JPH0698274B2 - Membrane separation device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a membrane separation device, and more specifically, it suppresses concentration polarization of solute and formation of gel and cake of solute on the surface of the membrane separation means, and has high permeability. The present invention relates to a membrane separation device capable of maintaining the above.

[Prior Art] Various membrane separation devices using a reverse osmosis membrane, an ultrafiltration membrane, a microfiltration membrane, etc. are known. When solutes and particles are subjected to membrane separation with such a membrane separation device, solutes are concentrated on the membrane surface and concentration polarization occurs, and depending on the type of solute or particles, a gel layer or a cake layer is formed on the membrane surface. For this reason, the passage speed of the solvent passing through the membrane surface is significantly lower than the initial value, and it may fall into a state where it cannot be put to practical use.

Various improved devices have been proposed to suppress this phenomenon and perform the membrane separation process for a long time. These measures are roughly classified into the following two.

A solution that uses the driving force of a pump or the like to pass through the surface of the fixed membrane surface.

A method in which a solution is filled in a pressurized tank and the membrane loaded in this tank is rotated.

Currently, the practical measure is the former measure,
As a module structure, a spiral type, a hollow type, a tubular type, a flat plate type and the like are known.

[Problems to be Solved by the Invention] In the above method, it is necessary to circulate the solution at a high flow rate, a large amount of energy is required, and the processing cost is high.

On the other hand, in the method (1), a method in which a rotating plate is used as a separation membrane is known, but since the rotating plate is used, the membrane area is limited and it is not suitable for the membrane separation treatment of a large amount of solution. Further, the solution between the rotating plates did not flow, the membrane could not be used effectively, and the cake layer on the membrane surface increased, causing a decrease in the amount of permeated water.

[Means for Solving Problems] The membrane separation apparatus of the present invention has a tank having an inlet for the liquid to be treated at one end and a discharge outlet for the concentrated liquid at the other end, and the tank in the tank. A hollow rotary cylinder coaxially arranged with the tank and rotatably arranged around an axis, a permeate outlet provided at one end of the rotary cylinder, and a plate-shaped membrane separating means, Membrane separating means that is provided so as to radially project from the outer peripheral surface of the rotary cylinder, and the plate surface of the plate extends obliquely with respect to the direction parallel to the axis of the rotary cylinder; It is opened in a cylinder,
And a communication hole that communicates the permeate side of the membrane separation means with the center hole of the rotary cylinder.

[Operation] In the present invention, the plate-shaped membrane separating means is radially arranged from the outer peripheral surface of the rotary cylinder, and the plate surface of the plate is oblique to the direction parallel to the axis of the rotary cylinder. Since the protrusion is provided so as to extend, the membrane area per unit volume and the surface area of the membrane separation means can be increased. Further, by rotating the rotary cylinder, the liquid can be passed along the surface of the membrane separation means at a predetermined speed, and a shearing force is applied to the gel layer and the cake layer formed on the surface of the membrane separation means during this passage. It acts, and the thickness of the gel layer and the cake layer can be suppressed. In particular, since the membrane separating means is arranged so that the plate surface of the plate body extends in the oblique direction with the axial direction of the rotating cylinder, the rotating shaft is rotated to move the membrane separating means in the tank. By rotating with, it is possible to form a constant circulation flow, and it is possible to agitate the liquid in the tank by this circulation flow. Therefore, high-concentration slurry or high-viscosity liquid can be subjected to membrane separation treatment at high speed.

[Examples] The present invention will be described in more detail below with reference to the examples shown in the drawings.

FIG. 1 is a perspective view of an essential part of a membrane separation device according to an embodiment of the present invention. Reference numeral 1 is a hollow rotary cylinder housed in a pressure tank 6, and a membrane separation means 2 such as a separation membrane is radially provided on the outer peripheral surface thereof. 2 is a side view of FIG. 1,
As shown in FIG. 2, in the present invention, the membrane separating means 2 is
The plate surface of the plate body is attached so as to be inclined with respect to a direction parallel to the axis of the rotary cylinder 1 (hereinafter referred to as “axial direction”) A, that is, a predetermined angle θ. (Note that this angle θ
May be selected at a desired angle between 0 ° and 90 °. ) As shown in FIG. 3 which is a sectional view taken along the line III-III of FIG. 1 and FIG. 4 which is a longitudinal sectional view of the rotary cylinder 1, the rotary cylinder 1 has a cylindrical shape in this embodiment, One end side 1a is closed and the other end side 1b is open. In addition, a plurality of communication holes 3 that communicate the inside and outside of the rotary cylinder 1 are formed at a substantially central position in the longitudinal direction of the rotary cylinder 1. As shown in FIG. 3, in the present embodiment, the membrane separation means 2 has a structure in which the separation membrane 5 is supported on both sides of the frame body 4, and the liquid permeation side B of the membrane separation means 2 is the inside of the rotary cylinder 1. Each membrane separation means 2 is provided so as to communicate with C.

FIG. 7 is a vertical cross-sectional view showing an embodiment apparatus in which the mechanism shown in FIG. 1 is incorporated in the pressure tank. In FIG. 7, a rotary cylinder 1 is pivotally supported in a pressure tank 6 so that both ends thereof stick out of the tank 6, and a large number of membrane separating means 2a, 2b are provided on the side peripheral surface of the rotary cylinder 1. , 2c, 2d are provided radially. In the figure, reference numeral 7 is a seal ring, and 8 is a supporting bearing. The open end side of the rotary cylinder 1 is an outlet for permeated liquid, and the closed side is connected to a rotary drive device 10 via a shaft coupling 9. Reference numeral 11 is a motor, and 12 is a speed reducer.

