JPH05329206A - Filter device for liquid - Google Patents

Abstract

PURPOSE:To lessen the clogging of the filter and to remove a large amt. of precipitate by providing the holes larger than individual particles in a primary filter and the holes smaller than these holes in a secondary filter, providing a gap between these filters and providing holes slightly larger than the individual particles and smaller than the holes of the secondary filter in the final filter. CONSTITUTION:The primary filter 5 has the many holes of the surface opening larger than the individual particles to be removed and enables the formation of the laminates of the individual particles on its surface. The secondary filter 6 has the many holes of the surface opening smaller than the holes of the primary filter 5 and forms the gap 8 between the secondary filter 6 and the primary filter 5. Further, the final filter 9 has the many holes of the surface opening slightly larger than the individual particles and smaller than the holes of the secondary filter 6. The individual particles in the liquid flowing in from a liquid inflow port 3 forms a primary cake layer on the surface of the primary filter 5 and the liquid past the primary filter 5 flows into the gap 8 and forms a secondary cake layer on the surface of the secondary filter 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid filter for removing solid particles in a liquid.

[0002]

2. Description of the Related Art In recent years, as part of plasma exchange therapy, immunoglobulin, which is considered to be a pathogenic substance from patient plasma,
BACKGROUND ART Autologous plasma purification methods have been performed in which large-molecular-weight proteins such as fibrinogen and immune complexes are removed, and useful plasma components such as albumin are converted into patients again. Recently, as one of such autologous plasma purification methods, a solubility fractionation method in which a salting-out agent or the like is added to plasma to precipitate and separate and remove a large molecular weight protein from the difference in solubility (JP-A-60-99265, etc.) Is being considered. Then, as a method of removing the protein salt-out product (in other words, solid particles) from the plasma, a centrifugation method and a filtration method using a filter are used.

As a general solid-liquid separation filter used for separating such a liquid, for example, a deep-layer trapping type (so-called depth type) in which crimped polyester fibers are packed in a cotton shape, Alternatively, knitted fabrics, woven fabrics, and screen-type fabrics using a porous body formed of a thermoplastic resin, metal, or the like as a material are known. However, in the case of the deep-layer trapping type, clogging is unlikely to occur, but there is a drawback in that due to the structure of the filter, there is a large variation between the dense portion and the rough portion of the filter material, and it is difficult to obtain filtration accuracy. Further, it is difficult to remove air from the filter medium before use, and there is a problem in that when a liquid is flown in, the air blocking due to the remaining air causes a reduction in the filtration treatment capacity. Further, since the filter has a certain thickness, there is a drawback that the amount of the liquid contained in the filter that cannot be recovered is large after filtering the liquid, and the liquid recovery rate is low. On the other hand, in the case of the screen type filter, although the filtering accuracy can be maintained, clogging is likely to occur and the filtering ability is low.

Therefore, the applicant of the present invention has disclosed, as a liquid filter for separating and removing the solid particles, which are the above-mentioned precipitates, from the liquid plasma, as disclosed in JP-A-63-29676.
We propose the one shown in No. 5. This liquid filter 50
As shown in FIG. 6, a concentric cylindrical filter medium is housed in a housing composed of a container body 51, a lid body 52 and a bottom body 53, and the filter medium includes a primary filter 57 located on the upstream side. The secondary filter 58 is located on the downstream side. The primary filter 57 has a layer thickness of 3.0 to 20 mm in which composite fibers having an average fiber diameter of 1.0 to 10 denier are entangled with each other and have a gap for capturing a relatively large substance among substances to be filtered. Is used, and the secondary filter 58 has an average fiber diameter of 0.
Layer thickness of 0.3 to 3.0 m, which is made of polymer fiber of 01 to 0.1 denier and has fine gaps capable of capturing substances that have not been captured by the primary filter among substances to be filtered.
m is used.

[0005]

The liquid filter described above has a small amount of clogging and a high filtration treatment amount and can be used satisfactorily, but it requires a relatively large volume. Therefore, there is a demand for a liquid filter having a smaller filtration capacity and a higher filtration accuracy capable of removing a large amount of precipitates even in a limited volume, less clogging, and a higher liquid recovery rate. Has been. Therefore, an object of the present invention is to provide a liquid having a sufficient filtration accuracy, a small clogging, a high filtration capacity capable of removing a large amount of precipitates even in a limited volume, and a high liquid recovery rate. A filter is provided.

[0006]

What achieves the above object is a liquid filter for removing the solid particles from a liquid containing the solid particles.
A housing having a liquid inlet and a liquid outlet, a primary filter housed in the housing, and a liquid inflow formed between the inner surface of the housing and the outer surface of the primary filter and communicating with the liquid inlet. Part, a secondary filter located downstream of the primary filter and housed in the housing so that the liquid that has passed through the primary filter contacts, and only the liquid that has passed through the secondary filter contacts. And a final filter housed within the housing, the primary filter having a number of pores having surface openings larger than the solid particles, and the primary filter having a stack of the solid particles on a surface thereof. Of the primary filter and the secondary filter has a number of surface openings smaller than the pores of the primary filter. And a void is formed between the secondary filter and the primary filter, and the final filter has a surface opening slightly larger than the solid particles and smaller than the pores of the secondary filter. It is a liquid filter having a large number of holes.

Further, it is preferable that a void be formed between the secondary filter and the final filter. And, the secondary filter is preferably capable of forming a laminate of the solid particles on the surface. Furthermore, the final filter is preferably capable of forming a laminate of the solid particles on the surface. Further, the primary filter and the secondary filter are preferably flat filters. And, the primary filter and the secondary filter are preferably cylindrical filters. Further, it is preferable that the solid particles are a precipitate formed in plasma by a solubility fractionation method, and the liquid filter is a liquid filter for removing the precipitate from plasma.

