Cross-flow membrane filtering device

Abstract

The invention discloses a cross-flow membrane filtering device which is characterized in that filtering assemblies with multiple layers of sandwich structures are arranged on a bracket of a cross-flow membrane filter at intervals, a liquid inlet channel, a filtrate channel and a concentrated liquid circulating channel are arranged in a manner of penetrating through the filtering assemblies, and the filtrate channel is isolated from the liquid inlet channel and the concentrated liquid circulating channel; the filtering assembly comprises a stainless steel disc fixedly connected with the support, flow guide film cushion layers communicated with the filtrate channel are arranged on the upper and lower surfaces of the stainless steel disc, and filtering films are arranged on the outer surfaces of the flow guide film cushion layers; a torsion bar is fixed to the bottom of the support, the other end of the torsion bar is fixed to a base, and a vibration mechanism is arranged on the base. The vibration mechanism drives the base to reciprocate in the horizontal direction, and the torsion bar drives the support to reciprocate to transmit high-frequency shearing force parallel to the membrane surface to the filter membrane, so that large particles are prevented from being deposited, large particle substances float to be combined with macromolecular polymers, the large particles are prevented from being deposited to the membrane surface again, the filter membrane is prevented from being polluted and blocked, and the filtering efficiency is improved. And the service life of the filter membrane is prolonged.

Description

Technical Field

[0001] The invention relates to a filtering device, in particular to a cross-flow membrane filtering device. Background Art

[0002] Filtration is generally divided into terminal filtration and cross-flow filtration. When the concentration of the substance to be separated in the original liquid is low, terminal filtration is generally used. Compared with traditional terminal filtration, the flow direction of the solution in cross-flow filtration is parallel to the filter membrane. The water flow generates two components on the membrane surface. One is the normal force perpendicular to the membrane surface, which makes water molecules and particles smaller than the membrane pores pass through the membrane surface to form a clean liquid. The other is the shear force parallel to the membrane surface, which flushes the retained substances on the membrane surface and continues to flow along the filter membrane surface, which can reduce the concentration difference polarization phenomenon and scaling problems. Therefore, it is not easy to form filter cakes on the surface of the filter membrane and cause the filter element to be blocked. However, as the filtration time increases or the shear force of the fluid is insufficient, it is still inevitable that small particles will be deposited on the edge of the filter to form a thin layer of filter cake to pollute the filter membrane and affect the filtration effect, increasing the difficulty of cleaning the filter element and shortening the service life of the filter element. Summary of the invention

[0003] Purpose of the invention: The purpose of the present invention is to reduce membrane surface pollution, improve filtering effect and extend the service life of the filter membrane, and to provide a cross-flow membrane filtration device.

[0004] Technical solution: A cross-flow membrane filtration device of the present invention comprises a cross-flow membrane filter, the cross-flow membrane filter comprises a housing and a bracket, a multi-layer sandwich structure filter assembly is arranged at intervals on the bracket, a liquid inlet channel connected to the liquid to be filtered, a filtrate channel and a concentrated liquid channel for circulating and filtering the material flowing through the filter are arranged through the filter assembly, and an O-ring for isolating the filtrate from the original liquid and the concentrated liquid is arranged between the filter assemblies and on the periphery of the filtrate channel; the filter assembly comprises a stainless steel plate fixedly connected to the bracket, a guide membrane cushion layer connected to the filtrate channel is arranged on the upper and lower surfaces of the stainless steel plate, and a filter membrane is arranged on the outer surface of the guide membrane cushion layer; a torsion bar is fixed at the bottom of the bracket, and the other end of the torsion bar is fixed on the base, and a vibration mechanism is arranged on the base to drive the base to reciprocate in the horizontal direction and then drive the bracket to reciprocate in the horizontal direction through the torsion bar to transmit high-frequency shear force parallel to the membrane surface to the filter membrane, and the torsion bar is suspended on the support rod through the buffer assembly; and also includes a control panel for controlling the vibration mechanism and the operation of the cross-flow membrane filter.

[0005] Furthermore, the cross-flow membrane filter adopts a frame structure, and the bracket is made of high-strength materials to provide all-round support for the filter membrane, firmly wrapping the multi-layer filter membrane, ensuring that the filter membrane will not be deformed by pressure during filtration and can maintain a stable shape and position relationship during the filtration process. The filter membrane is the core component for achieving material separation. It has a fine membrane pore structure. According to the molecular size or other physical and chemical properties of the substance to be filtered, the appropriate material and pore size are selected to screen and separate the components in the liquid.

