Rigid flat membrane supporting plate and membrane element

Abstract

The invention relates to a rigid flat membrane supporting plate and a membrane element, and relates to the technical field of sewage treatment equipment accessories. The rigid flat sheet membrane supporting plate comprises a supporting frame and a hollow plate, wherein the hollow plate is fixedly arranged in the supporting frame; the hollow plate comprises two corrugated plates which are oppositely arranged in parallel at intervals, the side face of each corrugated plate is a corrugated arc-shaped face formed by a plurality of spaced arc-shaped faces, and a platform is arranged between every two adjacent arc-shaped faces. A plurality of supporting beams are arranged between the double-side corrugated plates; a water catchment cavity is defined by the opposite arc-shaped surfaces and the adjacent supporting beams and platforms; a water collecting cavity is formed in the supporting frame and communicates with the water catchment cavity. A water producing nozzle communicated with the water collecting cavity is formed in the supporting frame. The invention further discloses a membrane element comprising the supporting plate. According to the rigid flat sheet membrane supporting plate and the membrane element, each water catchment cavity is provided with an arc-shaped side face structure, stress is effectively transmitted to a tangential face, and the mechanical performance in the flat sheet membrane is enhanced.

Description

Technical Field

[0001] The present application relates to the technical field of sewage treatment equipment accessories, and in particular to a rigid flat membrane support plate and a membrane element. Background Art

[0002] Membrane Bio-Reactor (MBR) is a new type of wastewater treatment system that organically combines membrane separation technology with biological treatment technology. It replaces the terminal secondary sedimentation tank of traditional biological treatment technology with membrane components, maintains a high concentration of activated sludge in the bioreactor, increases the organic load of biological treatment, thereby reducing the footprint of sewage treatment facilities and reducing the amount of residual sludge by maintaining a low sludge load. The membrane bioreactor mainly uses membrane separation equipment to intercept activated sludge and macromolecular organic matter in the water. Compared with traditional biological treatment processes, MBR membrane bioreactors have higher treatment efficiency and better water quality stability. They can efficiently remove organic matter, ammonia, phosphorus and other pollutants in sewage, and can also achieve solid-liquid separation and water reuse. MBR membrane bioreactors can be applied to a variety of different sewage treatment occasions.

[0003] Commercial MBR membrane elements are mainly flat membranes and hollow fiber membranes. Traditional rigid flat membrane elements in China are usually composed of two layers of flat membrane sheets, two layers of supporting lining cloth and a supporting plate. The supporting plates are mostly solid ABS plates with water collection grooves on both sides. In order to maintain a high water flux and membrane surface utilization rate in engineering, the flat membrane element support plates are often larger in size, such as 1.8 meters × 0.5 meters. At the same time, the MBR process also requires aeration to control the membrane fouling process. The long size and frequent aeration and scouring require the support plates to maintain high rigidity and strength. Therefore, the support plates have the following shortcomings in practical applications: (1) The thickness of the support plates is generally 5.5 mm to 6 mm, and the required thickness of the support plates increases exponentially with the increase in area; (2) The support plates are mostly solid plates, and their cost accounts for about 40% to 60% of the entire membrane element, which seriously limits the promotion and application of flat membranes. In addition, the support plates in traditional flat-plate membrane elements are mostly rectangular support plates with a suction port. When immersed in water, the pressure distribution on the plate surface in the vertical direction is different, and the pressure at the bottom is higher than the pressure at the top. At the same time, the vertical length of the support plate is much longer than the horizontal length, which causes the membrane surface near the suction port to be subjected to a larger suction pressure when the flat-plate membrane element is in operation. The membrane fouling near the suction port occurs earliest, and then the membrane fouling will spread rapidly in the form of an arc. The membrane surface near the suction port will therefore be in a supercritical flux operation state for a long time, and the life of the entire flat-plate membrane element will be greatly reduced.