Therefore, the filter for liquid of the present invention is used as a filter for liquid used in a solubility fractionation method in which a salting out agent or the like is added to plasma to precipitate a large molecular weight protein from the difference in solubility and the protein is separated and removed. A description will be given using an applied example.

The liquid filter 1 of the present invention is a liquid filter for removing solid particles from a liquid containing solid particles, and includes a housing having a liquid inlet 3 and a liquid outlet 4. , A primary filter 5 housed in the housing 2, and a liquid inflow portion 7 formed between the inner surface of the housing 2 and the outer surface of the primary filter 5 and communicating with the liquid inlet 3, and downstream of the primary filter 5. A secondary filter 6 located in the housing 2 such that the liquid passing through the primary filter 5 comes into contact with the primary filter 5, and the primary filter 5 has a large number of surface openings larger than the solid particles to be removed. The primary filter 5 is capable of forming a stack of solid particles (hereinafter referred to as "cake layer") on the surface thereof, and the secondary filter 6 is different from the pores of the primary filter 5 in its surface. In addition to having a large number of pores with small surface openings, an air gap 8 is formed between the secondary filter 6 and the primary filter 5, and the final filter 9 is slightly larger than the solid particles and of the secondary filter 6. It has a large number of holes with surface openings smaller than the holes.

Therefore, in the liquid filter 1, the solid particles in the liquid to be filtered, which have flowed in from the liquid inlet 3 of the liquid filter 1, form a primary cake layer on the surface of the primary filter 5 by the solid particles themselves. However, it prevents the passage of relatively large solid particles to be filtered. Then, the liquid that has passed through the primary filter 5 flows into the gap formed between the primary filter 5 and the secondary filter 6, contacts the secondary filter 6, and then the primary filter is formed on the surface of the secondary filter 6. A secondary cake layer having a narrower gap than the cake layer is formed. Then, the liquid that passes through the cake layer formed on each filter tries to pass through a place having a low filtration resistance, so that the cake layer is uniformly formed, that is, the entire surface of the two filters. Since the solid particles are captured by the solid particles, partial channeling hardly occurs and clogging is extremely rare. In addition, the final filter has a surface opening slightly larger than the solid particles, resulting in low pressure loss, high liquid recovery, and very little clogging. Further, since this filter does not try to trap solid particles in the surface openings of the pores of the filter, a high filtering capacity can be obtained without increasing the volume occupied by the filter in the filter.

The liquid filter of the embodiment shown in FIG. 1 will be described. FIG. 1 is a sectional view of a liquid filter 1 of the present invention. The liquid filter 1 of this embodiment includes a housing 2 having a liquid inlet 3 and a liquid outlet 4, a primary filter 5 housed in the housing 2, an inner surface of the housing 2 and a surface of the primary filter 5. Between the housing 2 and the liquid inflow portion 7 formed between the liquid inlet 3 and the liquid inlet 3 and the liquid having passed through the primary filter 5 are in contact with each other.
The primary filter 5 has a hole having a diameter larger than that of the solid particles to be removed, and the primary filter 5 is capable of forming a stack of solid particles on the surface thereof. Yes, secondary filter 6
Has pores with surface openings smaller than the pores of the primary filter 5 and larger than the solid particles, a void 8 is formed between the secondary filter 6 and the primary filter 5, and the final filter 9 is , A large number of pores having surface openings slightly larger than the solid particles and smaller than the pores of the secondary filter 6.

As shown in FIG. 1, the housing 2 has a cylindrical upper housing 2a whose lower end is opened and whose diameter is reduced toward the upper end, and a lower housing 2b which is liquid-tightly fixed to the lower end opening of the upper housing 2a. Consists of. A liquid inlet 3 is provided at the upper end of the upper housing 2a. The lower housing 2b is provided with a liquid outlet 4 at its lower end. The upper housing 2a and the lower housing 2b are preferably circular, square, rectangular, or the like in cross section, and are preferably made of a transparent material when the inside can be easily confirmed. In the liquid filter 1, the flat plate-shaped primary filter 5 is housed in the housing 2 so as to be orthogonal to the axis, as shown in FIG.

In the filtration of a liquid containing solid particles in the liquid, for example, a slurry having a concentration of 1% (volume) or more,
A cake filtration method in which a cake formed on a filter is used to perform a filtering action is generally used as an industrial filtration method. The cake here has a structure in which liquid is filled in the gaps of the solid particle layer, and the particles themselves can be regarded as a rigid body,
A non-compressible cake in which the porosity of particles does not change due to filtration pressure (for example, sand or crystalline particles) and a gradual aggregate of fine particles, and a compressible cake in which the porosity of particles changes due to filtration pressure (for example, , Colloidal hydroxide,
There are some protein deposits deposited by the solubility fractionation method in the field of biochemistry). This cake layer then forms a secondary surface opening diameter on the surface of the filter. Also,
The formation of the cake layer is generally said to occur when the surface opening diameter of the pores of the filter is larger than the solid particle diameter and 30 times or less, and particularly when the surface opening diameter is 1.5 to 10 times or less. Is said to be remarkable. Further, it is said that the more the properties of the solid particles, for example, those having high tackiness, those having small specific gravity, and those having large friction coefficient, are more likely to occur. Further, even if the surface opening diameter is not less than the above, a cake layer can be formed when the solid particles have properties such as high tackiness, low specific gravity, and high friction coefficient.

Also in the liquid filter 1 of the present invention, the cake that plays a major role in the filtration is formed on the surface of the primary filter 5 at first, and the filter has a strength capable of holding the cake. I need to have it. The primary filter 5 preferably has a surface opening diameter of about 1.5 to 50 times that of the solid particles to be removed, particularly 3 to 30.
It is preferably about double. Then, as the primary filter, a porous membrane, a porous polymer membrane, a porous body, a filter cloth, a filter mesh, a filter paper, a nonwoven fabric, a filter sheet, a felt, a porous ceramic, a porous plastic, an asbestos, a cellulose, a cotton pad. , Three-dimensional foams and the like. Particularly preferably,
A three-dimensional porous body composed of a nonwoven fabric having an average fiber diameter of 1 to 30 denier, and a fused body of such nonwoven fabric, having an average pore diameter of about 8 to 70 μm.

