MBR membrane module for sewage treatment

Abstract

The application discloses a kind of MBR membrane components for sewage treatment, including the water outlet pipe (1) with top wall, multiple hollow fiber membrane filaments (2), cleaning spray pipe (3) and carousel (4);The one end of hollow fiber membrane filament (2) is sealedly connected with the top wall of water outlet pipe (1), the other end is sealedly connected with carousel (4), and the hollow portion of hollow fiber membrane filament (2) is communicated with the outlet of water outlet pipe (1);The structure of the MBR membrane component is improved in the application, so that it is convenient to wash online after being applied to the membrane bioreactor for sewage treatment, without disassembling membrane component, and the cleaning effect and efficiency are effectively improved, and the operation is convenient, effectively avoids mechanical damage to membrane filament.

Description

Technical Field

[0002] This invention relates to the field of membrane bioreactor technology, and more specifically to an MBR membrane module for wastewater treatment. Background Technology

[0003] As the core component of a membrane bioreactor (MBR), the filtration performance of the MBR membrane module directly determines the overall system's treatment efficiency and effluent quality. Membrane fouling is an unavoidable problem during the long-term operation of a membrane bioreactor. Impurities such as activated sludge, colloidal particles, microorganisms, organic matter, and inorganic salts in wastewater continuously adsorb and deposit on the membrane surface or clog the membrane pores, forming a sludge cake, biofilm, and scaling. If the membrane module is not cleaned in a timely manner, it will lead to a sharp increase in transmembrane pressure (TMP) and a significant decrease in membrane flux, resulting in increased system energy consumption, deterioration of effluent quality, and in severe cases, membrane fiber breakage and irreversible damage to the membrane module, significantly shortening its lifespan and increasing the system's operating costs and maintenance burden.

[0004] Current MBR membrane modules simply have terminals at both ends of a bundle of hollow fiber membrane filaments to connect the hollow parts of the filaments. If periodic cleaning is required, the membrane module must be disassembled from the reaction tank and transported to a dedicated cleaning area for cleaning using methods such as chemical soaking and high-pressure rinsing. Online cleaning is not possible. This cleaning method has the following drawbacks: 1) The process of disassembling, transporting, and reassembling the membrane module is cumbersome, requiring significant manpower, resources, and time, leading to decreased wastewater treatment efficiency; 2) Disassembly and reassembly can easily cause mechanical damage to the membrane filaments, further shortening the lifespan of the membrane module; 3) Offline cleaning requires dedicated cleaning sites and equipment, resulting in high cleaning costs; 4) Due to the large amount of stubborn sludge adhering to the outer wall of the membrane filaments and between the filaments, the filaments have become bonded together without gaps, significantly reducing the effectiveness of cleaning with water jets alone. Therefore, the development of an MBR membrane module with online cleaning capabilities and improved cleaning efficiency is of significant economic importance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art: to provide an MBR membrane module for wastewater treatment. The present invention improves the structure of the MBR membrane module so that it can be easily cleaned online after being applied to the membrane bioreactor for wastewater treatment without disassembling the membrane module. The cleaning effect and efficiency are effectively improved, and the operation is convenient and effectively avoids mechanical damage to the membrane fibers.

[0006] The technical solution of the present invention is as follows: An MBR membrane module for wastewater treatment includes an outlet pipe with a top wall, multiple hollow fiber membrane filaments, a cleaning spray pipe, and a rotating disk; one end of each hollow fiber membrane filament is sealed to the top wall of the outlet pipe, and the other end is sealed to the rotating disk; the hollow portion of each hollow fiber membrane filament communicates with the outlet of the outlet pipe; the rotating disk and the cleaning spray pipe are rotatably coupled; multiple hollow fiber membrane filaments are distributed around the cleaning spray pipe; the wall of the cleaning spray pipe is uniformly provided with radially arranged spray holes.

