Patent Description:
For example, for manufacturing semiconductors, a large amount of ultrapure water is indispensable. Ultrapure water is produced in a system having a hollow fiber membrane module. The hollow fiber membrane module is used in various fields, e.g., for waste water treatment, food production, and the medical field as well as production of ultrapure water.

The hollow fiber membrane module disclosed in Patent Literature <NUM> includes a bundle of hollow fiber membranes, a housing, a cap, and a potting material. An O-ring is disposed between the cap and the potting material. The potting material is fixed to the housing by an adhesive.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose other examples of a hollow fiber membrane module. Document <CIT> discloses a hollow fiber membrane module according to the preamble of claim <NUM>.

In the above-described structure, liquid tends to be accumulated in a groove of the O-ring, and a contamination such as particulates may be accumulated in the groove. Cleaning liquid does not easily flow in the groove of the O-ring, and the hollow fiber membrane module is not easily cleaned without disassembling the module. The accumulation of a contamination may negatively affect various processes using permeate liquid, for example, a process of cleaning a semiconductor substrate.

Patent Literature <NUM> suggests a structure for narrowing a region in which fluid is accumulated. However, there is still room for improvement.

Furthermore, since the potting material is fixed to the housing by the adhesive, the bundle of hollow fiber membranes cannot be taken out from the housing without breaking the hollow fiber membrane module.

An object of the present invention is to provide a hollow fiber membrane module in which a contamination such as particulates is hardly accumulated and components such as hollow fiber membranes can be easily cleaned, changed, or repaired.

The present invention is directed to a hollow fiber membrane module, according to the appended claim <NUM>.

The present invention provides the hollow fiber membrane module in which a contamination such as particulates is hardly accumulated and the components such as the hollow fiber membranes can be easily cleaned, changed, or repaired.

The present invention is not limited to the embodiments described below.

<FIG> is a perspective cross-sectional view of a hollow fiber membrane module according to one embodiment of the present invention. <FIG> illustrates a partially enlarged cross-section of the hollow fiber membrane module shown in <FIG>. <FIG> is a partially enlarged view of <FIG>.

As shown in <FIG> and <FIG>, a hollow fiber membrane module <NUM> of the present embodiment includes a plurality of hollow fiber membranes <NUM>, a binding portion <NUM>, a cap <NUM>, and a housing <NUM>. The plurality of hollow fiber membranes <NUM> are bound at one end portions thereof by the binding portion <NUM>. The plurality of hollow fiber membranes <NUM> are sealed at the other end portions thereof by a sealing portion <NUM>. The hollow fiber membranes <NUM> and the binding portion <NUM> are housed in the housing <NUM>. The cap <NUM> is integrated with the binding portion <NUM>, and attached to one end portion of the housing <NUM>. A unit <NUM> is formed by the hollow fiber membranes <NUM>, the binding portion <NUM>, and the cap <NUM>. The unit <NUM> can be detached from the housing <NUM> in a non-destructive manner. That is, the unit <NUM> can be detached from the housing <NUM> and the unit <NUM> can be attached to the housing <NUM> while integration of the binding portion <NUM> and the cap <NUM> is maintained.

In the description herein, the "integration" represents a state where separation of components in a non-destructive manner cannot be performed. The "non-destructive manner" represents a state where separation and integration are reversible. For example, separation of components fixed to each other by an adhesive is not included in the concept of being the non-destructive manner.

The hollow fiber membrane module <NUM> is, for example, an external-pressure-type hollow fiber membrane module. In the hollow fiber membrane module <NUM>, raw liquid flows outside the hollow fiber membranes <NUM>, and permeate liquid flows in the hollow fiber membranes <NUM>. The raw liquid is, for example, water to be treated. The permeate liquid is, for example, pure water or ultrapure water.