The primary filter 5 has a large number of pores having surface openings larger than those of the solid particles to be removed (for example, salted out products of large molecular weight proteins), and further,
A material capable of forming a cake layer, which is a laminate of solid particles, is used on the surface (outer surface). Specifically, a flat-plate filter, for example, a filter having a rectangular flat plate shape, a square flat plate shape, a disk shape, or the like is used. Further, the primary filter 5 varies depending on the type of liquid to be treated and the filtration amount of one time, and is not a uniform value. For example, the total protein amount is 6.0 g / dl from 20 ml of plasma, and In the case of filtering the salted-out product of (1), a product having a thickness of about 0.5 to 10 mm is suitable, more preferably 1 to 5 mm, and a surface area of 0.5 to 50.
It is preferably about 1 cm ² , more preferably 1.
It is preferably 0 to 40 cm ² .

Further, as the primary filter 5, as shown in FIG. 1, it is preferable to use a stack of a plurality of filters. In particular, it is preferable to stack a plurality of filters having different basis weights. In particular, each of the filters 5 on the liquid inlet side (upstream side) has a hole with a surface opening that is about 1.5 to 50 times the size of the solid particles to be removed.
It is preferable that the basis weight of a is larger than the basis weight of the downstream filter 5b, in other words, the downstream filter 5b has a finer mesh than the upstream filter 5a. By doing so, even if a considerably large agglomerate is contained in the slurry, it is possible to prevent the pores of the surface opening of the filter 5b from being rapidly closed due to this. Specifically, the holes of the filter 5b should be 15 to 50 μm.
m, and it is preferable to use a filter having a basis weight of the filter 5b of about 1.2 to 5 times the basis weight of the filter 5a.

Further, in the peripheral portion of the primary filter 5,
In order to facilitate potting with the potting agent 12, it is preferable to provide a reinforcing portion. This reinforcement is
For example, it can be formed by injecting a sealing material such as polyurethane or silicone rubber into the portion to be the reinforcing portion, or by performing a treatment such as heat depending on the material.

The primary filter 5 has a liquid inflow portion 7 communicating with the liquid inlet 3 between the inner surface of the upper housing 2a and the upper surface of the primary filter 5, and the liquid inflow portion 7 is formed. , The first solid particle capturing portion (cake layer forming portion). The height of the liquid inflow portion 7 varies depending on the type of liquid to be treated, the concentration of solid particles in the liquid, and the like, and is not uniform, but, for example, the total protein amount is 6.0 g / dl. 20 ml plasma
Therefore, when filtering out the salted-out product of protein,
It is preferably about 0 mm.

Below the primary filter 5, a secondary filter 6 is housed in the lower housing 2b so that only the liquid that has passed through the primary filter 5 comes into contact with it. A void 8 that forms a second solid particle capturing portion (secondary cake layer forming portion) is formed between the secondary filter 6 and the primary filter 5. The void 8 is
As shown in FIG. 1, it is preferable that the secondary filter 6 and the primary filter 5 are provided substantially parallel to each other so that the entire space is substantially equidistant from each other. It may be in contact with the filter 5. The thickness of the voids 8 varies depending on the type of liquid to be treated, the concentration of solid particles in the liquid, and the like, and is not uniform. For example, the total protein amount is 6.0 g.
When the protein salt-out is filtered from 20 ml of / dl plasma, it is preferably about 0.2 to 10 mm.

As shown in FIG. 1, the secondary filter 6 has a flat plate shape, specifically, a rectangular flat plate shape, for example.
A filter having a square flat plate shape, a disc shape, or the like is suitable, and has a large number of holes having surface openings smaller than the surface openings of the holes of the primary filter 5. Then, it is preferable to use a material capable of forming a cake layer, which is a laminate of solid particles, on the surface (upper surface) thereof. The filter material used for the secondary filter 6 preferably has a surface opening diameter of about 1.5 to 50 times that of the solid particles flowing out from the filter 5, and particularly 3 to 30.
It is preferably about double. As the secondary filter, a porous membrane, a porous polymer membrane, a porous body, a filter cloth, a filter mesh, a filter paper, a non-woven fabric, a filter sheet, a felt, a porous ceramic, a porous plastic, an asbestos, a cellulose, a cotton pad, Examples include three-dimensional foams. Particularly preferred is a three-dimensional porous body made of a non-woven fabric fused body having an average fiber diameter of 1 to 30 denier and an average pore diameter of about 1 to 20 μm.

The secondary filter 6 varies depending on the type of liquid to be treated and the filtration amount per time, and is not a uniform one. For example, the total protein amount is 6.0 g / d.
When filtering out a salted-out product of protein from 20 ml of 1-liter plasma, a thickness of about 0.5 to 10 mm is suitable, more preferably 1 to 5 mm, and a surface area of 0.5.
It is preferably about 50 to 50 cm ² , and more preferably 1.0 to 40 cm ² . Also,
As the secondary filter 6, it is preferable to use a stack of a plurality of filters as shown in FIG. In particular, it is preferable to stack a plurality of filters having different basis weights. In particular, 1.5 of the solid particles to be removed
Approximately 50 times as large as a surface opening hole, and the basis weight of the liquid inlet side (upstream side) filter 6a is larger than the basis weight of the downstream side filter 6b, in other words, on the downstream side. It is preferable that the filter 5b has a finer mesh than the filter 6a on the upstream side.

Specifically, the pore diameter is 3 to 20 μm, and the basis weight of the filter 6b is 1.
It is preferable to use one that is about 2 to 5 times. further,
In order to facilitate potting with the potting agent 12, it is preferable to provide a reinforcing portion on the peripheral portion of the secondary filter 6. The reinforcing portion can be formed, for example, by injecting a sealing material such as polyurethane or silicone rubber into the portion to be the reinforcing portion, or by performing heat treatment or the like depending on the material.

