Aeration component, MBR hollow fiber membrane component for water treatment

Abstract

The invention discloses an aeration component and an MBR hollow fiber membrane component for water treatment. The membrane component comprises at least two curtains of hollow fiber membranes for water treatment, an aeration main pipe and an aeration branch pipe component respectively arranged between two adjacent membrane curtains. The aeration branch pipe component comprises a first aeration pipe and a plurality of second aeration pipes respectively connected with the aeration main pipe. The first aeration pipe is provided with a plurality of parallel aeration holes, wherein the plurality of aeration holes have at least two groups of aeration holes of a first aperture which are arranged oppositely and at least two groups of aeration holes of a second aperture which are arranged oppositely. The second aeration pipe is provided with a plurality of aeration holes of a third aperture. By controlling the aperture size and orientation of each hole, the membrane component of the invention can have the advantages of uniform aeration, saving aeration energy consumption, high biochemical treatment efficiency, good pollution resistance and long service life while being highly efficient and energy-saving.

Description

[0001] This invention is a divisional application of the Chinese invention patent application with application date of November 23, 2021, application number 2021113934688, and name “A MBR hollow fiber membrane component”. Technical Field

[0002] The invention belongs to the technical field of separation membrane preparation, and specifically relates to an aeration component and an MBR hollow fiber membrane component for water treatment, which can have the advantages of uniform aeration, saving aeration energy consumption, high biochemical treatment efficiency, good pollution resistance and long service life while being highly efficient and energy-saving. Background Art

[0003] As water pollution becomes increasingly serious, the requirements for wastewater treatment and discharge are becoming increasingly higher. Membrane separation technology has the advantages of high water quality and high degree of automation, and has become the preferred choice for wastewater treatment upgrading and water reuse. In particular, the MBR technology that combines biochemical treatment technology and membrane separation technology has received increasing attention, among which hollow fiber membrane modules are increasingly used due to their high packing density and large specific surface area. However, since the wastewater in the MBR membrane pool contains a large amount of pollutants and the sludge concentration is high, the water treatment hollow fiber membrane is quickly contaminated during use, and the separation performance of the water treatment hollow fiber membrane decreases rapidly. Therefore, it is necessary to continuously or intermittently aerate the water treatment hollow fiber membrane during the filtration process to shake off and clean the pollutants on the surface of the water treatment hollow fiber membrane, so that the water treatment hollow fiber membrane maintains good long-term separation performance. Among them, too low aeration volume cannot achieve a cleaning effect on the hollow fiber membrane filaments for water treatment, and cannot meet the biochemical oxygen demand of biochemical bacteria, but too high aeration volume has the following disadvantages: 1) Too high aeration volume will destroy the structure of the sludge flocs, increase the fine sludge particles in the wastewater, and stimulate the dissolution of extracellular polymers (EPS), aggravate biological pollution, and increase the ratio of membrane pollution and irreversible membrane pollution; 2) and because the sludge flocs are destroyed and the biochemical bacterial colonies are broken up, the concentration of pollutants near the biochemical bacteria, especially the concentration of difficult-to-degrade small molecules, is reduced, which leads to a decrease in the degradation efficiency of the biochemical bacteria; 3) In addition, too large aeration volume will cause the hollow fiber membrane filaments for water treatment to break, causing them to completely lose their separation function; 4) If the aeration volume is too large, the energy consumption of the system operation will increase.

[0004] Traditional membrane module aeration generally adopts perforated aeration at the bottom of the membrane module, but this aeration method has the problems of uneven aeration and insufficient cleaning power. Usually, in order to achieve the cleaning effect of the membrane filaments, the aeration volume of this aeration method is very large, which leads to the breakage of the water treatment hollow fiber membrane filaments at the root, aggravates the biological pollution of the membrane, reduces the biochemical degradation efficiency in the MBR pool, and the aeration energy consumption is very high, accounting for about 40-80% of the energy consumption of the entire treatment system. In addition, since the water treatment hollow fiber membrane filaments can only be aerated at the bottom of the membrane module, the aeration volume of the entire water treatment hollow fiber membrane filaments from top to bottom is uneven, the aeration volume at the bottom of the water treatment hollow fiber membrane filaments is large, and the water treatment hollow fiber membrane filaments are easy to break at the bottom, but the aeration volume at the top of the water treatment hollow fiber membrane filaments is still small, and it is difficult to achieve a cleaning effect. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a novel MBR hollow fiber membrane component, which is not only highly efficient and energy-saving, but also has the advantages of uniform aeration, saving aeration energy consumption, high biochemical treatment efficiency, good pollution resistance and long service life.

