JPH05309242A - Filter element and liquid treating device - Google Patents

Abstract

PURPOSE:To enable the continuous and precise filtration treatment of an original liquid contg. suspended materials over a long period of time by radially connecting filter units to a central part, the inside of which is a flow passage, liquidtightly communicating the filtrate outflow parts of the filter units with the flow passage and rotating the central shaft part. CONSTITUTION:A filter unit juncture 2 is formed in a part of the central shaft part 1 and the filter units 3 are radially installed therein. Each filter unit is constituted by adhering and fixing both ends of the bundle of a hollow yarn-like filter membrane 5 into a supporting structural body 4 by a resin. The filter units 3 are liquidtightly connected by means of O-rings 7 to the filter unit juncture 2 of the central shaft part 1 in the filtrate outflow part 6 of the supporting structure 4 and are communicated with the liquid flow passage 8 of the central shaft part 1. The original liquid 10 enters the inner side of hollow yarn-like filter membranes 5 and enters the central shaft part 1 through the filtrate outflow parts 6 from the apertures when the original liquid 10 is supplied to the outer side of the filter membranes 5 at the time of filtration. This liquid is discharged as the filtrate 11 to the outside part of the filter element from the flow passage 8. The filtration is executed while the central shaft part 1 is kept rotated at this time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a filter element for the purpose of precisely filtering and separating fine particles and suspended substances from a solution containing various fine particles and suspended substances, and a liquid using the same. The present invention relates to a processing device.

[0002]

2. Description of the Related Art Conventionally, in the purification treatment of tap water, sewage and the like, sedimentation separation using a flocculating precipitant, sand filtration and the like have been used to remove various fine particles and suspended substances contained in a stock solution. The main purpose of sedimentation separation is to obtain a clear liquid and to obtain thick particles and suspended substances (sludge). Sand filtration or the like is performed for the purpose of further purifying the clear liquid (supernatant liquid) obtained by sedimentation. On the other hand, sludge is further concentrated by various filtration methods using filter cloth,
Furthermore, it is dried and treated by heating and incineration.
Moreover, not only in the case of tap water or sewage, etc., generally various fine particles,
Filter media such as filter cloth, filter paper, and diatomaceous earth are used for filtering a solution containing a large amount of microorganisms and suspended substances.

[0003]

In the treatment of tap water, sewage and the like, obtaining a more purified treatment liquid has become increasingly important in recent years from the viewpoint of environmental protection. Further, by further removing the water contained in the sludge separated by sedimentation or the like, it has been considered to obtain a thicker sludge and reduce the burden of the subsequent treatment to improve efficiency.
In this case as well, it is desired that the removed water be more purified. Further, in general, filtration of a liquid containing various fine particles and a large amount of suspended substances, for example, finer filtration separation has been required even for a culture liquid of microorganisms.

However, the above-mentioned sand filtration or filtration with a filter material such as a filter cloth is rough filtration, and it is possible to remove a large amount of relatively large particles and suspended substances, but the filtration accuracy is poor and fine particles are used. However, there was a problem that leakage of suspended solids was unavoidable. Further, with filter media such as filter cloth and filter paper, particles easily enter the filter media, and it is difficult to remove the particles that have entered even after washing the filter media, and gradually clogging occurs and the filtration performance deteriorates. There is a problem that it ends up.

Further, a belt press using a belt-shaped filter cloth, a cylindrical rotary dewatering machine, etc. are used as an apparatus capable of continuously performing filtration for the concentration of sludge such as sludge. The purpose is to collect sludge, and there is a problem that a precise filtrate cannot be obtained as described above.

The microfiltration method using a porous filtration material having controlled fine pores having a pore diameter of 1 μm or less enables highly accurate filtration and removal which solves the above problems. However, the microfiltration method is a method mainly used when the concentration of particles and suspended substances in the stock solution is relatively low. This is because the fine pores of the filter medium are extremely fine compared to the openings of the previous filter cloth, etc., and when a stock solution containing a large amount of particles and suspended substances is treated, they immediately accumulate and accumulate on the surface. This is because a layer is formed and the filtration rate is rapidly reduced.

