CN101234819B - A hollow fiber membrane module, membrane bioreactor and water treatment equipment - Google Patents

Abstract

The invention discloses a hollow fiber membrane module, which comprises a hollow fiber membrane bundle composed of a plurality of hollow fiber membrane filaments, one or both ends of the hollow fiber membrane bundle, an air inlet pipe, a water production pipe and a casing, the casing Outside the hollow fiber membrane bundle, the housing can accommodate the vertically placed hollow fiber membrane bundle. The side wall of the housing is a side wall without holes. The area percentage is greater than 10%, and the shell and the terminal are connected together through a detachable structure. The invention also discloses a membrane bioreactor and water treatment equipment using the hollow fiber membrane module. The characteristics of the hollow fiber membrane module disclosed in the present invention reduce the probability of hollow fiber membrane filament breakage, improve the flow state of the liquid flow inside the membrane module, improve the anti-pollution performance and material utilization rate of the hollow fiber membrane module, and prolong the hollow fiber membrane module. The service life of the fiber membrane module.

Description

A hollow fiber membrane module, membrane bioreactor and water treatment equipment

technical field

The invention relates to membrane separation water treatment equipment, in particular to a hollow fiber membrane module applied to water treatment and a membrane bioreactor using the hollow fiber membrane module, belonging to the technical field of water treatment.

Background technique

The membrane bioreactor (Membrane Bioreactor, MBR) process is an efficient sewage treatment and reuse technology that organically combines membrane separation technology and traditional biological treatment technology. Compared with the sludge method, it has outstanding advantages such as excellent and stable effluent quality, small footprint, strong impact load resistance, and low excess sludge output. It is a water treatment process with great development potential. Especially in terms of sewage recycling, the MBR process can process domestic sewage, urban sewage or similar industrial wastewater into high-quality recycled water that can be used as urban miscellaneous water, industrial circulating cooling water, etc., and is currently used worldwide It is receiving extensive academic attention, and large-scale engineering applications are gradually increasing.

According to the location of the membrane module, the membrane bioreactor can be divided into two types: external (or split type, split type) membrane bioreactor and built-in (or submerged, integrated, submerged) membrane bioreactor. kind.

The external membrane bioreactor is to separate the membrane module and the bioreactor. The mixed liquid in the bioreactor is pressurized by the circulating pump and sent to the filter end of the membrane module. Under the pressure, the liquid in the mixed liquid permeates the membrane. , become the system to treat the effluent, solids, macromolecular substances, etc. are intercepted by the membrane, and return to the bioreactor with the concentrated solution. The external membrane bioreactor is characterized by stable and reliable operation, easy membrane cleaning, replacement and addition, and the membrane flux is generally large, but under normal conditions, in order to reduce the deposition of pollutants on the membrane surface, prolong the membrane cleaning period , it is necessary to use a circulating pump to provide a higher cross-flow velocity on the membrane surface, resulting in an increase in the water circulation and the required head of the circulating pump, increasing the power cost, and the energy consumption per ton of water is as high as 2-10kWh/m ³ , and the high-speed rotation of the pump The resulting shear force will inactivate some microbial cells.

The built-in membrane bioreactor is to immerse the membrane module below the liquid level of the bioreactor. After the raw water enters the membrane bioreactor, most of the pollutants in it are decomposed or transformed by the activated sludge in the mixed solution, and then pumped Under the action of the negative pressure provided by the pump or the action of the water level difference, the water is filtered out by the membrane. The aeration system is installed under the membrane module. On the one hand, it provides the necessary oxygen for microorganisms to decompose organic matter. The gas-water two-phase flow performs hydraulic scouring on the outer surface of the membrane to inhibit the deposition of the sludge layer on the membrane surface. Compared with the external membrane bioreactor, the built-in membrane bioreactor omits the mixed liquid circulation system, has a more compact structure, occupies a small area, and relies on suction to produce water, and the energy consumption per ton of water is relatively low, down to 1~ 2.4kWh/m ³ . At present, among the actual projects of membrane bioreactors that have been put into use in the world, most of them use the built-in membrane bioreactor process. However, there are two main problems in the built-in membrane bioreactor. One is that the installation, maintenance and cleaning of the membrane modules are very inconvenient, and the cleaning labor intensity is high. It is 3 to 4 times that of other mature sewage biological treatment processes such as traditional activated sludge process and sequencing batch activated sludge process, which makes its energy consumption per ton of water still significantly higher than other processes.