[0006] Furthermore, the torsion bar is made of rubber material, which enables a flexible connection between the base and the bracket of the cross-flow membrane filter, thereby providing a certain degree of protection for the cross-flow membrane filter, effectively absorbing the expansion or contraction caused by impact, vibration or temperature changes in the transmission system, reducing vibration and noise, alleviating stress concentration, and reducing the occurrence of damage, thereby extending the service life of the entire system and equipment, and improving the stability, safety and filtration efficiency of the equipment.

[0007] Furthermore, the buffer assembly includes a pipe clamp mounted on the torsion bar, a rubber head for buffering is fixed on one side of the pipe clamp, and the other side of the rubber head is connected to the support bar through a connecting rod. By suspending the buffer assembly on the support bar, the cross-flow membrane filter is in a suspended state, and the buffer assembly can offset the influence of the torsion bar on the support bar during vibration, prevent the support bar from vibrating during the filtration process, and ensure the stability of the entire device.

[0008] Furthermore, the vibration mechanism includes a motor, and the base is a hollow structure, in which an eccentric block is arranged, and the motor drives the eccentric block to reciprocate in the horizontal direction, thereby driving the base to reciprocate in the horizontal direction. The motor drives the eccentric block to rotate in the horizontal direction, and the centrifugal force generated by the unbalanced mass changes with time in one direction, thereby generating a reciprocating motion in a straight line direction, thereby driving the base to reciprocate in the horizontal direction. The base is fixedly connected to the torsion bar, and the reciprocating motion is transmitted to the bracket of the cross-flow membrane filter through the torsion bar, thereby generating a high-frequency shear force parallel to the membrane surface on the surface of the filter membrane. This shear force has no direct relationship with the flow rate of the feed liquid. The feed flows along the filter membrane, and the small molecule filtrate passes through the filter membrane into the filtrate channel and is discharged. The high-frequency shear force can prevent large particles from depositing on the surface of the filter membrane. Under the action of the shear force, the particles are separated from the filter membrane surface and suspended in the feed liquid and flow away with the feed liquid flow, thereby avoiding pollution or blockage of the membrane surface, thereby improving the filtration efficiency and the service life of the filter membrane and reducing the pressure of the filter channel. In addition, the detached particles and pollutants will combine with the macromolecular polymers in the filtrate to form relatively large aggregates. After the size increases, it is difficult to attach to the membrane pores of the filter membrane again, thereby further effectively avoiding the blockage of the filter membrane pores and ensuring the continuous and efficient filtration process.

[0009] Furthermore, a coupling is provided between the output shaft of the motor and the eccentric block to reduce vibration and impact, and the other end of the coupling is connected to a transmission shaft fixed to the eccentric block. When the motor outputs high-speed rotational force, the coupling has the functions of buffering and shock absorption, ensuring that the rotational force of the motor can be smoothly transmitted to the eccentric block, ensuring that the eccentric block produces a smooth reciprocating motion, and further ensuring that an effective and stable high-frequency shear force is generated on the membrane surface of the filter membrane.

[0010] Furthermore, the transmission shaft passes through the base, and bearing seats for improving the stability of the transmission shaft are arranged on the upper and lower surfaces of the base, thereby further ensuring the stable transmission of the rotational force between the motor and the eccentric block.

[0011] Furthermore, a buffer block is arranged on the bottom surface of the base at a position opposite to the torsion bar. The buffer block is arranged at the bottom of the torsion bar to support and buffer vibration of the torsion bar, reduce vibration impulse to the frame, and prevent vibration of the frame during filtering.

[0012] Furthermore, a fixing ring is arranged on the periphery of the O-ring to enhance the stability of the O-ring, thereby further ensuring the isolation performance between the filter channel and the filtered material, thereby ensuring the filtering effect.

[0013] Furthermore, the liquid inlet channel and the filtrate channel are connected to the liquid storage tank through a pipeline. Small particles pass through the filter membrane and the guide membrane cushion layer into the filtrate and are discharged after passing through. The feed liquid with increasing concentration is continuously circulated and input into the cross-flow membrane filter for filtration. After a period of time, the concentrated liquid with a concentration reaching a certain index is collected in the liquid storage tank.

