JP5390499B2 - Hollow fiber membrane module and water treatment apparatus using the same - Google Patents

Description

  The present invention relates to an external pressure type hollow fiber membrane module and a water treatment device used for water purification treatment of river water or the like, or sewage purification treatment by a membrane separation activated sludge method such as sewage and industrial wastewater.

  In recent years, in a sewage purification process using a membrane-separated activated sludge method, the hollow fiber membrane is held so as to extend vertically in the aerobic treated water (activated sludge mixed liquid) in the biological reaction tank. An external pressure type hollow fiber membrane module is obtained which is soaked in and is subjected to solid-liquid separation by membrane filtration of water to be treated by sucking the inside of the hollow fiber membrane to obtain permeated water.

  And as this kind of hollow fiber membrane module, the thing of Unexamined-Japanese-Patent No. 2003-326140 is known. FIG. 7 is a conceptual diagram of this conventional hollow fiber membrane module, and a part thereof is shown in a sectional view. As shown in FIG. 7, the conventional hollow fiber membrane module 70 includes an upper fixing portion 72 and a lower fixing portion 74, and the two fixing portions 72 and 74 are connected and supported by a support rod 76.

  The upper fixing portion 72 is formed by arranging a plurality of hollow fiber membrane bundles 78 in which both ends of a plurality of hollow fiber membranes are bonded around the support rod 76 around the support rod 76. 80 is an integrated configuration. The upper end surface of the hollow fiber membrane bundle 78 is opened. The upper fixing portion 72 has a cap 73 integrated therewith. The cap 73 has a permeate collection chamber 75 therein, and the permeate collection chamber 75 is a permeate outlet. (Or back pressure washing water inlet) 82. On the other hand, the lower end surface of the hollow fiber membrane bundle 78 on the lower fixing portion 74 side is sealed with an adhesive 80.

  The lower fixing portion 74 has an air supply pipe 84 and a plurality of air ejection holes 86. The air ejection holes 86 are provided in the gap or the outer periphery of the hollow fiber membrane bundles 78. In this manner, the hollow fiber membrane bundle 78 is cleaned by air scrubbing through the air ejection holes 86 provided in the lower fixing portion 74.

  The hollow fiber membrane module 70 configured as described above is used by being immersed in a standing posture while holding the hollow fiber membrane in the biological water in the biological reaction tank so as to extend in the vertical direction. And at the time of filtration operation, it filters by the suction pump connected to the permeate outlet 82. Water to be treated flows from the outer surface of the hollow fiber membrane constituting the hollow fiber membrane bundle 78 into the internal space and is filtered, and the permeated water obtained passes through the hollow fiber membrane and passes over the hollow fiber membrane bundle 78. After being discharged from the end face side and flowing into the liquid collection chamber 75, it is discharged from the permeate outlet 82.

  When the filtration operation is continued for a long time, the suspended substance adheres to the surface of the hollow fiber membrane and the filtration performance deteriorates. Therefore, the air supply pipe 84 and the air ejection hole provided in the lower fixing portion 74 No. 86 is used to remove suspended substances (deposits) adhering to the membrane surface by performing air scrubbing as needed or during filtration operation at all times.

JP 2003-326140 A (FIGS. 1 and 2)

  However, in the above-described conventional hollow fiber membrane module 70, even if air scrubbing is performed by the air supply pipe 84 and the air ejection hole 86 provided in the lower fixing portion 74, fibrous contamination such as hair is increased over time. The matter adheres to or entangles with the roots of the hollow fiber membrane bundles 78 exposed from the upper fixing portion 72, and the accumulation of contaminants is likely to occur. The amount of permeated water is reduced by reducing the effective membrane area due to the accumulation of contaminants. So there was room for improvement in this regard.

  Then, the subject of this invention is equipped with the upper side fixing | fixed part to which the upper end part of a hollow fiber membrane is fixed, and the lower side fixing | fixed part to which the lower end part of the said hollow fiber membrane is fixed, and each hollow fiber membrane is made into an up-down direction. In hollow fiber membrane modules that are held so as to be stretched and immersed in the water to be treated, it is difficult for sediment to accumulate near the base of each hollow fiber membrane exposed from the upper fixed part, and stable filtration performance is demonstrated over a long period of time. An object of the present invention is to provide a hollow fiber membrane module that can be used. Another object of the present invention is to provide a water treatment apparatus capable of stably treating water over a long period of time.

  In order to solve the above problems, the present invention takes the following technical means.