Therefore, in order to filter the stock solution containing a large amount of particles and suspended substances as described above by the microfiltration method, an examination from the viewpoint of the filtration operation method is conducted, and the stock solution flows in parallel with the surface of the filter material. It is possible to reduce the formation of a deposited layer of particles and the like on the surface of the filter medium by using cross-flow filtration in which filtration is performed while forming a filter, and it is possible to adapt to filtration of a stock solution having a relatively high particle concentration. I understand, and it came to be used partly.

However, in the cross-flow filtration, it is necessary to form a stock solution supply system (stock solution circulation path) for always forming a flow of the stock solution on the surface of the filter material in order to carry out filtration, and to prevent clogging. In order to increase, increase the circulation flow rate, or install some structure on the surface of the filter medium,
It is necessary to set so that the stock solution flows at a higher flow rate. Therefore, the system is easy to set up and install and is an effective filtration means for small-scale applications such as very small amount of filtration in a laboratory or purification of a high-value-added stock solution. When it comes to large-scale systems such as water and sewage treatment, it is necessary to set up a complex and large-scale device for the supply and control of the undiluted solution, which requires a large amount of power and is difficult to manage. is there. Further, it could not be applied at all to a stock solution having a particle concentration and viscosity such that the flow necessary for cross-flow filtration could not be formed.

In view of the above problems, the inventors have considered
The inventors have earnestly studied a filtration element and a filtration device using a microfiltration method capable of efficiently treating a stock solution containing a large amount of particles, suspended substances, etc.
Thus, a filtration element and a device as shown in 99156 etc. having a configuration capable of easily removing deposits (sludge) such as suspended substances attached to the surface of the filtration element were obtained. Although these were extremely effective, they were basically batch processes in which filtration was carried out intermittently, and a more efficient system capable of carrying out continuous filtration for a long time was desired. The present invention solves the problems of rough filtration and microfiltration by the filter material such as the filter cloth,
It is an object of the present invention to provide a filtering element and a liquid processing apparatus that can more effectively and accurately perform the filtering process of the liquid continuously over a long period of time.

[0010]

A filtration unit using a porous filtration material is radially connected to a central shaft portion in which a liquid flow path is formed, and a filtrate outflow portion of the filtration unit and the liquid flow. The passage is fluid-tightly connected, and the filter element is configured so that stable rotation can be performed around the central shaft portion. By doing so, it is possible to obtain a filter element capable of efficiently filtering the stock solution. The configuration capable of performing stable rotation in this case means that the respective filtering units are arranged substantially evenly with respect to the central axis and the center of gravity is not extremely biased,
Due to the rotation, strong force, vibration, etc. do not act strongly on the central axis part, and the resistance of the liquid generated against the filtering element due to the rotation of the filtering element is not uneven, and the central axis when the filtering element is rotated. Similarly, it means a structure in which strong irregular force or vibration does not act strongly.

Further, the filtration element, a bearing mechanism for the central shaft portion of the filtration element, a rotation mechanism for rotating the central shaft portion, a collection mechanism for collecting the filtrate from the liquid flow path of the central shaft portion, the filtration At least a part of the filtration unit of the element has a holding structure for holding so as to be immersed in the undiluted solution, by configuring a device that performs filtration while rotating the filtration element during filtration, a liquid that solves the above problems It is possible to provide a processing device.

[0012]

FIG. 1 is a partial cross-sectional view showing an example of the filter element of the present invention when a hollow fiber filter membrane is used as a porous filter material. Based on this, the operation of the present invention will be described. A filtering unit connecting portion 2 is formed on a part of the central shaft portion 1, and filtering units 3 are radially installed on the connecting portion 2.
The filtration unit 3 includes a hollow fiber-shaped filtration membrane 5 in a support structure 4.
Both ends of the bundle are bonded and fixed with resin. The filtration unit 3 is a portion of the filtrate outflow portion 6 provided in the support structure 4, and the filtration unit connection portion 2 of the central shaft portion 1
Is liquid-tightly connected by an O-ring 7 and communicates with the liquid flow path 8 of the central shaft portion 1. An opening of the hollow fiber-shaped filtration membrane 5 is formed in the resin fixing portion 9 that is fixed to the central shaft portion 1 of the filtration unit 3.