The void 8 preferably has a stable shape. Therefore, for example, as shown in FIG. 1, a void forming material 8a is inserted between the primary filter 5 and the secondary filter 6. Preferably. Void forming material 8
As a, any material may be used as long as it does not impede the flow of liquid so much, for example, a coarse net, mesh, woven fabric, non-woven fabric, etc. are suitable, and a large number of rod-shaped members, etc. May be used. Further, in order to form the void, as shown in FIG. 3, an annular member 21 existing between the primary filter 5 and the secondary filter 6 and existing only at the peripheral edge portion may be used. In this case, there is a complete gap between the primary filter 5 and the secondary filter 6. Further, the secondary filter is not limited to one, and a plurality of secondary filters may be provided so as to be separated from each other so that a void is formed therebetween.

Below the secondary filter 6 (downstream side), a final filter 9 is provided so that only the liquid that has passed through the secondary filter comes into contact with it. The final filter 9 has pores with a surface opening that is smaller than the surface opening of the secondary filter and slightly larger than the solid particles. Furthermore, it is preferable that the final filter is capable of forming a cake layer, which is a laminate of solid particles, on its surface (on the outer surface). As the final filter 9, a non-woven fabric, a woven fabric, a porous membrane (for example, a polyolefin porous membrane such as polypropylene and polyethylene, a polyvinylidene fluoride porous membrane), a porous body, a filter cloth, a filter mesh, a filter paper, a nonwoven cloth, A filter sheet or the like can be used. Particularly preferably,
It is made of non-woven fabric and has an average pore size of filter 6
About 1.5 to 50 times as much as the outflowing solid particles, specifically, those having an average pore diameter of about 0.4 to 5 μm are used.

Further, the final filter 9 varies depending on the type of liquid to be treated and the filtration amount per time, and is not a uniform value. For example, the total protein amount is 6.0.
When a protein salt-out is filtered from 20 ml of g / dl plasma, a thickness of about 0.5 to 10 mm is preferable, more preferably 1 to 5 mm, and a surface area of 0.2 to it is preferably of about 50 cm ^2, more preferably, is preferably 0.7~40cm ^2. Further, as the final filter 9, as shown in FIG. 1, it is preferable to use a stack of a plurality of filters. In particular, it is preferable to stack a plurality of filters having different basis weights. In particular, each of the filters has a surface opening having a size of about 1.5 to 50 times that of the solid particles to be removed, and the basis weight of the liquid inlet side (upstream side) filter 9a is the downstream side filter 9b. It is preferable that the filter 9b on the downstream side has a finer mesh than the filter 9a on the upstream side. Specifically, it is preferable to use a filter having a basis weight of the filter 9b of about 1.2 to 5 times the basis weight of the filter 9a.

A gap 20 is formed between the secondary filter 6 and the final filter 9. It is preferable that this void 20 also has a stable shape. Therefore, for example, as shown in FIG. 1, it is preferable to insert a void forming material 20a between the secondary filter 6 and the final filter 9. As the void-forming material 20a, any material can be used as long as it does not impede the flow of the liquid so much. For example, a net, a mesh, a woven cloth,
Nonwoven fabric or the like is suitable, and a large number of rod-shaped members may be used. Further, in order to form the void, as shown in FIG. 3, an annular member 22 existing between the secondary filter 6 and the final filter 9 and existing only at the peripheral edge portion may be used. In this case, there is a complete gap between the secondary filter 6 and the final filter 9.

The final filter 9 forms a liquid outflow portion 10 communicating with the liquid outflow port 4 between itself and the inner surface of the lower housing 2b. Further, it is preferable that the shape of the liquid outflow portion 10 is also stable. Therefore, for example, as shown in FIG. 1, the gap forming material 10a is inserted between the final filter 9 and the lower housing 2b. Is preferred. As the void forming material 10a, any material can be used as long as it does not impede the flow of the liquid so much, for example, a net having a coarse mesh, a mesh, a woven cloth, a non-woven cloth, or the like is preferable. You may use a rod-shaped member. In addition, in order to form voids, FIG.
As shown in Figure 3, the final filter 9 and the lower housing 2b
And the annular member 23 existing only in the peripheral portion
May be used. In this case, there is a complete gap between the final filter 9 and the lower housing 2b.

Next, the liquid filter 3 of the embodiment shown in FIG.
0 will be described. The difference between the liquid filter 30 of this embodiment and the liquid filter of the embodiment shown in FIG. 1 is that a hollow fiber membrane is used for the final filter 9 and the shape of the lower housing 2b is different. , For other,
It is similar to that described above.

As shown in FIG. 3, the hollow fiber membrane bundle 9 is liquid-tightly fixed to the lower housing 2b by a potting agent 12, and the hollow fiber membrane bundle 9, the secondary filter 6 and the lower housing are also attached. A gap 20 is formed between the inner surface of 2b and
Are formed. Further, it is preferable that this void 20 also has a stable shape, and therefore, as shown in FIG. 3, a void forming material 20a is provided between the secondary filter 6 and the hollow fiber membrane bundle 9 which is the final filter. It is preferable to insert it. As the void forming material 20a, any material can be used as long as it does not impede the flow of the liquid so much, for example, a net having a coarse mesh, a mesh, a woven fabric, a non-woven fabric, or the like is preferable. You may use a rod-shaped member. A liquid outlet 4 that communicates with the inside of the hollow fiber membrane bundle 9 is provided in the lower portion of the side surface of the lower housing 2b.

