JPS6138605A - Ultrafiltration device - Google Patents

Abstract

PURPOSE:To obtain an ultrafiltration device having large membrane area per unit area permitting easy removal of deposited sludge on the surface of the membrane by providing a movable plate having holes for inserting hollow fiber into each hole and being movable between a fixing members contacting with the inside wall of a cylindrical vessel. CONSTITUTION:A movable plate 6 having many through holes 5 having hollow fibers 2 inserted therein is housed in a cylindrical vessel 1. When a part of the feed liquid introduced from an inlet port 7 comes out of a discharging port 7' of the feed liquid, the movable plate 6 is moved by the pressure of the feed liquid up to a stopper 8 for the movable plate. During the moving of the movable plate 6, the sludge deposited on the surface of the hollow fiber 2 is wiped off by the friction between the hole 5 and the hollow fiber 2. The filtrate having passed through the hollow fiber 2 is discharged from a discharging port 9,9' of the filtrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an ultrafiltration device, and more particularly to an ultrafiltration device having a function of cleaning the outer surface of a hollow fiber filtration membrane within the filtration device.

[Conventional technology]

BACKGROUND ART Conventionally, ultrafiltration has been used to obtain clear water and filtered solutions from various solutions and suspensions, and to obtain concentrated solutions of useful components. However, when ultrafiltration treatment is performed, suspended matter and the like gradually adhere and accumulate on the surface of the filtration membrane, and the ultrafiltration performance deteriorates over time. In order to prevent the accumulation of suspended matter on the surface of the filtration membrane, attempts have been made to increase the flow rate of the liquid to be treated on the membrane surface, and to chemically clean the surface of the membrane intermittently. However, increasing the flow rate alone does not provide a sufficient deposition prevention effect, and chemical cleaning may damage the membrane material, making it difficult to use strong chemicals. This is not necessarily an effective method because the sludge gets mixed into the unfiltered liquid.Therefore, a method is known in which the accumulated sludge is mechanically removed by passing a sponge pole inside a tubular membrane, and this method is effective in removing the deposit. That's an excellent method.

A filtration device using hollow fibers has the feature that the area of the filtration membrane per unit volume can be large, and has been used for water treatment with relatively few suspended substances. However, it is difficult to carry out mechanical cleaning such as pole cleaning, and backwashing using liquid or air has generally been used as a functional recovery treatment method.

[Problem that the invention seeks to solve]

However, with the above-mentioned tubular membrane having the sponge pole cleaning function, the inner diameter of the tubular membrane cannot be made very small due to the installation of the membrane and the pole cleaning mechanism. There is nothing below the layer,
For this reason, there is a drawback that the membrane area is small relative to the solution to be filtered that passes through the tubular membrane, and the filtration efficiency is low. Therefore, in order to obtain the necessary filtration flow rate, it is necessary to increase the membrane area, which increases the volume of the device and increases the power required to circulate the liquid.

The purpose of the present invention is to overcome the above-mentioned problems, have a large membrane area per unit volume, and easily remove sludge that accumulates on the membrane surface even when passing through a solution containing a large amount of suspended solids. The object of the present invention is to provide an ultrafiltration device that can be operated continuously for a long period of time.

[Means for solving problems]

That is, the ultrafiltration device of the present invention includes a cylindrical container, semipermeable hollow fibers disposed inside the container in parallel with the inner wall of the container, and at least one end of the hollow fibers having an opening. a fixing member that maintains an open state and fixes each in the container, and a movable plate that has holes into which the hollow fibers are inserted and can move between the fixing parts and materials in contact with the inner wall of the container. , a stock solution supply port and a stock solution discharge port, or a stock solution supply port and discharge port respectively arranged near both fixing member installation portions on the side wall of the container, and a semi-permeable hollow m-fiber connected to at least one end of the container. It is configured to have an undiluted solution outlet for discharging the filtered solution.