[0006] To achieve the above object, the technical solution adopted by the present invention is: an MBR hollow fiber membrane assembly, comprising: at least two water treatment hollow fiber membrane curtains arranged in parallel with each other, an aeration main pipe arranged at the bottom of the water treatment hollow fiber membrane curtains;

[0007] The MBR hollow fiber membrane assembly also includes an aeration branch pipe assembly respectively arranged between the two adjacent water treatment hollow fiber membrane curtains, the aeration branch pipe assembly includes a first aeration pipe and a plurality of second aeration pipes respectively connected to the aeration main pipe, the plurality of second aeration pipes are arranged on the left and right sides of the first aeration pipe, and the second aeration pipe is flexible;

[0008] Wherein, the first aeration tube is provided with a plurality of parallel aeration holes along its own extension direction, wherein the plurality of aeration holes include at least two groups of aeration holes of a first aperture arranged oppositely and at least two groups of aeration holes of a second aperture arranged oppositely;

[0009] The second aeration tubes are respectively provided with a plurality of groups of aeration holes with a third aperture;

[0010] The aperture of the first aperture aeration holes is larger than that of the third aperture aeration holes, the first aperture aeration holes face the second aeration tubes, the second aperture aeration holes face the water treatment hollow fiber membrane curtain, and the multiple groups of third aperture aeration holes include at least one group of third aperture aeration holes that independently face the first aperture aeration holes and the water treatment hollow fiber membrane curtain.

[0011] In the present invention, since the first aeration tube is provided on the membrane assembly, and the second aperture aeration hole on the first aeration tube can perform aeration and cleaning on the water treatment hollow fiber membrane curtain facing it, and the first aperture aeration hole facing the second aeration tube can expose a low-density large bubble flow (relatively large aperture), and form a circulation with the high-density small bubble flow exposed by the second aeration tube, the pressure difference generated by the rise and burst of the large bubble is filled by the small bubble and the mixed liquid driven by it, thereby increasing the movement of the activated sludge in the membrane pool and the turbulence degree of the mixed liquid driven by the bubble, thereby increasing the shaking of the water treatment hollow fiber membrane wire, and generating a stronger inclined cutting force on the surface of the water treatment hollow fiber membrane wire, so that the pollutants are easier to fall off from the surface of the water treatment hollow fiber membrane wire, improving the cleaning degree of the water treatment hollow fiber membrane wire, and improving the anti-pollution property of the entire membrane assembly. In addition, the large bubble flow exposed by the first aeration tube combined with the small bubble flow aerated by the second aeration tube can flush the sludge out of the membrane assembly, reduce the sludge concentration in the membrane assembly, and thus improve the anti-pollution property of the membrane assembly.

[0012] In the present invention, each group of aeration holes of the first aperture, each group of aeration holes of the second aperture, and each group of aeration holes of the third aperture independently include a plurality of aeration holes.

[0013] According to some preferred aspects of the present invention, the holes in each group of first aperture aeration holes, each group of second aperture aeration holes and each group of third aperture aeration holes may be arranged at equal intervals and evenly distributed on the first aeration tube or the second aeration tube.

[0014] According to some preferred aspects of the present invention, the extending direction of the first aeration tube and the extending direction of the second aeration tube are respectively parallel to the extending direction of the water treatment hollow fiber membrane curtain.

[0015] According to some preferred aspects of the present invention, the first aeration tube is located in the middle of the membrane assembly, and the plurality of second aeration tubes are arranged on the left and right sides of the first aeration tube and are evenly distributed.

[0016] According to some preferred aspects of the present invention, the diameter of the aeration holes of the first diameter is in the millimeter order, and the diameter of the aeration holes of the third diameter is in the micrometer order.

[0017] According to some preferred aspects of the present invention, the diameter of the aeration holes of the first diameter is more than 10 times the diameter of the aeration holes of the third diameter.

[0018] Furthermore, the aperture of the aeration holes of the first aperture is more than 20 times the aperture of the aeration holes of the third aperture.

[0019] According to some preferred and specific aspects of the present invention, the diameter of the first diameter aeration holes is 1 mm-10 mm, the diameter of the second diameter aeration holes is 0.1 mm-2 mm, and the diameter of the third diameter aeration holes is 0.5 μm-50 μm.

[0020] In some embodiments of the present invention, the aperture of the aeration holes of the second aperture size is larger than the aperture of the aeration holes of the third aperture size and smaller than the aperture of the aeration holes of the first aperture size.

[0021] According to some preferred aspects of the present invention, the diameter of the first aeration tube is greater than the diameter of the second aeration tube.

[0022] According to some preferred aspects of the present invention, the material of the first aeration tube is stainless steel or PVC-U. PVC-U is also called hard PVC, which is an amorphous thermoplastic resin made by polymerization of vinyl chloride monomer and certain additives (such as stabilizers, lubricants, fillers, etc.), and is commercially available.

[0023] According to some preferred aspects of the present invention, the second aeration tube includes an inner lining tube and a polyvinylidene fluoride film layer coated on the outer surface of the inner lining tube, the inner lining tube is a polyethylene terephthalate braided tube or a polyethylene terephthalate knitted tube, and the third aperture aeration holes are formed on the inner lining tube and the polyvinylidene fluoride film layer.

[0024] Furthermore, the outer diameter of the second aeration tube is 1 mm-10 mm, and the thickness of the polyvinylidene fluoride membrane layer is 10 μm-200 μm.

