Rotary organic nanofiltration membrane filtering device

Abstract

The rotary organic nanofiltration membrane filtering device comprises a pressure container, a driving device, a shaft body which extends out of the pressure container and is connected with the driving device, and a filtering structure which is arranged on the shaft body in the pressure container, the driving device drives the shaft body to drive the filtering structure to rotate, and filtrate penetrating through the filtering membrane enters the liquid discharging channel to the outside of the pressure container after passing through the collecting space to be discharged. By introducing a rotary motion mechanism, the problems of high energy consumption, easiness in blockage, difficulty in cleaning and the like of a traditional roll type nanofiltration membrane are successfully solved, and a filtering device which is more efficient, energy-saving and easy to maintain is provided for a user.

Description

Technical Field

[0001] The invention belongs to the field of filtration and purification, and in particular relates to a rotary organic nanofiltration membrane filtration device. Background Art

[0002] Nanofiltration is a pressure-driven membrane separation technology between ultrafiltration and reverse osmosis. It can effectively remove pollutants such as multivalent ions, organic matter and microorganisms in water. The pore size of nanofiltration membrane is usually around 1 nanometer, which is slightly larger than the pore size of reverse osmosis membrane, but smaller than the pore size of ultrafiltration membrane. Therefore, it can achieve selective separation of substances in a specific molecular weight range at a lower operating pressure. Nanofiltration technology is widely used in drinking water treatment, wastewater reuse, food processing and pharmaceutical industries.

[0003] Most nanofiltration membrane components use a roll structure. This structure is made of multi-layer membranes and support meshes wound in a spiral form and encapsulated in a cylindrical pressure vessel. By winding the multi-layer membranes and support meshes in a spiral form around a central tube, the roll membrane can provide a larger effective filtration area in a limited space, thereby improving the processing efficiency per unit volume; the entire component is encapsulated in a cylindrical pressure vessel, which occupies a small space and is suitable for installation in facilities of various sizes; the standardized design facilitates large-scale production and installation, reduces costs and increases market penetration.

[0004] The existing rolled nanofiltration membrane is placed statically inside a pressure vessel, but its internal flow channel is narrow, which can easily lead to uneven material flow and increase the risk of blockage. When liquids containing microorganisms, organic matter, inorganic salts and other suspended particles pass through, these substances can easily adhere to the membrane surface or deposit in the narrow filtration flow channel. Over time, these sediments will gradually accumulate to form a thick biofilm or dirt layer, resulting in a significant decrease in membrane flux, increased cleaning frequency and maintenance costs. At the same time, in order to ensure sufficient permeability and reduce the rate of contamination, it is usually necessary to increase the feed flow rate and operating pressure. However, this not only increases energy consumption, but may also cause mechanical damage to the membrane material and shorten its service life. At the same time, high-pressure operating conditions also require more durable pressure vessels and other supporting facilities, thereby increasing equipment investment costs. Summary of the invention

[0005] The present invention aims to provide a rotary organic nanofiltration membrane filtration device to solve the technical problems of low filtration effect, high energy consumption and easy pollution of traditional roll-type nanofiltration devices.

[0006] To achieve the above purpose, the specific technical solution of a rotary organic nanofiltration membrane filtration device of the present invention is as follows:

[0007] A rotary organic nanofiltration membrane filtration device comprises a pressure vessel, a driving device, a shaft extending from the pressure vessel and connected to the driving device, and a filtering structure arranged on the shaft in the pressure vessel;

[0008] The hollow interior of the shaft body is provided with a drainage channel, the drainage channel is opened at the protruding end of the shaft body relative to the pressure vessel to form a drainage port, the shaft body is provided with a drainage hole connected to the drainage channel, the drainage hole is connected to the filter structure, and the filtrate collected by the filter structure is introduced into the drainage channel;

[0009] The filtering structure comprises a filter guide plate and a filter membrane which are sequentially sleeved on the shaft body, the filter guide plate clamps the filter membrane on both sides, the filter membrane surface is covered with a filter membrane, and the interior is hollow to form a collection space, and the filter membrane is provided with a filtrate hole which communicates with the collection space and the drainage hole;

[0010] The driving device drives the shaft body to drive the filtering structure to rotate, and the filtrate that passes through the filtering membrane enters the drainage channel after passing through the collecting space and is discharged outside the pressure container.

