JPH0520123B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] Industrial Field of Application The present invention relates to a filter for recovering a purified liquid containing no solids from a suspension and obtaining a concentrated suspension.

BACKGROUND OF THE INVENTION Cross-flow filters are often used to obtain a purified filtrate by filtering a large amount of stock solution containing a relatively small amount of suspended matter. Such cross-flow type filters enable continuous operation for long periods of time without accumulating slag on the filter surface by setting the speed of the raw solution flowing parallel to the surface of the filter medium to be higher than the speed of the filtrate passing through the filter medium. It was common to use a cylindrical filter medium to distribute the stock solution uniformly and at high speed.

However, in a cross-flow type filter using a cylindrical filter medium, if you try to increase the area of the filter medium in order to increase the filtration capacity, you must increase the diameter or length of the filter medium and increase the amount of stock solution. On the other hand, in order to increase the capacity without increasing the flow rate of the stock solution or decreasing the flow rate, it is necessary to have a large number of filter media with small diameters, which causes the problem that the structure becomes complicated and large. The liquid pump and piping also had the disadvantage of having to withstand high pressure and have a large capacity.

Problems to be Solved by the Invention Therefore, the present invention solves the problems of conventional cross-flow type filters, allows the filtration capacity to be set freely, and extremely simplifies incidental equipment such as liquid pumps and piping. The present invention aims to provide a novel cross-flow type continuous filtration device that can be reduced in size and size.

Means for Solving the Problems The continuous filtration device of the present invention is divided into a primary chamber having a communication passage on the inside and a secondary chamber having a communication passage on the outside by a partition body that fixes a plurality of flat filter media in parallel. A filtration unit main body is provided in a circulating liquid tank, and a rotor that can rotate around a penetrating axis perpendicular to the surface of the filter medium and allows liquid to flow in a direction parallel to the axis is provided in the primary chamber in close proximity to the surface of the filter medium. an inlet port communicating between the inside of the primary chamber and the inside of the circulating liquid tank at a position near the axis of the filtration section main body, and an inlet port communicating between the inside of the primary chamber and the inside of the circulating liquid tank at a position near the periphery of the filter medium of the filtration section main body. a filtrate outlet path that is provided with a discharge port that communicates with the inside of the circulating liquid tank, and further leads the filtrate directly from the secondary chamber to the outside of the circulating liquid tank;
It is constructed by providing a stock solution introduction path connected to the circulating liquid tank and a concentrated liquid discharge path opening at the bottom of the circulating liquid tank.

Furthermore, in the device of the present invention, the filtration part main body is fixed coaxially within the cylindrical circulating liquid tank, and the discharge port provided on the outer surface of the filtration part main body is arranged so that the future discharged liquid is in a plane perpendicular to the axis of the circulating liquid tank. By forming it so that it flows out in the circumferential direction of the wall surface, a flow that rotates in one direction can be generated in the circulating liquid tank, and the efficiency of concentrating the suspended matter in the concentrated liquid can be promoted.

Function The continuous filtration device of the present invention applies rotational force and centrifugal force to the liquid in the primary chamber partitioned by parallel plane filter media by rotating the rotor, thereby causing a flow parallel to the surface of the filter media. As a result, the suspension in the circulating liquid tank enters the primary chamber from the suction port near the shaft and is discharged into the circulating liquid tank from the discharge port near the periphery. During this time, the filtrate that has passed through the filter medium and entered the secondary chamber is led out of the circulating liquid tank through the filtrate outlet path, but at least an amount of stock solution commensurate with the amount of filtrate drawn out is continuously transferred into the circulating liquid tank from the inlet path. was introduced in
On the other hand, a concentrated liquid containing sludge and the like is continuously or intermittently discharged from the bottom of the circulating liquid tank through a concentrated liquid discharge path.

Example 1 An example of the continuous filtration device of the present invention is shown in FIGS. 1 and 2.

1 is a cylindrical circulating liquid tank; 2 is a raw liquid introduction path provided in the circumferential direction to the upper wall of the circulating liquid tank 1; and 3 is a concentrated liquid discharge path provided at the bottom of the circulating liquid tank 1. be.

Inside the circulating liquid tank 1, a filter main body 4 is fixed perpendicularly to the lid 1a so as to be coaxial. The filter main body 4 is constructed by combining cylindrical members 4a, 4a', 4a'', disc-shaped members 4b, 4b', 4b'', and an annular member 4c, and a bearing 4d is provided in the cylindrical member 4a''. The annular member 4c is provided with a discharge port 4f facing outward.

A recess 4g constituting a secondary chamber is provided in the disc-shaped members 4b, 4b', 4b'', and a porous support member 5 is accommodated here to support a planar filter medium 6. The planar filter medium 6 is, for example, donut-shaped, and its inner edge is connected to the cylindrical member 4.
a,... and disc-shaped members 4b,...,
Further, the outer edges are sandwiched between the disc-shaped members 4b, . . . and the annular member 4c, and the filter media 6, which face each other,
A primary chamber is formed between 6 and 6. On the other hand, the concave portion 4g constituting the secondary chamber is communicated with the filtrate communication passage 4h provided in the disk-shaped member 4b' and the annular member 4c, and the filtrate communication path 4h provided in the disk-shaped member 4b'' It leads to the lead-out path 7.

On the other hand, a shaft 8a passing through the cylindrical members 4a, 4a', etc.
is supported at the lower part by a bearing 4d, and is configured to be rotationally driven by a drive device 9, which is connected to the upper part and includes, for example, a motor. The rotor 8b fixed to the shaft 8a may be, for example, disc-shaped, have a liquid passage hole 8c through which liquid can flow in a direction parallel to the shaft, and have an arched-back protrusion 8d. However, it may also be a combination of rod-shaped wings. The rotor 8b can rotate while maintaining a position close to the filter medium 6, and accordingly, the liquid in the primary chamber can be evenly distributed on both sides of the rotor 8b, and the liquid can be sent outward by a centrifugal pump action. do.

