JPH05154359A - Membrane separator - Google Patents

Abstract

PURPOSE:To improve the efficiency of the separation of gas, liquid, and solid individually from a treated liquid mixture of gas, liquid, and solid. CONSTITUTION:Fixed flat disk membranes 2 and baffle plates 4 fixed on a hollow rotary shaft 3 are arranged alternately in a pressure container 1. A gas separation membrane 6, which separates gas from the container 1, is fixed on the hollow rotary shaft 3 so that gas can be supplied into the container 1 through a gas supply passage 11. When external gas is supplied into the container 1, the gas, after thinning the velocity boundary layer on the surface of the flat disk membrane by its centrifugal force, is collected to the center by the density difference and discharged outside from the hollow rotary shaft 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a membrane separation apparatus capable of separately separating a gas, a liquid and a solid from a treatment liquid in which the gas, the liquid and the solid are mixed.

[0002]

2. Description of the Related Art As a membrane separator used in the fields of food, medical treatment, fermentation, wastewater treatment, chemistry, etc.
As described in JP 607, JP 61-181503 and JP 61-138505,
A disc-shaped flat membrane is rotated in the treatment solution to generate a shearing force between the filter medium surface and the treatment solution,
Alternatively, as described in Japanese Utility Model Publication No. 60-31761, between the turbulent flow of the treatment solution and the disc-shaped flat membrane, a baffle plate fixed to the rotary shaft with the disc-shaped flat membrane fixed is rotated. There is one that is designed to generate a shearing force.

[0003]

By the way, in the above-described membrane separation device, a velocity boundary layer of the treatment solution is formed in the vicinity of the membrane surface, and the thicker the velocity boundary layer, the more it joins the membrane surface. Since the shear stress decreases and the membrane separation efficiency decreases, it is desirable to thin the velocity boundary layer on the membrane surface. However, in the conventional membrane separation device, since no means for thinning the velocity boundary layer has been taken, the treatment efficiency is poor. On the other hand, it was necessary to separate the treatment solution into a permeate (liquid), a concentrate (solid), and a gas at the same time, but it was difficult to separate the liquid, solid, and gas at the same time even in the above-mentioned membrane separation device. ..

[0004]

In order to solve the above problems, the present invention uses a hollow rotary shaft as a rotary shaft to which a baffle plate is attached, and provides a means for allowing only gas to pass through the hollow rotary shaft.

[0005]

Since the gas can be taken out from the hollow rotary shaft to which the baffle plate is attached, the processing solution can be separated into three phases of liquid, solid and gas. In addition, by positively supplying gas from the outside into the container, the gas concentrates in the center due to the difference in specific gravity after the thinning of the velocity boundary layer on the surface of the disk-shaped flat membrane due to centrifugal force inside the container, and from the hollow rotating shaft to the outside. The velocity boundary layer on the flat membrane surface can be thinned.

[0006]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Here, FIG. 1 is a cross-sectional view of the membrane separation device according to the present invention.

The membrane separation device alternately comprises a plurality of disc-shaped flat membranes 2 fixed to the inner wall of a cylindrical container 1 and a plurality of baffle plates 4 attached to a hollow rotary shaft 3 rotatably supported in the container 1. It is installed in. A large number of small holes 5 are formed in the hollow rotary shaft 3,
The outer peripheral surface is covered with a separation membrane 6 that allows only gas to pass therethrough.

Then, the treatment solution is supplied into the container 1 through the valve 8, and the permeated liquid that has permeated the discoid flat membrane 2 from the outer peripheral portion of the container 1 passes through the valve 9 and the concentrated liquid passes through the valve 10. Each one is taken out through the outside. Further, the gas supply passage 11 and the valve 12 are provided from the outer peripheral portion of the container 1.
A gas such as air is supplied via the. The disk-shaped flat membrane 2 is composed of a porous layer 2b having a pore diameter of 10 μm to 100 μm and having a small permeation resistance, and a porous layer 2a provided on its surface having a pore diameter of 0.01 μm to 5 μm and having a fine permeation resistance. ing.

In the membrane separation apparatus constructed as described above, the permeated liquid that has permeated the disc-shaped flat membrane 2 is transferred to the container 1 by pumping and supplying the treatment solution into the container 1 through the valve 8. The concentrated liquid is taken out from the outer peripheral portion via the valve 9 and the concentrated liquid is taken out from the outer peripheral portion of the container 1 via the valve 10.

At this time, from the gas supply passage 11 to the valve 12
Gas is supplied to the inside of the container 1 via and is sucked from the hollow rotary shaft 3, so that the low density component is collected in the central portion by the action of the centrifugal force due to the rotation of the baffle plate 4. After the velocity boundary layer on the surface of the disk-shaped flat membrane 2 is thinned, it gathers in the central portion, and the gas gathered in the central portion is separated by the gas separation membrane 6 of the hollow rotating shaft 3 and hollow-rotated through the small holes 5. Removed externally from shaft 3.

Since the velocity boundary layer on the surface of the membrane can be made thin in this manner, the treatment efficiency can be improved and the treatment solution can be separated into gas, permeate (liquid) and concentrate (solid). Therefore, for example, a membrane bioreactor that needs to separate microorganisms, metabolites, and gas while continuously supplying oxygen, it is necessary to separate plasma and blood plasma and gas while continuously supplying oxygen. It can be applied to an artificial lung or a reactor in which a gas and a liquid are chemically reacted using a catalyst. When it is not necessary to completely separate the gas and the liquid, the hollow rotary shaft 3
Instead of the gas separation membrane 6 of FIG.

[0012]

As described above, according to the present invention,
Since the hollow rotating shaft to which the baffle plate is attached is provided with a means for allowing gas to pass therethrough, the treatment solution can be separated into three phases of gas, liquid and solid. Also, by supplying gas into the container from the outside, the gas is thinned by the action of centrifugal force on the velocity boundary layer on the surface of the disk-shaped flat membrane, and then gathers in the center part and is discharged from the hollow rotating shaft to the outside. Therefore, the velocity boundary layer on the surface of the disk-shaped flat film can be thinned, and the processing efficiency can be improved.

[Brief description of drawings]

FIG. 1 is a schematic view of a membrane separation device according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Discoid flat membrane, 3 ... Hollow rotating shaft, 4 ... Baffle plate, 6 ... Gas separation membrane, 11 ... Gas supply path.

Claims (2)

[Claims] 1. A membrane separation device in which a flat membrane is fixed in a container and a treatment solution is separated by rotating a baffle plate in parallel with the flat membrane, and a rotary shaft to which the baffle plate is attached is hollow-rotated. A membrane separation device, characterized in that the hollow rotating shaft is provided with means for allowing gas to pass therethrough. 2. The membrane separation device according to claim 1, wherein a supply path for supplying gas into the container is provided on an outer peripheral surface of the container.