JPH1099659A - Membrane module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the generation of the short pass of a primary passage even when a membrane is bent by the pressure difference between primary and secondary sides, to eliminate the generation of hemolysis or coagulation and to reduce the stagnation of a filtrate. SOLUTION: In a plate-shaped membrane module having a primary passage 7 connecting a primary inflow port 5 and a primary outflow port 8, pref., the vortex-shaped primary passage 7 from the peripheral part of a membrane to the center part thereof and a secondary passage 11 allowing the filtrate permeated through a filter membrane to reach a secondary outflow port 9 formed thereto, a partition 11 forming the secondary passage having a shape symmetric to the partition 6 constituting the primary passage is formed on a secondary side and the partition of the primary passage is just abutted to the partition of the secondary passage through the membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a partial filtration type membrane module incorporating a flat filtration membrane (flat membrane).
The present invention relates to a membrane module having excellent pressure resistance, anticoagulability, and precision. The membrane module can be used in the fields of medicine, the pharmaceutical industry, and the like, and is particularly suitable for collecting a sample for measuring a low-molecular-weight substance in blood, particularly for collecting a sample for measuring a low-molecular-weight substance in blood for an artificial dialysis monitor.

[0002]

2. Description of the Related Art A membrane module incorporating a flat membrane includes a total filtration type and a partial filtration type (also referred to as a concentration type or a recovery type).
The whole filtration type is mainly used for microfiltration, and the partial filtration type is mainly used for ultrafiltration or reverse osmosis filtration.

[0003] A partially filtered membrane module using a flat membrane, that is, having a liquid inlet and a liquid outlet on the primary side (stock solution side), a part of the stock solution flowing into the module passes through the filtration membrane. The remainder of the undiluted solution flows out of the primary outlet, and the filtrate that has passed through the membrane flows out of the filtrate outlet (secondary outlet) as a spiral type, plate type (laminated type or single layer type). Shapes) are known.
The spiral type is usually applied to large membrane area modules mainly used for industry, and the plate type is usually applied to small membrane area modules mainly used for research. In particular, when a small film area is required, a single-layer plate type is preferably used because it has a simple structure and can be manufactured at low cost.

In using a plate-type membrane module, for example, a one-layer plate-type membrane module, there are a method of pressurizing the primary side and a method of reducing the pressure of the secondary side. Must be received by the secondary (filtrate side) membrane support structure. On the secondary side, it is necessary to allow the filtrate to flow to the filtrate outlet while receiving the pressure applied to the membrane. Therefore, a porous body such as a sintered product is installed, and a thin groove is formed on the inside of the secondary side housing. For example, a method of forming a filtrate flow channel that guides a filtrate that has passed through a membrane to a secondary side outlet by digging in a shape has been adopted (for example, Japanese Utility Model Laid-Open No. 6-52836).

[0005]

However, in these methods, the pressure loss on the filtrate side is increased and the flux is reduced. In addition, when trying to measure the change with time of the component concentration in the filtrate, the retention of the filtrate permeating the membrane is difficult. Because of the presence of the portion, the mixed filtrate of the filtrate that passed through at various times flowed out, and it was not possible to accurately capture the change with time.

On the other hand, when the filtrate channel is formed on the filtrate side, the membrane is extruded into the groove of the filtrate channel, and a gap is formed between the primary-side channel partition and the membrane. A path was generated, causing hemolysis and blood coagulation in the short path section of the primary flow path.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies on a method for eliminating the stagnation of the filtrate and preventing the occurrence of a short path in the primary flow path due to the deflection of the membrane. A primary-side flow path connecting the inlet and the primary-side outlet, preferably a spiral-shaped primary flow path from the periphery of the membrane to the center of the membrane, and a filtrate that has passed through the filtration membrane flows to the secondary-side outlet. A plate-type membrane module in which a secondary channel is formed, and a secondary channel having a shape symmetrical to a partition constituting the primary channel is formed on the secondary side. The membrane module in which the partition is formed and the partition of the primary side flow path and the partition of the secondary side flow path are abutted without interfering with each other across the membrane, there is no stagnation of the filtrate, and 1 Since the occurrence of a short path in the secondary flow path can be prevented and the pressure loss on the filtrate side is also small, Mixing due to stagnation of the filtrate permeated at various times does not occur, and accurate temporal changes in the components of the filtrate can be captured. Hemolysis and coagulation are unlikely to occur. When the mounting angle is in the range of 5 to 45 ° with respect to the membrane surface, and preferably the mounting angle of the flow path of the primary outlet is also in the range of 5 to 45 ° with respect to the membrane surface, when used for blood filtration, The present inventors have found that hemolysis and blood clotting in the vicinity of the primary-side inlet and the primary-side outlet are more unlikely to occur, and have reached the present invention.