As the hollow fiber membrane used in the final filter 9, a hollow fiber membrane having a large number of side holes slightly larger than solid particles and smaller than the surface opening of the secondary filter is used. As the hollow fiber membrane, hydrophilic hollow fiber membranes such as regenerated cellulose (eg, cellulose acetate, cuprammonium cellulose), polyvinyl alcohol, etc., and further, polyolefins such as polypropylene, polyethylene, vinylidene fluoride, fluorine such as PTFE, ETFE, etc. A hydrophobic hollow fiber membrane such as a resin is used.

Next, the liquid filter 40 of the embodiment shown in FIGS. 4 and 5 will be described. FIG. 4 is a sectional view of an embodiment of the liquid filter of the present invention, and FIG.
It is a sectional view taken along line A-.

The liquid filter 1 of this embodiment is provided with a housing having a liquid inlet 3 and a liquid outlet 4, a cylindrical primary filter 5 housed in the housing 2, and a primary filter 5 located in the housing. And a cylindrical secondary filter 6 housed in the housing 2 so that only the liquid that has passed through the primary filter 5 comes into contact with the liquid that is located in the secondary filter 6 and that has passed through the secondary filter 6. And a cylindrical final filter 9 housed in the housing 2 so that only the two come into contact with each other.

As shown in FIG. 4, the housing 2 has a cylindrical upper housing 2a whose lower end is opened and whose diameter is reduced toward the upper end, and a lower housing 2b which is liquid-tightly fixed to the lower end opening of the upper housing 2a. Consists of. A liquid inlet 3 is provided at the upper end of the upper housing 2b. As shown in FIG. 5, the upper housing 2a preferably has a substantially cylindrical shape, and is further preferably formed of a transparent material so that the inside can be easily confirmed. The size of the upper housing 2a varies depending on the type of liquid to be treated, the amount of treatment at one time, and the like, and although it is not uniform, it is 200 m.
When filtering about 1 liter of liquid, the internal volume is 50
About 150 ml is used. Further, as shown in FIGS. 4 and 5, the lower housing 2b preferably has a cylindrical projecting portion 2c at the center thereof, and further preferably has a liquid outlet 4 near the projecting portion 2c.

In the liquid filter 1, the cylindrical primary filter 5 is housed in the housing 2 in a substantially concentric manner as shown in FIG.
As shown in FIG.
It is liquid-tightly fixed by 2. Cylindrical primary filter 5
5 is a cylindrical body having a large number of pores having a surface opening larger than that of the solid particles to be removed (for example, a salted out product of a large molecular weight protein) on the side wall, as shown in FIG. What can form a cake layer which is a laminate of solid particles on the surface (outer surface) is used.

Also in the liquid filter 1 of the present invention, the cake that plays a major role in the filtration is formed first on the surface of the primary filter 5, and the filter has a strength capable of holding the cake. I need to have it.

The primary filter 5 preferably has a surface opening diameter of about 1.5 to 50 times, more preferably about 3 to 30 times that of the solid particles to be removed. Then, as the primary filter, a porous membrane, a porous polymer membrane, a porous body, a filter cloth, a filter mesh, a filter paper, a nonwoven fabric, a filter sheet, a felt, a porous ceramic, a porous plastic, an asbestos, a cellulose, a cotton pad. , Three-dimensional foams and the like. Particularly preferred is a three-dimensional porous body composed of a non-woven fabric fused body having an average fiber diameter of 3 to 30 denier and an average pore diameter of about 8 to 70 μm. The tubular primary filter 5 varies depending on the type of liquid to be treated and the filtration amount of one time and is not uniform, but for example, from 200 ml of plasma having a total protein amount of 6.0 g / dl. When the salted-out product of protein is filtered from plasma, one having a thickness of about 1 to 20 mm is suitable, more preferably 3 to 10 mm, and a surface area of 90
It is preferably about 200 to ²⁰⁰ cm ² , and more preferably 100 to 150 cm ² . As described above, the tubular primary filter 5 is housed substantially concentrically in the housing 2, and the liquid inlet 3 is provided between the inner surface of the housing 2 and the outer surface of the tubular primary filter 5. A liquid inflow portion 7 communicating with the liquid inflow portion 7 is formed, and the liquid inflow portion 7 constitutes a first solid particle capturing portion (cake layer forming portion). The width of the liquid inflow portion 7 varies depending on the type of liquid to be treated, the concentration of solid particles in the liquid, and the like, and is not uniform, but, for example, plasma with a total protein amount of 6.0 g / dl. When the protein salt-out product is filtered from 200 ml, it is preferably about 1 to 20 mm.

The cylindrical secondary filter 6 is housed in the primary filter 5 so as to be positioned substantially concentrically, and only the liquid passing through the primary filter 5 comes into contact with the cylindrical secondary filter 6. .. And the secondary filter 6
A void 8 that forms a second solid particle trapping portion (secondary cake layer forming portion) is formed between and the primary filter 5. As shown in FIGS. 4 and 5, it is preferable that the voids 8 are provided substantially concentrically so that the entire circumference between the secondary filter 6 and the primary filter 5 is substantially equidistantly spaced, but not limited to this. The secondary filter 6 and the primary filter 5 may be partially in contact with each other. As the width of the void 8,
It varies depending on the type of liquid to be treated, the concentration of solid particles in the liquid, etc. and is not uniform, but for example, from 200 ml of plasma with a total protein amount of 6.0 g / dl,
When the protein salt-out product is filtered, 0.2 to 10
It is preferably about mm.

As shown in FIG. 5, the tubular secondary filter 6 is a tubular body, and the primary filter 5 is provided on the side wall.
It is preferable to have a large number of holes having a surface opening smaller than the surface opening of the holes. Furthermore, it is preferable to use a material capable of forming a cake layer, which is a laminate of solid particles, on its surface (on the outer surface). The secondary filter 6 has a surface opening diameter of 1.
It is preferably about 5 to 100 times, particularly preferably about 3 to 70 times. As the secondary filter, a porous membrane, a porous polymer membrane, a porous body, a filter cloth, a filter mesh, a filter paper,
Nonwoven fabrics, filter sheets, felts, porous ceramics, porous plastics, asbestos, cellulose, cotton pads, three-dimensional foams and the like can be mentioned. Particularly preferred is a three-dimensional porous body made of a non-woven fabric fused body having an average fiber diameter of 1 to 30 denier and an average pore diameter of about 1 to 20 μm.