[0014] Furthermore, it also includes a frame for preventing collision on the periphery, which is a hollow metal frame with a rectangular frame structure, and a metal connecting plate is fixed at the corner to ensure the firmness of the frame. The support rod is fixed on the frame, the base is suspended in the frame, and the motor is also fixed on the frame through a fixing block. This ensures that the motor rotates to drive the base to do reciprocating motion in the frame.

[0015] Furthermore, a plurality of universal wheels are arranged at the bottom of the frame, and adjacent universal wheels are connected by rubber blocks and fixed to the bottom of the frame. The universal wheels are Fumar wheels, connected to the frame by shock-absorbing rubber blocks and spring telescopic rods. The rubber blocks arranged at the connection parts are used to buffer the vibrations generated during use or movement, and to isolate the interference of adverse factors such as external vibrations and bumps on the accuracy and stability of the filtering operation to the greatest extent, providing a solid and reliable basic guarantee for the efficient and stable development of the filtering work.

[0016] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: 1. The vibration mechanism drives the cross-flow membrane support to reciprocate in the horizontal direction through the torsion bar, so that a high-frequency shear force perpendicular to the membrane surface is formed between the filter membrane and the feed liquid, preventing large particles from being deposited on the filter membrane surface, thereby preventing the filter membrane from being contaminated and blocked, improving the filtration efficiency, and extending the service life of the filter membrane. It has the advantages of high flux, high filtration rate, high concentration, high efficiency, low blockage, low energy consumption and low cost; 2. The shear force brought by the vibration mechanism disturbs the parallel and membrane surface formed between the filter membrane and the feed liquid. The shear force reduces or avoids the damage to the filter membrane caused by the flow of feed liquid, further extending the service life of the filter membrane; 3. The efficient shear force makes the large particles float up, and then combines with the macromolecular polymers in the filtrate, effectively avoiding the large particles from depositing on the membrane surface again. The filter membrane surface is not easy to be polluted and blocked, the filtrate recovery rate is improved, the pressure during filtration is reduced, and the frequency of filter membrane cleaning is reduced. It can be used with various filter membranes in a wide range of applications; 4. Shock-absorbing universal wheels are set to facilitate movement while preventing the influence of vibration and bumps on the filtration effect and damage to the filter membrane during movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention;

[0018] Figure 2 is a cross-sectional view of the structure of the present invention;

[0019] Figure 3 It is a schematic diagram of the structure of the cross-flow membrane filter of the present invention;

[0020] Figure 4 For the present invention Figure 2 Detail of point A in the middle. DETAILED DESCRIPTION

[0021] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0022] like Figure 1 and 2A cross-flow membrane filtration device shown in the figure comprises a cross-flow membrane filter 1, a vibration mechanism, a liquid storage tank 25, a frame 24 and a control panel 15 for controlling the vibration mechanism and the operation of the cross-flow membrane filter 1. Four universal wheels 23 are arranged at the bottom of the frame 24. The universal wheels 23 are Foma wheels and are connected to the frame 24 through shock-absorbing rubber blocks and spring telescopic rods. A torsion bar 12 is fixed at the bottom of the bracket 3. The other end of the torsion bar 12 is fixed to the base 13 through a flange. The base 13 is also provided with a vibration mechanism. The torsion bar 12 is suspended on the support rod 14 through a buffer assembly. The buffer assembly comprises a pipe clamp 26 sleeved on the torsion bar 12. A rubber head 27 for buffering is fixed on one side of the pipe clamp 26. The other side of the rubber head 27 is connected to the support rod 14 through a connecting rod 28. The support rod 14 is fixed to the frame 24. The base 13 is a hollow structure, in which an eccentric block 21 is arranged. The vibration mechanism includes a motor 16, which is fixed to the frame 24 through a fixing block 17. The output shaft of the motor 16 is connected to the shaft coupling 18, and the other end of the shaft coupling 18 is connected to the transmission shaft 19. The transmission shaft 19 passes through the base 13 and is fixedly connected to the eccentric block 21. The upper and lower surfaces of the base 13 are provided with a bearing seat 20 for improving the stability of the transmission shaft 19. The motor 16 drives the transmission shaft 19 to rotate and then drives the eccentric block 21 to rotate. The rotation of the eccentric block 21 drives the base 13 to reciprocate in the horizontal direction, and then drives the torsion bar 12 connected to the base 13 to reciprocate in the horizontal direction. The torsion bar 12 drives the bracket 3 of the cross-flow membrane filter to reciprocate in the horizontal direction, and transmits high-frequency shear force parallel to the membrane surface to the filter membrane 9, preventing large particles in the influent from being deposited on the membrane surface and reducing the filtering effect. A buffer block 22 is arranged on the bottom surface of the base 13 at a position opposite to the torsion bar 12, which plays a role in supporting and buffering vibration of the torsion bar 12.