[Preferred mode for carrying out the invention]

The ultrafiltration device of the present invention differs from conventional pole cleaning type ultrafiltration devices in that the liquid to be treated (hereinafter referred to as stock solution) is filtered from the outside of the hollow fibers to the inside inside the cylindrical container. The sludge is therefore deposited on the outside of the hollow fibers. Therefore, since there is no need to clean the inside of the hollow fiber with a pole or the like, its inner diameter can be reduced.

The cylindrical container forming the main body of the ultrafiltration device of the present invention is
Containers of various shapes can be used as long as they have approximately the same internal cross-sectional shape within the range in which the movable plate moves, and for example, cylindrical, rectangular, etc. containers can be suitably used.

It is preferable that the hollow fibers used in the present invention have an inner diameter of about 0.3 to 51 mm.If the inner diameter is less than 0.3 mm, the flow resistance of the filtrate in the hollow fibers will increase, resulting in a high operating pressure. Energy increases.

- Although it can be used satisfactorily even if the inner diameter exceeds 5 mm, as the inner diameter increases, the membrane area per volume decreases and the filtration efficiency decreases. The thickness of the hollow fibers is preferably about 30 scales to 1 layer.Any material can be used for the hollow fibers as long as it is semi-permeable, and a homogeneous film can be used. or a microporous membrane.

The ultrafiltration device of the present invention moves a moving plate up and down (or left and right) using the feeding pressure of the raw solution in order to remove the sludge accumulated on the outside of the hollow fibers. The sludge is separated by contact and by the pressure of the raw solution flowing between the moving plate and the hollow fibers. It is preferable that at least the portion facing the hollow fibers of the movable plate is made of a flexible material so as not to damage the hollow fibers even if it comes into contact with the hollow fibers. Examples of such materials include foamed polyurethane, foamed polyurethane, etc. Examples include polyethylene, soft felt made of fine fibers with a fineness of up to 5 d, and the like. Of course, if the moving plate does not come into contact with the hollow fibers and uses only the pressure of water flowing through the gap between the holes and the hollow fibers, it is clear that the material of the moving plate is not limited at all. The diameter of the holes provided in the moving plate depends on the water pressure of the stock solution introduced, but it is preferable that the diameter is less than twice the outer diameter of the hollow fibers. Although it is necessary to have holes equal to the number of holes, the moving plate may be water permeable or may have more holes as long as the back pressure necessary for moving the moving plate can be obtained.

The movable plate moves up and down between the fixed members while its outer periphery contacts the inner wall of the container, but in order to prevent the movable plate from deforming, a frame made of a rigid and slippery material is provided on the outer periphery. Preferably, such a frame material is Polytetraful! Examples include resins such as oleoethylene and nylon, and metals. In order to prevent the moving plate from rotating inside the container,
A guide or the like may be provided on the container and the moving plate.

Both ends of the hollow fibers are fixed parallel to the inner wall of the container by fixing members made of hardened epoxy resin, polyurethane, etc., and the fixing members are liquid-tightly fixed to the inner wall of the container. At least one end of the hollow fiber is kept open so that the filtrate that has passed through the membrane can flow out through this opening.

The other end of the hollow fiber may be kept open or closed, and may be folded back in a U-shape within the fixing member at the end of the chain to communicate with other hollow fibers. Good too.

The stock solution supply port and the unfiltered liquid discharge port to the cylindrical container are provided on the side wall of the container near each of the two fixing members, and the stock solution can be supplied from either stock solution supply port. ,
The unfiltered liquid is discharged from a discharge port located at a different end from the supply port supplying the stock solution. In this case, it is necessary to synchronize the opening and closing of the stock solution supply port and the unfiltered liquid discharge port so that the stock solution entered from the stock solution supply port at one end is not discharged from the discharge port at the same end. Alternatively, one port may function as both the stock solution supply port and the discharge port at both ends. In addition, excessive cleaning is performed due to the sliding of the moving plate, and in order to prevent damage to the hollow fibers, a stock solution supply port and stock solution discharge port, or a stock solution supply port and discharge port and a moving plate storage section are provided at one end for cleaning. The movable plate can be moved only when necessary, and stored in the storage section at other times.