Then, as the cylindrical secondary filter 6,
Although it varies depending on the type of liquid to be treated and the amount of one filtration, it is not a uniform value. For example, when filtering out a salted-out protein from 200 ml of plasma having a total protein amount of 6.0 g / dl. The thickness is preferably about 1 to 20 mm, more preferably 3 to 10 mm, and the surface area is preferably about 50 to 150 cm ² , more preferably 90 to 120 cm ² .

The void 8 preferably has a stable shape. For this reason, for example, as shown in FIG. 4, an annular protrusion 2d is provided in the lower housing 2b, and the annular protrusion 2d is the primary protrusion. It is preferable to house each filter in a housing so as to be located between the filter 5 and the secondary filter 6. Further, the annular protruding portion 2d does not protrude in a continuous annular shape as shown in FIG.
You may provide so that it may be scattered. By doing so, the filling of the sealing agent 12 becomes easy. In addition, the void 8
In order to further stabilize the shape of the above, it is preferable that the upper plate 14 supporting the upper portions of the primary filter 5 and the secondary filter 6 also be provided with the annular protrusion 14a. Further, the annular protruding portions 14a may be provided so as to be scattered instead of protruding in a continuous annular shape. A void forming material may be inserted between the primary filter 5 and the secondary filter 6 instead of the annular protrusion. As the void-forming material, any material can be used as long as it does not hinder the flow of the liquid, for example, a coarse net, a mesh,
Woven cloth, non-woven cloth, and the like are preferable, and a large number of rod-shaped members may be used.

Further, inside the cylindrical secondary filter 6, a cylindrical final filter 9 is housed so that only the liquid that has passed through the secondary filter comes into contact with it. And
The final filter 9 has pores with a surface opening that is smaller than the surface opening of the secondary filter and slightly larger than the solid particles. Furthermore, it is preferable to use a material capable of forming a cake layer, which is a laminate of solid particles, on its surface (on the outer surface). As the final filter 9, a non-woven fabric, a woven fabric, a porous membrane (for example, a polyolefin porous membrane such as polypropylene and polyethylene, a polyvinylidene fluoride porous membrane), a porous body, a filter cloth, a filter mesh, a filter paper, a nonwoven cloth, A filter sheet or the like can be used. Particularly preferably,
It is made of non-woven fabric and has an average pore size of filter 6
About 1.5 to 50 times as much as the outflowing solid particles, specifically, those having an average pore diameter of about 0.4 to 5 μm are used.

A void 20 is preferably formed between the secondary filter 6 and the final filter 9, and the void 8 preferably has a stable shape. For that purpose, for example, as shown in FIG. 4, an annular protrusion 2f is provided in the lower housing 2b, and each filter is housed so that the annular protrusion 2f is located between the secondary filter 6 and the final filter 9. It is preferable to store in. Further, as shown in FIG. 5, the annular protruding portions 2f may be provided so as to be scattered instead of protruding in a continuous annular shape. By doing so, the filling of the sealing agent 12 becomes easy. Further, in order to make the shape of the void 20 more stable, it is preferable to provide the upper plate 14 supporting the upper portion of the secondary filter 6 with the annular protrusion 14b. Further, the annular protruding portions 14b may be provided so as to be scattered instead of protruding in a continuous annular shape. A void forming material may be inserted between the secondary filter 6 and the final filter 9 instead of the annular protrusion. As the void-forming material, any material can be used as long as it does not impede the flow of the liquid so much, for example, a coarse net, mesh, woven cloth, non-woven cloth, etc. A member or the like may be used.

As shown in FIG. 4, an upper plate 14 and a cap 15 are liquid-tightly fixed to the upper part of the primary filter 5, the secondary filter 6 and the final filter 9 by a sealing material 11. As shown in FIG. 4, the cap 15 has a conical shape and has a function of dispersing the liquid flowing from the liquid outlet 3 to the peripheral portion of the housing.

In the above description, the liquid filter of the present invention is applied to a filter for removing protein precipitates in plasma. However, the present invention is not limited to this. Can be used for filtration. In addition, depending on the state of the solid-liquid system to be separated, the properties of the solid particles, the treatment amount, the treatment conditions, etc., it is not limited to the above-mentioned two-layer filter having one interlayer gap, and It may have three or more layers. The conditions such as the roughness of the surface opening of the pores of each filter and the width of the gap between the filters can be arbitrarily selected depending on the liquid to be separated.

The operation of the liquid filter of the present invention will be described with reference to FIG. The liquid to be filtered, which has flowed in from the liquid inlet 3 of the liquid filter 1, flows into the liquid inflow portion 7 and comes into contact with the primary filter 5. Then, when the solid particles in the liquid try to pass through the surface opening of the pores of the filter, the solid particles themselves form an arch near the entrance of the surface opening of the pores of the primary filter 5 in the initial stage of the crosslinking phenomenon (cake layer). The state is formed, the filter formed by the solid particles blocks the subsequent passage of the solid particles, and the cake layer grows. Then, when the liquid passes through the primary filter 5, a primary cake layer is formed on the outer surface of the primary filter 5 due to the above-mentioned crosslinking phenomenon. This primary cake layer has different filtration performance depending on the size of the surface opening of the pores of the primary filter 5 and the size distribution and properties of the solid particles to be filtered. Block the passage of large things. As a result, the liquid that has passed through the primary filter contains solid particles having a size capable of passing through the gaps in the primary cake layer and the primary filter. Then, the liquid that has passed through the primary filter 5 flows into the space 8 formed between the primary filter 5 and the secondary filter 6, and comes into contact with the secondary filter 6. Then, on the surface of the secondary filter 6, the crosslinking phenomenon occurs again due to the primary cake layer and the fine solid particles that have passed through the primary filter 5, and a secondary cake layer having a narrower gap than the primary cake layer is formed.