Chinese patent 03121949.7 discloses an air flushable external pressure column type hollow fiber membrane module. The membrane module is provided with a shell column outside the inverted U-shaped hollow fiber membrane. The top of the shell column has a feed liquid outlet, and the bottom has a feed liquid inlet and Through the water outlet, an air flushing part is provided at the bottom of the hollow fiber membrane bundle. The membrane module can be combined with the bioreactor to form an external membrane bioreactor, but different from the conventional external membrane bioreactor, the effluent of the system is not obtained by boosting the circulating pump, but provided by the additional suction pump Negative pressure is obtained, so that the flow rate and head of the circulating pump are greatly reduced. At the same time, there is an air flushing part in the membrane module for aeration. The setting of the shell cylinder greatly reduces the air lift section, so that the gas-water two-phase flow formed during aeration is bound inside the shell and rises along the axis of the membrane filament. , to avoid the gradual outward diffusion of bubbles during the ascent process, so a higher aeration intensity can be obtained in the hollow fiber membrane bundle with a smaller aeration amount, so that the air-water two-phase flow has a better effect on the outer surface of the membrane filament Good hydraulic scouring effect can better inhibit the development of membrane fouling, and save aeration energy consumption to a certain extent, which makes the overall energy consumption of the system lower than that of conventional built-in membrane bioreactors, but using conventional external membrane bioreactors The external form of the bioreactor facilitates the installation and maintenance of the membrane module. Therefore, this type of membrane bioreactor organically combines the two types of external and internal membrane bioreactors, taking advantage of their strengths and complementing their weaknesses. However, this patent has the following disadvantages: (1) The inverted U-shaped hollow fiber membrane is used. During the working process, one end of the membrane is fixed, and the other end is free to swing. . (2) The flow state of the liquid flow inside the shell cylinder is not good, and the root of the membrane filament is prone to mud accumulation. Since the fixed end of the membrane filament is completely bonded to the lower part of the shell cylinder as a whole, the feed liquid inlet can only be set on the side of the shell cylinder. Dead angles are prone to appear on the side walls where no holes are opened, and mud accumulation occurs. (3) The fixed end of the membrane filament and the shell cylinder are bonded as a whole. Once a part of the membrane filament breaks, the entire membrane assembly including the shell cylinder cannot be reused, resulting in unnecessary waste.

Chinese patent 200420109850.7 discloses an air-lift hollow fiber membrane module, as shown in Figure 6, the membrane module is provided with a spiral shell outside the hollow fiber membrane, and its water inlet and outlet are provided with grilles , and there is also an aeration port near the water inlet. When the membrane module realizes aeration of a small cross-section in the casing, the spiral design of the casing properly prolongs the flow channel of the gas-water two-phase flow, making the gas stay in the water for a longer time and enhancing the The degree of disturbance in the housing and the scouring effect on the outer surface of the membrane filaments have also improved the process of oxygen transfer and mass transfer, but the patent still has the following deficiencies: (1) The root of the hollow fiber membrane filaments has a high probability of fracture. The hollow fiber membranes are set in a spiral shell, and are subjected to the vibration generated by aeration for a long time in the working state. The membranes not only bear a certain torque on the axis, but also spiral in the air-water two-phase flow In the process of rising, the root will be subject to a large pulling force, especially when the membrane filament is long, the root of the membrane filament is easy to break due to excessive torque or tension. (2) The spiral housing shape is difficult to process or realize. When the housing is rigid, processing is more difficult; when the housing is made of plastic hose, the spiral shape is not easy to maintain. (3) The hollow fiber membrane and the shell are still cast together, and the membrane or the shell cannot be replaced separately. Once part of the membrane breaks or loses the filtering ability, the shell cannot continue to be used, and the membrane module can only be replaced as a whole. Cause a certain degree of material waste. (4) The whole membrane module is not easy to install and disassemble. When the membrane module is working, it is surrounded by the liquid to be filtered. The water inlet of the shell is close to the water bottom, the water outlet is close to the water surface, and the aeration port is set near the water inlet. In this way, the membrane module must be connected with the aeration pipe installed on the bottom of the water. When the membrane module needs to be repaired, the water level must be lowered to close to the bottom of the tank and the aeration pipe can be exposed before the corresponding operation can be performed. This is not only complicated to operate in actual engineering, but also easily causes the loss of activated sludge.

Contents of the invention

An object of the present invention is to provide a hollow fiber membrane module, which can effectively reduce the energy consumption of aeration and the probability of membrane filament breakage in the water treatment process, the internal liquid flow is smooth, and the membrane filaments can be replaced separately, and the processing and installation are also easy. convenient.

Another object of the present invention is to provide a membrane bioreactor utilizing the hollow fiber membrane module of the present invention.

Another object of the present invention is to provide a water treatment device utilizing the hollow fiber membrane module of the present invention or the membrane bioreactor of the present invention.

In order to realize the foregoing invention object, the present invention adopts following technical scheme:

A hollow fiber membrane module, comprising a hollow fiber membrane bundle composed of a plurality of hollow fiber membrane filaments, one or both ends of the hollow fiber membrane bundle, an air inlet pipe, a water production pipe and a housing, characterized in that: the housing Outside the hollow fiber membrane bundle, the housing is a housing that can accommodate the vertically placed hollow fiber membrane bundle, the side wall of the housing is a side wall without holes, and the ports at both ends of the housing are on the cross section The opening area accounts for more than 10% of the cross-sectional area of the port, and the shell and the terminal are connected together through a detachable structure.

The housing is a housing that can accommodate vertically placed hollow fiber membrane bundles. Such a housing is relatively easy to process and realize no matter whether it is made of rigid or flexible materials, and more importantly, it can make the hollow fiber inside it The fiber membrane bundle is in a straight line state, and the hollow fiber membrane hangs down naturally without any double fold in the middle, and no longer bears torque on the axis, which greatly reduces the probability of breaking the middle part and root of the membrane. In the hollow fiber membrane module disclosed in Chinese patent 200420109850.7, the hollow fiber membrane filaments are arranged in a spiral shell, and are subjected to the vibration generated by aeration for a long time in the working state, and the membrane filaments not only bear a certain torque on the axis , and the root of the gas-water two-phase flow will be subjected to a large pulling force during the spiral upward process. From the perspective of material mechanics, the material is easily damaged by such a combined force. And in the actual use process, most of the parts where the membrane filament breaks occur at the root.