That is, the present invention provides: (1) a primary casing and a secondary casing are liquid-tightly connected and integrated around a filtration membrane with a flat filtration membrane interposed therebetween; A primary side inlet and a primary side outlet are provided in the primary side housing, and a primary side inlet and a primary side are provided in a space surrounded by the inside of the primary side housing and the filtration membrane. A primary side flow path connecting the side outflow port is formed, a secondary side outflow port is provided in the secondary side housing portion, and a space surrounded by the inside of the secondary side housing portion and the filtration membrane. Is a membrane module in which a secondary channel through which a filtrate that has passed through a filtration membrane reaches a secondary outlet is formed, and a primary channel is formed inside the secondary housing. A partition that forms a secondary channel having a symmetrical shape to the partition that is formed is formed, and the partition of the primary channel and the partition of the secondary channel are abutted without interfering with each other across the membrane. ing A membrane module,

(2) The membrane module according to the above (1), wherein the mounting angle of the primary side channel opening is 5 to 45 ° with respect to the membrane surface, and (3) a projection onto the membrane surface. At
The membrane module according to (2), wherein the mounting angles of the liquid inlet channel and the liquid outlet channel are each ± 45 ° or less with respect to the tangential direction at the starting point and the ending point of the primary side channel. (4) The mounting angle of the flow path of the primary outlet is in the range of 5 to 45 ° with respect to the membrane surface.
Or the membrane module according to (3),

(5) The membrane module according to any one of the above (1) to (4), wherein the primary flow path has a spiral shape from a peripheral portion of the membrane to a central portion of the membrane, (6) a filtration membrane Is a circle, the membrane module according to any one of the above (1) to (5), (7) the effective membrane area of the filtration membrane is 10 to 5
(8) The membrane module according to any one of the above (1) to (6), which is 00 cm ² , (8) the membrane module according to any one of the above (1) to (7), wherein the filtration membrane is an ultrafiltration membrane. (9) The primary side housing part and the secondary side housing part are:
Any one of the above (1) to (8) made of plastic
Described membrane module,

(10) The above-mentioned (1), wherein the membrane module is a membrane module for collecting a sample for measuring the concentration of a low molecular weight substance in blood.
The membrane module according to any one of (1) to (9);
1) The membrane module according to the above (10), wherein the membrane module for collecting a sample for measuring a low-molecular-weight substance in blood is a membrane module for collecting a sample for measuring a low-molecular-weight substance in blood for an artificial dialysis monitor; and (12) the primary side. The channel is 2-10m wide
m, a depth of 1 to 10 mm, a cross-sectional area of 3 to 20 mm ² , and wherein the secondary flow path has a smaller cross-sectional area than the primary flow path. A membrane module according to any one of the preceding claims.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a primary casing and a secondary casing are sandwiched by a flat filtration membrane (hereinafter, the filtration membrane may be simply referred to as a membrane). In the section (all around)
A membrane module that is liquid-tight to the outside and liquid-tightly connected and integrated with respect to the front and back of the membrane (hereinafter, the membrane module may be simply referred to as a module),
The present invention relates to a plate type membrane module. The connection method between the primary housing part and the secondary housing part is arbitrary, and may be fusion (fusion), adhesion, fitting, screwing, screwing, etc., but fusion or adhesion is preferable.

On the primary side (stock solution side) of the module,
Inlet (primary side inlet) and outlet (primary side outlet)
And the other side of the membrane, ie the secondary side (filtrate side)
Is provided with a filtrate outlet (secondary outlet). In addition, it is also possible to provide an opening for sampling or air bleeding besides these.