According to a first aspect of the present invention, an upper fixing portion that is fixed in a state in which an upper end portion of the hollow fiber membrane is opened at the end of the hollow fiber membrane, and a lower end portion of the hollow fiber membrane that is sealed at the end of the hollow fiber membrane. A plurality of hollow fiber membrane modules that are fixed and have a lower fixing portion having a plurality of air introduction holes for air scrubbing and that are each immersed in the water to be treated while holding each hollow fiber membrane extending in the vertical direction. A plurality of hollow fiber membrane bundles, in which the hollow fiber membranes are joined at the upper end, are arranged on the radiation centered on the radial center of the upper fixing portion and fixed to the upper fixing portion. This is a hollow fiber membrane module.

The second invention is a water treatment apparatus comprising the hollow fiber membrane module of the first invention .

A hollow fiber membrane module according to a first aspect of the present invention includes a plurality of hollow fiber membrane bundles in which a plurality of hollow fiber membranes are joined at an upper end portion, arranged on a radiation centered on the radial center of the upper fixed portion. It is fixed to the upper fixed part. Therefore, the rising bubbles for air scrubbing and the rising flow of the water to be treated due to the rising bubbles rise while peeling impurities on the surface of the hollow fiber membrane, approach the upper fixing portion, and face each other arranged on the radiation. It is guided to the region between the matching hollow fiber membrane bundle rows, flows in the region that becomes wider as it goes outward in the radial direction from the center, and flows to the outer side in the radial direction without being blocked. As a result, it is possible to prevent the accumulation of impurities in the vicinity of the roots of the hollow fiber membrane bundles exposed from the upper fixing part, so that the effective membrane area is prevented from decreasing and the filtration performance is stably demonstrated for a long period of time. be able to.

According to the water treatment apparatus of the second aspect of the invention , since the hollow fiber membrane module is provided, the interval between membrane module washing can be extended compared to the conventional case, and the water treatment can be performed stably over a long period of time. Is possible.

It is sectional drawing which shows the structure of one Embodiment of the hollow fiber membrane module of this invention. It is a top view which shows arrangement | positioning of the hollow fiber membrane bundle fixed to the upper side fixing | fixed part in FIG. It is a top view which shows arrangement | positioning of the air introduction hole provided in the lower side fixing | fixed part in FIG. It is sectional drawing which shows the structure of another embodiment of the hollow fiber membrane module of this invention. It is composition explanatory drawing which shows one Embodiment of the water treatment apparatus of this invention. It is a structure explanatory view showing another embodiment of the water treatment equipment of the present invention. It is a conceptual diagram of the conventional hollow fiber membrane module.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of an embodiment of the hollow fiber membrane module of the present invention, FIG. 2 is a plan view showing the arrangement of hollow fiber membrane bundles fixed to the upper fixing part in FIG. 1, and FIG. It is a top view which shows arrangement | positioning of the air introduction hole provided in the lower side fixing | fixed part in FIG.

  As shown in FIG. 1, the hollow fiber membrane module 10 includes a lower fixing portion 20, an upper fixing portion 30 positioned above the lower fixing portion 20 with a predetermined interval, a lower fixing portion 20 and an upper side. A plurality of support members (not shown) extending in the vertical direction to support the fixing portion 30 while maintaining their spacing, and the lower end portion is fixed to the lower fixing portion 20 with its membrane end sealed, The upper end portion is constituted by a plurality of hollow fiber membranes 11 fixed to the upper fixing portion 30 with the membrane end opened. A plurality of hollow fiber membranes 11 extending in the vertical direction are formed into a plurality of hollow fiber membrane bundles 12 on the upper fixing portion 30 side, in which a predetermined number of hollow fiber membranes 11 are bundled and bonded together at the upper end. A plurality of hollow fiber membrane bundles 12 are fixed to the upper fixing portion 30.