Filtration of the stock solution is performed as follows. During filtration, the stock solution 10 is supplied to the outside of the hollow fiber-shaped filtration membrane 5,
The liquid flow passage 5 passes from the outside to the inside of the hollow fiber-shaped filtration membrane 5, flows out from the opening of the hollow fiber-shaped filtration membrane 5 formed in the resin fixing portion 9, passes through the filtrate outflow portion 6, and enters the central shaft portion. 8
As a result, filtrate 11 flows out of the filter element. At this time, filtration is performed while rotating the filter element around the central shaft portion 1 as shown by the arrow 12. By rotating the filtration element in this manner during filtration, a flow of the undiluted solution relative to the membrane surface of the hollow fiber-shaped filtration membrane 5 occurs, and it is possible to reduce the attachment of sludge to the membrane surface, and Therefore, stable filtration can be carried out.

Even when sludge gradually adheres to the filtration unit due to filtration, as the amount of sludge increases, the force of peeling off the sludge from the surface of the hollow fiber-shaped filter membrane is increased due to the rotation. Therefore, sludge can be easily removed and separated. Further, it becomes possible to more effectively obtain the stripping effect when backwashing from the filtrate side.

It is not necessary that the entire filtering element be immersed in the stock solution, and it is sufficient that about half of the filter element is immersed with respect to the central shaft portion 1, and each filtration unit is immersed in the stock solution by rotation. It is enough. Further, in this case, the effect of peeling off the attached sludge can be obtained by contact stirring with the liquid surface of the stock solution.

When the filter element is rotated, it may be reversed not only in one direction but at an appropriate interval. By doing so, a stirring effect of the undiluted solution occurs, and it is possible to prevent sludge from adhering and enhance the peeling effect.

By radially arranging each filter unit at the filter unit connecting portion of the central shaft portion as in the present invention,
A well-balanced filtration element capable of performing stable rotation can be easily manufactured with a simple configuration.
Further, since the respective filtration units are separated from each other, a larger stirring action of the undiluted solution can be obtained by the rotation of the filtration element, so that the sludge adhesion prevention and the peeling effect can be enhanced.

The filtering unit shown in the example is constructed by cutting a part of the cylindrical shape so that the filtering surface of the filtering unit is just parallel to the rotation direction of the filtering element. The filter unit may be installed so as to be inclined with respect to the rotating surface, or a filtration unit having a propeller shape may be installed.
In this case, the rotation of the filter element forms a flow of the undiluted solution relative to the surface of the filtration membrane, and the flow of the undiluted solution to the filtration element is formed by the filtration unit itself. The prevention effect can be further enhanced.

As described above, when the filtration surface of the filtration unit is inclined with respect to the rotation direction of the filtration element or the shape of the filtration unit is a propeller, there is an advantage that the stirring effect of the stock solution can be obtained. The resistance of the undiluted solution to the rotation of the element is larger than that of the previous embodiments, and more power is required to rotate the filtration element. Further, since the resistance force of the stock solution acting on the filtration unit becomes large, it is necessary to make settings so as to further increase the strength of the filtration unit so as to withstand this. The shape of the filtration unit is not limited to the above as long as the rotation of the filtration element can be easily carried out, and various shapes can be used, but reduction of power for rotation of the filtration element and From the viewpoint of ease of setting, it is preferable that the filtering surface of the filtering unit is just parallel to the rotation direction of the filtering element.

It is more preferable that the filtration unit 3 is detachably connected to the central shaft portion 1. By making the filtration unit 3 detachable, when a part of the filtration unit 3 is damaged, it is possible to restore the function as a filtration element by replacing only this unit portion, and it is possible to recover other functions of the filtration element. The components can be used without waste.