In the module of the present invention, the mounting angle of the primary inlet and the primary outlet is arbitrary, but the mounting angle of the primary inlet is different from the membrane surface. 5 to 45 °, particularly 10 to 30 °, that is, the connection angle of the primary inlet channel with the primary channel is 5 to 45 °,
In particular, it is preferable that the angle is 10 to 30 ° because hemolysis and coagulation hardly occur. Above all, it is more desirable that the mounting angles of the primary inlet and the primary outlet are both 5 to 45 °, preferably 10 to 30 ° with respect to the membrane surface. Of course, these mounting angles may be different between the primary side inlet and the primary side outlet. If the mounting angle is too large, hemolysis or coagulation tends to occur, and if the angle is less than 5 °, further improvement of the effect is not recognized, and molding is difficult. However, in the case where the angle can be set to 5 ° or less in terms of molding technology, at least one of the mounting angle of the flow path of the primary inlet and / or the mounting angle of the flow path of the primary outlet is set to 5 ° or less. It is also possible to The mounting angle of the primary inlet and the primary outlet is the mounting angle of the inner flow path of the primary inlet and the primary outlet. In addition, when the flow path inside the primary-side inlet or the primary-side outlet is not linear, it refers to the angle of a tangent at a connection portion of the module with the primary-side flow path.

On the other hand, the primary inlet of the module and 1
The mounting angle of the secondary outlet in the projection view onto the membrane surface (that is, the mounting angle as viewed from a direction perpendicular to the membrane surface) is determined at the start point of the primary flow path and the end point of the primary flow path. It is preferably ± 45 ° or less, more preferably ± 30 ° or less, more preferably ± 10 ° or less, more preferably ± 10 ° or less, with respect to the tangential direction of the flow path, ie, the direction of movement of the liquid. Most preferably. If the angle is too large, hemolysis and blood coagulation also tend to occur. Of course, these angles may be different between the primary side inlet and the primary side outlet.

The connecting portion between the liquid flow passage in the primary inlet and the primary outlet and the primary flow passage in the housing has a shape having no corners and a smooth change in each flow passage. Preferably, there is.

The mounting angle between the primary side inlet and the primary side outlet can be set irrespective of the shape of the secondary side flow path, which will be described later, even if it is not symmetrical to the shape of the primary side flow path. It is effective in preventing hemolysis and blood clotting in the vicinity of the primary side inlet and the primary side outlet.

The space between the primary inlet and the primary outlet of the module of the present invention and enclosed by the inside of the housing and the filtration membrane, that is, the shape of the primary passage is arbitrary. For example, it may be linear, radial, spiral, zigzag (folding linear), etc., and among them, spiral or zigzag, especially spiral, increases the membrane surface flow rate of the stock solution. When it is used for blood filtration, a spiral shape is more preferable because hemolysis and coagulation can be reduced. There may be a plurality of flow paths.

The shape of the primary side flow path is usually a partition (guiding wall) provided in a space surrounded by the inside of the housing and the filtration membrane.
It is formed with. The partition may be a part of the housing or may be built separately from the housing, but it is configured as a part of the housing, and the flow path is apparently dug inside the housing. It is preferably configured as a space between the groove and the film.

In the space surrounded by the inside of the casing on the secondary side of the module and the filtration membrane, there is provided a flow channel for guiding the filtrate permeating the membrane to the filtrate outlet, ie, a secondary flow channel. ing.
There is no restriction on the mounting angle of the secondary outlet, and it is preferable that the secondary outlet be perpendicular to the membrane surface for ease of manufacture.

In the module of the present invention, the partition (conductive wall) constituting the secondary flow path is formed in a shape symmetrical to the partition (conductive wall) constituting the primary flow path, and It is essential that the partition of the flow path and the partition of the secondary flow path are abutted without interfering with each other across the membrane. That is, there is a secondary flow path partition on the opposite side of the membrane along the primary flow path partition. Therefore, even when the membrane is deflected by the pressure difference between the primary side and the secondary side, there is no gap between the primary side flow path partition and the membrane. No path occurs. Further, the retention of the filtrate in the secondary flow path is small.

According to the present invention, as described above, even when the membrane is deflected by the pressure difference between the primary side and the secondary side, it is possible to prevent a gap from being formed between the primary side flow path partition and the membrane. As long as this object is achieved, the module of the present invention does not necessarily require that the shape of the partition forming the secondary flow path be completely symmetric with the shape of the partition forming the primary flow path. . For example, a notch may be provided in the partition of the secondary flow path as described later, the length of the secondary flow path may be longer or shorter than the length of the primary flow path, or one may be provided on the secondary side. A partition other than the partition symmetric to the next partition may be provided. Further, the thickness of the partition forming the primary flow path and the thickness of the partition forming the secondary flow path may be different.

The partition of the secondary side flow path of the module may be a part of the housing as in the case of the primary side flow path, or a partition manufactured separately from the housing may be incorporated. It is preferable that the channel is apparently configured as a space between the groove and the groove dug inside the housing.