[0025] In some embodiments of the present invention, the second aeration tube is a PVDF composite hollow fiber membrane (an inner liner tube and a polyvinylidene fluoride membrane layer coated on the outer surface of the inner liner tube) prepared by a wet phase conversion method, and the third aperture aeration holes are formed during the process of preparing the membrane by a wet phase conversion method.

[0026] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0027] (1) Since the aeration branch pipe assembly is distributed between every two curtains of the water treatment hollow fiber membrane and can be parallel to them, each part of the water treatment hollow fiber membrane, such as the upper, middle and lower parts, can be evenly aerated, and only a small aeration volume is required to achieve a cleaning effect on each part of the water treatment hollow fiber membrane. Therefore, the total aeration volume and local aeration volume of the entire membrane assembly will be reduced, thereby reducing aeration energy consumption, reducing the breakage rate of the water treatment hollow fiber membrane, and increasing the service life of the water treatment hollow fiber membrane.

[0028] (2) Since the total aeration volume and local aeration volume are reduced, and the aeration aperture of the second aeration tube is smaller, the bubbles aerated are smaller, and the cutting and destructive force on the sludge flocs and biochemical colonies is smaller, thereby reducing the concentration of small particle sludge and extracellular polymers dissolved in the wastewater, thereby reducing the probability of membrane fouling and the irreversible biological fouling rate, thereby improving the anti-fouling ability of the membrane assembly.

[0029] (3) Since the bubbles emitted by the second aeration tube are smaller, the cutting and destructive power on the sludge flocs and biochemical bacterial colonies is smaller, and the concentration of pollutants near the biochemical bacteria, especially the concentration of small molecules that are difficult to degrade, is higher, thereby improving the biochemical degradation efficiency of pollutants by biochemical bacteria, improving the water quality of the MBR system and reducing the probability of membrane pollution.

[0030] (4) Since the first aeration tube is provided on the membrane assembly, and the second aperture aeration holes on the first aeration tube can aerate and clean the water treatment hollow fiber membrane curtain facing it, and the first aperture aeration holes (relatively large aperture) facing the second aeration tube can expose a low-density large bubble flow, forming a circulation with the high-density small bubble flow exposed by the third aperture aeration holes (relatively small aperture) of the second aeration tube, the pressure difference generated by the rise and burst of large bubbles is filled by the small bubbles and the mixed liquid driven by them, thereby increasing the movement of activated sludge in the membrane pool and the turbulence of the mixed liquid driven by the bubbles, thereby increasing the shaking of the water treatment hollow fiber membrane fibers, and generating a stronger inclined cutting force on the surface of the water treatment hollow fiber membrane fibers, so that pollutants are easier to fall off from the surface of the water treatment hollow fiber membrane fibers, thereby improving the cleaning degree of the water treatment hollow fiber membrane fibers and improving the anti-pollution property of the entire membrane assembly. In addition, the large bubble flow aerated from the first aeration tube combined with the small bubble flow aerated from the second aeration tube can flush the sludge out of the membrane module, reduce the sludge concentration in the membrane module, and thus improve the anti-pollution performance of the membrane module.

[0031] In summary, the MBR hollow fiber membrane assembly with a specific structure of the present invention can not only uniformly aerate different parts of the water treatment hollow fiber membrane fibers and achieve a cleaning effect on the surface of the water treatment hollow fiber membrane fibers, but also can save aeration energy consumption without reducing the biochemical efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 Schematic diagram of top view and cross section of an MBR hollow fiber membrane assembly according to an embodiment of the present invention;

[0034] Figure 2 AA cross-sectional schematic diagram of an MBR hollow fiber membrane assembly according to an embodiment of the present invention;

[0035] Figure 3 BB is a cross-sectional schematic diagram of an MBR hollow fiber membrane assembly according to an embodiment of the present invention;

[0036] Figure 4 For attachment Figure 2 An enlarged schematic diagram of a local C;

[0037] Figure 5 For attachment Figure 2 An enlarged schematic diagram of a local D;

[0038] Figure 6 This is a schematic diagram of the structure of the aeration branch pipe assembly in the MBR hollow fiber membrane assembly according to an embodiment of the present invention (the water treatment hollow fiber membrane curtain, etc. are hidden);

[0039] Figure 7 for Figure 6 A magnified schematic diagram of the local E in the middle;

[0040] In the above figures: 1, hollow fiber membrane; 21, upper fixed end; 22, first aeration tube fixing slot; 31, lower fixed end; 32, first aeration tube hole; 41, aeration main pipe; 42, first aeration tube; 43, second aeration tube; 44, first aperture aeration hole; 45, second aperture aeration hole; 46, third aperture aeration hole; 51, water production pipe; 52, membrane assembly joint. DETAILED DESCRIPTION

[0041] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0042] In the description of the present invention, "multiple roots" means at least two roots, such as two roots, three roots, etc., unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the invention, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0045] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be an intermediate element at the same time.

