Vortex oscillation on-line cleaning membrane bioreactor

Abstract

The invention discloses a vortex oscillation on-line cleaning membrane bioreactor. Comprising a membrane bioreactor which comprises a non-magnetic shell and a membrane assembly arranged on the membrane bioreactor; the magnetic stirrer comprises a magnetic stirring base and a magnetic stirring driven rotor; the magnetic stirring base is arranged on one side of the membrane bioreactor; the magnetic stirring driven rotor is rotationally arranged on the inner side wall, corresponding to the magnetic stirring base, of the non-magnetic shell; wherein the magnetic stirring driven rotor can be driven by the magnetic stirring base to rotate in the non-magnetic shell so as to stir water in the non-magnetic shell. Double mechanisms of spiral turbulence scouring and vibration cleaning are combined, membrane pollution is attacked from the macroscopic level and the microcosmic level, cleaning is more uniform and thorough, and compaction and solidification of a filter cake layer can be effectively restrained.

Description

A Vortex Oscillation Online Cleaning Membrane Bioreactor Technical Field

[0001] This invention relates to an online cleaning membrane bioreactor using eddy current oscillation. Background Technology

[0002] Membrane bioreactors (MBRs) are a novel water treatment technology that combines efficient membrane separation technology with the traditional activated sludge process. They have significant advantages such as excellent effluent quality, small footprint, and low sludge production, and have been widely used in the treatment of municipal sewage and industrial wastewater.

[0003] However, membrane fouling remains a key challenge limiting the techno-economic viability of MBR systems during long-term operation. Activated sludge flocs, colloidal substances, dissolved organic matter, and microbial metabolites in the mixed liquor adsorb and deposit on the membrane surface and inside the pores, forming a filter cake or gel layer. This leads to a decrease in membrane flux and a continuous increase in transmembrane pressure. To maintain system permeate, the power of the suction pump must be increased, directly resulting in a significant increase in operating energy consumption. When fouling accumulates to a certain level, the system must be cleaned to restore membrane performance.

[0004] Traditional cleaning methods mainly include physical cleaning and chemical cleaning. Physical cleaning (such as backwashing and air scrubbing) is effective for reversible fouling, but it is often not thorough enough. While periodic offline chemical cleaning is more effective, it requires removing the membrane module from the reactor or stopping operation, which is cumbersome, time-consuming, and labor-intensive. Furthermore, frequent use of chemical agents may damage membrane materials, affect microbial activity, and cause secondary pollution. Therefore, developing a technology that can control membrane fouling online, continuously, and efficiently, and reduce or even avoid chemical cleaning, is of vital importance for reducing MBR operating energy consumption, extending membrane life, and improving system stability and economy.

[0005] Existing technologies include methods that utilize rising air bubbles to generate turbulence and scour the membrane surface by adding aeration devices near the membrane module. However, this method has some inherent drawbacks: First, aeration energy consumption typically accounts for more than 70% of the total energy consumption of an MBR system; while increasing aeration intensity can improve the cleaning effect, it exacerbates the energy consumption problem. Second, the shear flow field generated by aeration is unevenly distributed, creating scouring dead zones, and the bottom or fixed areas of the membrane module may not be thoroughly cleaned. Third, membrane modules in traditional MBRs are usually rigidly fixed and cannot dynamically respond to scouring forces, limiting cleaning efficiency. Furthermore, over-aeration can lead to excessively high dissolved oxygen levels in the return liquid from the membrane tank to the anaerobic / anoxic zone, thereby disrupting the anaerobic / anoxic environment and affecting the efficiency of nitrogen and phosphorus removal from wastewater. Summary of the Invention

[0006] To overcome the above shortcomings, the present invention aims to provide an eddy current oscillation online cleaning membrane bioreactor.

[0007] To achieve the above objectives, the present invention provides an eddy current oscillation online cleaning membrane bioreactor, comprising: a membrane bioreactor including a non-magnetic shell and a membrane module disposed in the membrane bioreactor; a magnetic stirrer including a magnetic stirring base and a magnetic stirring driven rotor; the magnetic stirring base is disposed on one side of the membrane bioreactor; the magnetic stirring driven rotor is rotatably disposed on the inner wall of the non-magnetic shell corresponding to the magnetic stirring base; wherein, the magnetic stirring driven rotor can rotate within the non-magnetic shell under the drive of the magnetic stirring base to stir the water in the non-magnetic shell.