[0004] A Chinese patent with announcement number CN201722204U discloses a novel flat sheet membrane element of a sedimentation membrane bioreactor, in which evenly distributed circular convex columns are used on both sides of the support plate to form an internal space as a permeate channel. The complete cavity formed in this way can reduce the flow channel resistance. However, compared with the traditional flat support plate at the same thickness, the strength and rigidity of the support plate will be greatly reduced; and the support of the circular convex columns makes it easy to cause damage to the membrane surface under the action of water pressure.

[0005] The Chinese patent application document with publication number CN103239999A discloses a flat-plate membrane element with uniform water production flux, which is composed of a substrate and two layers of membrane. The substrate forms a plurality of cavities, which are arranged in an "I" shape. A plurality of flow-limiting water production holes are provided on the substrate to achieve uniform water production. In order to ensure the uniformity of water production, the opening parameters of the flow-limiting water production holes of the membrane element need to be coordinated with the characteristics of the membrane material. At the same time, the pressure distribution of the membrane is not in a uniform plane when the membrane element is pumped. The stability of the "I"-shaped support beam structure is poor when under pressure, and it is difficult to maintain the morphology of the element.

[0006] It can be seen that the current support plates of flat membranes generally have problems such as high material cost, complex preparation methods, low water production efficiency and poor membrane pollution control. How to reduce the weight and material cost of a single membrane plate and improve water production efficiency and service life while ensuring the strength of the membrane element is a technical problem that needs to be solved urgently. Summary of the invention

[0007] In order to improve the support strength of a rigid flat membrane support plate and increase the service life of a flat membrane, the present application provides a rigid flat membrane support plate and a membrane element.

[0008] In the first aspect, the present application provides a rigid flat membrane support plate adopting the following technical solution: A rigid flat membrane support plate, comprising a support frame and a hollow plate, wherein the hollow plate is fixedly arranged in the support frame; The hollow plate comprises two parallel and spaced corrugated plates arranged opposite to each other, the side surfaces of the corrugated plates are formed by a plurality of intermittent arc-shaped surfaces to form a corrugated arc-shaped surface, and a platform is arranged between two adjacent arc-shaped surfaces; the platforms on the corrugated plates on both sides are arranged one by one, and a plurality of support beams are arranged between the corrugated plates on both sides, and the two sides of each support beam are respectively fixed on two opposite platforms; the opposite arc-shaped surfaces and the adjacent support beams and platforms enclose a water collection cavity; A water collecting cavity is arranged in the supporting frame, and the water collecting cavity is communicated with the water collecting cavity; a water producing nozzle which is communicated with the water collecting cavity is arranged on the supporting frame.

[0009] In the present application, the arrangement of the water producing nozzles can be relatively flexible, the number of the water producing nozzles can be set to 1-2, and the positions of the water producing nozzles can be set at the top or on both sides.

[0010] By adopting the above technical solution, the support frame in this application helps to strengthen the overall strength of the entire membrane element; the hollow plate has an arc-shaped side structure for each water collection cavity, which is combined with the discontinuous support beams arranged inside to form a common bridge structure, which can effectively transfer stress to the tangential surface and strengthen the mechanical properties inside the flat membrane support plate. The entire support plate has a sufficient number and space of water collection cavities to ensure the smoothness of the flow channel, and uses less material while ensuring the structural strength, overcoming the problems of high material cost, complex preparation method, low water production efficiency, and poor membrane pollution control in the prior art.

[0011] Optionally, each of the arc-shaped surfaces is provided with a plurality of water collection ports extending into the corresponding water collection cavity, wherein at least one of the water collection ports is located at the top of the arc-shaped surface, and the other water collection ports are distributed on both sides of the top of the arc-shaped surface.

[0012] By adopting the above technical solution, it can effectively ensure that the water production pressure is more evenly distributed on the entire membrane surface, reducing the pressure difference between different areas of the membrane surface, thereby reducing the risk of membrane pollution. In addition, the reasonable layout of the water collection port also helps to improve the water production efficiency, accelerate the flow rate of the produced water, and thus increase the service life of the entire membrane element.