The plurality of hollow fiber membranes <NUM> are aligned parallel to each other, and are bound by the binding portion <NUM>. Examples of the hollow fiber membranes <NUM> include microfiltration membranes, ultrafiltration membranes, and reverse osmosis membranes. The number, dimensions, and material of the hollow fiber membranes <NUM> are not particularly limited. The number of the hollow fiber membranes <NUM> is, for example, <NUM> to <NUM>. The outer diameter of the hollow fiber membrane <NUM> is, for example, <NUM> to <NUM>. The length of the hollow fiber membrane <NUM> is, for example, <NUM> to <NUM>. Examples of the material of the hollow fiber membrane <NUM> include polysulfone, polyether sulfone, poly(vinylidene fluoride), polyacrylonitrile, a poly(vinyl chloride)-polyacrylonitrile copolymer, polyamide, and cellulose acetate.

The binding portion <NUM> is a portion that binds the plurality of hollow fiber membranes <NUM> at one end portions thereof. The binding portion <NUM> has, for example, a columnar shape or truncated-cone shape. The binding portion <NUM> is formed by, for example, potting. In this case, the binding portion <NUM> is also called a potting portion. The binding portion <NUM> can be formed of resin that is filled between the hollow fiber membrane <NUM> and the hollow fiber membrane <NUM>. Examples of the resin that forms the binding portion <NUM> include epoxies and urethanes.

The binding portion <NUM> partitions the flow path of the raw liquid and the flow path of the permeate liquid. The flow path of the raw liquid is, for example, an internal space <NUM> of the housing <NUM>. The flow path of the permeate liquid is, for example, an internal space <NUM> of the cap <NUM>. The internal space <NUM> of the housing <NUM> is isolated from the internal space <NUM> of the cap <NUM> by the binding portion <NUM>.

The cap <NUM> is a funnel-shaped component which is integrated with the binding portion <NUM>. The cap <NUM> has the internal space <NUM> that communicates with each of the plurality of hollow fiber membranes <NUM>. Each of the plurality of hollow fiber membranes <NUM> extends up to an end surface 20p of the binding portion <NUM>, and is opened at the end surface 20p of the binding portion <NUM> toward the internal space <NUM> of the cap <NUM>. The permeate liquid is delivered from the hollow fiber membranes <NUM> through the internal space <NUM> of the cap <NUM> to the outside of the hollow fiber membrane module <NUM>. A component such as piping and a connector can be connected to an end portion <NUM> of the cap <NUM>. The end portion <NUM> has, for example, a tubular shape. In the present embodiment, the cap <NUM> is integrated with the binding portion <NUM> by an adhesive.

The material of the cap <NUM> is not particularly limited. The cap <NUM> may be formed of resin such as vinyl chloride, polycarbonate, and polysulfone.

The housing <NUM> is a cylindrical component in which the plurality of hollow fiber membranes <NUM> and the binding portion <NUM> are housed. The housing <NUM> is opened at both end portions thereof. The cap <NUM> is attached to the one end portion of the housing <NUM>. The housing <NUM> has a nozzle-like outlet 40a for discharging liquid from the internal space <NUM>. The outlet 40a projects in the direction perpendicular to the longitudinal direction of the housing <NUM>, and communicates with the internal space <NUM> of the housing <NUM>.

The longitudinal direction of the housing <NUM> is parallel to the longitudinal direction of the hollow fiber membrane <NUM>. A central axis O of the housing <NUM> extends parallel to the longitudinal direction of the housing <NUM> through the center of the housing <NUM>.

The material of the housing <NUM> is not particularly limited. The housing <NUM> may be formed of resin such as vinyl chloride, polycarbonate, and polysulfone. The material of the cap <NUM> may be the same as the material of the housing <NUM>.

The hollow fiber membrane module <NUM> further includes a fastening member for fixing the cap <NUM> and the housing <NUM> to each other. When the cap <NUM> and the housing <NUM> fixed by the fastening member are unfixed, the unit <NUM> can be detached from the housing <NUM>. The fastening member is a mechanical means that allows the unit <NUM> to be attached to the housing <NUM> and allows the unit <NUM> to be detached from the housing <NUM>.

The hollow fiber membrane module <NUM> has a nut <NUM> as the fastening member. The housing <NUM> has a screw portion <NUM> on the outer circumferential surface of the one end portion thereof, and the nut <NUM> is screwed onto the screw portion <NUM> in a state where the housing <NUM> is covered with the cap <NUM>. The material of the nut <NUM> is not particularly limited. The nut <NUM> may be formed of resin or metal.

The hollow fiber membrane module <NUM> further includes a cap <NUM> and a nut <NUM>. The cap <NUM> is a funnel-shaped component that is attached to the other end portion of the housing <NUM>. The nut <NUM> is an example of a fastening member for fixing the cap <NUM> and the housing <NUM> to each other. The nut <NUM> is screwed onto a screw portion (not shown) provided on the outer circumferential surface of the other end portion of the housing <NUM>. Thus, the cap <NUM> is fixed to the housing <NUM>. Raw liquid is guided through the cap <NUM> from the outside of the hollow fiber membrane module <NUM> into the internal space <NUM> of the housing <NUM>. The concentrated raw liquid is discharged through the outlet 40a to the outside of the housing <NUM>.

The cap <NUM> may be formed of the same material as that of the cap <NUM>. The nut <NUM> may be formed of the same material as that of the nut <NUM>. The other end portion of the housing <NUM> may be nozzle-shaped instead of the cap <NUM> and the nut <NUM> being disposed.

The fastening member is not limited to one that includes a nut and a screw portion. For example, the fastening member may include a bolt and a nut.

The sealing portion <NUM> is formed of, for example, the same resin as that of the binding portion <NUM>. Instead of the sealing portion <NUM>, the binding portion <NUM> may be provided at the other end portions of the hollow fiber membranes <NUM>. That is, the hollow fiber membranes <NUM> may be opened at both end portions thereof. The hollow fiber membrane module <NUM> may be an internal-pressure-type hollow fiber membrane module.

The structure of the hollow fiber membrane module <NUM> will be described in more detail.

As shown in <FIG>, in the hollow fiber membrane module <NUM> of the present embodiment, no other component is present between the binding portion <NUM> and the cap <NUM>. The other component is typically a seal ring. There is no groove for fitting the seal ring between the binding portion <NUM> and the cap <NUM>. That is, there is no groove for fitting the seal ring on both the surface of the binding portion <NUM> that faces the cap <NUM> and the surface of the cap <NUM> that faces the binding portion <NUM>. In such a structure, liquid accumulation is unlikely to occur or does not occur between the binding portion <NUM> and the cap <NUM>. In other words, liquid such as permeate liquid is unlikely to be accumulated or is not accumulated between the binding portion <NUM> and the cap <NUM>. A contamination such as particulates is unlikely to be accumulated or is not accumulated between the binding portion <NUM> and the cap <NUM>. Therefore, the hollow fiber membrane module <NUM> can be easily cleaned by using cleaning liquid without disassembling the module <NUM>.

The above-described effect is particularly significant when the hollow fiber membrane module <NUM> is an external-pressure-type hollow fiber membrane module. When the hollow fiber membrane module <NUM> is an external-pressure-type hollow fiber membrane module, permeate liquid passes through the inside of the hollow fiber membranes <NUM> and the internal space <NUM> of the cap <NUM>, is discharged from the hollow fiber membrane module <NUM>, and is supplied to a point of use. When no liquid accumulation occurs between the binding portion <NUM> and the cap <NUM>, the contamination is not accumulated in the liquid accumulation and the contamination does not affect the degree of cleaning for the permeate liquid. Furthermore, the hollow fiber membrane module <NUM> can be easily cleaned.

In the present embodiment, the unit <NUM> can be detached from the housing <NUM> and the unit <NUM> can be attached to the housing <NUM> while integration of the binding portion <NUM> and the cap <NUM> is maintained. The unit <NUM> is detached from the housing <NUM>, and the hollow fiber membranes <NUM> and/or the binding portion <NUM> are cleaned or repaired, and, thereafter, the unit <NUM> can be attached to the housing <NUM>. Alternatively, a new unit <NUM> may be attached to the housing <NUM>. That is, the hollow fiber membrane module <NUM> of the present embodiment can allow the hollow fiber membranes <NUM> and/or the binding portion <NUM> to be quickly and easily cleaned, changed, or repaired. The hollow fiber membranes <NUM> can be detached from the housing <NUM> without breaking each component, thereby reducing cost for the components.

As shown in <FIG> and <FIG>, the cap <NUM> is joined to the outer circumferential portion of the binding portion <NUM>. The hollow fiber membranes <NUM> are not provided on the outer circumferential portion of the binding portion <NUM>. Therefore, even when the cap <NUM> is joined to the outer circumferential portion of the binding portion <NUM>, the hollow fiber membranes <NUM> are not affected.

In the present embodiment, the cap <NUM> has a sleeve <NUM>. The sleeve <NUM> extends along the longitudinal direction of the hollow fiber membrane <NUM> and surrounds the binding portion <NUM> in the circumferential direction. Specifically, the sleeve <NUM> surrounds the binding portion <NUM> over <NUM> degrees. The sleeve <NUM> is joined to the binding portion <NUM>. In such a structure, the surface at which the binding portion <NUM> and the cap <NUM> are joined can assuredly have a sufficient area. Therefore, the binding portion <NUM> and the cap <NUM> can be firmly fixed to each other.

In the present embodiment, an adhesive <NUM> is filled between the inner circumferential surface of the sleeve <NUM> and the outer circumferential surface of the binding portion <NUM>. Use of the adhesive <NUM> allows the binding portion <NUM> and the cap <NUM> to be integrated while a gap between the binding portion <NUM> and the sleeve <NUM> is assuredly filled. A gap in which liquid is accumulated is unlikely to be formed between the binding portion <NUM> and the sleeve <NUM>. The kind of the adhesive <NUM> is not particularly limited. Examples of the adhesive <NUM> include epoxy-based adhesives, silicone-based adhesives, and acrylic adhesives. Instead of the adhesive <NUM> being used, the cap <NUM> may be welded to the binding portion <NUM>.

The cap <NUM> further includes a conical cap body <NUM>. In the present embodiment, the cap <NUM> has the sleeve <NUM>, the end portion <NUM>, and the cap body <NUM>. The sleeve <NUM> has a tubular shape, and is provided on the wider-opening side of the cap body <NUM>. The end portion <NUM> is nozzle-shaped, and is provided on the narrower-opening side of the cap body <NUM>.

<FIG> and <FIG> show a cross-section that includes the central axis O of the housing <NUM> and is parallel to the longitudinal direction of the hollow fiber membrane <NUM>. On the cross-section, the sleeve <NUM> is wedge-shaped. In other words, the thickness of the sleeve <NUM> is gradually reduced toward the end thereof. In such a structure, a gap in which liquid is accumulated is unlikely to be formed between the binding portion <NUM> and the sleeve <NUM>. Furthermore, filling of the adhesive <NUM> between the binding portion <NUM> and the sleeve <NUM> can be facilitated. The thickness of the sleeve <NUM> represents the dimension of the sleeve <NUM> in the direction perpendicular to the central axis O.

<FIG> is a partially enlarged cross-sectional view of the unit <NUM> that includes the hollow fiber membranes <NUM>, the binding portion <NUM>, and the cap <NUM>. In the present embodiment, the binding portion <NUM> has a truncated-cone shape. That is, the binding portion <NUM> and the sleeve <NUM> are shaped so as to fit into each other. In the binding portion <NUM>, the end surface 20p that faces the internal space <NUM> of the cap <NUM> is the upper surface (having a smaller diameter) of the truncated cone. An outer circumferential surface 20q (side surface) of the binding portion <NUM> is tilted relative to a longitudinal direction LD of the housing <NUM>. A tilt angle θ of the outer circumferential surface 20q relative to the longitudinal direction LD is, for example, greater than <NUM> degrees, and less than or equal to <NUM> degrees. An inner circumferential surface 32r of the sleeve <NUM> has the same tilt angle θ. The adhesive <NUM> is smoothly filled between the binding portion <NUM> and the sleeve <NUM>, so that a gap is unlikely to be formed between the binding portion <NUM> and the sleeve <NUM>. That is, a contamination such as particulates is unlikely to be accumulated between the binding portion <NUM> and the sleeve <NUM>. The binding portion <NUM> may have a columnar shape. In this case, the outer circumferential surface 20q of the binding portion <NUM> and the inner circumferential surface 32r of the sleeve <NUM> are parallel to the longitudinal direction LD.

As long as liquid accumulation between the binding portion <NUM> and the cap <NUM> can be avoided, the length of the sleeve <NUM> in the longitudinal direction of the hollow fiber membrane <NUM> is not particularly limited. In the present embodiment, the end of the sleeve <NUM> reaches the lower end of the binding portion <NUM>.

The cap <NUM> further includes a shoulder portion 34d located inward of the sleeve <NUM>. In the present embodiment, the shoulder portion 34d is a part of the cap body <NUM>. The shoulder portion 34d overlaps the binding portion <NUM> in the radial direction of the hollow fiber membrane module <NUM>, and the shoulder portion 34d is further joined to the binding portion <NUM>. The adhesive <NUM> can be present not only between the binding portion <NUM> and the sleeve <NUM> but also between the binding portion <NUM> and the shoulder portion 34d. In such a structure, the cap <NUM> can be assuredly fixed to the binding portion <NUM>, and the internal space <NUM> of the cap <NUM> can be assuredly isolated from the internal space <NUM> of the housing <NUM>. Liquid accumulation can be prevented from occurring between the binding portion <NUM> and the cap <NUM>.

Apart of the end surface 20p of the binding portion <NUM> is in contact with the shoulder portion 34d through the adhesive. Thus, the hollow fiber membranes <NUM> and the binding portion <NUM> are prevented from moving so as to approach the end portion <NUM> of the cap <NUM>. The shoulder portion 34d acts as a stopper for preventing the binding portion <NUM> from moving relative to the cap <NUM>. When the hollow fiber membrane module <NUM> is used, a strong impact may be imparted to the binding portion <NUM> due to water flow. Repeated strong impacts may cause shear fracture between the binding portion <NUM> and the cap <NUM>, so that a crack may occur between the outer circumferential surface 20q of the binding portion <NUM> and the inner circumferential surface 32r of the sleeve <NUM>. However, in the structure according to the present embodiment, the shoulder portion 34d receives the impact caused by water flow, and, therefore, even if repeated strong impacts are imparted to the binding portion <NUM>, the above-described defect is unlikely to occur. Furthermore, even if the defect occurs, the unit <NUM> can be quickly changed or repaired.

On the cross-section shown in <FIG>, the sleeve <NUM> and the shoulder portion 34d form an obtuse corner, and the binding portion <NUM> fits into the corner. Thus, the hollow fiber membranes <NUM> and the binding portion <NUM> are prevented from moving so as to approach the end portion <NUM> of the cap <NUM>, and the hollow fiber membranes <NUM> and the binding portion <NUM> are prevented from moving in the direction perpendicular to the longitudinal direction LD.

As shown in <FIG>, the hollow fiber membrane module <NUM> further includes a seal ring <NUM>. The seal ring <NUM> is disposed between the housing <NUM> and the cap <NUM>, and seals a gap between the housing <NUM> and the cap <NUM>. In the present embodiment, a groove 40c is provided in the opening end surface of the housing <NUM>, and the seal ring <NUM> fits into the groove 40c. The groove 40c is positioned so as to be covered by a surface 34p of the cap <NUM>, specifically, by the surface 34p of the cap body <NUM>. In such a structure, the cap <NUM> can be assuredly fixed to the housing <NUM>, and, therefore, the hollow fiber membrane module <NUM> can have excellent pressure resistance. The "opening end surface of the housing <NUM>" represents the end surface of the housing <NUM> in the direction parallel to the central axis O.

The seal ring <NUM> is formed of, for example, a resin material having rubber elasticity. The seal ring <NUM> may be quadrangular packing or an O-ring.

The sleeve <NUM> is located between the binding portion <NUM> and the housing <NUM> in the radial direction of the hollow fiber membrane module <NUM>. The sleeve <NUM> and the binding portion <NUM> are joined to each other. Meanwhile, the sleeve <NUM> and the housing <NUM> are not joined to each other. The seal ring <NUM> is disposed outward of the sleeve <NUM> in the radial direction. In such a structure, the cap <NUM> can be assuredly fixed to the housing <NUM>, and, therefore, the hollow fiber membrane module <NUM> can have excellent pressure resistance.

The inner diameter of the housing <NUM> gently increases in a range in which the binding portion <NUM> and the sleeve <NUM> are located. That is, the inner diameter of the housing <NUM> at the opening end is larger than the inner diameter of the housing <NUM> in a range in which the hollow fiber membranes <NUM> are located. The binding portion <NUM> is not in contact with the inner circumferential surface of the housing <NUM>. In such a structure, the unit <NUM> can be easily detached from the housing <NUM>, and the unit <NUM> can be easily attached to the housing <NUM>, so that workability for cleaning, changing, and repairing the unit <NUM> is improved.

The nut <NUM> has a shoulder portion <NUM> that is in contact with the upper surface of the cap <NUM>, and fixes the cap <NUM> and the housing <NUM> to each other while deforming the seal ring <NUM>. When the cap <NUM> is screwed onto the screw portion <NUM> provided on the outer circumferential surface of the housing <NUM>, a force in the direction in which the cap <NUM> approaches the housing <NUM> is applied from the shoulder portion <NUM> of the nut <NUM> to the cap <NUM>. Thus, the cap <NUM> can be assuredly fixed to the housing <NUM>, and pressure resistance of the hollow fiber membrane module <NUM> can be sufficiently assured.

According to the present embodiment, the seal ring <NUM> and the groove 40c are present between the cap <NUM> and the housing <NUM>. However, neither seal rings nor grooves are present at a position, between the binding portion <NUM> and the cap <NUM>, which is able to be reached by the permeate liquid. Therefore, liquid accumulation is unlikely to occur in the flow path of permeate liquid, and, furthermore, the flow path of the permeate liquid is easily cleaned by using the cleaning liquid or the like.

When the hollow fiber membrane module <NUM> of the present embodiment is an external-pressure-type hollow fiber membrane module, a space around the plurality of hollow fiber membranes <NUM>, that is, the internal space <NUM> of the housing <NUM> is used as the flow path of raw liquid. The internal space <NUM> of the cap <NUM> is used as the flow path of permeate liquid. The structure of the present embodiment is effective particularly for an external-pressure-type hollow fiber membrane module. This is because various processes using permeate liquid are unlikely to be negatively affected even when liquid accumulation occurs in the flow path of raw liquid to accumulate contaminations.