  The upper fixing portion 30 includes a cylindrical body 31, a circular upper plate 32 having a permeate outlet 32a and attached to the upper side of the cylindrical body, and a circular lower plate 33 having a membrane bundle through hole and attached to the lower side of the cylindrical body. It is comprised by. As shown in FIG. 2, a plurality of hollow fiber membrane bundles 12 are included inside the upper fixing portion 30 in terms of radiation centering on the radial center of the upper fixing portion 30, in this embodiment, including the radial center position. Are arranged on the eight radiations L <b> 1 to L <b> 8 and fixed to the upper fixing part 30. Reference numeral 12 a denotes a hollow fiber membrane bundle binding portion in which a plurality of hollow fiber membrane bundles 12 are bonded with an adhesive, and 34 denotes an adhesive portion that fixes the hollow fiber membrane bundle 12 to the upper fixing portion 30. When assembling the upper fixing portion 30, the hollow fiber membrane bundle 12 is passed through the respective membrane bundle through holes of the circular lower plate 33, and then the hollow space between the hollow fiber membrane bundles 12 is filled with an adhesive so as to be hollow in the cylindrical body 31. The thread membrane bundle 12 is bonded and fixed, and then the circular lower plate 33 is attached to the cylindrical body 31.

  A water collection chamber 35 is formed in the upper portion of the upper fixing portion 30, and the permeated water collection chamber 35 is formed in the opening at the upper end of the hollow fiber membrane 11 constituting each hollow fiber membrane bundle 12. It communicates and is defined by the lower surface of the circular upper plate 32, the inner wall surface of the cylindrical body 31, the upper end surface of the hollow fiber membrane bundle 12, and the adhesive portion 34. A pipe from a suction pump installed outside the biological reaction tank is connected to the permeate outlet 32 a connected to the water collection chamber 35.

  Further, the lower fixing portion 20 has a cylindrical body 21 having the same inner diameter as the cylindrical body 31 of the upper fixing portion 30 and eight air introduction holes 23 in the present embodiment for air scrubbing. The air scrubbing bubble releasing member 22 (hereinafter simply referred to as a bubble releasing member) 22 is formed in a disk shape attached to the upper portion of the inside 21.

  As shown in FIG. 3, the eight air introduction holes 23 in the bubble discharge member 22 are radiations L1 ′ to L8 ′ whose phases are shifted from the radiations L1 to L8 in the upper fixing part 30 by an angle of 22.5 °. They are provided at a predetermined distance from the center in the radial direction. That is, the air introduction hole 23 is provided at a position in the lower fixing portion 20 corresponding to a position between the 12 rows of mutually facing hollow fiber membrane bundles arranged on the radiations L1 to L8 in the upper fixing portion 30. Yes. Unlike the example shown in FIG. 3, a plurality of air introduction holes 23 may be provided at each of the positions (one in each of the positions shown in FIG. 3).

  On the upper surface of the bubble releasing member 22, the lower end portion of the hollow fiber membrane 11 forming the hollow fiber membrane bundle 12 is distributed almost uniformly in the portion other than the air introduction hole 23 to seal the end of the hollow fiber membrane. In this state, the adhesive is fixed. Further, a tip portion of an air scrubbing air supply pipe 25 from a blower installed outside the biological reaction tank is positioned on the lower end side of the cylindrical body 21. Air is pressed into the cylindrical body 21 from the air scrubbing air supply pipe 25 so that air from the air reservoir 24 below the bubble release member 22 is discharged as bubbles from the air introduction hole 23 into the water to be treated. Yes. Then, the deposits on the surface of the hollow fiber membrane are removed by the collision of the bubbles with the hollow fiber membrane 11 and the upward flow of the water to be treated by the rising bubbles.

  Thus, the hollow fiber membrane module 10 according to the present embodiment has a plurality of hollow fiber membrane bundles 12 in which a plurality of hollow fiber membranes 11 are coupled at the upper end as a center in the radial direction of the upper fixing portion 30. It arrange | positions on a radiation and it fixes to this upper side fixing | fixed part 30 (cylindrical body 31). Therefore, ascending bubbles for air scrubbing, and the rising flow of the water to be treated due to the rising bubbles rise while peeling foreign matter and sludge on the surface of the hollow fiber membrane, approach the upper fixing part 30, and on the radiations L1 to L8 The upper fixing portion 30 is guided to the region between the arranged hollow fiber membrane bundle rows that are arranged and flows radially outward without being blocked in the region that becomes wider radially outward from the center. To the outside. As a result, it is possible to prevent accumulation of contaminants and sludge in the vicinity of the roots of the hollow fiber membrane bundles 12 exposed from the upper fixing portion 30, so that the effective membrane area can be prevented from decreasing and filtered stably for a long period of time. Performance can be demonstrated.

  In this case, as shown in FIG. 3, the air introduction hole 23 of the lower fixing portion 20 is positioned at a position between the mutually facing hollow fiber membrane bundle rows arranged on the radiations L1 to L8 in the upper fixing portion 30. By providing at the position in the corresponding lower fixing part 20, the rising flow of the rising water and the treated water due to the rising bubble between the hollow fiber membrane bundle rows facing each other fixed to the upper fixing part 30. It is possible to reliably lead to the area.