[0011] As a further improvement of the present invention, a plurality of relatively protruding protrusions are provided on the side of the filter guide plate surface facing the filter membrane, and the protrusions guide the flow of the material to be filtered between the filter guide plate and the filter membrane.

[0012] As a further improvement of the present invention, the filter guide plate protrudes on both sides to form a clamping portion, and the clamping portion clamps the filter membrane on both sides.

[0013] As a further improvement of the present invention, a sealing groove is concavely provided on the surface of the clamping portion, and a sealing gasket is placed in the sealing groove.

[0014] As a further improvement of the present invention, a filter bracket is arranged inside the filter membrane, and the filter bracket divides the collection space into a plurality of filter slots. The filter slots are provided with the filtrate holes on the contact side between the filter membrane and the shaft body, and the filter membrane covers the filter slots. The filtrate passing through the filter membrane enters the filter slots and is discharged through the filtrate holes.

[0015] As a further improvement of the present invention, the driving device includes a driving housing and a driving motor. After the shaft extends out of the pressure vessel, it is rotatably connected to the driving housing. The output shaft of the driving motor drives the shaft to rotate in the driving housing. The drain port passes through the driving housing to discharge the filtrate or serves as a liquid inlet to connect to the cleaning liquid to realize backwashing of the filter membrane.

[0016] As a further improvement of the present invention, a connection port for the shaft to pass through is provided on one side of the pressure vessel, a dynamic seal is provided on the inner side of the pressure vessel, and the connection port is covered with the drive housing on the outer side of the pressure vessel.

[0017] As a further improvement of the present invention, the pressure vessel is provided with a feed port and a discharge port for the material to be filtered, and the feed port is connected to a high-pressure pump, through which the material to be filtered is discharged into the pressure vessel.

[0018] As a further improvement of the present invention, one end of the shaft body located in the pressure vessel is relatively concave to form a connecting section, the filter guide plate and the filter disc are stacked and sleeved on the connecting section in sequence, and the locking structure squeezes the filter structure along the connecting section to achieve the installation of the filter structure on the connecting section.

[0019] As a further improvement of the present invention, the filtration membrane is an organic nanofiltration membrane.

[0020] Beneficial effects:

[0021] The drive device drives the shaft and the filter structure installed on it to rotate, changing the working mode of the traditional static membrane assembly. This rotational motion can effectively break the boundary layer, promote the uniform flow of liquid on the membrane surface, reduce the phenomenon of excessive or low local flow rate, and thus improve the overall fluid dynamics. The rotational motion causes the material to be filtered to form a surface tangential force on the surface of the filter membrane. This tangential force not only helps to maintain the uniform distribution of the material on the membrane surface, but more importantly, it can effectively prevent particles from directly impacting and adhering to the membrane surface. When the material passes over the membrane surface in a tangential direction, solutes and water molecules with smaller molecular weights are more likely to pass through the membrane, while substances with larger molecular weights are retained. This mechanism significantly improves filtration efficiency and reduces the possibility of clogging, while also helping to maintain higher flux and lower pressure loss.

[0022] A number of relatively protruding protrusions arranged on the surface of the filter guide plate guide the flow of the material to be filtered between the filter guide plate and the filter membrane, further enhancing the turbulence of the fluid and reducing the risk of clogging.

[0023] Since the rotary motion improves the mass transfer efficiency, the same filtering effect can be achieved at a lower operating pressure, reducing energy consumption. At the same time, since the occurrence of fouling is reduced, there is no need to frequently increase the feed flow rate to maintain the permeability, further saving energy consumption.

[0024] The shear force brought by the rotational motion helps to remove pollutants attached to the membrane surface, plays a certain self-cleaning role, and slows down the rate of membrane fouling. In addition, the rotational motion can also prevent microorganisms and other substances from forming a stable biofilm on the membrane surface, reducing the cleaning frequency and maintenance costs.