The opening area of the ports at both ends of the housing accounts for more than 10% of the cross-sectional area of the ports, preferably greater than 80%, so that when the membrane module is working, the liquid to be filtered can flow from the bottom of the housing. The port instead of the side wall enters the shell, and the gas-water two-phase flow gradually rises along the central axis of the shell due to the airlift effect generated by aeration, and finally flows out of the shell from the upper port of the shell instead of the side wall, so that The direction of the liquid flow does not change when it flows through the hollow fiber membrane bundle, especially avoiding the problems of dead ends and sludge deposition caused by the sudden turn of the liquid flow caused by setting the feed liquid inlet or outlet on the side wall of the shell, and at the same time There are no holes on the side wall of the shell. During this process, the shell always has a binding effect on the gas-water two-phase flow, so that the gas-water two-phase flow will not spread to the periphery of the shell, thereby greatly reducing the gas lift section. , in the case of a small aeration rate, a higher aeration intensity can be obtained in the hollow fiber membrane bundle, so that the air-water two-phase flow has a better hydraulic scouring effect on the outer surface of the membrane filament, which can be well Inhibit the development of membrane fouling, and can significantly save aeration energy consumption. The percentage of the opening area on the cross-section of the ports at both ends of the housing to the cross-sectional area of the port refers to the ratio of the opening area on the cross-section of the port at any one end of the housing to the cross-sectional area of the port at this end. The area ratio, the result is expressed as a percentage. For example: For a cylindrical shell, due to some engineering or other reasons at the upper port, there is a metal sheet with a hole to cover the upper port. At this time, the area of the hole is required to account for the cross-sectional area of the cylindrical shell. The percentage is greater than 10%, preferably greater than 80%. This is beneficial to the flow of the liquid flow, so as to better complete the exchange with the liquid to be treated outside.

The cross section of the housing can be circular, rectangular, square or any other known shape. Preferably, the cross section of the housing is circular. The cylindrical shell is easy to process and shape, and has no edges and corners, which will not cause damage to the surrounding membrane wires or installers during installation and use. The areas of the cross-sections of the housing from top to bottom can be the same or different. As a preference, the area of each cross-section of the housing from top to bottom is the same; or the cross-sectional area of the middle part is slightly smaller than the cross-sectional area of the upper and lower ends, such as can be designed to be similar to a Venturi tube or a Venturi nozzle Such a design can enhance the scouring effect of the air-water two-phase flow on the upper part of the hollow fiber membrane bundle. The length of the shell is in the range of 0.1m to 4.0m, preferably 1.5m to 2.0m. The diameter of the shell is in the range of 5 mm to 500 mm, preferably 30 mm to 300 mm.

The hollow fiber membrane can have and only one end is cast and sealed in an end with a permeated water collection chamber, while the other end can swing freely and be made into a closed-cell state by any known method; The two ends can be respectively cast and sealed in the two ends, and at least one of the two ends should be provided with a product water collection chamber. A water production pipe should be provided outside the end with a water production collection chamber, and the production water collection chamber should be connected to the water production pipe. When the hollow fiber membranes have and only one end is cast and sealed in an end with a permeated water collection chamber, the end can be located at the upper part or the lower part of the vertically placed hollow fiber membrane bundle . As a preference, when the hollow fiber membrane has and only one end is cast and sealed in an end with a water collection chamber, the end is located at the lower part of the vertically placed hollow fiber membrane bundle, so that Avoid the problem that the membrane filaments are easily entangled with each other due to the rise of the gas-water two-phase flow when the lower end of the membrane filaments swings freely.

The housing and the terminal are connected together through a detachable structure, such a design allows the upper terminal or (and) the lower terminal to be separated from the housing, which allows the hollow fiber membrane bundle and the housing to be replaced independently of each other , which improves the utilization rate of materials to a certain extent. The detachable structure is a rope connection structure, a buckle connection structure, a bolt connection structure, a socket connection structure, a screw connection structure and the like. Among them, the way of the rope connection structure is relatively unique. This way is relatively easy to implement and simple. For example, a hole is respectively set on the upper end and the upper part of the casing. The setting of the hole cannot affect the normal operation of other hollow fiber membrane modules. A cord is threaded through both holes and knotted so as to complete the connection of the upper end to the housing. The ropes can be made of metal ropes, soft ropes made of chemical fibers, etc., preferably water-resistant metals or metal alloys, such as copper, aluminum, stainless steel, etc., and must meet certain strength requirements. The choice of buckles and bolts can be selected according to the existing national or industry standards, or designed by yourself, but no matter which way the buckles and bolts are used, the setting method and connection position must meet the requirements of the working conditions of the hollow fiber membrane module , and easy to disassemble, for example, the buckle connection should be designed near the upper end and close to the top of the shell; the bolt connection should be designed on the side of the shell. For the rope connection structure, the buckle connection structure, the bolt connection structure and the known detachable connections, one can be selected to complete the connection, or several can be selected to complete the connection. In addition, the shell and the terminal described in this article are connected together through a detachable structure, including the shell and the terminal are directly connected together through a detachable structure, and also include such a connection method: the shell and the terminal are respectively connected to the first Three parts, even the fourth part, the fifth part... are connected together, and the third part, even the fourth part, the fifth part... are relative to The shell and the end are distinguished, that is, the shell and the end are considered to be the first part and the second part respectively, or the end and the shell are considered to be the first part and the second part respectively. For example: if the water production pipe is a water production hose, the upper end can be connected to a third part through the water production hose through a rope connection structure, and then the third part is connected with a snap connection structure or a bolt connection structure Connect with the shell. This completes the connection of the terminal to the housing. It is considered that the water production hose here has the performance of a rope, so the connection between the water production hose and the third part is a rope connection structure. The inserts mentioned below in this article can be used as third parts.

