JP2000051663A5 - - Google Patents

Claims (16)

A reverse osmosis membrane module unit is arranged in multiple stages downstream of the pressurizing pump for pressurizing the supply water, and the concentrate flow path from the previous reverse osmosis membrane module unit is connected to the supply liquid flow path of the next reverse osmosis membrane module unit. A reverse osmosis membrane separation device which is in communication with at least one stage of the reverse osmosis membrane module unit and which is provided with a means for adjusting permeate pressure or permeate flow rate. Permeate pressure or permeate water flow rate means for adjusting the found pressure regulating valve provided in permeate channel, flow control valve, to claim 1, characterized in that comprises at least one of the pressure energy recovery device The reverse osmosis membrane separation device according to the above. A device for recovering the pressure energy of concentrated water of the reverse osmosis membrane module unit of the permeate and / or the final stage, the recovery device of the pressure energy, the first-stage reverse osmosis membrane module supply water boost pressure of the unit The reverse osmosis membrane separation device according to claim 1 or 2 , which is connected to a pump. The reverse osmosis membrane separation device according to any one of claims 1 to 3 , further comprising means for adding a scale inhibitor. The reverse osmosis membrane separation device according to any one of claims 1 to 4 , wherein a membrane filtration device is provided as a pretreatment upstream of the first-stage reverse osmosis membrane module unit. The reverse osmosis membrane separation device according to any one of claims 1 to 5 , wherein the pressure resistance of the permeated water channel of at least the first-stage reverse osmosis membrane module unit is 2.0 MPa or more. In the method of reverse osmosis separation of feed water using reverse osmosis membrane module units arranged in multiple stages, the concentrated liquid flow path from the previous reverse osmosis membrane module unit is supplied to the supply liquid flow path of the next reverse osmosis membrane module unit communicating the allowed Rutotomoni, reverse osmosis membrane separation method characterized by adjusting the permeate pressure or permeate water flow rate in at least one stage of the reverse osmosis membrane module unit. The operating pressure "P (n + 1)" of the reverse osmosis membrane module unit of the operating pressure of the reverse osmosis membrane module unit of the "n" th stage as "P (n)", "n + 1" th stage, in the range of below The reverse osmosis membrane separation method according to claim 7, characterized in that:
1.15 ≦ P (n + 1) / P (n) ≦ 1.8 Regarding the membrane surface flow velocity of the concentrated water of the reverse osmosis membrane module unit at each stage, the concentrated membrane surface flow velocity (maximum concentrated water membrane surface velocity) of the reverse osmosis membrane module unit having the largest membrane surface velocity and the smallest membrane surface velocity The reverse osmosis membrane separation according to claim 7 or 8 , wherein the reverse osmosis membrane module unit is operated so that the concentrated water membrane surface flow rate (minimum concentrated water membrane surface flow rate) has the following relationship. Method.
Maximum concentrated water film surface velocity / minimum concentrated water film surface velocity ≦ 1.5 The reverse osmosis membrane separation method according to any one of claims 7 to 9 , wherein the supply liquid is an aqueous solution having a solute concentration of 0.5% by weight or more. The total amount of the permeated water obtained from the reverse osmosis membrane module units each stage, according to any one of claims 7 to 10, characterized in that at least 50% of the feed water of the reverse osmosis membrane module unit of the first stage Reverse osmosis membrane separation method. Reverse osmosis membrane separation method according to any one of claims 7 to 11 the flux per membrane area of the reverse osmosis membrane, characterized in that less 0.75m ³ / m ² · day. Permeation flux at standard conditions per membrane area in the reverse osmosis membrane module unit of the reverse osmosis membrane module unit and the final stage of the first stage, to any of the claims 7-12, characterized in that a relation of the following The method for separating reverse osmosis membrane according to the above.
1.0 ≦ first stage permeation flux / final stage permeation flux ≦ 1.2 Claim 7, characterized by using a permeate and / or feed water of the reverse osmosis membrane module unit of the pressure energy of concentrated water of the reverse osmosis membrane module unit of the last stage to recover the first stage to pressurize 14. The method for separating a reverse osmosis membrane according to any one of 13 . The reverse osmosis membrane separation method according to any one of claims 7 to 14 , wherein at least the water supplied to the reverse osmosis membrane module unit at the final stage contains a scale inhibitor, a complex of a scale inhibitor, or a complex. . The reverse osmosis membrane separation method according to any one of claims 7 to 15 , wherein the permeate of the membrane filtration device is used as a supply liquid for the first- stage reverse osmosis membrane module unit.