  FIG. 4 is a cross-sectional view showing the configuration of another embodiment of the hollow fiber membrane module of the present invention. Here, since it is the same structure as the hollow fiber membrane module shown by the said FIGS. 1-3 except that the upper side fixing | fixed part 30 'is equipped with the water flow direction change member (inverse conical lower board 36), both are common The same reference numerals are given to the parts to be described, and the description is omitted.

  As shown in FIG. 4, the upper fixing portion 30 ′ includes an inverted conical lower plate 36 having a membrane bundle through hole and attached to the lower side of the cylindrical body 31. The inverted conical lower plate 36 has an upward inclined surface from the center portion toward the outer peripheral portion, and a water flow direction changing member that guides the rising flow for air scrubbing and the upward flow of the water to be treated by the rising bubble to the outside. Is configured.

  As described above, in the hollow fiber membrane module 10 ′ according to the present embodiment, the upper fixing portion 30 that fixes the hollow fiber membrane bundle 12 by placing it on the radiation has an inverted cone as a water flow direction changing member on the lower surface side. The lower plate 36 is provided. Accordingly, the rising bubbles and the rising flow of the water to be treated due to the rising bubbles approach the upper fixing portion 30 and are guided to the region between the mutually facing hollow fiber membrane bundle rows arranged on the radiation. After reaching 30, the inverted conical lower plate 36 ensures that the region flows radially outward and is guided out of the upper fixing portion 30. Thereby, accumulation of impurities and sludge near the roots of the hollow fiber membrane bundles 12 exposed from the upper fixing portion 30 can be more reliably prevented.

  Although the plate member having an inverted conical shape is used as the water flow direction changing member, a plate member having an inverted frustoconical shape may be used.

  FIG. 5 is a configuration explanatory view showing an embodiment of the water treatment apparatus of the present invention.

  In this embodiment, the water treatment apparatus 40 performs water purification treatment of river water that is to-be-treated water. As shown in FIG. 5, the water treatment device 40 is immersed in the for-treatment water tank 42 to which the for-treatment water (river water) is supplied from the for-treatment water supply line 41 and the for-treatment water in the for-treatment water tank 42. A plurality of hollow fiber membrane modules 10 ′ (hollow fiber membrane modules having the configuration shown in FIG. 4) arranged in this manner, and connected to these hollow fiber membrane modules 10 ′ and having a suction pump 43a, the suction pump A hollow fiber membrane module 10 'having a permeate water extraction line 43 for performing solid-liquid separation by membrane filtration of the water to be treated by suctioning the inside of the hollow fiber membrane by 43a and taking out permeate water, and a blower 44a. An air scrubbing air supply line 44 for supplying air scrubbing air and a sludge discharge line 45 for discharging sludge in the water tank 42 to be treated are provided.

  In FIG. 5, 43b is a water collection pipe connected to the permeate outlet 32a of each hollow fiber membrane module 10 ', 43c is a water collection header pipe communicating with each water collection pipe 43b, and 43d is a permeate take-out pipe. The water collection pipe 43b, the water collection header pipe 43c, the permeate water take-out pipe 43d, and the suction pump 43a constitute a permeate water take-out line 43. 44b is an air supply pipe for supplying air pressurized by the blower 44a, 25 is branched from the air supply pipe 44b, and the tip portion thereof is positioned on the lower end side of the cylindrical body 21 of each hollow fiber membrane module 10 ′. An air scrubbing air supply pipe (see FIGS. 1 and 4). The blower 44 a, the air supply pipe 44 b, and the air scrubbing air supply pipe 25 constitute an air scrubbing air supply line 44. Each hollow fiber membrane module 10 'is installed such that the inverted conical lower plate 36 of the upper fixing portion 30' is located below the water surface (in FIG. 5, the entire membrane module is completely immersed). ing).

  According to the water treatment apparatus 40 configured as described above, since the above-described hollow fiber membrane module 10 'is provided, the interval between membrane module cleaning can be extended compared to the conventional case, and stable for a long period of time. Water purification treatment can be performed.

  FIG. 6 is a configuration explanatory view showing another embodiment of the water treatment apparatus of the present invention.