When using the ultrafiltration device of the present invention, a mechanism for alternately feeding the stock solution to the stock solution supply port and a mechanism for discharging the unfiltered solution from the stock solution outlet in synchronization with the delivery of the stock solution are attached. However, the mode of these liquid feeding mechanism and discharge mechanism is not particularly limited as long as it is a mechanism that can perform the above functions.

[Effect]

The configuration and operation of the ultrafiltration device of the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a schematic cross-sectional view showing an embodiment of the ultrafiltration device of the present invention. #2 is container l
It is fixed with fixing members 3 and 3' with both opening ends kept open, and is arranged parallel to the side wall 4 of the container l. There is a hollow rim inside the container! a moving plate 6 having a number of through holes 5 into which holes 12 are inserted;
is housed therein, and a hollow fiber fixing part is fixed to the side wall of the container l. The stock solution is introduced from the stock solution supply lower, and when a part of it exits from the stock solution discharge lower', the moving plate 6 is moved by the pressure of the stock solution to the moving plate stopper 8 in the lower part of the figure. As the movable plate 6 moves, the sludge accumulated on the surface of the hollow fibers 2 is wiped off by friction between the holes 5 and the hollow fibers 2. The filtrate that has passed through the hollow fiber membrane 2 is taken out from the filtrate outlets 9 and 9'.

FIG. 2 is a schematic sectional view showing another embodiment of the present invention,
In the apparatus shown in FIG. 2, compared to the apparatus shown in FIG. 1, a stock solution supply port/discharge U10 and a movable plate storage section 11 are further provided at one end of the cylindrical container l.2. In the device shown in Figure 2, normally the stock solution is introduced from the stock solution supply lower and part of it is discharged from the stock solution discharge lower', or vice versa, it enters from the stock solution supply lower' and a part of it flows out from the stock solution discharge lower. . If sludge accumulates on the surface of the hollow rim #Il and the filtration speed decreases, the undiluted solution flow path is switched and the undiluted solution is introduced from the undiluted solution supply and discharge port 10, and a part of it is discharged from the undiluted solution discharge lower. When the plate is moved and the movable plate 6 reaches the upper end, the undiluted solution is discharged from the undiluted solution supply port/discharge port 10, and the movable plate 6 is moved.
is moved to the movable plate storage section 11 at the lower end. By repeating this operation as necessary, the filtration function can be restored.

The device of the present invention can be manufactured as follows. If the moving plate is made of a soft material, the required number of hollow fibers are arranged to have the same length as C, and the hollow fibers are inserted into the holes of the moving plate that have been punched in advance, or the holes are made by press-fitting the hollow fibers. Hollow ml by inserting hollow fibers and drilling holes at the same time! i
After passing through the filter, the device can be fabricated in the same manner as a filtration module using ordinary hollow Jli fibers.

[Effects of the present invention]

According to the present invention, even when filtering a solution containing a large amount of suspended solids, it is possible to easily remove sludge that accumulates on the membrane surface of hollow fibers, and to increase the membrane area per unit volume as much as possible. An ultrafiltration device was obtained, and the problems of conventional ultrafiltration devices were solved at once.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing one embodiment of the ultrafiltration apparatus of the present invention, and FIG. 2 is a schematic sectional view showing another embodiment. 1: Container 2: Hollow fiber 3.3': Fixed member 4: Side wall 5: Hole 6: Moving plate 7.7', lO: Stock solution supply port and outlet 8: Moving plate stopper

Claims (1)

[Claims] 1) A cylindrical container, semipermeable hollow fibers disposed inside the container in parallel with the inner wall of the container, and at least one end of each of the hollow fibers keeping an opening in an open state. A fixing member to be fixed in the container, a movable plate having holes into which the hollow fibers are inserted and movable between the fixing members in contact with the inner wall of the container, and both fixing members installed on the side wall of the container. a stock solution supply port and a stock solution discharge port or a stock solution supply port and discharge port provided near each of the parts; and a filtrate discharge port for discharging the filtered liquid through a semipermeable hollow fiber at at least one end of the container. An ultrafiltration device comprising: