JP2011235205A - Hollow fiber membrane module and method for removing filtration residue of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure of a hollow fiber membrane module and a method for removing filtration residue of the hollow fiber membrane module hardly causing plugging even if used for filtration of a fluid containing a filtrated substance at a high concentration, and quickly and easily removing the filtration residue even if once plugged.SOLUTION: The hollow fiber membrane module includes a mechanism for physically removing the filtration residue deposited on the surface by filtration. A hollow fiber membrane filter of the hollow fiber membrane module is formed by inserting a reinforcing core material into a filter hollow part, the reinforcing core material having a clearance that communicates in the length direction of the filter, between itself and the inner surface of the hollow part so as to be arranged in a non-contact manner between the respective hollow fibers, and fixing at least one end of the core material to a support member so as to stand upright in parallel.

Description

  The present invention relates to a hollow fiber membrane module and a method for removing the filtration residue thereof. More specifically, the present invention is less likely to cause clogging even when used for filtration of a fluid containing a high concentration of the substance to be filtered. The present invention relates to a structure of a hollow fiber membrane module that can quickly and easily remove a filtration residue even if clogging occurs and a method for removing the filtration residue.

The hollow fiber membrane module is composed of an assembly of a plurality of hollow fiber membrane filters. Usually, in order to increase the filtration area in the unit space, the hollow fiber membranes have a smaller diameter and are more densely integrated. I am letting.
As a result, the gap between adjacent filter tubes becomes too narrow and is used in a state where they are in contact with each other or entangled with each other.

  If it is applied to the filtration of fluid with low turbidity even if they are in contact with each other or entangled, this will not be a big problem, but when applied to the filtration of fluid with high turbidity If they are in contact with each other or entangled with each other, a clogging phenomenon due to adhesion deposition of contaminating particles occurs, which causes a significant decrease in the surface area of the filtration membrane. Once this phenomenon occurs, it becomes difficult to remove and remove the contaminated particles deposited on the filter surface only by back washing. For this reason, when the particles deposited on the surface are forcibly removed by scraping or other physical means, the hollow fiber membrane filter is inherently thin and soft, so that the membrane of the filter is cut or the membrane surface is damaged.

  When the conventional hollow fiber membrane module is applied to the filtration of fluids with high turbidity, the cause of the laminating clogging phenomenon due to the adhesion deposition of contaminated particles is due to the fact that the hollow fiber membrane filters are too dense. However, the biggest cause is that the filter is too weak and the neighbors come into contact with each other or become entangled.

  In order to improve the mechanical strength of a soft filter, the following Patent Documents 1 to 4 describe that the hollow fiber membrane itself is reinforced.

  Patent Document 1 (Japanese Patent Laid-Open No. 11-319519) describes that a reinforcing material is embedded in a spiral shape in the hollow fiber membrane itself for reinforcement.

  Patent Document 2 (Japanese Patent Laid-Open No. 2001-334131) describes that a reinforcing material is spirally wound around the outer surface of a hollow fiber membrane for reinforcement.

  Patent Document 3 (Japanese Patent Application Laid-Open No. 2004-42024) describes that reinforcing ribs extending radially from the center reinforce the lack of pressure strength and tensile strength of the hollow fiber membrane.

  In the inventions described in Patent Document 1 and Patent Document 2, the reinforcing material is both embedded in a spiral shape or wound to be reinforced, but it is possible to prevent the long hollow fiber membrane from standing upright. It is difficult to prevent contact and entanglement between adjacent causes of clogging. The inventions of Patent Documents 1 and 2 both have a drawback that cannot be applied to a widely used hollow fiber membrane filter itself. In addition, the manufacturing cost is higher than that of general-purpose products.

  In the invention described in Patent Document 3, contact between adjacent causes of clogging and prevention of entanglement are possible, but since the pores on the surface of the hollow fiber membrane are blocked by the presence of ribs, the surface of the hollow fiber membrane The effective filtration area is reduced, and the filtration capacity is lowered. Further, it is necessary to integrally mold the hollow fiber membrane filter and the rib, and there is a disadvantage that is difficult to apply to the widely used hollow fiber membrane filter itself. In addition, there is a drawback that the manufacturing cost is extremely high.

  Further, in Patent Document 4 (Japanese Patent Laid-Open No. 2009-11965), in a hollow fiber membrane module whose upper end is a free end, in order to make the hollow fiber membrane self-supporting, the hollow fiber membrane is folded in half and its folded portion is free. As an end, it is described that the free end is supported by being suspended and supported. Further, it is described that the hollow fiber membranes are separated from each other by suspending and supporting to prevent entanglement.

  In the invention described in Patent Document 4, since the strength of the hollow fiber membrane itself is not improved, the filter is cut or damaged when the deposit is removed by physical means. In addition, a suspension mechanism is indispensable for self-supporting and preventing separation and entanglement, and the structure is complicated. There is also a problem that cannot be applied to a hollow fiber membrane module having a structure in which both ends are fixed.

  Patent Document 5 (Japanese Patent Application Laid-Open No. 2004-25112) describes that when washing water is sprayed on the surface of the hollow fiber membrane, a net-like body is attached to the surface of the hollow fiber membrane to prevent entanglement and damage of the hollow fiber membrane filter. Yes.

  In the invention described in Patent Document 5, since it is limited to washing with washing water and air, the adhesion of the filtration residue is limited to a light one, and it can be applied to the removal of the strongly adhered filtration residue. There are some drawbacks. In addition, in the case where the hollow fiber membranes are arranged in multiple stages, there is a drawback that it is difficult to clean the inside sufficiently.

JP 11-319519 A JP 2001-334131 A JP200442024 JP2009-11965 JP 2004-25112 A

  The present invention has been made in view of such a problem, and the first object thereof is a novel structure capable of preventing contact and entanglement between closely packed hollow fiber membranes and quickly and easily removing the filtration residue. An object of the present invention is to provide a hollow fiber membrane module.

  In addition, the second problem is that in the hollow fiber membrane module having a structure in which the upper end is a free end, the hollow fiber membrane itself is made upright, self-standing, and separated without using a suspension mechanism or the like. An object of the present invention is to provide a hollow fiber membrane module having a novel structure capable of preventing contact and entanglement.

  The third problem is to provide a novel removal method that can quickly and easily remove the filtration residue on the surface of the hollow fiber membrane filter, which is difficult to remove by backwashing.

  The present inventor has conducted earnest research on the above problems and has obtained the following knowledge.

  That is, the means for achieving the first problem is as follows.

  The inventor inserts a reinforcing core material into the hollow portion of the hollow fiber membrane filter, and fixes at least one end of the core material to the support member, thereby allowing the filter to stand upright and mechanically removing the filter hollow portion. It has become possible to reinforce backup, and it has been found that the hollow fiber membrane filter can be prevented from being broken and damaged against the bending and stretching forces acting on the filter when the filtration residue is forcibly removed by physical means. It was. And as the insertion method of the core material, the filtered fluid is formed by having a structure having a gap communicating between the hollow fiber membrane hollow portion inner surface and the core material over the entire length from the lower end to the upper end of the core material. It has been found that it can be smoothly discharged outside through the communicating gap.

  And it discovered that the porosity of the clearance gap between the said filter inner surface and the reinforcing core material is 10% or more.

In the present invention, the fluid containing a high concentration of the substance to be filtered out means a fluid in the following state. In other words, when a fluid containing contaminated particles is filtered through a hollow fiber membrane filter, the filtration capacity is high at the initial stage of filtration, but after a steady state is maintained for a while, the filtration capacity is accompanied by clogging of filtration residue as the filtration continues Gradually declines and finally becomes unfilterable.
In such a state, in order to restore the filtration capacity, if a clean fluid (for example, water) that has been filtered is applied and backwashed by applying a pressure in the opposite direction to that during filtration, the filtration residue deposited on the surface is removed. Usually, the filtration ability is recovered by peeling off, but if the content of the contaminated particles is increased, the adhesion and stacking of the contaminated particles due to contact and entanglement of the hollow fiber membranes are likely to occur. It takes an extremely long time to remove the filtration residue deposited on the substrate by backwashing and restore the filtration function to a practical level, and practically it becomes inoperable.
The fluid containing a high concentration of the substance to be filtered of the present invention intends a fluid in such a high concentration region.

  The turbidity of such a high-concentration region fluid has a content of contaminated particles of approximately 100 ppm or more as a guide. The difficulty of peeling off the residue after filtration does not depend only on the turbidity (content of contaminated particles: ppm), but the particle size, shape, chemical activity of the contaminated particles, and the eye of the hollow fiber membrane filter. Needless to say, the present invention does not mean only a fluid having a content of pollutant particles of 100 ppm or more because it varies depending on roughness and the like.

The filtration ability of the fluid in the high concentration region targeted by the present invention is that in the steady state, when filtering water with a fine filtration amount per unit time that is filtered and discharged from the inside of the hollow fiber membrane filter. Approximately 50%.
That is, when a fluid in a high concentration region is filtered, the amount of filtration is reduced, so that only about 50% or less of the original discharge capacity of the inner diameter of the hollow fiber membrane filter is discharged.

[Reason for limiting porosity]
When the core material is inserted through the hollow fiber membrane, the gap between the hollow fiber membrane inner diameter and the core material is narrowed, and the ability to discharge the filtered fluid to the outside of the filter is reduced, but when the fluid with high turbidity is filtered Is a steady state in a state where the above-mentioned core material is not inserted if the hollow fiber membrane inner diameter has a margin due to a decrease in the filtration amount, and the void ratio between the hollow fiber membrane inner diameter and the core material can be secured 50% or more. Can be discharged outside without delay. That is, if the porosity can be ensured to be 50% or more, even if the reinforcing material is inserted into the hollow portion, the filtration discharge ability equivalent to the case where the core material is not inserted can be obtained.
If the porosity is less than 50%, the filtered fluid is delayed in discharge, resulting in a decrease in the filter discharge capacity of the filter. In addition, as long as filtration can be performed, if the filtering ability is not questioned, the porosity by inserting the core material is not particular.

[Reason for limitation of inner diameter and tensile strength]
As the inner diameter of the hollow fiber membrane becomes smaller, the ratio (2 / R) of the filtration area (surface area) to the inner diameter cross-sectional area becomes larger and the filtration capacity per unit volume of the hollow fiber membrane becomes higher.
Taking a hollow fiber membrane that is widely used as an example,
The hollow fiber membranes that are widely used generally have an inner diameter of a minimum inner diameter of 0.5 mm to a maximum inner diameter of 3 mm. With respect to this inner diameter, when the porosity is 50%, the inner diameter that the core material can take is the highest in the core material. The small diameter is 0.35 mm to the core maximum diameter 2.12 mm.
On the other hand, in the case where the porosity is 10%, a reinforcing core material having a larger diameter than that in the case where the core material can have a porosity of 50% can be used.
For example, a hollow fiber membrane having an inner diameter of 0.5 mm has a core material diameter of 0.48 mm, and a hollow fiber membrane having an inner diameter of 3 mm has a core material diameter of 2.86 mm.
2 / R is a value obtained by dividing the surface area of the hollow fiber membrane by the area of the cross section, and is an index indicating the filtration capacity per unit volume of the hollow fiber membrane.

Therefore, in the case of a hollow fiber membrane (inner diameter: 0.5 to 3 mm) that is widely used, in the case of 50% porosity, the core material having a minimum core material diameter of 0.35 mm is straightly stretched and inserted through the hollow fiber membrane, It is necessary to select a core material having a strength that prevents the core material from being deformed by a bending force when backing up and removing the filtration residue by backing up the yarn film. For example, for a hollow fiber membrane having a minimum inner diameter (0.5 mm), a material of the highest strength group, for example, a hard wire is preferable. The hard wire is a hard steel wire, a hard iron wire, such as a piano wire, a stainless steel wire, a W wire or the like. Incidentally, when a piano wire and a stainless steel wire having a tensile strength of 2000 MPa are applied to a core material having a diameter of 0.35 mm, a core material that can withstand a load of 192 MPa can be obtained.
A core material that can withstand a load of 361 MPa with a porosity of 10% can be obtained.

For the purpose of the present invention, if the core material has a strength capable of withstanding a load of 100 MPa or more, it can be easily removed by wiping, and the core material will not be deformed and the hollow fiber membrane will not be cut. Piano wires and stainless steel wires are sufficient for small-diameter cores.
When the adhesion force of the residue after filtration is strong and removal of the residue is difficult, if the core material diameter is increased to a porosity of about 10%, a force of 3 to 4 times the load is applied compared to the case of 50% porosity. However, the core material is not deformed and the hollow fiber membrane is not cut.

[Filter separation and filter removal mechanism]
As described above, when a fluid containing high-concentration contaminated particles intended by the present invention is filtered with a hollow fiber membrane module, the filtration residue deposited on the filter surface can be quickly and easily removed by backwashing. Have difficulty. Therefore, it is difficult to say that back washing alone is practical as a means for removing the filtration residue.

  In the present invention, the reinforcing core material is inserted into the hollow fiber membrane filter, the hollow fiber membrane filter is reinforced and upright, and the hollow fiber membrane filters are separated from each other to prevent entanglement and contact. It was found that the residue deposited on the filter surface can be removed quickly and easily by using backwashing together with the physical removal mechanism described above. Also, by reinforcing and standing upright and separating from each other to prevent entanglement and contact, the time until the filter becomes clogged and becomes unfilterable, that is, the filtration until the next removal is performed after removing the deposit We also found that the possible time can be greatly extended.

  In particular, it has been found that when backwashing and the above-described physical removal mechanism are used in combination, it can be removed most effectively by physical removal while simultaneously applying, that is, applying the pressure of backwashing.

The reason why the combined use of backwashing and physical removal mechanism has a significant effect on the removal of deposits is presumed to be as follows.
That is, the pressure of backwashing has the effect of raising the deposit from the contact surface with the filter, which is presumed to facilitate physical removal.
In addition, liquid (for example, filtered water) is filled between the hollow fiber membrane and the core material by back washing, and the liquid penetrates to the surface of the hollow fiber membrane and wets, thereby binding the deposit and the surface of the hollow fiber membrane. It is assumed that this is relaxed and this facilitates the exfoliation of the deposit.

In addition, when the fluid to be filtered has a low water content such as high-concentration sludge, for example, in the case of a high-concentration sludge having a water content of 90% or less, the operation of removing water from the sludge is not water filtration. Rather, the expression dehydration is appropriate, but in this case, clogging occurs frequently, and once clogging occurs, removal of the filter residue becomes difficult.
When removing by physical means, it is necessary to apply a higher load force even if back washing is used together. Since strong wiping force, high-pressure washing, strong vibration, etc. are required, the hollow fiber membrane filter is severely damaged, and accidents such as breakage of the hollow fiber membrane are likely to occur, so the diameter of the reinforcing core material is made thicker As a result, the porosity between the reinforcing core and the inner diameter of the hollow fiber membrane is reduced.

The limit of increasing the reinforcing core diameter is up to a porosity of 10%.
If the porosity is less than 10%, it will be difficult to lift the filtration residue even when a reverse washing water pressure is applied. Even if physical removal is combined with back washing, the filtration residue on the surface of the hollow fiber membrane It becomes difficult to remove. Moreover, if the operation | work which removes a residue physically is continued, a tear of a hollow fiber membrane filter will occur easily.
Therefore the porosity is preferably on 10% or more. That is, it is necessary to set the porosity to 10% or more and select a core material that can withstand high load pressure under these conditions.
For example, even if the hollow fiber membrane filter has a minimum diameter of 0.5 mm and a piano wire is used as the reinforcing core material, the hollow fiber membrane is not cut even when a force of 361 MPa is applied at a porosity of 10%. The work of physically removing the residue can be continued.

In the present invention, when the filtration residue is physically removed, the surface of the hollow fiber membrane is rubbed by a physical removing means, so that the surface of the hollow fiber membrane is easily damaged or cut.
Liquid by backwashing (for example, filtered water) is filled between the hollow fiber membrane and the core material, the liquid penetrates to the surface of the hollow fiber membrane, and the surface is coated with the liquid membrane, thereby expressing lubricity on the surface Thus, the surface damage and cutting of the hollow fiber membrane are prevented.

The combined use of backwashing for physical removal facilitates the removal of the filtration residue, and has a remarkable effect on the surface damage and cutting prevention of the hollow fiber membrane.
When the liquid membrane is present and the surface of the hollow fiber membrane is wetted with the liquid membrane, the rupture and damage rate of the hollow fiber membrane is 1/50 to 1/100 compared with the case where the liquid membrane is not present. To drop. That is, the life of the filter is extended 50 to 100 times.

The mechanism for physically removing the filtration residue in the present invention is a mechanism for scraping with a wiping means such as a brush, brush, scraper, etc., a mechanism for blowing a pressure fluid such as water or air, a vibration, and an ultrasonic wave. It means a mechanism for peeling and a mechanism for removing a deposit by applying a physical force from the outside. Wiping, blowing, vibration, peeling with ultrasonic waves, and other physical removal means may be used in combination as appropriate. For example, a blowing mechanism such as a cleaning nozzle may be provided in the wiping mechanism.
Of the physical removal mechanisms described above, the wiping mechanism is the most effective, and it is more effective when the cleaning mechanism is used in combination with wiping.

(Wiping mechanism)
The physical removal mechanism includes a mechanism that horizontally moves along the length direction of the filters arranged upright in parallel.
For example, when the mechanism for physically removing is a combination of wiping and a cleaning mechanism, the residue on the surface of the filter is horizontally moved and reciprocated while scraping off with a wiping means such as a brush or brush to remove the residue. At this time, if necessary, a cleaning mechanism (water and air spray nozzle) is integrally attached to the wiping means, and water and air are sprayed as appropriate to soften the residue, or loosen the bond and scrape with a brush or brush. take.

  When the parallel array of hollow fiber membrane filters (horizontal single-row hollow fiber membrane module) in which a plurality of hollow fiber membrane filters are arranged in parallel is stacked in multiple stages, from the gap between the filters arranged in parallel, Insert wiping means such as brushes, brushes, and scrapers that reach from the uppermost filter to the lowermost filter in the direction that intersects the length direction of the filter, and the wiping means that is inserted in this intersecting direction is the length direction of the filter. The filter separation residue deposited on the filter surface is scraped off and removed. At this time, other means (cleaning mechanism) or the like are used together as necessary.

Or the following structure may be sufficient.
That is, a plurality of vertical and horizontal parallel arrays, that is, an array in which a plurality are arranged in the horizontal direction and a plurality thereof are arranged in the vertical direction may be used.
In this case, the length of the brush blade is a long blade brush that can reach from the hollow fiber membrane arranged at the front to the hollow fiber membrane arranged at the back, and from the hollow fiber membrane at the uppermost stage to the lowermost stage. Using a long vertical and horizontal brush that reaches the hollow fiber membrane, it is inserted into the innermost hollow fiber membrane and reciprocated horizontally to scrape off the filtration residue.
It is even better if the brush is scraped so that the position is slightly shifted from the opposite side and the brush is sandwiched from both sides.

〔Direction of movement〕
The physical removal mechanism is preferably horizontally moved along the length of the filters arranged upright in parallel. When the filter is moved in the direction intersecting the length direction of the filter, the hollow fiber membrane is easily broken and damaged, which is not preferable.

[Durability of hollow fiber membrane filter with and without reinforcing core]
If there is no core material, moving the wiping means in a right angle direction and scraping it may cause the hollow fiber membrane filter to break and become unrepairable only by repeating 20 to 50 times. However, when the reinforcing core material is present, the durability of the hollow fiber membrane extends to 1500 to 16000 times.

  In the present invention, the core material for reinforcing and standing up the hollow fiber membrane filter needs to be fixed to the support member at one or both ends. In addition, airtight isolation is essential between the contaminated fluid side to be filtered and the space inside the hollow fiber membrane.

Material of the reinforcing core material for the hollow fiber membrane of 0.5mm internal diameter, tensile load 100MPa or more, may be selected from among materials withstanding higher tensile loads 30MPa for 3mm internal diameter. For materials having an intermediate diameter of 0.5 to 3 mm, a material having a strength capable of withstanding a load of at least 100 MPa may be selected as appropriate.
Examples of the wire having a strength capable of withstanding a load of 100 MPa or more include the following materials.
Metal materials: Steel wire (stainless steel, ordinary steel, special steel), W, Mo wire, hard alloy wire, work hardened wire, etc. Organic materials: Nylon, polyethylene, polyamide, polycarbonate, polypropylene, phenol resin, etc. Inorganic materials: carbonized Silicon fiber, glass fiber, etc. As described above, these materials may be selected and used according to the inner diameter of the hollow fiber membrane.

There are no particular restrictions on the cross-sectional shape of the reinforcing core. Any shape can be used as long as it is a shape capable of forming a gap communicating with the inner surface of the hollow fiber membrane and the entire length of the core material and satisfies the above-described strength conditions. That is, any shape such as circular, irregular, square, triangular, polygonal shape may be used, but steel wire is most preferable from the viewpoint of strength.
The steel wire may be a single wire or a composite wire in which a plurality of wires are combined.
The steel wire is most preferably straightened so as to stand upright.

  It is possible to disinfect, sterilize, and deodorize the filtered liquid by carrying a sterilizing, sterilizing and deodorizing catalyst or chemical (sustained release) for preventing bacterial infection on the surface of the reinforcing core. Become.

The following methods are effective as means for supporting the catalyst or the drug.
That is, silver plating and copper plating of the core material are effective for sterilization and sterilization. It is also effective to mix and apply particles having sterilizing and bactericidal effects to the resin.
In addition, the supporting method may be a means such as coating, painting, or pickling, and is not particularly limited.

Means for solving the second problem of the present invention are as follows.
That is, a hollow fiber having a structure in which a plurality of hollow fiber membrane filters are arranged at intervals, the lower end opening of the hollow fiber membrane filter is opened and fixed in the collecting tank, and the upper end is hermetically sealed to be a free end. In the membrane module, a reinforcing core material is inserted into the filter hollow portion, the core material end is fixed to the collecting tank on the filter lower end opening side, and the core material end on the filter free end side is integrated with the filter. It was found that a hollow fiber membrane module having a free end structure with one end extremely excellent in self-supporting property can be obtained by joining and sealing and reinforcing the hollow fiber membrane filter with a reinforcing core material so as to stand upright.
And, as the core material, by having a structure having a gap communicating between the inner surface of the hollow portion of the hollow fiber membrane and the core material over the entire length from the lower end to the upper end of the core material, the filtered fluid passes through the communicated gap. Can be discharged smoothly outside.

  As described above, if the porosity of the gap between the inner surface of the filter and the reinforcing core material can be ensured to be 10% or more, the filtration residue can be removed. In addition, as long as filtration can be performed, if the filtering ability is not questioned, the porosity by inserting the core material is not particular.

There is no special restriction on the cross-sectional shape of the reinforcing core as described above.
Any shape can be used as long as it is a shape capable of forming a gap that communicates with the inner surface of the hollow fiber membrane and the entire length of the core material and satisfies the above-described strength to withstand the tensile stress.
That is, it may be any shape such as circular, irregular, square, triangular, polygonal, but for a hollow fiber membrane module having a free end structure at one end, a steel wire having the most upright and self-supporting properties is most preferable.
The steel wire may be a single wire or a composite wire in which a plurality of wires are combined.
The steel wire is most preferably straightened so as to stand upright.

  The fluid of the present invention means a fluid in which a substance to be filtered is mixed in a gas or liquid, and the kind of the substance to be filtered is a micro-organism or bacteria having a volume from an inorganic or organic powder. Including. The properties of the fluid include liquids, slurries, and plastic fluids such as clay. For example, when the liquid is water-based, it includes liquids having a higher water content, slurries having a lower water content, and plastic fluids such as clay having a lower water content.

As described above, the method for solving the third problem of the present invention is as follows.
That is, when a fluid containing a high concentration of the substance to be filtered is filtered through the hollow fiber membrane module to remove the filtration residue deposited on the surface of the hollow fiber membrane, between the hollow fiber membrane filter hollow portion inner surface, Insert a reinforcing core material with a gap communicating in the length direction of this filter, reinforce this hollow fiber membrane filter and arrange it upright and parallel to the support member, along the length direction of the filter By moving the means for physically removing the filtration residue and physically removing the residue, the filtration residue can be removed without breaking the filter.
Further, when the physical back removal is combined with the back washing of the filter, the filter residue can be removed quickly and easily.
The physical removal and the back washing are most preferably used simultaneously. By this reverse cleaning, the filter residue can be removed more quickly and easily by filling the gap between the filter inner diameter and the reinforcing core material with a liquid film of liquid and moistening and lubricating the filter surface.

  When a parallel array of hollow fiber membrane filters (horizontal single-row hollow fiber membrane modules) in which a plurality of hollow fiber membrane filters are arranged in parallel is stacked in multiple stages, the gap between the stages Insert a physical removal means with a length that reaches from the uppermost filter to the lowermost filter in the direction that intersects the length direction, and horizontally reciprocate the removal means inserted in this intersecting direction in the length direction of the filter. The filter residue deposited on the surface is scraped off and removed.

Alternatively, the following method may be used.
That is, in the case of a plurality of parallel arrays in the vertical and horizontal directions, i.e., a plurality of these arrayed in the horizontal direction, the lengths of the brush blades are arranged farthest from the hollow fiber membranes arranged in front. Insert a long blade that can reach the hollow fiber membrane into the longest hollow fiber membrane and reach the innermost hollow fiber membrane. The filter residue is scraped off by reciprocating horizontally.
It is even better if the brush is scraped so that the position is slightly shifted from the opposite side and the brush is sandwiched from both sides.

The physical removal means can remove the filtration residue most effectively when it is reciprocated horizontally so as to be sandwiched from both sides, regardless of whether it is a horizontal single-row hollow fiber membrane module or a vertical and horizontal parallel arrangement module.
As the physical removal means, wiping is effective. In addition to wiping, it is more effective to use other removal means such as washing and vibration in combination.

As described above, the fluid to be filtered of the present invention means a fluid in which a substance to be filtered in a gas or a liquid is mixed, and there are cases where the liquid component is small and the gas component is large. For example, when a liquid component is filtered from a fluid containing a small amount of liquid in a gas, this corresponds to, for example, the separation of moisture in the air, that is, dehumidification. In this case, a large amount of moisture is filtered. There is no separate discharge and sufficient moisture is not filled between the hollow fiber membrane and the core material, and no water membrane is formed. In such a case, in order to form a water film by backwashing, not only simply pressurizing the outlet on the inner diameter side of the hollow fiber membrane with air pressure but also supplying sufficient water or injecting water from the outlet side, When sufficient water is applied, a sufficient water film can be formed.
The reverse cleaning of the present invention includes a case where a liquid film is not sufficiently formed due to excess and deficiency of fluid during reverse pressurization, and a case where a sufficient amount of fluid is present and a liquid film is sufficiently formed. When a film is not sufficiently formed, when a liquid film is formed, a new fluid is replenished when reverse pressurization is performed.

The present invention has the following effects.
1 It can be filtered directly from high turbidity water to fresh water.
2. The filtration residue of a fluid containing high-concentration contaminated particles that cannot be removed by backwashing can be removed without breaking or damaging the hollow fiber membrane filter.
3 In a hollow fiber membrane module having a structure in which one end is a free end, the hollow fiber membrane itself can be made to stand upright without using an auxiliary mechanism such as hanging. Further, it can be separated to prevent entanglement.
4. It can be applied to hollow fiber membrane modules that are widely used at present.
5 The structure is simple and can be manufactured inexpensively
6 Since the hollow fiber membrane filters can be arranged at a higher density without contacting them, the filterable area becomes wider than when there is no core material.

  The present invention will be described with reference to the drawings. It should be noted that the drawings are specifically described for better understanding of the gist of the invention, and it is needless to say that the invention is not limited thereto.

FIG. 1 is a diagram illustrating the overall structure of a single-row hollow fiber membrane module having a structure in which both ends of a reinforcing core are fixed.
FIG. 2 is a view for explaining a mounting and fixing structure of the hollow fiber membrane filter and the reinforcing core material.
FIG. 3 is an explanatory diagram of a structure in which the hollow fiber membrane modules of FIG. 1 are stacked in multiple stages, and a mechanism (wiping and washing) for physically removing the filtration residue is inserted into the gaps between the stages.

1 and 2, reference numeral 1 denotes a hollow fiber membrane support member.
In this figure, the support member 1 is made of a rigid pipe and is hollow inside.
The liquid from which the contaminant particles are filtered by the hollow fiber membrane filter 2 flows through the pipe and is collected in a collecting tank (tank) (not shown).

The reinforcing core material 3 is inserted from one side of the hollow fiber membrane filter 2 to the other end, and screws are attached to both ends of the reinforcing core material 3 so as to support the support members 1 (rigidity) on opposite sides. As shown in FIG. 2, it is fixed to the support member 1 (rigid pipe) with bolts.
The means for joining the reinforcing core member 3 and the support member is not limited to fastening with screws and bolts, and all other existing joining, adhesion, and mechanical fastening means such as adhesion and welding are adopted. I can do it.

  As shown in FIG. 2, both ends of the hollow fiber membrane filter 2 are inserted into and bonded to support members 1 (rigid pipes) on opposite sides. At this time, the fluid to be filtered including the contaminating particles is hermetically bonded 5 so as not to flow into the pipe.

  Since the hollow fiber membrane filter is reinforced from the inside with the reinforcing core member 3 that is straightened at both ends, the hollow fiber membrane filter may be bent when attached to the support member 1 (rigid pipe) and bonded. 1 without being entangled or in contact between adjacent hollow fiber membrane filters, and parallel hollow fiber membrane filters in which hollow fiber membrane filters as shown in FIG. 1 are arranged upright and in parallel. An array (single-row hollow fiber membrane module) is completed.

  As shown in FIG. 2, it is necessary to secure a gap for flowing the filtered liquid between the hollow fiber membrane filter and the reinforcing core, but the gap may be only on one side, not on both sides.

In FIGS. 1 and 2, the support member 1 (rigid pipe) also serves as a flow path for flowing the filtered liquid, but it is not necessarily the same.
The hollow fiber membrane filter needs to be hermetically bonded to the flow path through which the filtered liquid flows, but the reinforcing core material does not need to be joined to the flow path through which the filtered liquid flows. The support member for the material and the support member for the hollow fiber membrane filter may be separate.

The filtration residue deposited on the surface of the hollow fiber membrane filter is scraped by moving the wiping brush 5 parallel to the length direction of the hollow fiber membrane filter.
The wiping brush 5 is attached to a brush attachment shaft 6, and the attachment shaft 6 is disposed at an angle intersecting the length direction of the hollow fiber membrane filter and horizontally moves along the length direction of the filter (not shown). Not) and reciprocates horizontally.
The wiping brush 5 is disposed on both sides of the hollow fiber membrane filter and moved so as to sandwich the hollow fiber membrane filter to scrape the residue.

The brush mounting shaft 6 is also provided with a nozzle for jetting cleaning water, and sprays cleaning water as necessary to blow off the filtration residue.
Note that other physical removal means may be provided as needed.

The hollow fiber membrane filter can be appropriately selected to have an inner diameter of 0.5 mm or more and a practical length of about 3 m.
If the inner diameter of the hollow fiber membrane filter is a minimum diameter of 0.5 mm and the porosity is 10%, the diameter of the reinforcing core material can be selected up to a maximum diameter of 0.48 mm.
An appropriate distance between the hollow fiber membrane filters is approximately 0.5 mm or more.

  As the material of the wiping brush, soft resin fibers used in ordinary brushes and brushes can be used as they are.

FIG. 3 is an explanatory view of a hollow fiber membrane module in which the parallel array of the hollow fiber membrane filters of FIG. 1 (horizontal single-row hollow fiber membrane module) is stacked in four stages.
The filtered liquid of each stage flows through the flow path in the support member 1 (rigid pipe) and is collected in the collecting tank 9.
The wiping brush 6 is inserted into the gap between the hollow fiber membrane modules of each stage at an angle that intersects the length direction of the hollow fiber membrane filter. The movement of the wiping brush is basically the same as in the case of FIG. 1 and moves in parallel in the length direction of the hollow fiber membrane filter.
In the case of this figure, the wiping brush 6 and the brush attachment axis | shaft 7 are inserted in the clearance gap between the hollow fiber membrane modules of each step.

The attachment shaft 7 to which the wiping brush is attached is attached and fixed to an attachment base 8 that translates in the length direction of the hollow fiber membrane filter.
The mounting base 8 is provided with a roller 11, and the roller rotates on a rail (not shown) so that the mounting base 8 moves in parallel with the length direction of the hollow fiber membrane filter.
The mounting base 8 is attached to a rotating belt 10 as shown in the figure, and reciprocates left and right as the belt 10 moves.
Needless to say, the mechanism for moving the mounting base 8 in parallel is not limited to this example. At least the mounting shaft 7 for mounting the wiping brush is parallel to the length direction of the hollow fiber membrane filter. Any mechanism may be used as long as it can move.

FIG. 4 is an explanatory diagram of a hollow fiber membrane module in which a plurality of rows and columns are arranged side by side, that is, a plurality of rows are arranged side by side and arranged in the lengthwise direction.
The support member (rigid pipe) 1 collects the liquid filtered by the hollow fiber membrane modules arranged in a plurality of four rows and three rows.
As in the case of FIG. 1, the reinforcing core material 3 and the hollow fiber membrane filter 2 are fixed to a support member (rigid pipe) 1. The reinforcing core is fixed with bolts 4.
The wiping brush has long blades that can reach from the hollow fiber membrane arranged in front to the hollow fiber membrane arranged in the innermost part. The brush has a length that reaches from the uppermost hollow fiber membrane to the lowermost hollow fiber membrane.
Insert a brush with adjusted length and width to the innermost hollow fiber membrane, and reciprocate it horizontally to scrape off the filtration residue. Also, a brush of the same length is inserted on the opposite side with a slight shift in position, and the hollow fiber membrane module is sandwiched by both brushes to scrape the residue.
Although not shown in the figure, a water injection nozzle or the like may be provided as needed.

FIG. 5 is a diagram illustrating the overall structure of the hollow fiber membrane module with one end being a free end.
FIG. 6 is a view for explaining a sealing structure on the free end side of the hollow fiber membrane filter and the reinforcing core material of FIG. 5.
FIG. 7 is a view for explaining a structure for fixing the hollow fiber membrane filter and the reinforcing core shown in FIG. 5 to the collecting tank.

  Since the upright reinforcing core material 3 is inserted into the hollow fiber membrane filter 2 of the present invention and reinforced, as shown in FIG. 5, each hollow fiber membrane is also a hollow fiber membrane module having one end at a free end. The filter is upright and does not entangle with the adjacent hollow fiber membrane filter.

  At the tip of the free end, the reinforcing core 3 and the hollow fiber membrane filter are hermetically bonded 5 so that the contaminated fluid and the filtered clean fluid do not mix.

The hollow fiber membrane filter 2 inserted into the collecting tank 9 is hermetically bonded to the housing 12 of the collecting tank 9 and fixed to the housing 12.
The reinforcing core member 3 is inserted into a core member insertion hole as shown in the figure of the core member fixing plate 13 fixed in the collecting tank 9 and bonded and fixed.
In the portion where the hollow fiber membrane filter is bonded and fixed to the housing 12, a gap 14 is formed between the hollow fiber membrane filter and the reinforcing core material 3, and the filtered fluid flows into the collecting tank from here.
Needless to say, the means for fixing the reinforcing core 3 in the collecting tank 9 is not limited to the structure shown in this figure, and any means can be used as long as it can be fixed.

Using the single-row hollow fiber membrane module with the structure shown in FIG. 1 to confirm the insertion effect of the core material, the wiping test of the filtration residue under the following test conditions with and without the core material Carried out.
The structure and material of the wiping brush is a stainless steel channel brush with a diameter of 0.3mm, cut to a length of 25mm.
The two stainless steel plates fixed by sandwiching the nylon fiber were attached to the attachment base having the structure shown in FIG. 3 and reciprocated.
In this example, the hollow fiber membrane module is a single-row, horizontal single-row hollow fiber membrane module in a parallel arrangement, and therefore the nylon brush is disposed so as to be sandwiched from both the left and right sides.

[Material of hollow fiber membrane used]
Uses two types of hollow fiber membranes that are widely used. Manufacturers are all manufactured by Kuraray Co., Ltd. Type 1: Polyvinylidene fluoride membrane (PVDF)
Type 2: Polysulfone membrane

A 20A iron pipe is used for the rigid pipe of the support member.
Two types of hollow fiber membrane filters were used: Inner diameter 0.6 mm x Length 500 mm
1.2mm inside diameter x 500mm length

[Structure with core material]
The reinforcing core material was inserted into 20 hollow fiber membrane filters and attached to both ends of the iron pipe with the structure of FIG.
The interval between the hollow fiber membrane filters was 5 mm.
[Inner diameter of hollow fiber membrane and type and diameter of core material]
A hollow fiber membrane with an inner diameter of 0.6 mm uses a piano wire with a diameter of 0.4 mm as the core material.
A hollow fiber membrane with an inner diameter of 1.2 mm uses a 0.8 mm diameter stainless steel wire as the core material.

[Structure without core material]
The hollow fiber membrane filter was directly attached to both ends of the iron pipe with the structure shown in FIG. 2 without passing through the reinforcing core material.
The interval between the hollow fiber membrane filters was 5 mm.

Both ends of the core were inserted into bolts with a through hole in the center and fixed by soldering.
Bolts at both ends were inserted through an iron pipe, stretched, and fixed at both ends with bolts. The hollow fiber membrane was inserted into an iron pipe and hermetically bonded with a silicone adhesive.

[Filtration test]
Only the hollow fiber membrane module part is immersed in an iron tank, the collecting tank part is placed under the tank, and the gap between the bottom of the tank and the iron pipe is filled with putty material and sealed to prevent water leakage. A muddy water containing 1000 ppm of contaminating particles was put in the tank and subjected to a filtration test.
During the filtration, the inside of the collecting tank was subjected to suction filtration with a reduced pressure of 0.1 Torr.
When filtration was continued for 15 minutes, clogging occurred and filtration was impossible.

[Wiping test]
In the case of no backwashing, the number of times of wiping until the hollow fiber membrane filter was ruptured when the residue separated by filtration was tested was investigated.
The moving speed of the wiping brush was 1 reciprocation / 10 seconds.
The results are shown in Table 1.

From the above test results,
It was confirmed that by inserting the core material, there was a remarkable effect in preventing the hollow fiber membrane from being cut.

A test was conducted to confirm the combined effect of backwashing by using backwashing together with wiping.
The test conditions were the same as in Example 1 with the core material.
The conditions for backwashing were injection of pressurized water (2 atm) from the inner diameter side of the hollow fiber membrane filter.
The time interval for pressurizing the water pressure was performed under the following two conditions.
1: Simultaneous use of wiping and backwashing pressure 2: Wiping back and forth for 10 seconds, and then backwashing pressure for 20 seconds. Table 2 shows the test results.

From the above test results,
It was confirmed that the filtration residue could be removed reliably by using backwashing together.
It was confirmed that the back washing was most preferably simultaneous use.

(If one end is free)
The hollow fiber membrane module in which one end of the structure shown in FIG. 5 was a free end was subjected to a filtration test.
The test conditions are as follows.
A PVDF hollow fiber membrane manufactured by Kuraray with an outer diameter of 1.25 mm, an inner diameter of 0.75 mm, and a length of 500 mm was used.
Number of hollow fiber membrane filters: 30 For the reinforcing core material, a piano wire having an outer diameter of 0.5 mm and a length of 500 mm is used.

Insert the piano wire from one end of the hollow fiber membrane and let it go out a little from the other end of the hollow fiber membrane, and the boundary between the hollow fiber membrane and the piano wire on the side where this piano wire is slightly out Adhering hermetically with a silicone adhesive (structure shown in FIG. 6).
As with the structure shown in FIG. 7, the piano wire on the insertion side was inserted into the insertion hole of the iron reinforcing core member fixing plate, and was similarly adhered and fixed with a silicone adhesive.
The iron reinforcing core fixing plate is bonded and fixed to the housing of the collecting tank in the iron collecting tank.
When the hollow fiber membrane filter reinforced with a piano wire was erected as shown in FIG. 5, it was not entangled with each other although there was some deflection.

[Filtration test]
The completed hollow fiber membrane module at one free end was inverted, the free end side was immersed in muddy water, the collecting tank side was depressurized (0.1 torr), and muddy water was filtered.
Clean water filtered from the collecting tank side was obtained.
When filtration was performed for 15 minutes, clogging occurred and the filtration ability was reduced, so filtration was stopped and the hollow fiber membrane module was lifted from the muddy water.
Contaminated particles separated by filtration adhered to the surface of the hollow fiber membrane filter.

  Washing water was sprayed on the hollow fiber membrane filter while applying back pressure by applying water pressure (2 atm), and the filter residue could be removed.