[0046] The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0047] At present, most MBR hollow fiber membrane components use bottom perforated aeration to aerate and clean the water treatment hollow fiber membrane fibers. However, the aeration volume of this aeration method must be relatively large to achieve a cleaning effect on the surface of the water treatment hollow fiber membrane fibers. Therefore, the aeration energy consumption is high, and the aeration is uneven. The water treatment hollow fiber membrane fibers are prone to breakage at the bottom, while the upper part of the water treatment hollow fiber membrane fibers cannot achieve a cleaning effect. In addition, the biochemical efficiency in the MBR membrane pool is low, and due to the dissolution of small particle sludge and extracellular polymers, the ratio of membrane pollution and irreversible pollution is aggravated. Based on this, the present invention provides an efficient and energy-saving MBR hollow fiber membrane component, which aerates the water treatment hollow fiber membrane filaments in an aeration manner that combines a second aeration tube and a first aeration tube that are evenly distributed between every two curtains of water treatment hollow fiber membrane membrane curtains, so that each part of the water treatment hollow fiber membrane filaments is evenly aerated, and while achieving the membrane surface cleaning effect, the total aeration amount and the local aeration amount are reduced, thereby saving aeration energy consumption, improving the biochemical efficiency in the membrane pool, reducing the water treatment hollow fiber membrane filament breakage rate, and reducing the membrane pollution and irreversible pollution ratio, thereby improving the service life of the membrane component.

[0048] Specifically, Figure 1-7 As shown, this example provides an MBR hollow fiber membrane assembly, which includes: an upper fixed end 21, a lower fixed end 31, a water production pipe 51 connected to the upper fixed end 21, an aeration main pipe 41 connected to the lower fixed end 31, a membrane assembly joint 52, and at least two water treatment hollow fiber membrane curtains respectively arranged between the upper fixed end 21 and the lower fixed end 31 and arranged in parallel with each other, the water treatment hollow fiber membrane curtain is composed of a plurality of hollow fiber membrane filaments 1, the upper end of the hollow fiber membrane curtain is fixed on the upper fixed end 21, and the lower end of the hollow fiber membrane curtain is fixed on the lower fixed end 31, that is, the aeration main pipe 41 is arranged at the bottom of the water treatment hollow fiber membrane curtain.

[0049] Furthermore, the MBR hollow fiber membrane assembly also includes an aeration branch pipe assembly respectively arranged between two adjacent water treatment hollow fiber membrane curtains, that is, an aeration branch pipe assembly is arranged between each two adjacent water treatment hollow fiber membrane curtains, and the aeration branch pipe assembly includes a first aeration pipe 42 and a plurality of second aeration pipes 43 respectively connected to the aeration main pipe 41, and the plurality of second aeration pipes 43 are arranged on the left and right sides of the first aeration pipe 42, and the second aeration pipe 43 is flexible, and the flexible second aeration pipe 43 can give itself a vibration during the aeration process, and then can infinitely approach or even directly contact the water treatment hollow fiber membrane curtain, and can better remove sludge on the water treatment hollow fiber membrane curtain without causing damage to the water treatment hollow fiber membrane curtain;

[0050] The first aeration tube 42 is provided with a plurality of parallel aeration holes along its own extension direction, wherein the plurality of aeration holes include at least two groups of aeration holes 44 of the first aperture arranged oppositely and at least two groups of aeration holes 45 of the second aperture arranged oppositely.

[0051] The second aeration pipe 43 is provided with a plurality of aeration holes 46 of a third aperture.

[0052] The aperture of the first aperture aeration holes 44 is larger than the aperture of the third aperture aeration holes 46. The first aperture aeration holes 44 face the second aeration tube 43, and the second aperture aeration holes 45 face the water treatment hollow fiber membrane curtain. The above-mentioned multiple groups of third aperture aeration holes 46 include at least one group of third aperture aeration holes 46 that independently faces the first aperture aeration holes 44 and the water treatment hollow fiber membrane curtain.

[0053] In this example, each group of first aperture aeration holes 44, each group of second aperture aeration holes 45 and each group of third aperture aeration holes 46 independently include multiple aeration holes, and the holes in each group of first aperture aeration holes 44, each group of second aperture aeration holes 45 and each group of third aperture aeration holes 46 can be arranged at equal intervals and evenly distributed on the first aeration tube 42 or the second aeration tube 43.

[0054] In this example, the extension direction of the first aeration tube 42 and the extension direction of the second aeration tube 43 are respectively parallel to the extension direction of the water treatment hollow fiber membrane curtain, and the first aeration tube 42 is located in the middle of the membrane assembly, and the above-mentioned multiple second aeration tubes 43 are arranged on the left and right sides of the first aeration tube 42 and are evenly distributed.

[0055] In this example, the aperture of the first aperture aeration hole 44 is in the millimeter level, and the aperture of the third aperture aeration hole 46 is in the micrometer level. Preferably, the aperture of the first aperture aeration hole 44 is more than 10 times the aperture of the third aperture aeration hole 46, more preferably more than 20 times, and further can be 20-20000 times. Specifically, in this example, the aperture of the first aperture aeration hole 44 is 1mm-10mm, the aperture of the second aperture aeration hole 45 is 0.1mm-2mm, and the aperture of the third aperture aeration hole 46 is 0.5μm-50μm. As some optional embodiments, the aperture of the second aperture aeration hole 45 is larger than the aperture of the third aperture aeration hole 46 and smaller than the aperture of the first aperture aeration hole 44.