[0025] By optimizing the structure of the membrane assembly (such as setting up a filter support inside and dividing the collection space into multiple filter slots), not only the mechanical strength of the membrane is improved, but also the stress concentration points during the filtration process are dispersed, reducing the risk of membrane rupture, thereby extending the service life of the membrane. The filter membrane covering the surface of the filter membrane can efficiently intercept the target pollutants, while the collection space formed inside ensures that the filtrate is quickly collected and enters the drainage channel through the drainage hole, improving the efficiency of the entire filtration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic structural diagram of a rotary organic nanofiltration membrane filtration device of the present invention;

[0027] Figure 2 It is a schematic diagram of the shaft body and the filter structure;

[0028] Figure 3 It is a schematic diagram of the structure of the filter guide plate and the filter membrane;

[0029] Explanation of the markings in the figure: 1. Pressure vessel; 11. Feed inlet; 12. Discharge outlet; 13. Connection port; 14. Dynamic seal; 2. Shaft; 21. Drain channel; 22. Drain hole; 23. Drain port; 24. Connecting section; 25. Locking structure; 3. Filter structure; 31. Filter guide plate; 311. Protrusion; 312. Clamping portion; 313. Sealing groove; 314. Sealing gasket; 32. Filter membrane; 321. Filter membrane; 322. Filter bracket; 323. Filter tank; 324. Filtrate hole; 4. Driving device; 41. Driving housing; 42. Driving motor. DETAILED DESCRIPTION

[0030] In order to better understand the purpose, structure and function of the present invention, a rotary organic nanofiltration membrane filtration device of the present invention is further described in detail below in conjunction with the accompanying drawings.

[0031] Implementation example:

[0032] like Figure 1 A rotary organic nanofiltration membrane filtration device is shown, which filters the material to be filtered in a closed pressure vessel 1. The driving device 4 drives the shaft 2 to drive the filtering structure 3 to rotate in the pressure vessel 1. The material to be filtered flows in the filtering structure 3, and the particles are retained and filtered through the clear liquid under the action of the surface shear force.

[0033] The pressure vessel 1 is used as a container for the entire filtration process. Since the nanofiltration process needs to be carried out under a certain pressure to ensure that the material to be filtered can effectively pass through the nanofiltration membrane, the pressure vessel 1 can withstand and maintain this operating pressure, ensuring the smooth progress of the filtration process. The pressure vessel 1 has a feed port and a discharge port on both sides. The feed port is connected to a high-pressure pump. The high-pressure pump discharges the material to be filtered into the pressure vessel 1. The high-pressure pump serves as the pressure supply end for filtration, ensuring that the liquid can effectively pass through the membrane surface to achieve selective separation. At the same time, by adjusting the working parameters of the high-pressure pump (such as speed, displacement, etc.), the material flow rate entering the system can be accurately controlled to adapt to different processing requirements and working conditions. The pressure vessel 1 prevents internal liquid or gas from leaking into the external environment through a sealing design, and also prevents external pollutants from entering the system, maintaining the cleanliness and safety of the system.

[0034] like Figure 2 As shown, the shaft body 2 is a hollow tube, one end of which is located in the pressure vessel 1, and the other end extends out of the opening of the pressure vessel 1. The hollow interior is a drainage channel 21, and the collected filtrate is discharged through the drainage port 23 at the open end. The shaft body 2 passes through the connection port 13 on the side of the pressure vessel 1. The inner side of the connection port 13 is provided with a dynamic seal 114, and the outer side is covered by the drive housing 41, which ensures the sealing of the pressure vessel 1. There is a thinner connecting section 24 at one end of the shaft body 2 located in the pressure vessel 1, and the filter structure 3 is set on the connecting section 24. The connecting section 24 is closed at the top of the shaft body 2 by the locking structure 25 to press the filter structure 3. In this embodiment, the locking structure 25 is a screw, and the inner side of the opening at the top of the connecting section 24 is an internal thread structure. The external thread of the screw enters the opening, and the nut presses the filter structure 3 on the outside. A drainage hole 22 is radially provided on the surface of the connecting section 24, and the drainage hole 22 is used to discharge the filtrate collected by the filter structure 3 into the drainage channel 21. The locking structure 25 allows the filtration structure 3 to be easily installed and disassembled, and is convenient for regular inspection and replacement of membrane elements, thereby ensuring long-term stable operation of the system.