[0023] like Figure 3 As shown, the cross-flow membrane filter 1 includes a housing 2 and a support 3, on which a multi-layer sandwich structure filter assembly is arranged at intervals, and a liquid inlet channel 4 connected to the liquid to be filtered, a filtrate channel 5 and a concentrated liquid channel 6 for circulating and filtering the material flowing through the filter are arranged through the filter assembly, and an O-ring 7 for isolating the filtrate from the original liquid and the concentrated liquid is arranged between the filter assemblies and around the filtrate channel 5, and a fixing ring 8 for improving the stability of the O-ring 7 is also arranged around the O-ring 7, and the output end of the liquid inlet channel 4 is connected to the liquid storage tank 25, and the input end of the concentrated liquid channel 6 is connected to the liquid storage tank 25. Figure 4 As shown, the filter assembly includes a stainless steel plate 11 fixedly connected to the bracket 3, and the upper and lower surfaces of the stainless steel plate 11 are provided with a guide membrane cushion layer 10 connected to the filtrate channel 5, and the outer surface of the guide membrane cushion layer 10 is provided with a filter membrane 9.

[0024] When in use, a suitable filter membrane is selected according to the properties of the filtered liquid, the liquid to be filtered is connected to the cross-flow membrane filter device through the liquid inlet channel 4, and a suitable amplitude is selected through the control panel 15 to start the motor 16 to rotate, thereby driving the eccentric block 21 to rotate in the horizontal direction, so that the base 13 reciprocates in the horizontal direction, driving the upper torsion bar 12 fixed on the base 13 to move, and then driving the bracket 3 of the cross-flow membrane filter 1 to reciprocate horizontally, so that the filter membrane 9 and the feed liquid generate high-frequency shear force parallel to the membrane surface, and this shear force has no direct correlation with the flow rate of the feed liquid. The high-frequency shear force can prevent large particles from depositing on the surface of the filter membrane. The feed flows along the filter membrane 9, and the small molecule filtrate passes through the filter membrane 9 into the filtrate channel 5 for discharge. The large particles are separated from the filter membrane surface and suspended in the feed liquid and flow away with the feed liquid flow, avoiding pollution or blockage of the membrane surface, thereby improving the filtration efficiency and the service life of the filter membrane, reducing the pressure of the filtration channel, and ensuring the continuous and efficient filtration process.

[0025] The device has a wide range of application scenarios, and can be matched with microfiltration membranes, ultrafiltration membranes, nanofiltration membranes and reverse osmosis membranes. It is mainly used in environmental protection, such as industrial wastewater treatment, urban wastewater treatment, oilfield produced water treatment, etc.; chemical industry, such as dye recovery, waste oil recovery, PVC latex concentration, lubricating oil recovery, etc.; food, such as yeast solution treatment, beer filtration, etc.; pharmaceuticals, such as traditional Chinese medicine purification, etc.; new energy materials, such as zirconium dioxide purification, etc. Now take the treatment of landfill leachate and beer filtration as examples to illustrate the beneficial effects of the device.

[0026] In the process of treating landfill leachate, the sewage after anaerobic reaction and denitrification treatment is sent to the cross-flow membrane filtration device for deep treatment. The filter membrane 9 is a nanofiltration membrane or a reverse osmosis membrane, the pore size of the nanofiltration membrane is 1-2nm, and the pore size of the reverse osmosis membrane is less than 1nm. The amplitude and vibration frequency of the vibration mechanism are controlled. The ideal amplitude range is 1.5-2.5cm and the frequency range is 45-50Hz. The eccentric block 21 on the drive shaft rotates to generate inertial force, which is transmitted to the cross-flow membrane filter through the torsion bar 12, causing the membrane disk to vibrate and forming a Stokes flow on the membrane surface, generating a strong sinusoidal shear wave on the membrane surface, greatly reducing the deposition of particulate matter on the membrane surface and effectively preventing and controlling membrane clogging: by introducing high shear force at the membrane surface, the gel layer is suspended on the membrane surface, thereby increasing the filtration flux. The filtration flux of the overfrequency vibration membrane is 3-10 times that of conventional filtration; the operating cost is low, the membrane assembly is not easily contaminated, the membrane life is longer, the vibration energy utilization rate is high, and the entire device occupies a small area. It has obvious economic advantages in both capital investment and operation and maintenance.