Further, the central shaft portion 1 has a connecting portion for connecting a plurality of filter elements in a multiple direction in the direction of the central shaft portion 1.
It is also preferable to form. By connecting the filtering elements in the axial direction, the filtering area can be easily increased.

As the filter element of the present invention, various materials and porous filter materials having various shapes can be used as long as they can form the shape as described above. Membrane filter materials, particularly hollow fiber filter materials, can be used. Membranes are suitable for use. This is because the hollow fiber-shaped filtration membrane can have an extremely large filtration area compared to that of other structures such as a flat-plate-shaped filtration membrane because of its shape, and the filtration membrane itself is supported by the filamentous shape. Since it has a function as a structure, a complicated membrane support is not required, and the configuration of the filter element can be simplified.
From the above points, it is possible to configure a filter element that can relatively easily remove the deposited layer by an operation such as applying a fluid flow to the filter membrane itself. Further, with a hollow fiber-shaped filtration membrane, filtration can be carried out from either the outside or the inside of the membrane. A support is unnecessary, and effective removal can be performed.

The average pore size of the fine pores of the porous filter medium used is preferably 1 μm or less as described above. If it is 1 μm or more, it will be close to rough filtration using filter cloth or diatomaceous earth,
The advantages of microfiltration are diminished.

Furthermore, the liquid treatment apparatus of the present invention is configured to perform filtration while rotating the filtration element, using the filtration element. That is, at least the bearing mechanism of the central shaft portion of the filter element, the mechanism for rotating the central shaft portion, and the sampling for collecting the filtrate from the liquid flow path of the central shaft portion while the rotation of the central shaft portion is blocked from the outside. It has a mechanism and further has a holding structure for holding the filtration element so that at least a part of the filtration unit of the filtration element is immersed in the stock solution. By using the apparatus configured in this way, more efficient microfiltration that solves the above-mentioned problems can be continuously performed.

FIG. 2 is a schematic view showing an example of a liquid processing apparatus using the filter element of the present invention. This device has a filter element 15
Are connected in multiples at the central shaft portion to form a filtering unit 16, which is installed in a dipping tank 17. Both ends of the central shaft portion are held by bearing mechanisms 18 provided on the dipping tank wall. A rotation mechanism 21 including a rotation motor 19 and a rotation transmission portion 20 is provided on one of the central shaft portions.
The other side of the central shaft portion is a collection mechanism 2 capable of collecting the filtrate while the rotation of the central shaft portion is blocked from the outside.
2 are installed. A storage tank 23 that temporarily stores the filtrate is connected to the collection mechanism 22, and a decompression pump 24 is connected to this tank.

The stock solution 10 is fed from the stock solution inlet 25 to the dipping tank 17
Will be introduced to. The dipping tank 17 is provided with a discharge port 26, which is used for discharging a part of the stock solution or discharging sludge accumulated in the dipping tank according to the condition of filtration.
The filtration is performed by rotating the filtration unit 16 with the motor 19 and using the decompression pump 24 to remove the air 27 in the storage tank
Is discharged to reduce the pressure. Filter element 15
The filtrate 11 filtered in (1) flows out of the collection mechanism 22 and into the storage tank 23. The filtrate 11 stored in a predetermined amount is appropriately discharged from the storage tank according to the purpose. It is also possible to perform filtration by installing a pump between the storage tank and the dipping tank, instead of performing the filtration by depressurizing the storage tank 23 with a decompression pump.

In this embodiment, the filtering section 16 is provided in the dipping tank 17 and the stock solution is introduced into the dipping tank to carry out the filtration. At least a part of the filtering unit constituting the filter element is immersed in the stock solution. The immersion tank itself functions as a holding structure for the filtering element so as to have such a positional relationship.