[0035] like Figure 3As shown, the filter structure 3 includes a filter guide plate 31 and a filter disc 32 stacked in sequence along the shaft 2. The filter guide plate 31 and the filter disc 32 are corresponding annular structures. The two sides of the filter guide plate 31 are relatively protruding to form a clamping portion 312. The end surface of the clamping portion 312 is concave and provided with a sealing groove 313. The sealing groove 313 is provided with a sealing gasket 314 to ensure the sealing connection between the filter guide plate 31 and the filter membrane 32 to avoid leakage. The filter membrane 32 includes a filter support 322 and a filter membrane 321 containing the filter support 322. In this embodiment, the filter membrane 321 is an organic nanofiltration membrane. The filter support 322 divides the collection space inside the filter membrane 32 into a plurality of filter slots 323. Each filter slot 323 is provided with a filtrate hole 324 on the inner side of the annular filter membrane 32. The filtrate passing through the filter membrane 321 is stored in the filter slot 323 and flows into the drainage hole 23 through the filtrate hole 324. The filter bracket 322 provides the necessary mechanical support for the filter membrane 321 to ensure that it will not be deformed or damaged due to external pressure under high-pressure environment. In particular, during rotational movement, the filter bracket 322 can stably maintain the shape of the filter membrane to prevent it from shifting or twisting, thereby reducing the risk of rupture of the filter membrane 321 due to stress concentration.

[0036] The surface of the filter guide plate 31 is provided with an array of protrusions facing the filter membrane 32. The protrusions 311 extending toward the surface of the filter membrane 32 further strengthen the clamping effect and break the laminar flow state formed by the liquid on the membrane surface, causing the liquid to generate turbulence. This turbulence can distribute the material to be filtered more evenly, reduce concentration polarization, and improve mass transfer efficiency. Turbulence increases the contact opportunity between the liquid and the membrane surface, allowing more solute molecules to have the opportunity to approach and pass through the nanofiltration membrane, thereby improving the filtration effect. Due to the presence of the protrusions 311, the liquid forms a local high-speed flow area when passing through, which helps to prevent particles from directly impacting and depositing on the membrane surface, reducing the possibility of blockage. When the liquid bypasses the protrusions at a higher speed, the shear force generated can effectively remove the pollutants that have been attached to the membrane surface, play a certain self-cleaning role, and slow down the speed of membrane pollution. The flow direction of the material to be filtered is guided between the filter guide plate and the filter membrane to ensure that the material flows along the expected path, avoid the formation of dead corners, and improve the filtration efficiency.

[0037] The driving device 4 is arranged on the outside of the pressure vessel 1, and the driving shell 41 covers the connecting port 13 and is connected to the side of the pressure vessel 1. The output shaft of the driving motor 42 extends into the driving shell 41, and drives the shaft body 2 to rotate inside the driving shell 41. The shaft body 2 is connected to the driving shell 41 through a bearing in the shell, and the discharge port 23 of the shaft body 2 passes through the driving shell 41. The discharge port 23 can not only be used as a channel for discharging the filtrate, but also as an inlet for accessing the cleaning liquid, which is used to backwash the filter membrane 321, thereby increasing the operational flexibility and maintenance convenience of the system.