The liquid to be treated can be introduced under pressure from the pump 13 into the liquid inlet 6a of the pressure tank, and the concentrated liquid can be taken out from the liquid outlet 6b of the pressure tank 6. In such an apparatus, when the liquid to be treated pressurized from the pump 13 is introduced into the pressure tank 6 while the motor 11 is operated and the rotary cylinder 1 is rotated, the permeated liquid that has permeated the membrane separating means 2a-2b is rotated in the rotary cylinder. 1
It is taken out from the device through the opening 1b through the inside. On the other hand, the concentrated liquid is taken out from the outlet 6b.

The liquid in the pressure tank 6 permeates the separation membrane 5 and flows into the inside B of the membrane separation means 2, then passes through the communication hole 3 and the rotary cylinder 1
It flows into the inside C and is extracted from the device through the opening 1b.

In the apparatus of this embodiment, since a large number of separation membranes 5 are provided radially, the membrane area occupied per unit volume of the apparatus can be increased, and efficient membrane separation processing can be performed.

Further, since the membrane separation means 2 is provided on the outer periphery of the rotary cylinder 1 in a direction in which the plate surface obliquely intersects the axial direction of the rotary cylinder and radially, the liquid to be treated is transferred to the surface (membrane) of the membrane separation means 2. The gel layer or cake layer formed on the surface of the membrane separation means 2 can be maintained at a constant thin thickness. That is, the gel layer or the cake layer adheres to and grows on the surface (membrane surface) of the membrane separating means 2 as the apparatus operating time elapses. However, when the liquid flows along the surface of the membrane separating means 2. A shearing force is applied to the gel layer or the cake layer, and the thickness of the gel layer or the cake layer is limited to a thickness at which the adhesive force between the gel layer or the cake layer and the surface of the membrane separating means 2 balances the shearing force. Is done. Then, the thickness of the gel layer or the cake layer can be maintained at a predetermined thin thickness, an increase in pressure loss at the time of liquid passage can be prevented, and a high liquid passage amount can be secured.

Particularly, in the present invention, since the membrane separation means 2 is arranged so that the plate surface thereof is in the oblique direction with the axial direction of the rotary cylinder 1,
By accommodating the device in the tank and rotating it, it is possible to form a constant circulation flow, and it is also possible to achieve stirring in the tank by this circulation flow.

The above embodiment is an example of the present invention, and the present invention can be implemented in other modes. For example, in the apparatus of the above-described embodiment, the rotary cylinder 1 has a cylindrical shape, but it may have a hexagonal shape or an octagonal equiangular shape. Further, as shown in FIG. 5, a rotary cylinder having a hollowed-out shape from the opening 1b side to a midway portion.
It may be 1A. Further, as shown in FIG. 6, a pipe-shaped rotary cylinder with a substantially central portion partitioned by a partition plate 1c 1B
May be

In the above embodiment, the membrane separating means 2 has a structure in which the separating membranes 5 are attached to both sides of the frame body 4, but instead of the frame body 4, a punching plate or a porous sintered metal plate or a ceramic plate is used. May be used.

INDUSTRIAL APPLICABILITY The device of the present invention can be used for separating a solvent from a high-concentration slurry or a high-viscosity solution, concentrating solutes and particles, and separating the solvent. It can also be used in a reaction vessel such as a bioreactor.

[Effects of the Invention] As described in detail above, the membrane separation device of the present invention is such that the plate surface is on the outer periphery of the rotary cylinder arranged in the pressurizing tank so as to be in the oblique direction with the axial direction of the rotary cylinder. In addition, since a large number of membrane separating means are provided radially, the surface area of the membrane separating means per unit volume can be increased. Further, by rotating, a constant circulating flow can be formed in the tank to agitate the inside of the tank. Moreover, the thickness of the gel layer or the cake layer can be suppressed to a predetermined thickness by the flow of the liquid to be treated flowing on the surface of the membrane separation means. Therefore, even a high-concentration slurry or a high-viscosity liquid can be stably subjected to membrane separation treatment at a high speed over a medium engine.

[Brief description of drawings]

FIG. 1 is a perspective view showing a main part of an apparatus according to an embodiment of the present invention, FIG. 2 is a side view of the same, FIG. 3 is a sectional view taken along line III-III of FIG. 1, FIG. 4 and FIG. 6 and 6 are cross-sectional views of the rotary cylinder, and FIG. 7 is a cross-sectional view showing the structure of the apparatus of the embodiment. 1 ... Rotary cylinder, 2 ... Membrane separation means, 3 ... Communication hole, 4 ... Frame, 5 ... Separation membrane, 6 ... Pressure tank, 10 ... Rotary drive device, 13 ... Pump.

Claims (1)

[Claims] 1. A tank having an inlet for the liquid to be treated at one end and an outlet for the concentrated liquid at the other end; and a tank in the tank, which is coaxial with the tank and rotates about an axis. A hollow rotary cylinder that is movably arranged, a permeate outlet provided on one end side of the rotary cylinder, and a plate-shaped membrane separation means that is radially provided from the outer peripheral surface of the rotary cylinder. Further, the plate surface of the plate member extends in an oblique direction with respect to the direction parallel to the axis of the rotary cylinder, and the permeated liquid of the membrane separator provided in the rotary cylinder. A membrane separation device having a communication hole whose side communicates with the center hole of the rotary cylinder.