The present invention relates to a concentration device that concentrates a subject solution that is a subject to be treated.
A technique of concentrating a subject solution by passing a permeate (mainly water) from the subject solution through a semipermeable membrane is available (for example, PTL 1).
Devices that can be installed in a small space and efficiently concentrate a subject solution have been demanded in recent years.
In order to solve the problem, the inventors finally completed the present invention as a result of diligent studies. The present invention is configured as follows:
[1] A concentration device including a membrane module having a first flow path and a second flow path that are separated by a semipermeable membrane, wherein the membrane module includes a U-shaped tube in which the semipermeable membrane is disposed, a first flow-path-inlet connection part and a first flow-path-outlet connection part that are an inlet and an outlet of the first flow path respectively, and a second flow-path-inlet connection part and a second flow-path-outlet connection part that are an inlet and an outlet of the second flow path respectively, and the concentration device includes a liquid introducing means for introducing a subject solution with a predetermined pressure into the first flow path from the first flow-path-inlet connection part, separating the subject solution into a concentrate and a permeate through the semipermeable membrane, passing the permeate through the second flow path, draining the concentrate from the first flow-path-outlet connection part, introducing the subject solution with a pressure lower than the predetermined pressure into the second flow path from the second flow-path-inlet connection part, and draining a diluent, which is diluted with the permeate, from the second flow-path-outlet connection part.
[2] The concentration device according to [1], wherein the semipermeable membrane is a hollow-fiber membrane, the hollow-fiber membrane being charged in a U-shape into the U-shape tube, the U-shaped tube has hollow-fiber membrane support parts on both ends of the U-shaped tube, the hollow-fiber membrane being fixed with opened hollow-fiber ends to the U-shaped tube in a fluid-tight state by the hollow-fiber membrane support parts, the first flow-path-inlet connection part and the first flow-path-outlet connection part are configured to communicate with an external passage of the hollow-fiber membrane that is the first flow path, and the second flow-path-inlet connection part and the second flow-path-outlet connection part are configured to communicate with an internal passage of the hollow-fiber membrane that is the second flow path.
[3] The concentration device according to [2], wherein a contact surface between the U-shaped tube and the hollow-fiber membrane support part is subjected to roughening.
[4] The concentration device according to any one of [1] to [3], wherein the concentration device includes the plurality of membrane modules, the first flow-path-outlet connection part of the n-th membrane module and the first flow-path-inlet connection part of the n+1-th membrane module are connected to each other, and the second flow-path-outlet connection part of the n+1-th membrane module and the second flow-path-inlet connection part of the n-th membrane module are connected to each other.
A concentration device of the present invention configured as described above includes a membrane module having a U-shaped tube and thus can be installed in a small space and can efficiently concentrate a subject solution.
An embodiment of the present invention will be specifically described with reference to the accompanying drawings. In the following embodiment, the same or common parts in the drawings are indicated by the same reference numerals and a repetition of the description is omitted. In the case of a plurality of embodiments, it is assumed that the characterizing portions of the embodiments are properly combined unless otherwise specified.
U-shaped tube 110 is a tube having a U-shaped structure, in which hollow-fiber membrane 120 is disposed. U-shaped tube 110 has a structure in which the tube is bent in a U shape. The bending radius, the tube diameter, the length, and the material or the like of the tube can be properly designed according to the installation space, durability, and the components and the throughput of a subject solution. Hollow-fiber membrane 120 may be a semipermeable membrane shaped like a hollow fiber, e.g., a reverse osmosis membrane, a forward osmosis membrane, or a nano-membrane filter. The pressure resistance, the pore size, the thickness, and the material of hollow-fiber membrane 120 may be properly selected according to the subject solution. Hollow-fiber membrane module 100 is divided into an external passage (first flow path) and an internal passage (second flow path) by hollow-fiber membrane 120.
Hollow-fiber membrane module 100 includes hollow-fiber membrane support parts 130. Hollow-fiber membrane support part 130 is disposed on each end of U-shaped tube 110. Both ends of hollow-fiber membrane 120 are fixed by hollow-fiber membrane support parts 130 such that a fluid-tight state is obtained in U-shaped tube 110 with opened hollow-fiber ends. The materials of hollow-fiber membrane support parts 130 can be formed of, but not limited to resin or the like. The material can be selected according to the subject solution or pressure resistance.