[0007] As an optimization, the MBR membrane module includes a driven wheel and a cylindrical shaft that are rotatably engaged with the upper end of the cleaning spray pipe; the driven wheel and the cylindrical shaft are coaxially and fixedly connected.

[0008] As an optimization, the turntable is coaxially and fixedly connected to the cylindrical shaft.

[0009] As another optimization, the turntable is circumferentially limited and axially elastically connected to the cylindrical shaft.

[0010] As an optimization, the turntable and the cylindrical shaft are elastically connected by a tension spring arranged coaxially; the two ends of the tension spring are respectively embedded in the turntable and the cylindrical shaft, the turntable is provided with at least one guide hole perpendicular to its surface, and the cylindrical shaft is provided with a guide rod that slides with the guide hole.

[0011] As an optimization, the driven wheel is either a gear or a synchronous belt pulley.

[0012] As an optimization, the lower opening of the cleaning spray pipe is sealed to the top wall of the water outlet pipe; the upper end of the cleaning spray pipe passes through the turntable, the cylindrical shaft and the driven wheel in sequence and rotates in cooperation with them.

[0013] As an optimization, the cleaning method includes the following steps: First, washing water is pumped into the cleaning spray pipe to generate a radial jet of water; then, the driven wheel is driven by the drive mechanism to rotate alternately in both directions, causing the hollow fiber membrane fibers surrounding the cleaning spray pipe to twist, so that the inner and outer hollow fiber membrane fibers rub against each other, making the sludge more effectively washed away by the jet of water; at the same time, washing water at a certain pressure is pumped into the outlet pipe through the pipeline to backwash the hollow fiber membrane fibers.

[0014] As an optimization, when the driven wheel rotates to its maximum angle in either the forward or reverse direction, the hollow fiber membrane filaments are at their maximum length.

[0015] The beneficial effects of this invention are as follows: By improving the structure of the MBR membrane module, this invention facilitates online cleaning in membrane bioreactors used for wastewater treatment, eliminating the need to disassemble the membrane module. This effectively improves cleaning efficiency and effectiveness, while also providing convenient operation, effectively avoiding mechanical damage to the membrane fibers, and reducing cleaning costs. This invention generates a radial high-pressure jet of water through a cleaning spray pipe located in the middle of the membrane fibers. By controlling the twisting motion of the hollow fiber membrane fibers, the inner and outer layers of the hollow fiber membrane fibers rub against each other, causing relative displacement and peeling / cracking of the sludge. Combined with the radial high-pressure jet of water in the middle, the sludge is more effectively washed away. Furthermore, each hollow fiber membrane fiber sweeps across a certain area during twisting, allowing the jet of water to more comprehensively wash the hollow fiber membrane fibers, greatly reducing cleaning dead zones and significantly improving the cleaning effect. Attached Figure Description

[0016] Figure 1-2 This is a three-dimensional structural diagram of the MBR membrane module for wastewater treatment in Example 1.

[0017] Figure 3 This is a cross-sectional view of the MBR membrane module used for wastewater treatment in Example 1.

[0018] Figure 4 This is a three-dimensional cross-sectional view of the MBR membrane module for wastewater treatment in Example 1.

[0019] Figure 5 This is a schematic diagram of the cross-sectional structure of the MBR membrane module for wastewater treatment in Example 1.

[0020] Figure 6 This is a schematic diagram of the spatial state of the outermost hollow fiber membrane filaments of the MBR membrane module for wastewater treatment in Example 1 after the turntable is twisted at a certain angle.

[0021] Figure 7 This is a schematic diagram of the application state structure of the MBR membrane module for wastewater treatment in Example 1.

[0022] Figure 8 This is a partial cross-sectional view of the MBR membrane module for wastewater treatment in Example 2.

[0023] In the diagram: 1. Water outlet pipe; 2. Hollow fiber membrane filament; 3. Cleaning spray pipe; 4. Turntable; 5. Driven wheel; 6. Cylindrical shaft; 7. Tension spring; 8. Guide rod. Detailed Implementation

[0024] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions apply.