[0056] In this example, the diameter of the first aeration tube 42 is larger than the diameter of the second aeration tube 43. At the same time, the material of the first aeration tube 42 is stainless steel or PVC-U, which is also called hard PVC. It is an amorphous thermoplastic resin made by polymerization of vinyl chloride monomer and certain additives (such as stabilizers, lubricants, fillers, etc.), and is commercially available. The second aeration tube 43 includes an inner liner tube and a polyvinylidene fluoride film layer coated on the outer surface of the inner liner tube. The inner liner tube is a polyethylene terephthalate braided tube or a polyethylene terephthalate knitted tube, and the third aperture aeration hole 46 is formed on the inner liner tube and the polyvinylidene fluoride film layer. Further, the outer diameter of the second aeration tube 43 is 1mm-10mm, and the thickness of the polyvinylidene fluoride film layer is 10μm-200μm. Optionally, the second aeration tube 43 is a PVDF composite hollow fiber membrane filament (an inner lining tube and a polyvinylidene fluoride membrane layer coated on the outer surface of the inner lining tube) prepared by a wet phase conversion method, and the third aperture aeration holes 46 are formed in the process of preparing the membrane filament by a wet phase conversion method. The third aperture aeration holes 46 formed by such a preparation method not only have a diversity of orientations and a sludge removing force in more directions, but also have a simple preparation method, are softer as a whole, and have a stronger deformation ability, which can better remove sludge on the water treatment hollow fiber membrane curtain and will not cause damage to the water treatment hollow fiber membrane curtain.

[0057] In one aspect, the second aeration tube 43 can be a hydrophobic PVDF composite hollow fiber membrane supported by an inner lining tube, and the inner lining tube is a braided tube made of PET material. A PVDF membrane layer is coated on the surface of the inner lining tube by a wet phase conversion method. During the membrane preparation process by the wet phase conversion method, countless micron-sized aeration pores (third pore size aeration holes 46) are formed on the surface of the PVDF composite hollow fiber membrane, and the pore size of the aeration pores is 0.5-50μm.

[0058] Specifically, in this example, a first aeration tube fixing groove 22 is provided on the upper fixed end 21, and a first aeration tube hole 32 is provided on the lower fixed end 31. The upper and lower ends of the first aeration tube 42 are respectively fixed to the upper fixed end 21 and the lower fixed end 31 through the first aeration tube fixing groove 22 and the first aeration tube hole 32, and the lower part of the first aeration tube 42 also passes through the first aeration tube hole 32 to be connected with the aeration main pipe 41.

[0059] In this example, if Figure 2-3As shown, the membrane assembly in this example is provided with two vertical curtains of water treatment hollow fiber membranes arranged in parallel, the second aeration tube 43 and the first aeration tube 42 are also arranged vertically, and multiple second aeration tubes 43 are evenly distributed on both sides of the first aeration tube 42, and the second aeration tube 43 and the first aeration tube 42 are distributed in parallel in the middle of the two curtains of water treatment hollow fiber membranes. The upper ends of the water treatment hollow fiber membrane curtain, the second aeration tube 43 and the first aeration tube 42 are cast in the upper fixed end 21, and the lower ends of the water treatment hollow fiber membrane curtain, the second aeration tube 43 and the first aeration tube 42 are cast in the lower fixed end 31.

[0060] In this example, the upper fixed end 21 is bonded to the water production pipe 51 , the lower fixed end 31 is bonded to the aeration main pipe 41 , and the four membrane module joints 52 are bonded to both ends of the water production pipe 51 and the aeration main pipe 41 .

[0061] The inner hollow water production pipeline of the water treatment hollow fiber membrane 1 is communicated with the water production pipe 51 , and is communicated with the water production pipe parts outside the membrane assembly through the membrane assembly joint 52 .

[0062] Among them, the hollow aeration pipe of the second aeration pipe 43 is connected to the hollow aeration pipe of the aeration main pipe 41, the hollow aeration pipe of the first aeration pipe 42 is connected to the hollow aeration pipe of the aeration main pipe 41 through the first aeration pipe hole 32 on the lower fixed end, and the aeration main pipe 41 is connected to the external air source through the membrane assembly joints 52 at both ends.

[0063] Specifically, the membrane assembly in this example can be prepared by the following method, but is not limited to the following method, which is only illustrative:

[0064] 1) First, a PVDF membrane layer is coated on the surface of a PET braided tube, and a PVDF composite hollow fiber membrane is prepared by a wet phase conversion method. The casting liquid ratio and membrane making process parameters are controlled to make the PVDF composite hollow fiber membrane hydrophobic, and a large number of micron-sized aeration pores (third pore size aeration pores 46) are formed on the surface of the PVDF composite hollow fiber membrane. The pore size of the aeration pores is 0.5-50μm. The prepared PVDF composite hollow fiber membrane is the second aeration tube 43 with a hydrophobic function.