Peripheral-side connection parts (a first flow-path-inlet connection part and a first flow-path-outlet connection part) 111 are components mounted on U-shaped tube 110. Peripheral-side connection parts 111 are opened ports for introducing the subject solution so as to be into contact with the external passage of hollow-fiber membrane 120 from the outside of hollow-fiber membrane module 100 and draining the subject solution out of hollow-fiber membrane module 100. Hollow-fiber membrane module 100 includes at least two peripheral-side connection parts 111 that correspond to an inlet and an outlet for the subject solution and are configured to communicate with the external passage of hollow-fiber membrane 120. End connection parts (a second flow-path-inlet connection part and a second flow-path-outlet connection part) 112 are components mounted on U-shaped tube 110. End connection parts 112 are opened ports for introducing the subject solution so as to be into contact with the internal passage (second flow path) of hollow-fiber membrane 120 from the outside of hollow-fiber membrane module 100 and draining the subject solution out of hollow-fiber membrane module 100. Hollow-fiber membrane module 100 includes at least two end connection parts 112 that correspond to an inlet and an outlet for the subject solution and are configured to communicate with the internal passage of hollow-fiber membrane 120. Types of connection of peripheral-side connection parts 111 and end connection parts 112 include a tube-joint connection and a screw-in connection and may be selected as appropriate. Moreover, the materials of peripheral-side connection parts 111 and end connection parts 112 may be selected as appropriate.
As described above, the subject solution with the predetermined pressure is introduced into the external passage from peripheral-side connection part 111 on the inlet side, and the subject solution with a pressure lower than the predetermined pressure is introduced into the internal passage from end connection part 112 on the inlet side, so that the introduced solution is treated as follows: the subject solution introduced into the external passage is separated through hollow-fiber membrane 120 into a permeate that permeates through the membrane and a concentrate that does not permeate through the membrane. The concentrate is drained from peripheral-side connection part 111 on the outlet side. On the other hand, the separated permeate joins the subject solution introduced into the internal passage in hollow-fiber membrane module 100 from end connection part 112 on the inlet side, and then the permeate is drained as a diluent from the end connection part 112 on the outlet side. Thus, the concentrate drained from peripheral-side connection part 111 on the outlet side is concentrated more than the subject solution introduced from peripheral-side connection part 111 on the inlet side, and the diluent drained from end connection part 112 on the outlet side is diluted more than the subject solution introduced from end connection part 112 on the inlet side. The subject solution introduced from peripheral-side connection part 111 on the inlet side and the subject solution introduced from end connection part 112 on the inlet side may have different concentrations.
Furthermore, concentration device 200 may be provided with a priming pot 250 on the suction side of pump 210. Priming pot 250 is a device for removing air in pump 210 to suppress a reduction in the amount of discharge, the reduction being caused by trapped air. As illustrated in
Moreover, as illustrated in
Concentration device 300 drains the concentrate of the subject solution from peripheral-side connection part 111 on the outlet side and drains the diluent of the subject solution from end connection part 112 on the outlet side. The ratio of the amount of the collected concentrate and the amount of the concentrate introduced into end connection parts 112 on the inlet side is adjusted by valves 320 and 330.
Also in concentration device 300, a priming pot 340, an accumulator 360, and a pressure controller 370 may be provided as necessary. A concentrate drained from peripheral-side connection part 111 on the outlet side may be introduced into pump 310 to circulate the subject solution.
In concentration device 400 illustrated in
Furthermore, in concentration devices 200, 300, and 400, pipe devices such as a switching valve and a joint and measuring instruments such as a flowmeter, a pressure gauge, and a thermometer may be installed as appropriate. Operation conditions such as a pressure, a flow rate, and a temperature may be set according to the degree of concentration and throughput of the subject solution.
By adopting the hollow-fiber membrane modules and the concentration devices according to the present invention described above, the subject solution can be more efficiently concentrated than in a reverse osmosis membrane method (RO method). Moreover, because of the shape of U-shaped tube 110, the dimensions of the module in the longitudinal direction are about half those of a linear straight pipe, advantageously saving the space of the concentration device. Peripheral-side connection parts 111 and end connection parts 112 are opened as illustrated in
It should be understood that the disclosed embodiments are merely exemplary and are not restrictive in all the aspects. The scope of the present invention is not indicated by the foregoing description but the claims. The scope of the present invention is intended to include meanings equivalent to the claims and all changes in the scope.
Number | Date | Country | Kind |
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202110207619.X | Feb 2021 | CN | national |
202120408482.X | Feb 2021 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2022/006934 | 2/21/2022 | WO |