In the continuous filtration apparatus of the present invention configured as described above, when a suspension supply source such as a storage tank is connected to the stock solution introduction path 2 and the circulating liquid tank 1 is filled with the stock solution, the drive device 9 is operated. As the rotor 8a rotates, the liquid in the circulating liquid tank 1 is sucked through the suction port 4e, passes through the primary chamber, and is discharged into the tank 1 again from the discharge port 4f. At this time, if the discharge port 4f is oriented in the circumferential direction of the wall surface of the tank 1 in a plane perpendicular to the axis, that is, in a horizontal plane, the discharged liquid will flow in a swirling manner in the tank 1 and gradually move downward. It circulates so that it reaches the lower part of , and is sucked into the suction port 4e again.

During this time, the suspension flowing parallel to the surface of the filter medium 6 is
A portion of the filtrate passes through the filter medium 6 and enters the secondary chamber as a filtrate, and flows out of the device from the filtrate outlet path 7 through the filtrate communication path 4h. At this time, if the circulating fluid tank 1 is a closed container, an amount of stock solution corresponding to the amount of filtrate flowing out is automatically replenished into the circulating fluid tank 1 by the siphon action without using a pump for supplying the stock solution. . In this case, since the stock solution flows into the wall surface of the circulating liquid tank 1, it does not interfere with the swirling flow in the tank, but rather acts to make the swirling smoother.

In addition, the suspension concentrated in the circulating liquid tank 1 promotes the sedimentation of a part of the suspended liquid to the bottom of the tank due to the swirling flow, and the suspended liquid is further removed from the concentrated liquid discharge path 3. It is discharged as a concentrated liquid. At this time, the concentrated liquid may be discharged continuously or discontinuously.

Example 2 Another example of the continuous filtration device of the present invention is shown in FIG.

In the device of this example, the circulating liquid tank 1' has an upper part formed in a cylindrical shape, and a bottom part formed in an inverted conical shape, and a concentrated liquid discharge path 3' is provided at the lower end. , and the filtrate outlet passage 7 are provided in the upper part of the filtration part main body 4, but the structure is almost the same as that of the previous example.

The device of this example basically has the same functions as the previous example, except that during continuous operation, the sedimentation and concentration of suspended matter in the concentrate is smoother, and it is suitable for continuous withdrawal of the concentrate. are doing.

〔Effect of the invention〕

In the continuous filtration device of the present invention, a partition body in which a plurality of flat filter media are fixed in parallel is provided to form a primary chamber and a secondary chamber, and a rotor is provided in the primary chamber to circulate the liquid parallel to the surface of the filter media. A cross-flow type filtration machine is installed in the circulating liquid tank to circulate and concentrate the suspension in the tank and to continuously draw out the filtrate. The pump, piping, etc. are extremely simplified, the equipment area is small, it is economical, and its operation is easy to control.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an example of a continuous filtration device of the present invention,
FIG. 2 is a cross-sectional view of the main body of the filter, and FIG. 3 is a cross-sectional view of another example. 1, 1'... Circulating liquid tank, 2... Stock solution introduction path, 3,
3'...Drainage channel, 4...Filter unit main body, 6...Filtering material,
7...Filtrate outlet path, 8b...Rotor, 9...Drive device.

Claims (1)

[Scope of Claims] 1. A filtration unit main body which is divided into a primary chamber having a communication passage on the inside and a secondary chamber having a communication passage on the outside by a partition wall that fixes a plurality of flat filter media in parallel, is connected to a circulating fluid. A rotor is provided in the tank and is rotatable around a penetrating axis perpendicular to the outer filter medium surface and allows liquid to flow in a direction parallel to the axis, and is provided in the primary chamber close to the filter medium surface, and the filter main body a suction port that communicates between the inside of the primary chamber and the inside of the circulating liquid tank at a position near the axis; and a suction port that connects the inside of the primary chamber and the inside of the circulating liquid tank at a position near the periphery of the filter medium of the filtration section main body. Provided with a discharge port,
Furthermore, a filtrate outlet path for directly leading the filtrate out of the circulating liquid tank from the secondary chamber, a stock solution introduction path connected to the circulating liquid tank, and a concentrated liquid discharge path opening at the bottom of the circulating liquid tank. A continuous filtration device is provided. 2. The continuous filtration device according to claim 1, wherein the circulating liquid tank consists of a sealed container. 3. The continuous filtration device according to claim 1 or 2, wherein the filtration unit main body is provided above the circulating liquid tank so that its axis is perpendicular. 4. The continuous filtration device according to any one of claims 1 to 3, wherein a filtration part main body having a cylindrical outer shape is provided coaxially within a cylindrical circulating liquid tank. 5. The continuous filtration device according to claim 1, wherein the discharge port is provided on the outer surface of the filtration section main body. 6. The continuous filtration device according to claim 5, wherein the discharge port is formed so that the discharged liquid from the discharge port flows out in the circumferential direction of the wall surface within a plane perpendicular to the axis of the circulating liquid tank. 7. The continuous filtration device according to any one of claims 4 to 6, wherein the raw solution introduction path is provided toward the circumferential direction of the wall surface of the circulating liquid tank. 8. The continuous filtration device according to any one of claims 1 to 7, wherein the bottom of the circulating liquid tank is formed in an inverted conical shape, and a concentrated liquid discharge path is provided at the lower end. 9. When filtering a suspension using the continuous filtration device according to claim 1, the filtration speed or filtration accuracy is controlled by adjusting the flow resistance of the discharge port or the rotation speed of the rotor. Continuous filtration method.