[0065] 2) Install the upper end of the first aeration tube 42 in the first aeration tube fixing slot 22 of the upper fixed end 21; evenly distribute the plurality of second aeration tubes 43 on both sides of the first aeration tube 42, and divide the plurality of water treatment hollow fiber membranes 1 into two curtains of water treatment hollow fiber membrane curtains; then the two curtains of water treatment hollow fiber membrane curtains are parallelly distributed on both sides of the aeration plane formed by the first aeration tube 42 and the second aeration tube 43, and install the water treatment hollow fiber membrane curtain and the upper end of the second aeration tube 43 in the upper fixed end 21, and ensure that the top of the water treatment hollow fiber membrane 1 is 1-10 cm higher than the top of the first aeration tube 42, and the top of the second aeration tube 43 is 1-10 cm lower than the top of the first aeration tube 42. Then add sealant into the upper fixed end 21, and after the sealant is cured, the upper parts of the water treatment hollow fiber membrane curtain, the first aeration tube 42, and the second aeration tube 43 are all cast in the upper fixed end 21. Then cut off the upper end of the upper fixed end 21, and the cutting position should be between the top of the water treatment hollow fiber membrane 1 and the top of the first aeration tube 42 to ensure that the hollow water production pipe of the water treatment hollow fiber membrane 1 is opened, but the hollow aeration pipes of the first aeration tube 42 and the second aeration tube 43 are in a sealed state.

[0066] 3) Bond the upper fixed end 21 and the water production pipe 51 together, so that the hollow water production pipeline of the water treatment hollow fiber membrane 1 is connected to the water production pipe 51.

[0067] 4) Install the first aeration tube 42 in the first aeration tube hole 32 of the lower fixed end 31, and vertically install the lower ends of the plurality of second aeration tubes 43 and the two curtains of water treatment hollow fiber membrane curtains in the lower fixed end 31, and ensure that the positions of the first aeration tube 42, the second aeration tube 43, and the two curtains of water treatment hollow fiber membrane curtains are arranged in accordance with the upper part, that is, the plurality of second aeration tubes 43 are evenly distributed on both sides of the first aeration tube 42, and the two curtains of water treatment hollow fiber membrane curtains are distributed in parallel on both sides of the aeration plane formed by the first aeration tube 42 and the second aeration tube 43, and ensure that the bottom of the water treatment hollow fiber membrane curtain is 1-10 cm higher than the bottom of the first aeration tube 42, and the bottom of the second aeration tube 43 is 1-10 cm lower than the bottom of the upper first aeration tube 42. Then, the sealant is poured into the lower fixed end 31, and after the sealant is cured, the lower parts of the water treatment hollow fiber membrane curtain, the first aeration tube 42, and the second aeration tube 43 are poured into the lower fixed end 31. Then, the lower end of the lower fixed end 31 is cut off, and the cutting position should be between the bottom of the first aeration tube 42 and the bottom of the second aeration tube 43 to ensure that the hollow aeration pipes of the second aeration tube 43 and the first aeration tube 42 are opened, but the hollow water production pipe of the water treatment hollow fiber membrane curtain is still in a sealed state.

[0068] 5) Bond the lower fixed end 31 and the aeration main pipe 41 together, so that the first aeration pipe 42 and the second aeration pipe 43 are connected to the aeration main pipe 41.

[0069] 6) The four membrane module joints 52 are bonded together with the left and right ends of the water production pipe 51 and the aeration main pipe 41 respectively, and a complete high-efficiency and energy-saving MBR hollow fiber membrane module is manufactured.

[0070] In this example, the water produced by the membrane module enters the water production pipe 51 through the hollow water production pipeline of the water treatment hollow fiber membrane 1, and then is discharged to the water production pipe outside the membrane module through the membrane module joint 52.

[0071] In this example, the airflow enters the aeration main pipe 41 through the membrane module joint 52, then enters the second aeration pipe 43 and the first aeration pipe 42 embedded in the first aeration pipe hole 32 on the lower fixed end 31, and finally is exposed through the large and small aeration holes on the first aeration pipe 42 and the countless aeration micropores on the second aeration pipe 43.

[0072] In summary, the MBR hollow fiber membrane assembly of the present invention has the following effects:

[0073] 1) Since the second aeration tube 43 is evenly distributed between each two curtains of the water treatment hollow fiber membrane and is parallel to them, each part of the water treatment hollow fiber membrane filament 1, such as the upper, middle, and lower parts, can be evenly aerated, and only a small amount of aeration is required to achieve a cleaning effect on each part of the water treatment hollow fiber membrane filament 1, so the total aeration amount and local aeration amount of the entire membrane assembly will be reduced, which can significantly save aeration energy consumption. In addition, since each part of the water treatment hollow fiber membrane filament 1 can be evenly aerated and the local aeration amount is small, the broken rate of the water treatment hollow fiber membrane filament 1 can be reduced, and the service life of the membrane assembly can be increased.