[0025] Example 1 The following is combined with Figure 1-7 A membrane module for wastewater treatment is described, comprising an effluent pipe 1 with a top wall, multiple hollow fiber membrane filaments 2, a cleaning spray pipe 3, and a rotating disk 4; one end of each hollow fiber membrane filament 2 is sealed to the top wall of the effluent pipe 1, and the other end is sealed to the rotating disk 4, with the hollow portion of the hollow fiber membrane filament 2 communicating with the outlet of the effluent pipe 1; the rotating disk 4 is rotatably engaged with the cleaning spray pipe 3; the multiple hollow fiber membrane filaments 2 are distributed around the cleaning spray pipe 3; and the wall of the cleaning spray pipe 3 is uniformly provided with radially arranged spray holes.

[0026] In order to drive the turntable 4 to rotate relative to the cleaning spray pipe 3, the MBR membrane module includes a driven wheel 5 and a cylindrical shaft 6 that are rotatably engaged with the upper end of the cleaning spray pipe 3; the driven wheel 5 and the cylindrical shaft 6 are coaxially and fixedly connected; the turntable 4 and the cylindrical shaft 6 are coaxially and fixedly connected.

[0027] Optionally, the driven wheel 5 is either a gear or a timing belt pulley.

[0028] The lower end opening of the cleaning spray pipe 3 is sealed to the top wall of the water outlet pipe 1; the upper end of the cleaning spray pipe 3 passes through the turntable 4, the cylindrical shaft 6 and the driven wheel 5 in sequence and rotates in cooperation with them.

[0029] like Figure 7 As shown, the MBR membrane module for wastewater treatment of the present invention is vertically installed in the reaction tank. During operation, the hollow fiber membrane filaments 2 are immersed in the wastewater. The effluent pipe 1 is isolated from the wastewater and connected to a water pump outside the reaction tank through a pipeline. The driven wheel 5 is located on the top wall of the reaction tank. The cylindrical rotating shaft 6 is rotatably engaged with a through hole on the top wall of the reaction tank. The turntable 4 is located on the lower side of the top wall of the reaction tank. The upper end of the cleaning spray pipe 3 extends through the turntable 4, the cylindrical rotating shaft 6 and the driven wheel 5 to the outside of the top wall of the reaction tank, and is used to spray water at a certain pressure during cleaning.

[0030] The driven wheel 5 can be driven by a conventional motor, and the specific transmission method can be gears or synchronous belts, which is a conventional driving method.

[0031] In this embodiment, the driven wheel 5 is coaxially and fixedly connected to the cylindrical shaft 6; the turntable 4 is also coaxially and fixedly connected to the cylindrical shaft 6. To avoid excessive stretching of the hollow fiber membrane filament 2 during the rotation of the turntable 4, the length of the hollow fiber membrane filament 2 should be greater than the distance between the turntable 4 and the top wall of the outlet pipe 1. Specifically, the length is adjusted according to the rotation amplitude. The length of the hollow fiber membrane filament 2 is controlled so that when the driven wheel 5 rotates to its maximum angle in either the forward or reverse direction, the hollow fiber membrane filament 2 is at its maximum natural length, thus preventing excessive stretching of the hollow fiber membrane filament 2.

[0032] In the initial state of the MBR membrane module for wastewater treatment of the present invention, the line connecting the two ends of each hollow fiber membrane filament 2 is perpendicular to the lower surface of the turntable 4 and the upper surface of the top wall of the effluent pipe 1. In order to achieve the efficient spray cleaning function of the cleaning spray pipe 3, the hollow fiber membrane filament bundle of the MBR membrane module cannot be wrapped with an outer shell, and the MBR membrane modules in the reaction tank need to be spaced apart.