In the present invention, the upper end refers to the end of the membrane module near the water surface during the water treatment process, and the lower end refers to the end near the water bottom. The upper end and the lower end can exist at the same time, or there can be only one. The upper end and the lower end correspond to the upper port and the lower port of the housing respectively.

The terminal can be inside or outside the housing. Preferably, the end head is completely inside the housing, and the distance from the end surface of the adjacent housing port is 1/20-1/3 of the length of the housing.

In the above-mentioned hollow fiber membrane module, the upper port and the lower port of the housing can be completely opened, or can be covered with an insert with holes.

The insert with openings is sunkly arranged on at least one port of the casing to fix the ends of the hollow fiber membrane bundles. In addition, since there are holes in the insert, during the aeration process, The liquid to be filtered can freely enter and leave the housing through the holes on the insert, which facilitates the circulating flow of the liquid to be filtered. With the existence of air lifting effect, the liquid to be filtered enters the shell from the lower port of the shell and flows out from the upper port of the shell, forming an air-water circulation flow. Preferably, inserts are provided on both ports of the housing. The insert can be connected to the housing by snaps, bolts or any other known detachable means.

In the above-mentioned hollow fiber membrane module, the opening area of the insert in the cross section accounts for more than 10%, preferably more than 80%, of the cross-sectional area of the insert. A porosity greater than 10% can avoid clogging the liquid flow. When it is greater than 80%, the liquid will pass through the insert area more smoothly and with less resistance, which is conducive to the formation of a better gas-water two-phase flow to ensure the hollow fiber membrane bundle washout effect.

In the above-mentioned hollow fiber membrane module, the insert may have a circumference, and the outer diameter of the circumference is slightly smaller than the inner diameter of the casing, so that the insert is just embedded in the port of the casing. At least three radial support strips may extend from the center of the circumference to the circumferential direction, and there are holes between the support strips. Preferably 3 to 8 support bars are used. Compared with grid or mesh inserts, the manufacture and installation of support bars are simpler, the opening ratio is larger, and it is not easy to block the liquid flow.

When the hollow fiber membrane has and only one end is cast and sealed in an end with a permeated water collection chamber, several inserts can also be arranged at other positions inside the housing at appropriate intervals, It is used to properly limit the freely swinging end of the hollow fiber membrane to prevent the membrane from becoming soft due to water immersion during the water treatment process, so that it is easy to entangle with each other, resulting in poor fluid flow in the housing.

An air distribution device with air distribution holes may be provided inside the housing. The air distribution device can be arranged at any position inside the casing. Preferably, the air distribution device is arranged close to or closely attached to the upper end or (and) the lower end of the hollow fiber membrane bundle, and more preferably, the air distribution device is closely attached to the upper end or (and) lower end of the hollow fiber membrane bundle. (and) the casting end face of the lower end is set, when both ends of the hollow fiber membrane bundle are cast and sealed in the end head, the air distribution device is simultaneously set on the casting end faces of the upper end and the lower end of the hollow fiber membrane bundle .

The opening orientation of the air distribution hole of the air distribution device can be horizontal, vertically upward, vertically downward, obliquely upward, and obliquely downward. The preferred air distribution hole is oriented horizontally or obliquely. Downward towards the direction of the casting end face, so that the roots of the hollow fiber membranes can be scoured more thoroughly, which can well avoid the phenomenon of mud accumulation at the roots of the membranes during use.

In the above-mentioned hollow fiber membrane module, the air distribution device may have at least three hollow spokes, and the air distribution holes are opened on the side of the spokes.

The arrangement of multiple spokes makes the aeration more uniform, so the root of the hollow fiber membrane is also more comprehensively scoured, and the rising air-water two-phase flow is also more uniform. The spokes can be evenly distributed in a star shape with the center of the end as the center. It is preferable to use 3 to 8 radial or helically curved spokes to divide the casting end surface into 3 to 8 parts with equal areas. Correspondingly, the hollow fiber membrane bundle is also evenly divided into 3 to 8 parts. Small bundles, each of which is cast in the spaces between the spokes.

The orifices of the air distribution holes are opened on the side walls of the spokes, and the direction of the airflow coming out from the air distribution holes is generally towards the horizontal. When the side wall of the spoke has a certain thickness, the thickness of the spoke can be used to design the orifice of the air distribution hole in the process of processing, so that the airflow coming out of the air distribution hole is obliquely downward or upward. It is preferred to face downwards obliquely.

There are various shapes, quantities, sizes and distribution forms of the air distribution holes. The shape can be round or long, and the spokes are distributed linearly from the center of the end face to the edge of the end face. When the holes are strip-shaped, the long side of each hole should be roughly parallel to the end face. The distance between the hole of the air distribution hole and the end surface of the hollow fiber membrane can be equal or not, and the distance ranges from 1mm to 20mm, preferably 2mm to 10mm. The diameter of the air distribution hole or the length of the short side is 1 mm to 10 mm, preferably 1 mm to 5 mm.