[0074] 2) Since the total aeration volume and the local aeration volume are reduced, and the aeration aperture of the second aeration tube 43 is smaller, the bubbles aerated are smaller, and the cutting and destructive force on the sludge flocs and biochemical colonies is smaller, thereby reducing the concentration of small particle sludge and the concentration of extracellular polymer dissolution in the wastewater, thereby reducing the probability of membrane fouling and the irreversible biological fouling ratio, thereby improving the anti-fouling property of the membrane assembly.

[0075] 3) Since the bubbles aerated from the second aeration pipe 43 are smaller, the cutting and destructive power on the sludge flocs and biochemical bacterial colonies is smaller, so the concentration of pollutants near the biochemical bacteria, especially the concentration of small molecules that are difficult to degrade, is higher, thereby improving the biochemical degradation efficiency of pollutants by biochemical bacteria, thereby improving the water quality of the MBR system and reducing the probability of membrane pollution.

[0076] 4) Since the first aeration tube 42 is provided on the membrane assembly, the second aperture aeration holes on the first aeration tube 42 can aerate and clean the water treatment hollow fiber membrane curtain facing it, and the first aperture aeration holes 44 (with a relatively large aperture) facing the second aeration tube 43 can emit a low-density large bubble flow, forming a circulation with the high-density small bubble flow emitted by the third aperture aeration holes 46 (with a relatively small aperture) of the second aeration tube 43, and the pressure difference caused by the rise and burst of the large bubbles is filled by the small bubbles and the mixed liquid driven by them, thereby increasing the movement of the activated sludge in the membrane pool and the turbulence of the mixed liquid driven by the bubbles, thereby increasing the shaking of the water treatment hollow fiber membrane filament 1, and generating a stronger inclined cutting force on the surface of the water treatment hollow fiber membrane filament 1, so that pollutants are easier to fall off from the surface of the water treatment hollow fiber membrane filament 1, thereby improving the cleaning degree of the water treatment hollow fiber membrane filament 1 and improving the anti-pollution property of the entire membrane assembly. In addition, the large bubble flow exposed by the first aeration tube 42 and the small bubble flow exposed by the second aeration tube 43 can flush the sludge out of the membrane module, reduce the sludge concentration in the membrane module, and thus improve the anti-pollution performance of the membrane module.

[0077] 5) Since the second aeration tube 43 is a PVDF composite hollow fiber membrane, its material is the same as or close to that of the water treatment hollow fiber membrane 1, and the first aeration tube 42 can be embedded in the first aeration tube fixing groove 22 of the upper fixed end 21 and the first aeration tube hole 32 of the lower fixed end 31, the second aeration tube 43 and the first aeration tube 42 can be directly cast in the upper fixed end 21 and the lower fixed end 31 during the casting of the water treatment hollow fiber membrane curtain. The membrane assembly manufacturing process is simple, saving production time cost and adhesive cost.

[0078] 6) Since the second aeration tube 43 is a soft PVDF composite hollow fiber membrane, it can spontaneously vibrate and approach the water treatment hollow fiber membrane 1 during the aeration process, intermittently shortening the distance between the second aeration tube 43 and the water treatment hollow fiber membrane 1, thereby improving the cleaning power on the surface of the water treatment hollow fiber membrane 1, thereby achieving a better cleaning effect without damaging the water treatment hollow fiber membrane 1.

[0079] 7) Since the second aeration tube 43 and the first aeration tube 42 are arranged inside the membrane assembly, they are integrated with the hollow fiber membrane curtain for water treatment used for filtration, and the aeration main pipe 41 is bonded to the entire membrane assembly as a whole, compared with the membrane assembly that usually has a separate aeration tube, the membrane system's floor space and floor space cost are greatly saved.

[0080] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A MBR hollow fiber membrane module, characterized in that: The MBR hollow fiber membrane assembly comprises: at least two water treatment hollow fiber membrane curtains arranged in parallel with each other and an aeration main pipe, and an aeration branch pipe assembly respectively arranged between two adjacent water treatment hollow fiber membrane curtains; The aeration branch pipe assembly comprises a first aeration pipe and a plurality of second aeration pipes respectively connected to the aeration main pipe, wherein the plurality of second aeration pipes are arranged beside the first aeration pipe, and the first aeration pipe is located in the middle of the membrane assembly; Wherein, the first aeration tube is provided with a plurality of parallel aeration holes along its own extension direction, wherein the plurality of aeration holes include at least two groups of aeration holes of a first aperture arranged oppositely and at least two groups of aeration holes of a second aperture arranged oppositely; The second aeration tubes are respectively provided with a plurality of groups of aeration holes with a third aperture; The aperture of the first aperture aeration holes is larger than that of the third aperture aeration holes, the first aperture aeration holes face the second aeration tubes, the second aperture aeration holes face the water treatment hollow fiber membrane curtain, and the multiple groups of third aperture aeration holes include at least one group of third aperture aeration holes that independently face the first aperture aeration holes and the water treatment hollow fiber membrane curtain.