[0008] Furthermore, the membrane assembly includes a membrane frame, on which an upper membrane fiber support and a lower upper membrane fiber support are disposed, and hollow fiber membrane fibers are disposed between the upper membrane fiber support and the lower upper membrane fiber support.

[0009] Furthermore, the membrane frame is installed inside the non-magnetic housing via an elastic connector.

[0010] Furthermore, the magnetic stirring base is a magnetic stirring base with a heating function.

[0011] Furthermore, the magnetic stirring driven rotor is olive-shaped, cross-shaped, or star-shaped.

[0012] Furthermore, a rotating shaft is provided at the center of the magnetic stirring driven rotor, and the other end of the rotating shaft is rotatably disposed inside the non-magnetic shell of the membrane bioreactor via bearings and bushings.

[0013] This invention creatively introduces two physical cleaning mechanisms, "power-driven turbulence" and "elastic suspension vibration," and makes them work together: when the magnetic stirring base drives the magnetic stirring driven rotor to rotate at high speed, the magnetic stirring driven rotor is like a built-in submersible stirrer, generating strong swirling and upflow in the reactor, causing the water in the membrane frame to rise in a spiral. This spiraling turbulence washes over each bundle of membrane fibers fixed on the membrane frame in an omnidirectional and non-directional manner, forming the first macroscopic shear force on the membrane surface, breaking up and carrying away the initially deposited pollutants.

[0014] Because the membrane frame is suspended by flexible (elastic) spring links, when irregular water flow is generated inside the reactor due to magnetic stirring, the impact force of the water flow is transmitted to the membrane frame. The elasticity of the spring links allows the membrane frame to vibrate or oscillate slightly and in multiple directions with the force of the water flow. This vibration brings two key effects: a "shaking" effect on the membrane fibers: the connection point between the root of the membrane fiber and the frame is no longer a rigid constraint, and the vibration is transmitted to each membrane fiber, causing it to shake, which helps to shake off tightly attached fouling.

[0015] Changing the local flow field: The continuous micro-movement of the frame constantly changes the relative velocity and direction of the water flow around it, forming a dynamically changing local shear force on the membrane fiber surface, eliminating the "dead zone" caused by the fixed position, and realizing all-round, dead-angle-free micro-cleaning of the membrane surface.

[0016] "Global turbulence" and "local vibration" complement each other. Turbulence provides the initial power source for the vibration of the membrane frame, while vibration more effectively converts the macroscopic flow field energy into cleaning forces acting on the microscopic surface of the membrane fibers. The combination of the two forms a three-dimensional, dynamic online cleaning network, with a cleaning effect far superior to that of simple stirring or fixed aeration scrubbing.

[0017] Compared with existing technologies, this invention has the following significant advantages: High and thorough cleaning efficiency: Combining the dual mechanisms of spiral turbulent scouring and vibration cleaning, it attacks membrane fouling at both macroscopic and microscopic levels, resulting in more uniform and thorough cleaning and effectively inhibiting the compaction and solidification of the filter cake layer. Significantly reduced operating energy consumption, and the stirring intensity can be flexibly controlled by externally adjusting the rotation speed. Most importantly, due to the effective control of membrane fouling, the transmembrane pressure difference (TMP) increases slowly, and the energy consumption of the permeate pump is significantly reduced, which is the most significant energy saving point for the MBR system. High-energy-consuming enhanced aeration scrubbing can be eliminated, further saving energy. Truly online continuous cleaning: The entire cleaning process is carried out synchronously during normal MBR operation, without interrupting the permeate flow, eliminating the need for frequent chemical cleaning and maintenance, and achieving a high degree of automation, ensuring continuous and stable operation of the system and helping to extend the service life of the membrane modules. Attached Figure Description

[0018] Figure 1 is a three-dimensional view of the overall structure of the magnetic stirring online cleaning membrane bioreactor of the present invention.

[0019] Figure 2 is a detailed view of the magnetic stirring base of the present invention.