The liquid that has passed through the secondary filter 6 flows into the space 20 formed between the secondary filter 6 and the final filter 9 and comes into contact with the final filter 9. Then, on the surface of the final filter 9, the secondary cake layer and the fine solid particles that have passed through the secondary filter 5 cause a crosslinking phenomenon again to form a tertiary cake layer having a narrower gap than the secondary cake layer.

The liquid that has passed through the final filter 9 flows into the liquid outflow portion 10, and then flows out from the liquid inflow port 4.
Then, the liquid that passes through the cake layer formed on each filter tries to pass through a place with low filtration resistance, so that the cake layer is formed uniformly, that is, on the entire surface of each filter. Protein precipitates that are solid particles can be captured, partial channeling hardly occurs, and clogging is extremely small. Further, since this filter does not trap solid particles only in the surface openings of the pores of the filter, a high filtering capacity can be obtained without increasing the volume occupied by the filter in the filter.

[0048]

EXAMPLES Specific examples of the liquid filter of the present invention will be described below. (Example 1) Polycarbonate is used for the upper housing and has a shape as shown in FIG.
A 15 mm square having a height of 7 mm was prepared. As the lower housing, polycarbonate was used to have a shape as shown in FIG. 1, a square having a side length of 215 mm, and a height of 10 mm. As the primary filter, a square having a side length of 210 mm, a thickness of about 0.15 mm, an average fiber diameter of 3 denier, and a basis weight of 30 g /
m ² of non-woven fabric (nylon, trade name Aieru, manufactured by Asahi Kasei Corporation) on the upstream side, a square length 250mm sides a thickness of about 0.20 mm, an average fiber diameter of 3 denier, basis weight 40 g / m ² The non-woven fabric (made of nylon, product name Air, Asahi Kasei Co., Ltd.) was laminated on the downstream side. As a secondary filter, the side length 210
A square of mm, a thickness of about 0.3 mm, an average fiber diameter of 3 denier, and a basis weight of 70 g / m ² non-woven fabric (made of nylon, trade name AIL, Asahi Kasei Co., Ltd.) are placed on the upstream side, and the side length is 210 mm. A square non-woven fabric having a thickness of about 0.4 mm, an average fiber diameter of 3 denier, and a basis weight of 100 g / m ² (made of nylon, trade name Air, Asahi Kasei Co., Ltd.) was laminated on the downstream side. .. The final filter is a square with sides of 210 mm and a thickness of 0.4 m.
m, an average fiber diameter of 3 denier, and a basis weight of 100 g / m ² non-woven fabric (made of nylon, trade name Air, Asahi Kasei Co., Ltd.) is a square with a side length of 210 mm and a thickness of about 0.3 mm, Woven fabric with an average fiber diameter of 0.1 denier (made of nylon and polyester, trade name Savina Mini
max, manufactured by Kanebo Co., Ltd.) was used so as to be on the downstream side.

The gap between the inner surface of the upper housing and the upper surface of the primary filter is 3 mm, the gap width between the primary filter and the secondary filter is 2 mm, the gap width between the secondary filter and the final filter is 1 mm, the final filter and the lower filter. The gap between the inner surface of the housing is 2 mm, and the gap between the primary filter and the secondary filter, the gap between the secondary filter and the final filter, and the gap between the final filter and the inner surface of the lower housing are made of polypropylene (polypropylene). Net) was inserted. Then, as shown in FIG. 1, each filter was fixed to the lower housing using polyurethane. Then, the upper housing and the lower housing were fixed to each other to prepare the liquid filter of the invention (Example 1).

(Example 2) As a final filter, a square having a side length of 210, a thickness of about 0.4 mm, and an average fiber diameter of 3
^Two denier, 100 g / m ² basis weight non-woven fabric (made of nylon, product name Ayl, Asahi Kasei Co., Ltd.) are upstream and square with a side length of 210 mm and a thickness of about 0.25 m.
m, average fiber diameter 0.1 denier, basis weight 40 g / m ² non-woven fabric (made of nylon, polyester, trade name micno
Wove, manufactured by Kanebo Co., Ltd.) was used in the same manner as in Example 1 except that three sheets were laminated on the downstream side,
A filter for liquid of the invention (Example 2) was prepared.

(Example 3) Polycarbonate was used as the upper housing to have a square shape having a side length of 215 mm and a height of 7 mm using polycarbonate. Further, as the lower housing, a polycarbonate having a shape as shown in FIG. 2, a square with a side length of 215 mm, a height of 15 mm, and a liquid outlet on a side surface was prepared using polycarbonate. The same primary filters and secondary filters as in Example 1 were used. As the final filter, a bundle of about 205 hollow fiber membranes having an average pore diameter of 0.5 μm, a length of 210 mm, an outer diameter of 230 μm and an inner diameter of 200 μm was used. The total area of this hollow fiber membrane bundle was about 0.03 m ² . The gap between the inner surface of the upper housing and the upper surface of the primary filter is
The gap width between the primary filter and the secondary filter is 3 mm, the gap width between the secondary filter and the final filter and the gap between the final filter and the inner surface of the lower housing are 1.54 mm, and the primary filter and the secondary filter are 3 mm. A 3 mm-thickness void forming body (polypropylene net) was inserted into the void between and, and a 2 mm void forming body (polypropylene net) was inserted into the gap between the secondary filter and the final filter and the inner surface of the lower housing. .. Then, as shown in FIG. 2, each filter was fixed to the lower housing using polyurethane. Furthermore, and then
The upper housing and the lower housing were fixed, and the liquid filter of the invention (Example 3) was prepared.