[0038] The filter device of the present invention effectively breaks the static boundary layer formed by the liquid on the membrane surface by rotating the filter membrane, promotes the uniform distribution and flow of the liquid, and reduces the phenomenon of excessive or low local flow rate. The turbulence caused by the rotation increases the contact opportunity between the liquid and the membrane surface, significantly enhances the mass transfer efficiency, and reduces the concentration polarization phenomenon. Since the rotational motion improves the mass transfer efficiency, the same filtering effect can be achieved at a lower operating pressure, reducing energy consumption. Compared with the traditional static device, it is not necessary to maintain the permeability by increasing the feed flow rate, which further saves energy consumption. The shear force brought by the rotational motion helps to remove pollutants attached to the membrane surface, plays a certain self-cleaning role, and slows down the speed of membrane pollution. This not only reduces the cleaning frequency, but also prolongs the service life of the membrane. It can also prevent microorganisms and other substances from forming a stable biofilm on the membrane surface, reducing the blockage problem caused by the biofilm. The rotational motion causes the material to be filtered to form a surface tangential force on the surface of the filter membrane. This mechanism not only improves the filtration efficiency, but also reduces the possibility of blockage. Solutes and water molecules with smaller molecular weights are more likely to pass through the membrane, while substances with larger molecular weights are retained.

[0039] It is to be understood that the present invention is described by some embodiments, and it is known to those skilled in the art that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A rotary organic nanofiltration membrane filtration device, characterized in that: It comprises a pressure vessel, a driving device, a shaft extending from the pressure vessel and connected to the driving device, and a filtering structure arranged on the shaft in the pressure vessel; The hollow interior of the shaft body is provided with a drainage channel, the drainage channel is opened at the protruding end of the shaft body relative to the pressure vessel to form a drainage port, the shaft body is provided with a drainage hole connected to the drainage channel, the drainage hole is connected to the filter structure, and the filtrate collected by the filter structure is introduced into the drainage channel; The filtering structure comprises a filter guide plate and a filter membrane which are sequentially sleeved on the shaft body, the filter guide plate clamps the filter membrane on both sides, the filter membrane surface is covered with a filter membrane, and the interior is hollow to form a collection space, and the filter membrane is provided with a filtrate hole which communicates with the collection space and the drainage hole; The driving device drives the shaft body to drive the filtering structure to rotate, and the filtrate that passes through the filtering membrane enters the drainage channel after passing through the collecting space and is discharged outside the pressure container.

2. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: A plurality of relatively protruding protrusions are arranged on the side of the filter guide plate surface facing the filter membrane, and the protrusions guide the flow of the material to be filtered between the filter guide plate and the filter membrane.

3. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: The filter guide disc protrudes on both sides to form a clamping portion, and the clamping portion clamps the filter membrane on both sides.

4. The rotary organic nanofiltration membrane filtration device according to claim 3, characterized in that: The surface of the clamping portion is concavely provided with a sealing groove, and a sealing gasket is placed in the sealing groove.

5. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: A filter bracket is arranged inside the filter membrane, and the filter bracket divides the collection space into a plurality of filter slots. The filter slots are provided with the filtrate holes on the contact side between the filter membrane and the shaft body. The filter membrane covers the filter slots, and the filtrate passing through the filter membrane enters the filter slots and is discharged through the filtrate holes.

6. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: The driving device includes a driving housing and a driving motor. The shaft body is rotatably connected to the driving housing after extending out of the pressure vessel. The output shaft of the driving motor drives the shaft body to rotate in the driving housing. The drain port passes through the driving housing to discharge the filtrate or serves as a liquid inlet to connect the cleaning liquid to realize backwashing of the filter membrane.

7. The rotary organic nanofiltration membrane filtration device according to claim 6, characterized in that: A connection port for the shaft to pass through is arranged at one side of the pressure container, a dynamic seal is arranged on the inner side of the pressure container, and the connection port is covered with the drive housing on the outer side of the pressure container.

8. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: The pressure container is provided with a feed inlet and a discharge port for the material to be filtered to enter and exit, and the feed inlet is connected to a high-pressure pump, through which the material to be filtered is discharged into the pressure container.

9. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: One end of the shaft body located in the pressure vessel is relatively concave to form a connecting section, the filter guide plate and the filter disc are stacked and sleeved on the connecting section in sequence, and the locking structure squeezes the filter structure along the connecting section to achieve the installation of the filter structure on the connecting section.

10. The rotary organic nanofiltration membrane filtration device according to claim 1, characterized in that: The filtration membrane is an organic nanofiltration membrane.

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