In the module of the present invention, since the partition of the primary flow path and the partition of the secondary flow path are formed symmetrically, the primary flow path and the secondary flow path are also symmetric. The width, depth, and angle of the flow path may be different between the primary side and the secondary side. It is preferable that the cross-sectional area of the secondary flow path is smaller than that of the primary flow path because the hold-up of the filtrate can be reduced and the time delay of the measurement can be reduced.

The width, depth and cross-sectional area of the primary side flow path are arbitrary and can be designed according to the purpose of use. Among them, the width of the flow path is 2 to 10 mm, the depth is 1 to 10 mm, and the flow path is cut off. Area is 3 ~
It is preferably 20 mm ² , and particularly preferably when used as a membrane module for sampling a low-molecular-weight-substance concentration sample in blood for an artificial dialysis monitor.

The thickness of the partition is arbitrary for both the primary side and the secondary side, but is preferably 0.2 to 3 mm from the viewpoint of high strength, easy molding, and large effective film area.
More preferably, it is 0.5 to 1 mm.

The partition of the secondary flow path may be provided with a notch as long as the short path of the primary flow path does not occur as described above. A short path can be made to the adjacent flow path through the section. The length of the notch is preferably 0.2 to 5 mm,
5 to 3 mm is more preferable. If the length of the notch is shorter, the effect is reduced and molding difficulty is increased. If the length of the notch is longer than this, a short path in the primary flow path is likely to occur. The shape of the notch is arbitrary, and may be, for example, a square, a triangle, a semicircle, or the like.

The notch provided in the partition of the secondary flow path may be provided continuously on a line extending radially from the secondary outlet to the periphery of the filtration membrane, or may be provided continuously on a line perpendicular to the partition. Is preferred. For example, when the partition is formed in a spiral shape, the notch is preferably provided continuously on the line from the secondary outlet to the periphery of the filtration membrane in a radial manner, and the partition is formed in a zigzag shape. In such a case, it is preferable to provide them continuously on a plurality of parallel lines perpendicular to the partition or on a line extending radially from the secondary outlet to the periphery of the filtration membrane.

In the module of the present invention, the shape of the membrane or the module is arbitrary, but a circular or rectangular membrane is preferred from the viewpoint of ease of production and the like, and a circular membrane is preferred for preventing hemolysis and coagulation. Particularly preferred from the viewpoint.

As the dimensions of the module of the present invention, those having an effective film area of 10 to 500 cm ² are preferable because they are effective. Further, the module of the present invention exerts a high effect when used for microfiltration or ultrafiltration, particularly for ultrafiltration. The filtration membrane used has a cut-off molecular weight of 3,000.
It is preferably from 0 to 1,000,000.

Further, the module of the present invention is particularly effective when the primary casing and the secondary casing are made of plastic. The plastic material is optional,
For example, thermoplastic resins such as styrene-based resins, (meth) acrylic resins, polysulfone-based resins, polycarbonate-based resins, polyolefin-based resins, fluorine-based resins, and chlorine-based resins are mentioned, and those formed by injection molding are preferable. .

The module of the present invention is effective when used as a membrane module for measuring a low-molecular-weight substance concentration in blood for performing ultrafiltration of blood. It is particularly effective when used as a sample module for filtration of extracorporeal blood.

[0033]

The present invention will be described in detail below with reference to examples, comparative examples and drawings, but the scope of the present invention is not limited only to these examples.

Embodiment 1 Embodiment 1 will be described with reference to FIGS. FIG. 1 is a schematic diagram of a part and an assembly diagram of the membrane module according to the first embodiment.
2 is a front view, a side view, and a plan view of the primary housing, and FIG.
Rear view of the secondary housing, its AA sectional view and a partially enlarged view of the AA cross section, FIG. 4 is a front view, side view, and plan view of the secondary housing, and FIG. 5 is the secondary housing. Rear view and its BB sectional view and B
It is the elements on larger scale of -B cross section.

(Preparation of Membrane Module) A cross-linked polyacrylic acid ester-based ultrafiltration membrane 3 having a diameter of 7 cm and a thickness of 0.15 mm and a molecular weight cut off of 30,000 was subjected to AS with the dense layer side as the primary side. An O-ring (not shown; O-ring, not shown) is provided around the filtration membrane 3 around the primary side housing 1 and the secondary side housing 2 made of resin (acrylonitrile-styrene copolymer). The grooves 4 and 4 ′ are liquid-tight to the outside by means of the grooves and 4 ′, and at the same time, liquid-tight with respect to the front and back of the film. To produce a disk-shaped membrane module.