2. The MBR hollow fiber membrane assembly according to claim 1, characterized in that: The MBR hollow fiber membrane assembly also includes an upper fixed end, a lower fixed end, a water production pipe connected to the upper fixed end, and a membrane assembly joint. The aeration main pipe is connected to the lower fixed end. The upper end of the water treatment hollow fiber membrane curtain is fixed on the upper fixed end, and the lower end is fixed on the lower fixed end. The water treatment hollow fiber membrane curtain is composed of multiple hollow fiber membrane filaments.

3. The MBR hollow fiber membrane assembly according to claim 2, characterized in that: The upper fixed end is provided with a first aeration tube fixing groove, and the lower fixed end is provided with a first aeration tube hole. The upper end of the first aeration tube is fixed to the upper fixed end through the first aeration tube fixing groove, and the lower end of the first aeration tube is fixed to the lower fixed end through the first aeration tube hole. The lower part of the first aeration tube also passes through the first aeration tube hole to communicate with the aeration main pipe.

4. The MBR hollow fiber membrane assembly according to claim 2, characterized in that: The upper ends of the water treatment hollow fiber membrane curtain, the second aeration tube and the first aeration tube are respectively cast in the upper fixed end head, and the lower ends of the water treatment hollow fiber membrane curtain, the second aeration tube and the first aeration tube are respectively cast in the lower fixed end head; The top of the water treatment hollow fiber membrane is 1-10 cm higher than the top of the first aeration tube, and the top of the second aeration tube is 1-10 cm lower than the top of the first aeration tube; The bottom of the water treatment hollow fiber membrane curtain is 1-10 cm higher than the bottom of the first aeration tube, and the bottom of the second aeration tube is 1-10 cm lower than the bottom of the first aeration tube.

5. The MBR hollow fiber membrane assembly according to claim 1, characterized in that: The extension direction of the first aeration tube and the extension direction of the second aeration tube are respectively parallel to the extension direction of the water treatment hollow fiber membrane curtain, and the multiple second aeration tubes are arranged on the left and right sides of the first aeration tube and are evenly distributed; and / or the diameter of the first aeration tube is larger than the diameter of the second aeration tube; and / or the second aeration tube is flexible.

6. The MBR hollow fiber membrane assembly according to claim 1, characterized in that: The aperture of the first aperture aeration hole is in the millimeter order, and the aperture of the third aperture aeration hole is in the micrometer order; further, the aperture of the first aperture aeration hole is more than 10 times, preferably more than 20 times, and more preferably 20-20000 times, of the aperture of the third aperture aeration hole; and / or, the aperture of the second aperture aeration hole is larger than the aperture of the third aperture aeration hole and smaller than the aperture of the first aperture aeration hole.

7. The MBR hollow fiber membrane assembly according to claim 1, characterized in that: The aperture of the first aperture aeration hole is 1mm-10mm; and / or, the aperture of the second aperture aeration hole is 0.1mm-2mm; and / or, the aperture of the third aperture aeration hole is 0.5μm-50μm; and / or, the second aeration tube is a hydrophobic PVDF composite hollow fiber membrane supported by an inner liner tube.

8. The MBR hollow fiber membrane assembly according to claim 1, characterized in that: The second aeration tube can vibrate during the aeration process and intermittently shorten the distance between the second aeration tube and the water treatment hollow fiber membrane curtain during the vibrating process; and / or, the first aeration tube is made of stainless steel or PVC-U; and / or, the second aeration tube has a hydrophobic function.

9. The MBR hollow fiber membrane module according to claim 1, characterized in that: The second aeration tube includes an inner lining tube and a polyvinylidene fluoride film layer coated on the outer surface of the inner lining tube, the inner lining tube is a polyethylene terephthalate braided tube or a polyethylene terephthalate knitted tube, and the third aperture aeration holes are formed on the inner lining tube and the polyvinylidene fluoride film layer; further, the outer diameter of the second aeration tube is 1mm-10mm, and the thickness of the polyvinylidene fluoride film layer is 10μm-200μm.

10. An aeration assembly, characterized in that: The aeration assembly includes an aeration main pipe and an aeration branch pipe assembly, wherein the aeration branch pipe assembly includes a first aeration pipe and a plurality of second aeration pipes respectively connected to the aeration main pipe, and the plurality of second aeration pipes are arranged beside the first aeration pipe; Wherein, the first aeration tube is provided with a plurality of parallel aeration holes along its own extension direction, wherein the plurality of aeration holes include at least two groups of aeration holes of a first aperture arranged oppositely and at least two groups of aeration holes of a second aperture arranged oppositely; The second aeration tubes are respectively provided with a plurality of groups of aeration holes with a third aperture; The aperture of the first aperture aeration holes is larger than that of the third aperture aeration holes, the first aperture aeration holes face the second aeration tubes, the second aperture aeration holes face the water treatment hollow fiber membrane curtain, and the multiple groups of third aperture aeration holes include at least one group of third aperture aeration holes that independently face the first aperture aeration holes and the water treatment hollow fiber membrane curtain.

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