As shown in <FIG> and <FIG>, the hollow fiber membrane module <NUM> further includes a net <NUM>. The net <NUM> can be one component of the unit <NUM>. The plurality of hollow fiber membranes <NUM> are bound by the net <NUM>. The net <NUM> enhances stiffness of the bundle of the plurality of hollow fiber membranes <NUM>. In this case, the hollow fiber membranes <NUM> are unlikely to oscillate in the housing <NUM> due to water flow, and the hollow fiber membranes <NUM> are unlikely to be damaged. In particular, the hollow fiber membranes <NUM> can be prevented from being damaged near a boundary between the hollow fiber membranes <NUM> and the binding portion <NUM>. When the unit <NUM> is attached to the housing <NUM>, and when the unit <NUM> is detached from the housing <NUM>, the net <NUM> inhibits oscillation of the hollow fiber membranes <NUM>. Thus, damage to the hollow fiber membranes <NUM> can be prevented. The net <NUM> may include an inner-layer net and an outer-layer net. Such a double net structure is one of means for allowing water or cleaning liquid to flow at a high flow rate. The net <NUM> may be fixed to the bundle of the hollow fiber membranes <NUM> by a resin material such as an adhesive. In this case, the above-described effects can be more sufficiently exerted.

The sleeve <NUM> fits to the housing <NUM> by sliding. At least a part of the outer circumferential surface of the sleeve <NUM> is in contact with the inner circumferential surface of the housing <NUM>. No substantial gap is present between the sleeve <NUM> and the housing <NUM> (more specifically, between the outer circumferential surface of the sleeve <NUM> and the inner circumferential surface of the housing <NUM>). Therefore, the unit <NUM> can be assuredly fixed to the housing <NUM>. Such a structure also inhibits the hollow fiber membranes <NUM> from oscillating in the direction perpendicular to the longitudinal direction LD, and contributes to prevention of damage to the hollow fiber membranes <NUM>. The "no substantial gap" means that a gap is not designed to be intentionally provided between the sleeve <NUM> and the housing <NUM> except for a small gap for allowing the unit <NUM> to be attached to the housing <NUM> and allowing the unit <NUM> to be detached from the housing <NUM>.

<FIG> illustrates a method for joining the binding portion <NUM> and the cap <NUM> to each other. As shown in the upper portion in <FIG>, the adhesive <NUM> is firstly applied to the end surface 20p of the binding portion <NUM>, and the binding portion <NUM> and the cap <NUM> are brought into contact with each other. Next, as shown in the mid-portion in <FIG>, the adhesive <NUM> is injected, by using an injector <NUM>, into a gap <NUM> between the outer circumferential surface of the binding portion <NUM> and the sleeve <NUM> of the cap <NUM>. As shown in the lower portion in <FIG>, the adhesive <NUM> is hardened to obtain a unit including the hollow fiber membranes <NUM>, the binding portion <NUM>, and the cap <NUM>. By using the unit, the hollow fiber membrane module <NUM> can be assembled.

Claim 1:
A hollow fiber membrane module (<NUM>) comprising:
a plurality of hollow fiber membranes (<NUM>);
a binding portion (<NUM>) binding the plurality of hollow fiber membranes (<NUM>) at one end portions thereof;
a cap (<NUM>) having an internal space (<NUM>) that communicates with each of the plurality of hollow fiber membranes (<NUM>), the cap (<NUM>) being integrated with the binding portion (<NUM>),
the hollow fiber membrane module (<NUM>) further comprises a housing (<NUM>) that houses the plurality of hollow fiber membranes (<NUM>) and the binding portion (<NUM>), and that has one end portion to which the cap (<NUM>) is attached,
a unit (<NUM>) including the plurality of hollow fiber membranes (<NUM>), the binding portion (<NUM>), and the cap (<NUM>) which is detachable from the housing (<NUM>), and the unit (<NUM>) is suitable to be attached to the housing (<NUM>) while integration of the binding portion (<NUM>) and the cap (<NUM>) is maintained, and
characterized in that the cap (<NUM>) comprises a sleeve (<NUM>) that extends along a longitudinal direction of the hollow fiber membranes (<NUM>), and that surrounds the binding portion (<NUM>) in a circumferential direction,
and in that the sleeve is joined to the binding portion, and
the sleeve (<NUM>) is wedge-shaped on a cross-section parallel to the longitudinal direction of the hollow fiber membranes (<NUM>).