In the primary housing 1 of this membrane module,
A primary inlet 5 and a primary outlet 8 are provided. Further, a spiral primary flow path 7 is formed by a spiral partition 6 in a space partitioned by the inside of the primary housing 1 and the filtration membrane 3. 5 and the primary outlet 8 are connected.

The primary side inlet 5 and the primary side outlet 8 are
An angle of 15 ° with respect to the membrane surface, and an angle of 0 ° with the tangential direction of the primary channel 7 at the start point and the end point of the primary channel in the projection onto the membrane surface. (That is, when viewed from a direction perpendicular to the membrane surface, the tangential direction of the primary side flow path 7 at the connection between the primary side flow path 7 and the primary side inlet 5 and the primary side outlet 8 respectively (An angle of 0 °).

The primary partition 6 has a thickness of 1 mm and a height of 1.
The primary-side flow path 7 has a rectangular cross section, a width of 3 mm, and a depth of 1.5 mm, as shown in the enlarged view of the AA cross section in FIG. The effective membrane area of this flat membrane module is about 16 cm ² .

On the other hand, at the center of the secondary housing 2 of the membrane module, a secondary outlet 9 is provided at right angles to the membrane surface, and the inside of the secondary housing 2 and the filtration membrane are provided. A spiral secondary flow path 11 is formed in a space surrounded by 3 by a spiral partition 10, and communicates with a secondary outlet 9. A large number of notches 12 are formed in the partition 10 so as to be arranged on two orthogonal straight lines passing through the center.

The secondary partition 10 has a thickness of 1 mm and a height of 1.5 mm, and the secondary channel 11 has a cross section B-B in FIG.
It is a semicircle as shown in the partial enlarged view of the B section, and the width is 3 m.
m, depth 1.5 mm. The shape of the notch 12 is also a semicircle with a radius of 1.5 mm.

The primary flow path 7 formed in the primary housing 1
The partition 6 and the partition 10 of the secondary flow path 11 formed in the secondary housing 2 are formed in a symmetric spiral shape, and face each other with the filtration membrane 3 interposed therebetween. Assembled in butt. Accordingly, the primary side flow path 7 and the secondary side flow path 11 are also formed in a symmetric spiral shape, and face each other with the filtration membrane 3 interposed therebetween.

(Usage Test) Using the obtained membrane module, a blood filtration test was performed on bovine whole blood. Bovine whole blood adjusted to a hematocrit value of 35%, total protein of 7 g / dl, and 37 ° C. is put into a blood container, from which bovine blood flows into the primary inlet 5 of the flat membrane module via a blood flow pump. As described above, piping was performed using a transparent soft vinyl chloride tube.
In addition, a tube made of transparent soft vinyl chloride was connected to the primary side outlet 8 of the membrane module so that bovine blood was returned to the original blood container via the flow rate control valve. Furthermore,
A pressure gauge was connected near the primary inlet 5 and the primary outlet 8 of the pipe.

Further, a tube made of transparent soft vinyl chloride was connected to the secondary-side outlet 9 of the membrane module, and piping was provided to return the filtrate to the blood container.

Next, the blood flow pump was adjusted to a blood flow rate of 200 ml / min.
The pressure at the primary inlet 5 of the filtration unit was adjusted to 200 mmHg by a flow control valve connected to the filter unit, and a filtration test of bovine whole blood was started. At this time, the pressure at the primary outlet 8 was 140 mmHg.

After the filtration test for 4 hours, the bovine blood was replaced with physiological saline and pure water to wash the membrane module.
When the membrane module was disassembled and the filtration membrane 3 and the casing were observed, no blood clot was observed. In addition, when compared with the result of a blank test performed in the same manner as in this test except that this membrane module was not used, no increase in hemolysis caused by this membrane module was observed.

COMPARATIVE EXAMPLE 12 A membrane module was produced in the same manner as in Example 1 except that the secondary flow path was a grid-like flow path composed of a number of parallel straight lines and a number of parallel straight lines perpendicular thereto. This grid-like secondary flow path has a width of 3 mm,
The semicircle was 1.5 mm deep, and the partition was 1 mm wide.

When a test similar to that of Example 1 was performed using this membrane module, blood coagulation was observed at the primary passage of the ultrafiltration membrane. That is, it is considered that when the membrane is deflected by the primary pressure, a gap is generated between the partition and the membrane, a short path of the flow path is generated, and blood coagulation is formed at this portion.