For any of the above-mentioned hollow fiber membrane modules, when both ends of the hollow fiber membrane bundle are cast and sealed in the ends, air distribution devices with air distribution holes can be installed on the casting end faces of the two ends, and the two The two air distribution devices are connected through a hollow hose. The functions of the hollow hose include: first, to supply airflow to the upper and lower air distribution devices, so that the roots of the upper and lower ends of the hollow fiber membrane bundle can be directly purged and washed by the aeration airflow, so as to prevent the accumulation of the roots of the membrane filaments. Second, connect the upper and lower ends, and the length of the hose is slightly shorter than the length of the hollow fiber membrane, so as to bear the gravity of the lower end and the pulling force when swinging, so as to avoid the hollow fiber membrane from bearing the force. was pulled off.

One or both of the ends may be provided with an air inlet duct. Either of the ends may be provided with an air intake pipe and a water production pipe at the same time, or only an air intake pipe or a water production pipe. The number of water production pipes or air intake pipes can be selected according to the actual situation of the project. You can choose one air intake pipe or one water production pipe, or two or more air intake pipes, or two or more water production pipes, or Select two or more intake pipes and water production pipes at the same time. The inlet pipe and water production pipe can be rigid or flexible, preferably flexible, and their materials can be silicone rubber, fluororubber, soft polyvinyl chloride, polyurethane, etc.

In the above-mentioned hollow fiber membrane module, the air inlet pipe and the water production pipe can be inside the housing, and one end of the air inlet pipe connected to the gas source and one end of the water production pipe connected to the water collection pipeline extend from the top of the housing to the exterior of the housing.

With such an arrangement, the hollow fiber membrane module can be connected to the fixing device only through its upper end, which can facilitate the installation and disassembly of the hollow fiber membrane module. When the membrane module is working, only its upper end is connected to the fixing device, and the air inlet of the air inlet pipe and the water outlet of the water production pipe are located at the upper part of the casing, even if the whole membrane module is surrounded by the liquid to be filtered, but due to The connection point between the membrane module and the fixing device is located close to the water surface or above the water surface, so that the membrane module can be disassembled without lowering the water level or lowering the water level to a very low level when the membrane module needs maintenance.

When both ends of the hollow fiber membrane bundle are cast and sealed in the ends, a connecting pipe can be arranged between the two ends to connect the two ends.

The connecting pipe connects the upper end and the lower end as a whole, and its length can be the same as the hollow fiber membrane bundle, or slightly shorter than the membrane bundle. Preferably, the length of the connecting pipe is slightly shorter than the length of the hollow fiber membrane bundle. This can prevent the end from swinging too much and cause the membrane filaments to be stressed for a long time, and protect the membrane bundles.

The diameter range of the inlet pipe, water production pipe and connecting pipe is 1mm-50mm, preferably 5mm-20mm.

The hollow fiber membrane is a hollow fiber with micropores, and the material for making the hollow fiber membrane can be selected from polyvinylidene fluoride, polyethylene, polypropylene, polyethersulfone and other materials. Hollow fiber membranes are firstly end-capped and casted with casting resins such as epoxy resin and polyurethane, and then the roots of hollow fiber membranes are casted twice with flexible resins such as silicone rubber and polyurethane to reduce the probability of root breakage of the membranes. Preferably, the material of the hollow fiber membrane is polyvinylidene fluoride. The average membrane pore diameter of the hollow fiber membrane is 0.01 μm-5 μm.

The hollow fiber membrane bundle is composed of 10 to 1000 hollow fiber membrane filaments, and the length ranges from 0.1m to 3.0m. It is preferably composed of 50-500 hollow fiber membranes, and the length ranges from 1.0m to 2.0m.

When both ends of the hollow fiber membrane bundle are cast and sealed in the ends, the length of the hollow fiber membrane bundle can be equal to or slightly greater than the distance between the upper and lower ends. Preferably, the length of the hollow fiber membrane bundle is greater than the distance between the upper and lower ends, but less than the length of the casing.

The above-mentioned hollow fiber membrane module can be connected to the fixing device in any known way through any end, any part of the casing or an insert on any port of the casing. Preferably, the upper port of the housing or the insert on the upper port is connected to the fixing device through detachable hard connections such as sockets, threads, and unions, or through flexible connections such as soft cables or flexible pipes. way connected to the fixture. The soft rope can be a corrosion-resistant rope, steel wire or spring, etc. The soft rope makes the membrane module in a suspended state in the liquid to be filtered, and can swing with the water flow. When the upper end is provided with an air intake pipe or a water production pipe, and the air intake pipe or water production pipe is a flexible pipe, the membrane module can also be suspended on the fixing device through the air intake pipe or the water production pipe.

In the above-mentioned hollow fiber membrane module, the upper end or (and) the lower end may be connected to any part of the casing or an insert on any port of the casing in any known detachable manner. Preferably, said upper end or (and) lower end is connected to an insert located on an adjacent housing port. More preferably, the upper end or (and) the lower end is connected to the insert located on the adjacent housing port through a flexible connection such as a cable or a flexible tube.

In any of the above hollow fiber membrane modules, the casting end surface of the end head may be a plane, or a convex or concave end surface. Preferably, the casting section of the end head is a convex end surface. If the end face is a flat or concave end face, the sludge will have a serious deposition phenomenon. The characteristic of the raised structure is that the middle is high and the surrounding is low, which will form an inclination from the middle to the surrounding. This structure is conducive to the airflow to blow the pollutants such as sludge to the surrounding, which is conducive to reducing the accumulation of sludge. More preferably, the end surface of the protruding end is in the shape of a truncated cone. The frustum-shaped structure is easier to process, and is also conducive to setting other components such as connecting pipes in the middle.