[0020] Figure 3 shows detailed diagrams of the two membrane frames. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] This invention aims to introduce two mechanisms, "powered turbulence" and "elastic suspension," and make them work together: when the magnetic stirring base drives the magnetic stirring driven rotor to rotate at high speed, the magnetic stirring driven rotor is like a built-in submersible stirrer, generating strong swirling and upflow in the reactor, causing the water in the membrane frame to rise in a spiral. This spiraling upflow of turbulence washes over each bundle of membrane filaments fixed on the membrane frame in an omnidirectional and non-directional manner, forming the first macroscopic shear force on the membrane surface, breaking up and carrying away the initially deposited pollutants.

[0026] Because the membrane frame is suspended by flexible (elastic) spring links, when irregular water flow is generated inside the reactor due to magnetic stirring, the impact force of the water flow is transmitted to the membrane frame. The elasticity of the spring links allows the membrane frame to vibrate or oscillate slightly and in multiple directions with the force of the water flow. This vibration brings two key effects: a "shaking" effect on the membrane fibers: the connection point between the root of the membrane fiber and the frame is no longer a rigid constraint, and the vibration is transmitted to each membrane fiber, causing it to shake, which helps to shake off tightly attached fouling.

[0027] Changing the local flow field: The continuous micro-movement of the frame constantly changes the relative velocity and direction of the water flow around it, forming a dynamically changing local shear force on the membrane fiber surface, eliminating the "dead zone" caused by the fixed position, and realizing all-round, dead-angle-free micro-cleaning of the membrane surface.

[0028] "Global turbulence" and "local vibration" complement each other. Turbulence provides the initial power source for the vibration of the membrane frame, while vibration more effectively converts the macroscopic flow field energy into cleaning forces acting on the microscopic surface of the membrane fibers. The combination of the two forms a three-dimensional, dynamic online cleaning network, with a cleaning effect far superior to that of simple stirring or fixed aeration scrubbing.

[0029] A magnetic stirrer typically consists of a magnetic stirring base and a magnetic driven rotor. The magnetic stirring base provides a rotating magnetic field, driving the magnetic driven rotor (also called a magnetic stir bar) inside the container to rotate, thereby achieving liquid mixing. The magnetic driven rotor can be olive-shaped, cross-shaped, or star-shaped. To prevent the magnetic driven rotor from shifting when not in use, a rotating shaft is located at the center of the rotor. The other end of the rotating shaft is rotatably mounted inside the non-magnetic shell of the membrane bioreactor via bearings and a bushing.

[0030] Example 1, as shown in Figures 1 to 3, describes an online eddy current cleaning membrane bioreactor, comprising: a membrane bioreactor, including a non-magnetic shell 4 and a membrane module 3 disposed within the membrane bioreactor; and a magnetic stirrer, including a magnetic stirring base 1 and a magnetic stirring driven rotor 2. The magnetic stirring base is disposed on one side of the membrane bioreactor (shown as being disposed on the lower side in the figures). The magnetic stirring driven rotor is rotatably disposed on the inner wall of the non-magnetic shell corresponding to the magnetic stirring base. The magnetic stirring driven rotor can rotate within the non-magnetic shell under the drive of the magnetic stirring base to stir the water in the non-magnetic shell. As shown in the figure, the magnetic stirring driven rotor is olive-shaped, cross-shaped, or star-shaped. When the magnetic stirring base drives the magnetic stirring driven rotor to rotate at high speed, the magnetic stirring driven rotor is like a built-in submersible stirrer, generating strong swirling and upflow in the reactor. This causes the water in the membrane frame to rise in a spiral. This spiraling turbulent flow washes over each bundle of membrane fibers fixed on the membrane frame in an omnidirectional and non-directional manner, forming the first macroscopic shear force on the membrane surface, breaking up and carrying away the initially deposited pollutants.

[0031] Example 2 This example is an improvement based on the above examples.

[0032] The membrane module includes a membrane frame and hollow fiber membrane filaments (membranes) mounted on the membrane frame.

[0033] The membrane frame is not rigidly fixed inside the reactor, but is elastically connected to the top of the reactor shell via elastic connectors (such as spring assemblies or rubber elastic connectors). One or more elastic connectors can be designed as needed, making the entire membrane frame-membrane module assembly a movable suspension system.