[0033] During operation, wastewater in the reaction tank of the membrane bioreactor enters the hollow portion of the hollow fiber membrane filaments 2 through the porous outer wall, then converges into the effluent pipe 1. The filtered water in the effluent pipe 1 is continuously pumped out through the pipeline, achieving continuous filtration. However, over time, a large amount of sludge accumulates on the outer wall of the hollow fiber membrane filaments 2 and between the membrane filaments, reducing the filtration efficiency. If online cleaning of the hollow fiber membrane filaments 2 is required, the MBR membrane module of this invention can achieve the following online cleaning, with the specific steps as follows: 1) First, drain the water from the reaction tank, and then pump washing water into the cleaning spray pipe 3 through the pipeline so that the cleaning spray pipe 3 generates a radial jet of water; the washing water can be clean water or conventional cleaning solution.

[0034] 2) The driven wheel 5 is driven by a motor or other drive mechanism to rotate alternately in both directions. For example, starting from 0°, it first rotates clockwise to 30°, then counterclockwise back to its original position of 0°, and then continues to rotate to -30°. This causes the hollow fiber membrane filaments 2 surrounding the cleaning spray pipe 3 to twist, so that the inner and outer layers of hollow fiber membrane filaments 2 rub against each other, making the sludge more effectively washed away by the sprayed water. Because a large amount of stubborn sludge adheres to the outer wall of the hollow fiber membrane filaments 2 and between the membrane filaments, the membrane filaments have become bonded together without gaps. Directly relying on water spray cannot maximize the shear force of the water flow, resulting in poor cleaning effect. However, this invention generates a radial high-pressure spray of water from the cleaning spray pipe 3 located in the middle of the membrane filaments, while simultaneously controlling the twisting action of the hollow fiber membrane filaments 2. Figure 6The spatial state of the outermost hollow fiber membrane filament 2 is shown after the turntable 4 is twisted at a certain angle. At this time, the spatial state of the hollow fiber membrane filament 2 changes, and the inner and outer hollow fiber membrane filaments 2 will also rub against each other, causing the sludge to be relatively displaced and peeled off and cracked, which makes it easier for the high-pressure jet water flow to more effectively wash away the sludge. Moreover, when each hollow fiber membrane filament 2 is twisted, it sweeps around the cleaning spray pipe 3 and passes over a certain area, so that the jet water flow can more comprehensively wash the hollow fiber membrane filament 2, greatly reducing the dead corners of washing. The length of the hollow fiber membrane filament 2 is controlled so that when the driven wheel 5 rotates to the maximum angle in the forward or reverse direction, which is 30° in this embodiment, the hollow fiber membrane filament 2 is just at its maximum length, so as to avoid excessive stretching of the hollow fiber membrane filament 2.

[0035] 3) To optimize the cleaning effect, washing water is pumped through pipelines into the outlet pipe 1 of each MBR membrane module, then into the hollow portion of the hollow fiber membrane filament 2 and discharged from its porous outer wall. This achieves backwashing of the hollow fiber membrane filament 2, further improving the cleaning effect. The pumping pressure of the washing water is the same as the working pressure of the hollow fiber membrane filament 2; the hollow fiber membrane filament 2 is made of conventional polyvinylidene fluoride.

[0036] Example 2 like Figure 8 As shown, unlike the structure of Embodiment 1, the turntable 4 and the cylindrical shaft 6 are circumferentially limited and axially connected by a tension spring 7 coaxially arranged; the two ends of the tension spring 7 are respectively embedded inside the turntable 4 and the cylindrical shaft 6. The turntable 4 is provided with two guide holes perpendicular to its surface, and the cylindrical shaft 6 is provided with a guide rod 8 that slides with the guide holes. The MBR membrane module structure of this embodiment can make the length of the hollow fiber membrane filament 2 equal to the distance between the turntable 4 and the top wall of the outlet pipe 1 when the turntable 4 is in the initial position, without reserving too much redundant membrane filament length to accommodate the membrane filament twisting space. This allows each membrane filament to be stretched straighter, maintaining a larger gap between the hollow fiber membrane filaments 2 and reducing sludge adhesion during operation. After the turntable 4 and the cylindrical shaft 6 are circumferentially limited by the guide rod 8 and axially elastically connected by the tension spring 7, when the turntable 4 rotates a certain angle from its initial position, the turntable 4 can move downward elastically, ensuring that the movement stroke of the turntable 4 is within the stroke range of the guide rod 8. This avoids excessive stretching of the membrane filaments during the rotation of the hollow fiber membrane filaments 2 by the turntable 4, and a certain degree of tension in the membrane filaments can effectively peel off the sludge on their surface, further improving the cleaning effect.