When both ends of the hollow fiber membrane bundle are cast and sealed in the ends, the shapes of the upper end and the lower end may be the same or different. Preferably, the upper end is slightly larger than the lower end, so that the lower end of the entire hollow fiber membrane bundle can have a certain swing range in the casing.

The overall shape of the upper end or (and) the lower end may be in the shape of a cylinder, a cone, a basin, a cup, or the like. Preferably, the overall shape of the upper end or (and) the lower end is basin-shaped or cup-shaped.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The probability of breakage of the hollow fiber membrane filament is reduced, and the service life of the hollow fiber membrane module is prolonged. The hollow fiber membrane bundle is in a suspended state in the liquid to be filtered, and the hollow fiber membrane thread hangs naturally without any folds in the middle, and no longer bears torque on the axis. , air inlet pipe, water production pipe, etc., so that the membrane bundle can swing together with the end within a certain range, the swing angle between the root of the membrane filament and the casting end surface is also greatly reduced, and the tension between the root of the membrane filament and the casting end surface is greatly increased. Therefore, the probability of root breakage of the membrane filament is greatly reduced, the working stability of the membrane module is improved, and its service life is prolonged.

(2) The flow state of the liquid flow inside the membrane module is improved, and the problem of easy mud accumulation at the root of the membrane filament caused by the sudden turn of the liquid flow caused by the end completely blocking one or both ends of the shell in the prior art is avoided phenomenon, improving the anti-fouling performance of the hollow fiber membrane module.

(3) The hollow fiber membrane bundle and the housing can be replaced independently of each other, which avoids the waste phenomenon that once part of the membrane filaments breaks, the whole membrane module including the housing cannot continue to be used. , improving the material utilization rate of the hollow fiber membrane module.

(4) The convenience of hollow fiber membrane module processing, assembly, installation and maintenance is improved. The internal structure of the end of the casting hollow fiber membrane of the membrane module of the present invention is simple, and there are no complicated structural parts inside, which reduces the difficulty and waste rate of the casting process, and the membrane module as a whole can realize an assembled structure, and the product is easy to realize rapid assembly . Fixed to the fixture in a flexible connection, each membrane module can be installed and disassembled independently, and all operations can be completed by a single person, unlike the existing hollow fiber membrane modules that must pass through lifting equipment after forming a large membrane module unit Overall hoisting is labor-intensive and cannot be operated by a single person.

Description of drawings

Fig. 1 is a longitudinal sectional view of a hollow fiber membrane module according to Example 1 of the present invention.

Fig. 2 is a longitudinal sectional view of a hollow fiber membrane module according to Example 2 of the present invention.

Fig. 3 is a cross-sectional view at A-A in Fig. 1 and Fig. 2 .

Fig. 4 is a longitudinal sectional view of one end of a membrane module in the prior art.

Fig. 5 is a cross-sectional view at B-B in Fig. 4 .

Fig. 6 is a schematic diagram of the membrane module described in Chinese patent 200420109850.7.

Fig. 7 is a schematic diagram of a membrane module unit composed of several hollow fiber membrane modules of the present invention in Example 1.

Fig. 8 is a schematic diagram of a membrane module unit composed of several hollow fiber membrane modules of the present invention in Example 3.

Explanation of each mark in the accompanying drawings:

1—shell; 2—hollow fiber membrane; 3—hollow fiber membrane bundle; 4—upper end; 5—lower end; 6—water production pipe; 7—intake pipe; 8—hollow Hose; 9—air distribution device with air distribution holes; 10—air distribution holes; 11—water collection chamber; 12—insert piece; 13—quick plug connector; 14—soft cable; 15— Support bar; 16—water collection branch pipe; 17—aeration branch pipe; 18—water collection end; 19—central pipe; 20—water outlet; 21—feed liquid inlet.

Detailed ways

The technical solutions of the present invention will be further specifically described below in conjunction with the accompanying drawings and embodiments.

Example 1

As shown in FIG. 1 , a hollow fiber membrane module includes a cylindrical casing 1 with an inner diameter of 85mm, the central axis of the casing is a straight line, and the sidewall of the casing is a sidewall without holes. A hollow fiber membrane bundle 3 composed of 240 hollow fiber membranes 2 arranged in the casing 1, the average pore diameter of the micropores of the hollow fiber membranes 2 for passing liquid is 0.01 μm, and the outer diameter of the hollow fiber membranes is The diameter is 1.2mm, the material is polyvinylidene fluoride, the two ends are casted with epoxy resin and collected in the upper end 4 and the lower end 5, and it is re-cast with polyurethane to protect the root of the membrane. The overall shape of the upper end 4 and the lower end 5 is cup-shaped, and the diameter of the upper circle of the two ends is 45mm. The hollow fiber membrane filament 2 is in an open state in the water production collection chamber 11 in the upper end 4, and in a closed state in the lower end 5. The upper end 4 is provided with a water production pipe 6 with an outer diameter of Φ8mm, and the lower end 5 is provided with There is an inlet pipe 7 with an outer diameter of Φ8mm, and the two ends are connected as a whole by a hollow hose 8 with an outer diameter of Φ6mm, and the hollow fiber membranes 2 are evenly distributed around the hollow hose 8. The water production pipe 6, the intake pipe 7 and the hollow hose 8 are all hollow plastic hoses. The parts connected among the hollow hose 8, the air distribution device 9 with air distribution holes, the water production pipe 6, and the air intake pipe 7 are all connected by a quick-plug connector 13, and the connection method is shown in FIG. 1 . The water production pipe 6 communicates with the water production collection chamber 11 in the upper end 4 . The inserts 12 are arranged above the upper end 4 and below the lower end 5 respectively, the upper end 4 and the lower end 5 are connected to the adjacent inserts 12 through the rope 14, and the inserts 12 are connected to the housing 1 by screws , The insert 12 has a round hole with an inner diameter of Φ10mm at the center, and the water production pipe 6 and the air inlet pipe 7 pass through the round hole. The housing 1 is made of UPVC (un-plasticized polyvinyl chloride) plastic.