A mount using an angle is provided, and a filter element, a bearing mechanism, a rotating mechanism, a filtrate collecting mechanism and the like are attached at predetermined positions to form an integrated device, which is installed in a place where the stock solution is stored. It is also possible to install and perform filtration. For example, when water such as a lake is used as the undiluted solution, the above apparatus is installed so that a part of the filter unit of the filter element is directly immersed in the lake to carry out the filtration. In this case, the gantry functions as a holding structure that holds a part of the filtration unit of the filtration element so as to be immersed in the stock solution. If you have installed the mount as described above,
In particular, since it is not necessary to install a dipping tank, the structure becomes compact, and it becomes easy to install the device very close to the place where the necessity of filtration occurs. Further, it can be configured to be movable. Alternatively, the settling tank or the like already installed can be used as a kind of immersion tank, and there is an advantage that the structure can be made lean.

The effect obtained in the case where the dipping tank is not installed as described above is particularly advantageous when it is premised that the filtrate obtained by filtration is mainly used, but the effect is eliminated. When the solid content such as sludge is collected and used, it is desirable to install a dipping tank as in the previous embodiment and perform concentration in this portion. In any case, it is preferable to set the filtration unit so that the undiluted solution does not dip into the filtration unit when the filtration element is rotated, because the filtration area is not wasted.

The dipping tank 17 may be a closed container that houses the entire filtering element, and the inside may be pressurized for filtration. In this case, the filtration pressure can be increased as compared with the case of vacuum filtration, so that the filtration rate can be increased.

FIG. 3 shows another example of the liquid processing apparatus according to the present invention. A part of the dipping tank 17 has a circulating line 30 for the undiluted solution.
Is installed and the outflow portion 31 is formed in the vicinity of each filter element 15 to form a stirring mechanism. The undiluted solution 10 in the dipping tank 17 is pressure-fed in the circulation line 30 by the circulation pump 32, becomes a jet flow from the outflow portion 31, and becomes the filtering element 15.
Spill out to wash the sides of. By this flow, it is possible to effectively prevent the sludge from adhering by filtration or to effectively remove the sludge that has adhered. In addition to the circulation line as described above, a blade-shaped structure may be provided as a stirring mechanism in the central shaft portion between the filter elements 15.
In addition to the flow of the undiluted solution relative to the surface of the porous filter medium due to the rotation of the filtration element, the flow of the undiluted solution with respect to the filtration element is formed by this blade-shaped structure, and the effects of both are combined to further enhance the sludge adhesion prevention effect. be able to. By installing the stirring mechanism for the stock solution as described above, it is possible to obtain an efficient liquid processing apparatus capable of performing stable filtration for a longer period of time.

[0031]

EXAMPLES Examples using the filter element and the liquid processing apparatus of the present invention will be shown below. Example 1 A filtration unit was prepared by using 250 hollow fiber-shaped polypropylene-made filtration membranes (pore diameter 0.1 μm, outer diameter 500 μm) as a porous filtration material, and 8 filtration units were installed in the central shaft portion. A filter element having a structure as shown in FIG. 1 and having a membrane area of about 5000 cm 2 was prepared. Since this filtration membrane is hydrophobic, it was hydrophilized using a surfactant (Triton X-100). Three filtration elements were connected at the central axis to form a filtration section having a membrane area of about 1.5 m @ 2, and a liquid processing apparatus having the configuration shown in FIG. 2 was produced and filtration was performed. The undiluted solution is a processing solution (SS concentration 2.0
%) Was used. The filtration element was rotated 180 times per minute, the pressure in the storage tank was reduced to −0.8 kg / cm 2, filtration was performed, and the filtration rate at each filtration time was measured.

Example 2 A liquid treatment apparatus having the same filtration area and configuration as that used in Example 1 was provided with a circulation line for the undiluted solution to prepare a liquid treatment apparatus having the configuration shown in FIG. Filtration was performed under the same conditions as in Experimental Example 1 while circulating the stock solution and stirring, and the filtration rate was measured.

Comparative Example 1 Using a liquid treating apparatus having the same filtration area and constitution as used in Example 1, the inside of the apparatus was filled with the stock solution so that all the filter elements were in contact with the stock solution, and the filter element was rotated. Without filtration. The stock solution and filtration pressure conditions were the same as in Example 1.