[Removal test of filtration residue when the concentration and porosity of the pollutant particles are changed]
The apparatus of Example 1 is used for the test.
Using turbid water containing 1000 ppm of pollutant particles and high-concentration sludge with a water content of 90%, a removal test of the residue after filtration was performed when the porosity was changed.

The hollow fiber membrane filter used was a polyvinylidene fluoride membrane (PVDF).
Outer diameter 1.25 mm x inner diameter 0.75 mm x length 500 mm.
In order to change the gap between the core material and the hollow fiber membrane, the diameter of the core material was changed as follows.
A piano wire was used as the core material.
When the porosity of the gap between the core material and the hollow fiber membrane is 5%, the core material diameter is 0.8 mm.
When the porosity of the gap between the core material and the hollow fiber membrane is 10%, the core material diameter is 0.7 mm.
When the porosity of the gap between the core material and the hollow fiber membrane is 30%, the core material diameter is 0.6 mm.

The above three types of hollow fiber membrane filters having different porosity are filtered until clogging occurs. For the clogged ones, a brush is used to reversely inject pressurized water (2 atm) into the hollow fiber membrane. Attempts were made to remove residue by wiping repeatedly.
The test conditions were the same as in Example 1 with the core material.

Results of filtration test The results are shown in Table 3.

From the above test results,
When the porosity was less than 10%, it was confirmed that the removal of the residue was difficult even when wiping and back washing were used at the same time.

1. High-concentration polluted water can be drunk.
2. Dehydration treatment from water-containing materials, dehydration from gas, and drying can be performed without using thermal energy. Low cost and extremely excellent energy saving.

FIG. 1 is a diagram illustrating the overall structure of a single-row hollow fiber membrane module having a structure in which both ends of a reinforcing core are fixed. FIG. 2 is a view for explaining a mounting and fixing structure of the hollow fiber membrane filter and the reinforcing core material. FIG. 3 is a diagram illustrating a structure in which the hollow fiber membrane modules of FIG. 1 are stacked in multiple stages, and a mechanism (wiping and cleaning) for physically removing the filtration residue is inserted into the gaps between the stages. FIG. 4 is an explanatory diagram of a plurality of hollow fiber membrane modules arranged in parallel in the vertical and horizontal directions. FIG. 5 is a diagram illustrating the overall structure of the hollow fiber membrane module with one end being a free end. FIG. 6 is a view for explaining a sealing structure on the free end side of the hollow fiber membrane filter and the reinforcing core material of FIG. 5. FIG. 7 is a view for explaining a structure for fixing the hollow fiber membrane filter and the reinforcing core shown in FIG. 5 to the collecting tank.

DESCRIPTION OF SYMBOLS 1 Support member 2 Hollow fiber membrane filter 3 Reinforcing core material 4 Bolt 5 Airtight adhesion 6 Wiping brush 7 Brush mounting shaft 8 Mounting base 9 Collecting tank 10 Belt 11 Roller 12 Collecting tank housing 13 Core material fixing plate 14 Gap

Claims (11)

  A hollow fiber membrane module, which is used for filtering a fluid containing a high concentration of a substance to be filtered, and has a mechanism for physically removing the filtration residue deposited on the surface by the filtration, the hollow fiber membrane module In the hollow fiber membrane filter, a reinforcing core material having a gap communicating with the filter hollow portion in the length direction of the filter is inserted between the filter hollow portion and at least one end of the core material is inserted. A hollow fiber membrane module, wherein the hollow fiber membrane module is fixed to the support member and is arranged upright and in parallel.   The means for physically removing the filtration residue includes a mechanism for wiping and washing the filtration residue, and a mechanism for horizontally moving the wiping and washing mechanism along the length direction of the filter. The hollow fiber membrane module according to claim 1, wherein   A plurality of hollow fiber membrane filters are arranged at intervals, one end of the hollow fiber membrane filter is opened and fixed to the collecting tank, and the other end is hermetically sealed and becomes a free end to be self-supporting. In the hollow fiber membrane module, a reinforcing core material having a gap communicating with the hollow portion inner surface is inserted in the hollow portion of the hollow fiber membrane filter in the length direction of the filter, and the end of the core material is The end of the filter is fixed to the collecting tank while maintaining a gap with the filter, and the core end of the free end of the filter is integrally airtightly joined to the filter. A hollow fiber membrane module comprising:   The hollow fiber membrane module according to any one of claims 1 to 3, wherein a porosity of a gap between the filter inner surface and the reinforcing core is 10% or more.   The hollow fiber membrane module according to any one of claims 1 to 4, wherein the reinforcing core material is a hard wire.   The hollow fiber membrane according to any one of claims 1 to 5, wherein a surface of the reinforcing core material is coated or supported with a catalytic substance or a drug having a sterilizing, sterilizing or deodorizing effect. module. A method of filtering a fluid containing a high concentration of a substance to be filtered through a hollow fiber membrane module and physically removing a filtration residue deposited on the surface of the hollow fiber membrane,
A hollow fiber membrane filter hollow part of the module is inserted into the hollow part inner surface with a reinforcing core material having a gap communicating in the length direction of the filter to reinforce the hollow fiber membrane filter and support member The filter is characterized in that the residue is physically removed by moving means for physically removing the filter residue along the length of the filter. Removal method of hollow fiber membrane module filtration residue.   The method for removing a hollow fiber membrane module filtration residue according to claim 7, wherein a backwashing pressure is applied to the filter when the filtration residue is physically removed.   9. The method for removing a hollow fiber membrane module filtration residue according to claim 8, wherein the reverse cleaning and physical removal are simultaneously used in combination.   10. The filter according to claim 7, wherein the back surface is wet and lubricated by filling a gap between the filter inner diameter and the reinforcing core with a liquid film of liquid. Removal method of hollow fiber membrane module filtration residue. The removal method of the hollow fiber membrane module filtration residue of any one of Claims 7-10 whose porosity of the clearance gap between the said hollow fiber membrane inner surface and the core material for reinforcement is 10% or more.