As shown in FIG. 1 , both ends are provided with air distribution devices 9 with air distribution holes on the end faces where the hollow fiber membranes are cast. As shown in Figure 3, the air distribution device 9 with air distribution holes has six radially distributed spokes, each spoke is 5mm wide and 4mm high, and the angle between two adjacent spokes is 60°. The center of the end surface extends to the circumference of the upper end 4 or the lower end 5, and there is a cavity inside. The two side walls of the spoke are perpendicular to the casting end surface, and the other side facing away from the casting end surface is rounded. There are four circular air distribution holes 10 with a diameter of Φ2mm at the center position on the side wall. The central axis of the air distribution hole 10 is perpendicular to the side wall surface of the spoke, and the height from the casting end surface is 2mm. The center axis distance of each air distribution hole Both are 4mm, and the cavity of the spoke communicates with the hollow hose 8.

The spokes divide the casting end surface into six parts with equal areas, and correspondingly, the hollow fiber membrane bundles 3 are also divided into six small bundles, and each small bundle is composed of 40 hollow fiber membrane filaments 2, all of which are cast in the gaps between the spokes inside. The end surfaces of the upper end 4 and the lower end 5 that are cast with hollow fiber membranes have a flat-topped conical or frustum-shaped projection, and the projections on the upper and lower ends are just opposite to each other. The diameter of the raised bottom circle is Φ40mm, the diameter of the top circle is Φ12mm, and the height is 10mm. The air distribution device 9 with air distribution holes is just buckled on the protrusion, sticks together with the protrusion, and the parts in contact are completely sealed.

The insert 12 is composed of six support bars 15 arranged in a star shape around the center of the circle and the circumference, the angle between each support bar 15 is also 60°, and the outer edge of the circumference is in contact with the housing 1 . The connection between the circumference and the shell is a bolted connection. The opening area of the insert 12 in the cross-section accounts for 93% of the cross-sectional area of the insert.

The length of the casing 1 is 1.4m, the average length of the hollow fiber membrane bundle 3 is 1.2m, the total height of the upper end 4 and the air distribution device 9 with air distribution holes is 70mm, the lower end 5 and the air distribution device 9 with air distribution holes The total height of the gas device 9 is 50mm, and the length of the hollow hose 8 is 1.0m. The distance between the upper insert and the upper port of the housing is 10 mm, and the distance between the lower insert and the lower port of the housing is 10 mm.

The water production pipe 6 is connected with a water collection branch pipe 16 located above the membrane module, and the air inlet pipe 7 is connected with an aeration branch pipe 17 located above the membrane module.

The water collection branch pipe 16 is connected with a water suction pipe of a water pump capable of providing negative pressure, and the water to be purified enters the inside of the membrane through the micropores on the wall of the hollow fiber membrane 2, and then flows into the produced water collection chamber 11, and then passes through the produced water collection chamber 11. The water pipe 6 flows into the water collecting branch pipe 16, and finally is extracted by the water pump. The aeration branch pipe 17 is connected with an air source, and the compressed air provided by the air source enters the intake pipe 7 through the aeration branch pipe 17, and then diffuses out through the air distribution holes 10 on the air distribution device 9 with air distribution holes at the upper and lower ends, and directly Purge the root of the membrane filament.

The water production pipes 6 and air inlet pipes 7 of several hollow fiber membrane modules are respectively connected in parallel to the water collection branch pipe 16 and the aeration branch pipe 17, thus forming a matrix membrane module unit (as shown in Figure 7).

Example 2

As shown in FIG. 2 , a hollow fiber membrane module includes a cylindrical casing 1 with an inner diameter of 60mm, the central axis of the casing is a straight line, and the sidewall of the casing is a sidewall without holes. A hollow fiber membrane bundle 3 composed of 240 hollow fiber membranes 2 arranged in the casing 1, the average pore diameter of the micropores of the hollow fiber membranes 2 for passing liquid is 0.08 μm, and the outer surface of the hollow fiber membranes 2 The diameter is 1.35mm, and the material is polyvinylidene fluoride. The upper end of the hollow fiber membrane bundle 3 can swing freely, and each membrane filament is in a closed-cell state. The lower end is cast with epoxy resin and collected in the lower end head 5, and it is re-cast with polyurethane to clean the root of the membrane filament. Protect. The overall shape of the lower end 5 is cup-shaped, and the diameter of the upper circle is 45mm. The hollow fiber membranes 2 are open in the lower end 5, and the lower end 5 is provided with a water production pipe 6 with an outer diameter of Φ8mm, and the water production pipe 6 communicates with the water production collection chamber 11 in the lower end 5. The air intake pipe 7 with an outer diameter of Φ8mm is connected to the air distribution device 9 with air distribution holes through a quick-plug connector 13, and the hollow fiber membranes 2 are evenly distributed around the air intake pipe 7. Inserts 12 are arranged at the upper and lower ports of the housing 1, the lower end 5 is connected with the insert 12 located at the lower port of the housing 1 through a rope 14, the insert 12 is connected with the housing 1 by screws, and the insert 12 There is a round hole with an inner diameter of Φ10mm at the center, and the water production pipe 6 and the air inlet pipe 7 pass through the round hole. The housing 1 is made of UPVC (un-plasticized polyvinyl chloride) plastic. The structure of the air distribution device 9 with air distribution holes and the insert 12 is the same as that of the first embodiment.