[0037] The above are merely exemplary embodiments of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent exchange or substitution fall within the scope of protection of the present invention.

Claims

1. An MBR membrane module for wastewater treatment, characterized in that, It includes a water outlet pipe (1) with a top wall, multiple hollow fiber membrane filaments (2), a cleaning spray pipe (3), and a turntable (4); one end of the hollow fiber membrane filament (2) is sealed to the top wall of the water outlet pipe (1), and the other end is sealed to the turntable (4); the hollow part of the hollow fiber membrane filament (2) is connected to the outlet of the water outlet pipe (1); the turntable (4) rotates with the cleaning spray pipe (3); multiple hollow fiber membrane filaments (2) are distributed around the cleaning spray pipe (3); the wall of the cleaning spray pipe (3) is uniformly provided with radially arranged spray holes.

2. The MBR membrane module for wastewater treatment according to claim 1, characterized in that, The MBR membrane module includes a driven wheel (5) and a cylindrical shaft (6) that are rotatably engaged with the upper end of the cleaning spray pipe (3); the driven wheel (5) and the cylindrical shaft (6) are coaxially and fixedly connected.

3. The MBR membrane module for wastewater treatment according to claim 2, characterized in that, The turntable (4) is coaxially and fixedly connected to the cylindrical shaft (6).

4. The MBR membrane module for wastewater treatment according to claim 2, characterized in that, The turntable (4) is circumferentially limited and axially elastically connected to the cylindrical shaft (6).

5. The MBR membrane module for wastewater treatment according to claim 4, characterized in that, The turntable (4) and the cylindrical shaft (6) are elastically connected by a tension spring (7) arranged coaxially. The two ends of the tension spring (7) are respectively embedded in the turntable (4) and the cylindrical shaft (6). The turntable (4) is provided with at least one guide hole perpendicular to its surface, and the cylindrical shaft (6) is provided with a guide rod (8) that slides with the guide hole.

6. The MBR membrane module for wastewater treatment according to claim 2, characterized in that, The driven wheel (5) is either a gear or a synchronous belt pulley.

7. The MBR membrane module for wastewater treatment according to claim 3, characterized in that, The lower end opening of the cleaning spray pipe (3) is sealed to the top wall of the water outlet pipe (1); the upper end of the cleaning spray pipe (3) passes through the turntable (4), the cylindrical shaft (6) and the driven wheel (5) in sequence and rotates with them.

8. The MBR membrane module for wastewater treatment according to claim 7, characterized in that, The cleaning method includes the following steps: First, by pumping washing water into the cleaning spray pipe (3), the cleaning spray pipe (3) generates a radial jet of water; then, by driving the driven wheel (5) to rotate alternately in the forward and reverse directions through the drive mechanism, the hollow fiber membrane filaments (2) surrounding the cleaning spray pipe (3) will rotate, so that the inner and outer hollow fiber membrane filaments (2) will rub against each other, so that the sludge will be more effectively washed away by the jet of water; at the same time, a certain pressure of washing water is pumped into the outlet pipe (1) through the pipeline to backwash the hollow fiber membrane filaments (2).

9. The MBR membrane module for wastewater treatment according to claim 8, characterized in that, When the driven wheel (5) rotates to its maximum angle in either the forward or reverse direction, the hollow fiber membrane filament (2) is at its maximum length.

Images