[0048]

According to the present invention, even when the membrane is deflected due to the pressure difference between the primary side and the secondary side, a gap is formed between the primary side flow path partition and the membrane, so that the primary side flow path is formed. Since there is no short path, there is no occurrence of hemolysis or coagulation, and since there is little retention of the filtrate, mixing of the filtrate permeated at various times does not occur, and it is possible to capture the accurate temporal change of the filtrate component. . Further, the pressure loss on the filtrate side is also small.

[Brief description of the drawings]

FIGS. 1A and 1B are a schematic diagram of a part and an assembly diagram of a membrane module according to a first embodiment.

FIG. 2 is a front view, a side view, and a plan view of a primary housing.

FIG. 3 is a rear view of the primary housing, a cross-sectional view taken along line AA of FIG.
It is the elements on larger scale of A section.

FIG. 4 is a front view, a side view, and a plan view of a secondary housing.

FIG. 5 is a rear view of the secondary housing, a sectional view taken along line BB of FIG.
It is the elements on larger scale of B cross section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary-side housing part 2 Secondary-side housing part 3 Filtration membrane 4 0-Ring groove 4'0-Ring groove 5 Primary-side inlet 6 Partition 7 Primary-side channel 8 Primary-side outlet 9 2 Secondary outlet 10 Partition 11 Secondary passage 12 Notch

Continued on the front page (72) Inventor Takanori Anawazawa 4-35-4 Osakidai, Sakura City, Chiba Prefecture (72) Inventor Naoki Kurai 519-3 Katakuracho, Hachioji City, Tokyo

Claims (12)

[Claims] 1. A primary casing and a secondary casing are liquid-tightly connected and integrated around a filtration membrane with a flat filtration membrane interposed therebetween, and are connected to the primary casing. Is provided with a primary-side inlet and a primary-side outlet, and a space connecting the primary-side inlet and the primary-side outlet is provided in a space surrounded by the inside of the primary housing and the filtration membrane. A secondary flow path is formed, and a secondary outlet is provided in the secondary housing, and a filtration membrane permeates a space surrounded by the inside of the secondary housing and the filtration membrane. Is a membrane module in which a secondary-side flow path from which the filtrate obtained reaches the secondary-side outlet is formed, and a shape symmetrical to a partition constituting the primary-side flow path inside the secondary-side housing portion. Wherein a partition forming a secondary flow path is formed, and a partition of the primary flow path and a partition of the secondary flow path are abutted with each other across a membrane. Membrane moji Wool. 2. The membrane module according to claim 1, wherein the mounting angle of the primary side channel opening is in the range of 5 to 45 ° with respect to the membrane surface. 3. The angle of attachment of the liquid inlet channel and the liquid outlet channel in the projection onto the membrane surface is ±± with respect to the tangential directions at the starting point and the ending point of the primary side channel, respectively.
3. The membrane module according to claim 2, wherein the angle is 45 ° or less. 4. The membrane module according to claim 2, wherein the mounting angle of the primary outlet is in a range of 5 to 45 ° with respect to the membrane surface. 5. The membrane module according to claim 1, wherein the primary flow path has a spiral shape extending from a peripheral portion of the membrane to a central portion of the membrane. 6. The membrane module according to claim 1, wherein the filtration membrane is circular. 7. The effective membrane area of the filtration membrane is 10 to 500 c.
membrane module according to any one of claims 1 to 6 is m ^2. 8. The method according to claim 1, wherein the filtration membrane is an ultrafiltration membrane.
8. The membrane module according to any one of 7 above. 9. The membrane module according to claim 1, wherein the primary housing and the secondary housing are made of plastic. 10. The membrane module according to any one of claims 1 to 9, wherein the membrane module is a membrane module for sampling a sample for measuring a low-molecular-weight substance in blood. 11. The membrane module according to claim 10, wherein the membrane module for collecting a sample for measuring a low-molecular-weight substance in blood is a membrane module for collecting a sample for measuring a low-molecular-weight substance in blood for an artificial dialysis monitor. 12. The primary side channel has a width of 2 to 10 mm and a depth of 1
The membrane according to any one of claims 1 to 11, wherein the membrane has a flow path of 10 to 10 mm and a cross-sectional area of 3 to ²⁰ mm ² , and the secondary flow path has a smaller cross-sectional area than the primary flow path. module.