerance-limit pressure for the reverse-osmosis membrane. CONSTITUTION:The liquid permeation rate Q measured by a liquid flow sensor 14 placed in a pipe 9 for transmission of a penetrated liquid from a reverse-permeable membrane tank 1 is compared with a predetermined liquid rate Qo of liquid permeation. In the case of Q<Qo, a controller 15 signals a speed-changing means 11 of a high-pressure pump 6 to increase its revolution number or reciprocation number; and in the case of Q>Qo, it signals to reduce the number. At the same time, the supplying pressure P and temperature T of a liquid to be condensed are measured by a pressure sensor 13 and a temperature sensor 12 placed in a supplying pipe 8 for supplying the liquid to be condensed. The controller 15 compares the measured value of the supplying pressure P with a tolerance-limit pressure Pa which is lower by a suitable value than the critical pressure Pm at which a reverse-permeable membrane 2 suffers damage at the temperature T of the liquid to be condensed. Where P exceeds Pa, the controller 15 signals the speed-changing means 11 to reduce the revolution number or reciprocation number. |