[0034] Because the membrane frame is suspended by flexible (elastic) spring links, when irregular water flow is generated inside the reactor due to magnetic stirring, the impact force of the water flow is transmitted to the membrane frame. The elasticity of the spring links allows the membrane frame to vibrate or oscillate slightly and in multiple directions with the force of the water flow. This vibration brings two key effects: a "shaking" effect on the membrane fibers: the connection point between the root of the membrane fiber and the frame is no longer a rigid constraint, and the vibration is transmitted to each membrane fiber, causing it to shake, which helps to shake off tightly attached fouling.

[0035] Changing the local flow field: The continuous micro-movement of the frame constantly changes the relative velocity and direction of the water flow around it, forming a dynamically changing local shear force on the membrane fiber surface, eliminating the "dead zone" caused by the fixed position, and realizing all-round, dead-angle-free micro-cleaning of the membrane surface.

[0036] "Global turbulence" and "local vibration" complement each other. Turbulence provides the initial power source for the vibration of the membrane frame, while vibration more effectively converts the macroscopic flow field energy into cleaning forces acting on the microscopic surface of the membrane fibers. The combination of the two forms a three-dimensional, dynamic online cleaning network, with a cleaning effect far superior to that of simple stirring or fixed aeration scrubbing.

[0037] Example 3, as a variation of the above embodiments, can also be configured according to the needs and the structural form of the membrane module, by placing the magnetic stirring base on any side of the membrane bioreactor, such as the left, right, front, rear and / or top side, or at an angle of 30 degrees, 45 degrees, 60 degrees, etc., with respect to the membrane module, so as to use the magnetic stirring driven rotor to rotate in the non-magnetic shell from one or more desired directions to stir the water in the non-magnetic shell.

[0038] In summary, this invention offers the following significant advantages: High and thorough cleaning efficiency: Combining the dual mechanisms of spiral turbulent scouring and vibration cleaning, it attacks membrane fouling at both macroscopic and microscopic levels, resulting in more uniform and thorough cleaning and effectively inhibiting the compaction and solidification of the filter cake layer. Significantly reduced operating energy consumption: The magnetic stirring base can be driven by magnetic stirring or a motor, and the stirring intensity can be flexibly controlled by externally adjusting the speed. Most importantly, due to the effective control of membrane fouling, the transmembrane pressure difference (TMP) increases slowly, significantly reducing the energy consumption of the permeate pump, which is the most significant energy saving point for the MBR system. High-energy-consuming enhanced aeration scrubbing can be eliminated, further saving energy. Truly continuous online cleaning: The entire cleaning process is carried out synchronously during normal MBR operation, without interrupting the permeate flow or requiring frequent chemical cleaning and maintenance. The high degree of automation ensures continuous and stable operation of the system, helping to extend the service life of the membrane modules.

[0039] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0040] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0041] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A vortex-oscillation online cleaning membrane bioreactor, characterized in that, include: A membrane bioreactor, comprising a non-magnetic shell and a membrane module disposed within the membrane bioreactor; A magnetic stirrer, comprising a magnetic stirring base and a magnetic stirring driven rotor; A magnetic stirring base is positioned on one side of the membrane bioreactor. The magnetic stirring driven rotor is rotatably mounted on the inner wall of the non-magnetic shell corresponding to the magnetic stirring base; wherein, the magnetic stirring driven rotor can rotate inside the non-magnetic shell under the drive of the magnetic stirring base to stir the water in the non-magnetic shell.

2. The eddy current oscillation online cleaning membrane bioreactor as described in claim 1, characterized in that, The membrane assembly includes a membrane frame, on which an upper membrane fiber support and a lower upper membrane fiber support are disposed, and hollow fiber membrane fibers are disposed between the upper membrane fiber support and the lower upper membrane fiber support.

3. The eddy current oscillation online cleaning membrane bioreactor as described in claim 2, characterized in that, The membrane frame is installed inside the non-magnetic housing via elastic connectors.

4. The eddy current oscillation online cleaning membrane bioreactor as described in claim 1, characterized in that, The magnetic stirring base is a magnetic stirring base with a heating function.

5. The eddy current oscillation online cleaning membrane bioreactor as described in claim 1, characterized in that, The magnetic stirring driven rotor is olive-shaped, cross-shaped, or star-shaped.

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