The length of the housing 1 is 1.4m, the average length of the hollow fiber membrane bundle 3 is 1.2m, the total height of the lower end 5 and the air distribution device 9 with air distribution holes is 50mm, and the distance between the upper insert and the upper port of the housing is 50mm. The distance is 10mm, and the distance between the lower insert and the lower port of the housing is 10mm.

All the other parts are identical with embodiment 1. Reference numeral 7 in FIG. 3 indicates the water production pipe and the gas inlet pipe in this embodiment.

Example 3

The structure of the membrane module is the same as that of Example 1.

As shown in FIG. 8 , eight hollow fiber membrane modules, water collection head 18 , central pipe 19 and water outlet 20 form a radial membrane module unit. The water production pipe 6 is connected with eight quick-plug joints evenly distributed on the lower end surface of the water collection end 18 with a diameter of 150mm. The membrane modules are evenly distributed around the central pipe 19, and the lower part of the central pipe 19 is connected with the inlet pipes 7 of the eight hollow fiber membrane modules through eight quick-plug joints 13. When the membrane module unit is working, the hollow fiber membrane bundle 3 is surrounded by the liquid to be filtered, and the compressed air provided by the air source enters from the upper opening of the central pipe 19, and enters the inlet pipe 7 of the eight membrane modules, and finally passes through the upper and lower ends. The air distribution holes 10 on the air distribution device 9 with air distribution holes diffuse out to directly purge the roots of the membrane filaments. The water outlet 20 is connected with a water pump capable of providing negative pressure. The water to be purified passes through the hollow fiber membrane filaments on the wall 2 The micropores enter the interior of the membrane filament, and flow into the water production collection chamber 11, and then flow into the water collection terminal 18 through the water production pipe 6, and finally pumped out through the water pump.

The hollow fiber membrane module provided by the present invention has been introduced in detail above. In this description, specific examples are used to illustrate the principles and implementation methods of the present invention. For those skilled in the art, there may be changes in the implementation process and application scope according to the ideas of the present invention. . Therefore, the contents described in this specification should not be understood as limiting the present invention.

Claims (17)

1. A hollow fiber membrane module, comprising a hollow fiber membrane bundle composed of a plurality of hollow fiber membrane filaments, a termination at one or both ends of the hollow fiber membrane bundle, an inlet pipe, a water production pipe and a housing, characterized in that: the The casing is outside the hollow fiber membrane bundle, the casing is a casing that can accommodate the vertically placed hollow fiber membrane bundle, the side wall of the casing is a side wall without holes, and the ports at both ends of the casing are The area of the opening on the surface accounts for more than 10% of the cross-sectional area of the port, and the housing and the terminal are connected together through a detachable structure. 2. The hollow fiber membrane module according to claim 1, wherein the casing is a rigid casing. 3. The hollow fiber membrane module according to claim 1, wherein the casing is a cylindrical casing. 4. The hollow fiber membrane module according to claim 1, characterized in that: the opening area of the ports at both ends of the housing in cross-section accounts for more than 80% of the cross-sectional area of the port. 5. The hollow fiber membrane module according to claim 1, characterized in that: an air distribution device with air distribution holes is provided on the casting end surface of at least one end. 6. The hollow fiber membrane module according to claim 5, characterized in that: the openings of the air distribution holes face the root of the hollow fiber membrane. 7. The hollow fiber membrane module according to claim 5, wherein the air distribution device has at least three hollow spokes, and the air distribution holes are opened on the side of the spokes. 8. The hollow fiber membrane module according to claim 7, wherein the spokes are evenly distributed in a star shape with the center of the end as the center. 9. The hollow fiber membrane module according to claim 1, characterized in that: the air inlet pipe and the water production pipe are inside the casing, and the end of the air inlet pipe connected to the gas source and the end of the water production pipe connected to the water collection pipeline are connected from The top of the housing extends to the outside of the housing. 10. The hollow fiber membrane module according to claim 1, characterized in that: there is an insert with holes at the upper port or the lower port of the casing. 11. The hollow fiber membrane module according to claim 10, characterized in that: the opening area of the insert in the cross section accounts for more than 10% of the cross-sectional area of the insert. 12. The hollow fiber membrane module according to claim 11, characterized in that: the opening area of the insert in the cross section accounts for more than 80% of the cross-sectional area of the insert. 13. The hollow fiber membrane module according to claim 12, characterized in that: said insert has at least three support bars, and there are holes between the support bars. 14. The hollow fiber membrane module according to claim 13, characterized in that: said insert has 3-8 support bars. 15. The hollow fiber membrane module according to claim 1, wherein the detachable structure is a rope connection structure, a buckle structure or a bolt structure. 16. A membrane bioreactor utilizing any one of the hollow fiber membrane modules of claims 1-15. 17. Water treatment equipment using any one of the hollow fiber membrane modules of claims 1-15 or the membrane bioreactor of claim 16.

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