COMPARATIVE EXAMPLE 2 A disk-shaped support having a central shaft portion was sandwiched on both sides by flat plate-shaped filtration membranes (pore diameter: 0.1 μm), and a filtrate outflow portion was formed in the central shaft portion. A disk-shaped filter element was manufactured, and the filter elements were connected to manufacture a liquid processing apparatus having a configuration similar to that of the first embodiment. The size of the dipping tank, the filtration area, etc. were set to be the same as in Example 1, and filtration was performed under the same conditions.

The results are shown in FIG. 4. In Examples 1 and 2, although the filtration rate was decreased up to about 30 minutes after the start of filtration, there was no significant decrease thereafter and the filtration was almost constant after 60 minutes. The speed was maintained. In particular, in Example 2 in which the circulation line was used for stirring, a higher filtration rate was maintained. On the other hand, in Comparative Example, the filtration rate gradually decreased with the lapse of filtration time, and particularly in Comparative Example 1, only a very small amount of filtrate was obtained 2 hours after the start of filtration. In Comparative Example 2, the effect of rotating the disc-shaped filter element was observed, and a high filtration rate was obtained at the initial stage of the start of filtration. However, with the passage of filtration time, sludge was clogged between the filtration elements and the filtration rate decreased, resulting in a value lower than that of the example.

Although the filter element of the present invention and the liquid processing apparatus using the same have been described above with reference to the embodiments, various shapes and configurations other than the above examples are also possible without departing from the scope thereof. Application examples can be adopted.

[0037]

As described above, the filter element of the present invention,
Also, by using a liquid treatment apparatus using the same, a stock solution containing a large amount of fine particles, suspended substances such as microorganisms and other colloids can be stably and continuously subjected to precise filtration over a long period of time. It will be possible.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a filter element of the present invention.

FIG. 2 is a schematic diagram showing an example of a liquid processing apparatus of the present invention.

FIG. 3 is a schematic diagram showing another example of the liquid processing apparatus of the present invention.

FIG. 4 is a graph showing experimental results.

[Explanation of symbols]

 1 Central Shaft Part 2 Filtration Unit Connection Part 3 Filtration Unit 4 Support Structure 5 Hollow Fiber Filtration Membrane 6 Filtrate Outflow Part 7 O-Ring 8 Liquid Channel 9 Resin Fixing Part 10 Undiluted Liquid 11 Filtrate 12 Arrows 15 Filtration Element 16 Filtration Part 17 Immersion tank 18 Bearing mechanism 19 Motor 20 Transmission part 21 Rotation mechanism 22 Sampling mechanism 23 Storage tank 24 Decompression pump 25 Undiluted solution inlet 26 Discharge port 27 Air 30 Circulation line 31 Outflow part 32 Circulation pump

Claims (5)

[Claims] 1. A filter element in which a filter unit using a porous filter material is radially connected to a central shaft portion in which a liquid channel is formed, wherein a filtrate outflow portion of the filter unit and the liquid. A filter element, characterized in that the flow paths are in fluid-tight communication with each other and are configured to be able to perform stable rotation about the central shaft portion. 2. The filter element according to claim 1, wherein the porous filter material is a hollow fiber filter membrane. 3. A filtration unit using a central shaft portion having a liquid flow passage formed therein and a porous filter material radially connected to the central shaft portion as a basic structure, and the filtration unit being provided in the liquid flow passage. And a filtration element configured such that the filtrate outflow portion of the filter fluidly communicates with each other and is capable of performing stable rotation about the central shaft portion, and the central shaft portion of the filtration element. Bearing mechanism and rotating mechanism of the central shaft portion, a collecting mechanism for collecting filtrate from the liquid flow path of the central shaft portion, and holding the filtration element so that at least a part of the filtration unit is immersed in the stock solution. A liquid treatment apparatus having a holding structure, wherein filtration is performed while rotating the filtration element. 4. The liquid processing apparatus according to claim 3, wherein the porous filter material is a hollow fiber filter membrane. 5. The liquid processing apparatus according to claim 3, wherein a liquid stirring mechanism is installed near the filtration unit.