(Comparative Example) Polycarbonate was used as the upper housing, and a square having a side length of 215 mm and a height of 7 mm was prepared. The lower housing is made of polycarbonate and has a side length of 21
A 5 mm square having a height of 6.5 mm was prepared.
As the primary filter, secondary filter and final filter, the same filters as in Example 1 were used. Then, the filters were laminated so that voids were not substantially formed between the filters. Then, the gap between the inner surface of the upper housing and the upper surface of the primary filter is 3 mm, the gap between the final filter and the inner surface of the lower housing is 2 mm, and the gap between the final filter and the inner surface of the lower housing is 2 mm. The void forming body (polypropylene net) was inserted. Then, each filter was fixed to the lower housing using polyurethane. Furthermore, and then
By fixing the upper housing and the lower housing, a liquid filter of the invention (comparative example) was prepared.

[Experiment] The following experiment was conducted using the liquid filters of Examples 1 to 3 and Comparative Example. As the liquid to be filtered, plasma with a total protein amount of 670 g / dl 2
00 ml was heated to 37 ° C., and as a salting-out agent, sodium chloride 5.1 mol / l and glycine 2.0 mol / l.
1 was added and mixed to obtain a plasma protein that was deposited. As an experimental method, the liquid to be filtered is contained in a soft bag having a capacity of 300 ml, the liquid outlet of the soft bag and the liquid inlet of the filter are connected by a tube, and further, the liquid outlet of the filter and the filtrate are collected. The flexible container of No. 1 was connected by a tube, a pump was attached in the middle of this tube, and suction filtration was performed at a flow rate of 15 ml / min.
The experimental results show that in the liquid filters of Examples 1 to 3, the protein precipitate did not flow into the filtrate collection container, the plasma recovery amount of the liquid filter of Example 1 was 197 ml, and the plasma recovery rate was , 98.5%, plasma recovery of the liquid filter of Example 2 was 193 ml, plasma recovery was 96.5%, plasma recovery of the liquid filter of Example 3 was 194 ml, plasma recovery The rate was 97.0%. Further, the filter was not clogged during the filtration. In the liquid filter of the comparative example, the protein precipitate did not flow into the filtrate collection container, but the plasma recovery amount was 140 ml, the plasma recovery rate was 70%, and the filter was removed during the filtration. Clogged up, it was not possible to filter all the liquid to be filtered,
5 ml remained.

[0054]

The liquid filter of the present invention is a liquid filter for removing the solid particles from the liquid containing the solid particles. The liquid filter has a liquid inlet and a liquid. A housing having an outlet, a primary filter housed in the housing, a liquid inflow portion formed between an inner surface of the housing and an outer surface of the primary filter, the liquid inflow portion communicating with the liquid inlet, and the primary The secondary filter, which is located on the downstream side of the filter and is housed in the housing so that the liquid that has passed through the primary filter comes into contact with the housing, so that only the liquid that has passed through the secondary filter comes into contact with the housing. A final filter contained therein, the primary filter having a number of pores having surface openings larger than the solid particles, and Is capable of forming a laminate of the solid particles on the surface, and the secondary filter has a large number of pores having surface openings smaller than the pores of the primary filter, and the secondary filter and the primary filter. A void is formed between the filters, and further, the final filter has a large number of pores having surface openings slightly larger than the solid particles and smaller than the pores of the secondary filter. In the vessel, the solid particles in the liquid to be filtered, which have flowed in from the liquid inlet of the liquid filter, form a primary cake layer on the surface of the primary filter due to the solid particles themselves. Obstruct passage. Then, the liquid that has passed through the primary filter flows into the void formed between the primary filter and the secondary filter, comes into contact with the secondary filter, and has a gap more than the primary cake layer on the surface of the secondary filter. To form a narrow secondary cake layer of. Then, the liquid that passes through the cake layer formed on each filter tries to pass through a place having a low filtration resistance, so that the cake layer is uniformly formed, that is, the entire surface of the two filters. Since the solid particles are captured by the solid particles, partial channeling hardly occurs and clogging is extremely rare. In addition, the final filter has a surface opening that is slightly larger than the solid particles, resulting in low pressure loss,
High liquid recovery rate and very little clogging.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a liquid filter of the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the liquid filter of the present invention.

FIG. 3 is a cross-sectional view of another embodiment of the liquid filter of the present invention.

FIG. 4 is a cross-sectional view of another embodiment of the liquid filter of the present invention.

5 is a cross-sectional view taken along the line AA of FIG.

FIG. 6 is a cross-sectional view of a conventional liquid filter.

[Explanation of symbols]

 1 Filter for liquid 30 Filter for liquid 40 Filter for liquid 2 Housing, 2a Upper housing, 2b Lower housing, 2c Cylindrical protrusion 2d Annular protrusion 3 Liquid inlet 4 Liquid outlet 5 First filter 6 Second Filter 7 Liquid inflow part 8 Void 8a Void forming material 9 Third filter 10 Liquid outflow part 10a Void forming material 20 Void 20a Void forming material

Claims (1)

[Claims] 1. A filter for liquid for removing solid particles from a liquid containing solid particles, the filter for liquid comprising a housing having a liquid inlet and a liquid outlet, A primary filter stored in the housing,
A liquid inflow portion, which is formed between the inner surface of the housing and the outer surface of the primary filter and communicates with the liquid inlet, is in contact with the liquid located downstream of the primary filter and passing through the primary filter. As described above, the secondary filter is housed in the housing, and the final filter is housed in the housing so that only the liquid passing through the secondary filter comes into contact with the primary filter. With a large number of pores with surface openings larger than the particles, the primary filter is
It is possible to form a stack of the solid particles on the surface, and the secondary filter has a large number of pores having a surface opening smaller than the pores of the primary filter,
A void is formed between the secondary filter and the primary filter, and further, the final filter has a large number of pores having surface openings slightly larger than the solid particles and smaller than the pores of the secondary filter. A liquid filter characterized by having.