  In this embodiment, the water treatment apparatus 50 performs sewage purification treatment of water to be treated containing organic substances such as sewage and wastewater by a membrane separation activated sludge method. As shown in FIG. 6, the water treatment device 50 includes a biological reaction tank 52 as a water tank to be treated to which primary treated water is supplied from a water supply line 51 to be treated, and water to be treated in the biological reaction tank 52 ( A plurality of hollow fiber membrane modules 10 ′ (hollow fiber membrane modules having the structure shown in FIG. 4) arranged soaked in the activated sludge mixed solution), and suction pumps connected to these hollow fiber membrane modules 10 ′. And a permeated water take-out line 53 for taking out permeated water by performing solid-liquid separation by membrane filtration of water to be treated by suctioning the inside of the hollow fiber membrane by the suction pump 53a. Further, the water treatment device 50 has a blower 54 a and an air scrubbing air supply line 54 for supplying air scrubbing air to the hollow fiber membrane module 10 ′, and the hollow fiber membrane module 10 in the biological reaction tank 52. An air diffuser 56 disposed below 'and a sludge discharge line 55 for discharging sludge in the biological reaction tank 52 are provided.

  The permeated water extraction line 53 includes a water collection pipe 53b, a water collection header pipe 53c, a permeated water extraction pipe 53d, and a suction pump 53a. The air scrubbing air supply line 54 includes a blower 54 a, an air supply pipe 54 b, and an air scrubbing air supply pipe 25. In this embodiment, the air diffuser 56 is supplied with the pressurized air from the blower 54a via a pipe branched from the air supply pipe 54b. The air diffuser 56 performs activated sludge treatment (aerobic treatment) by supplying oxygen with air bubbles (air) diffused from the air diffuser holes, and generates an upward flow generated by the air lift action of the air bubbles to the hollow fiber membrane module. It is for acting on the film surface of 10 'and also performing film surface cleaning. Each hollow fiber membrane module 10 'is installed such that the inverted conical lower plate 36 of the upper fixing portion 30' is positioned below the water surface (in FIG. 6, the entire membrane module is completely immersed). ing).

  According to the water treatment device 50 configured as described above, since the hollow fiber membrane module 10 ′ described above is provided, the interval between membrane module cleaning can be extended as compared with the conventional case, and stable for a long period of time. Thus, the sewage purification treatment by the membrane separation activated sludge method can be performed.

DESCRIPTION OF SYMBOLS 10,10 '... Hollow fiber membrane module 11 ... Hollow fiber membrane 12 ... Hollow fiber membrane bundle 12a ... Hollow fiber membrane bundle coupling | bond part 20 ... Lower side fixing | fixed part 21 ... Cylinder 22 ... Bubble release member for air scrubbing 23 ... Air introduction Hole 24 ... Air reservoir 25 ... Air scrubbing air supply pipe 30, 30 '... Upper fixing part 31 ... Cylindrical body 32 ... Circular upper plate 32a ... Permeate outlet 33 ... Circular lower plate 34 ... Adhesive part 35 ... Water collecting chamber 36 ... Reverse conical lower plate 40 ... Water treatment device 42 ... Water tank 43 ... Permeate take-out line 44 ... Air scrubbing air supply line 50 ... Water treatment device 52 ... Biological reaction tank 53 ... Permeate take-out line 54 ... Air Scrubbing air supply line 56 ... Air diffuser

Claims (3)

An upper fixing portion that is fixed with the upper end portion of the hollow fiber membrane being opened at the end of the hollow fiber membrane, and a lower end portion of the hollow fiber membrane that is fixed with the end of the hollow fiber membrane being sealed, for air scrubbing A hollow fixing module having a plurality of air-introducing holes, and holding the hollow fiber membranes so as to extend in the vertical direction and immersing them in the water to be treated. A plurality of bundles of hollow fiber membranes bonded at the portion are arranged on the radiation centered on the radial center of the upper fixing portion and fixed to the upper fixing portion;
The air introduction hole is provided at a position in the lower fixing portion corresponding to a position between the rows of the hollow fiber membrane bundles in the upper fixing portion,
The hollow fiber membrane module, wherein the upper fixing portion has an upward inclined surface that is inclined upward from a radial center portion of the upper fixing portion toward an outer peripheral portion.   A water treatment apparatus comprising the hollow fiber membrane module according to claim 1. A blower for supplying the air scrubbing air to the lower fixed portion;
An air diffuser disposed below the hollow fiber membrane module and supplied with air from the blower,
The water treatment apparatus of Claim 2 provided with.