[0027] In the filtration process of beer, the press is usually used to process the remaining yeast, and the turbidity of the beer is 2-3EBC. At the same time, due to the high process pressure of 8-9 bar, some yeast cell walls are broken, and the yeast contents enter the beer, affecting the taste of the beer. After using this equipment to process the remaining yeast, the turbidity of the beer is less than 1EBC, and the filtration pressure is reduced, resulting in less yeast cell wall rupture, and the taste of the beer is also improved.

Claims

1. A cross-flow membrane filtration device, comprising a cross-flow membrane filter (1), characterized in that: The cross-flow membrane filter (1) comprises a housing (2) and a support (3); a multi-layer sandwich structure filter assembly is arranged at intervals on the support (3); a liquid inlet channel (4) connected to the material to be filtered, a filtrate channel (5) and a concentrated liquid channel (6) for circulating and filtering the material flowing through the filter are arranged through the filter assembly; an O-ring (7) for isolating the filtrate from the original liquid and the concentrated liquid is arranged between the filter assemblies and on the periphery of the filtrate channel (5); the filter assembly comprises a stainless steel plate (11) fixedly connected to the support (3); a guide membrane communicating with the filtrate channel (5) is arranged on the upper and lower surfaces of the stainless steel plate (11); A cushion layer (10), a filter membrane (9) is arranged on the outer surface of the guide membrane cushion layer (10); a torsion bar (12) is fixed at the bottom of the bracket (3), the other end of the torsion bar (12) is fixed on a base (13), and a vibration mechanism is provided on the base (13) for driving the base (13) to make reciprocating motion in the horizontal direction, thereby driving the bracket (3) to make reciprocating motion in the horizontal direction through the torsion bar (12) to transmit high-frequency shear force parallel to the membrane surface to the filter membrane (9), and the torsion bar (12) is suspended on the support rod (14) through a buffer component; and also includes a control panel (15) for controlling the operation of the vibration mechanism and the cross-flow membrane filter (1).

2. The cross-flow membrane filtration device according to claim 1, characterized in that: The torsion bar (12) is made of rubber.

3. The cross-flow membrane filtration device according to claim 1, characterized in that: The buffer assembly comprises a pipe clamp (26) sleeved on the torsion bar (12), a rubber head (27) having a buffering function fixed on one side of the pipe clamp (26), and the other side of the rubber head (27) is connected to the support bar (14) via a connecting rod (28).

4. The cross-flow membrane filtration device according to claim 1, characterized in that: The vibration mechanism comprises a motor (16); the base (13) is a hollow structure with an eccentric block (21) arranged inside; the motor (16) drives the eccentric block (21) to perform reciprocating motion in the horizontal direction, thereby driving the base (13) to perform reciprocating motion in the horizontal direction.

5. The cross-flow membrane filtration device according to claim 4, characterized in that: A shaft coupling (18) for reducing vibration and impact is arranged between the output shaft of the motor (16) and the eccentric block (21), and the other end of the shaft coupling (18) is connected to a transmission shaft (19) fixed to the eccentric block (21).

6. The cross-flow membrane filtration device according to claim 5, characterized in that: The transmission shaft (19) passes through the base (13), and the upper and lower surfaces of the base (13) are provided with bearing seats (20) for improving the stability of the transmission shaft (19).

7. The cross-flow membrane filtration device according to claim 4, characterized in that: A buffer block (22) is arranged on the bottom surface of the base (13) at a position opposite to the torsion bar (12).

8. The cross-flow membrane filtration device according to claim 1, characterized in that: A fixing ring (8) is also provided on the periphery of the O-type sealing ring (7) to enhance the stability of the O-type sealing ring (7).

9. The cross-flow membrane filtration device according to claim 1, characterized in that: The liquid inlet channel (4) and the filtrate channel (5) are connected to a liquid storage tank (25) via pipelines.

10. The cross-flow membrane filtration device according to claim 1, characterized in that: The vehicle also comprises a frame (24) on the periphery for preventing collisions, a plurality of universal wheels (23) are arranged at the bottom of the frame (24), and the support rod (14) is fixed on the frame (24).

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