[0013] Optionally, there are three water collection ports on each of the arc-shaped surfaces, and the three water collection ports are arranged along the horizontal direction of the arc-shaped surface, wherein the first water collection port is arranged at the top of the arc-shaped surface, and the other two water collection ports are distributed at equal angles on both sides of the first water collection port along the center of the circle where the arc-shaped surface is located, and the angle formed by the line between the centers of two adjacent water collection ports and the center of the circle where the arc-shaped surface is located is in the range of 15 degrees to 30 degrees.

[0014] By adopting the above technical solution, the layout of the water collection port on the arc surface is more reasonable, which can effectively balance the suction pressure on the membrane surface, prevent the acceleration of membrane pollution caused by excessive local pressure, and extend the service life of the membrane element. At the same time, this layout method can also ensure that the flow speed of the produced water is faster, improve the water production efficiency, and achieve uniform distribution of the produced water.

[0015] Optionally, the aperture of the water collection port is 1 mm to 2 mm, the distribution distance is 5 mm to 10 mm, and the cross-sectional flow velocity is 0.18 to 0.22 mm / s.

[0016] By adopting the above technical solution, the aperture, distribution distance and cross-sectional flow rate of the water collection port are reasonably designed, which can effectively improve the water production efficiency. The smaller aperture and moderate distribution distance ensure that the water collection port will not cause the structural strength of the support plate to decrease due to being too large, nor will it increase the difficulty of processing due to being too dense. At the same time, the appropriate cross-sectional flow rate ensures the smooth flow of water, reduces the water flow resistance, makes the water production more uniform, and avoids the uneven distribution of water on the membrane surface, reducing the risk of membrane pollution.

[0017] Optionally, a plurality of water flow connection ports are provided on the support beam, and the water flow connection ports are arranged at intervals on the support beam. The height of the water flow connection ports is 1mm to 2mm, the width is 5mm to 8mm, and the center distance between two adjacent water flow connection ports is 10mm to 20mm.

[0018] By adopting the above technical solution, the water connection port is used to balance the water production pressure inside multiple water collection chambers, making the water production pressure distribution more uniform, avoiding the problem of accelerated membrane pollution caused by excessive pressure near the suction port of the traditional support plate, and extending the service life of the membrane element.

[0019] Optionally, the width of the platform is 2mm to 5mm; the height of the support beam is 3mm to 5mm, and the width is 2mm to 3mm; the thickness of the arc surface of the corrugated plate is 1mm to 2mm, and the side length of the arc surface corresponding to the water collection cavity is 5mm to 8mm; The overall opening rate of each arc-shaped surface on the hollow plate is not less than 10% and not higher than 30%.

[0020] By adopting the above technical solution, the support beam can effectively transmit and disperse stress, enhance the mechanical properties of the support plate, and prevent structural damage caused by stress concentration. The thickness design of the arc surface of the corrugated plate ensures the strength and toughness of the arc surface, which can withstand external pressure and ensure sufficient flexibility, so that the compressive strength of the hollow plate meets the use requirements.

[0021] Optionally, the hollow plate is rectangular, the supporting frame is a rectangular frame structure, the left and right sides and the bottom side of the supporting frame are solid plate structures, the water collecting chamber is located on the top side of the supporting frame and is arranged along the width direction of the supporting frame; the bottom of the water collecting chamber is connected to all the water collecting chambers at the same time; the length of the supporting frame is 600mm~2500mm, and the width is 300mm~1000mm.

[0022] By adopting the above technical solution, the supporting frame has sufficient supporting strength, meets market demand, and has high working efficiency.

[0023] Optionally, welding lines are provided on the four sides of the supporting frame; and water stop lines are provided on both sides of the welding lines on the four sides of the supporting frame.

[0024] By adopting the above technical solution, welding lines are set along the four sides of the supporting frame, which are used to weld and install the separation membrane and the flow channel cloth, thereby ensuring the stability and sealing of the connection between the separation membrane and the flow channel cloth on the support plate; the water stop line is located on the inner and outer sides of the welding line to prevent water on both sides from flowing to the welding line, thereby facilitating welding and improving the sealing effect of the connection between the separation membrane and the flow channel cloth and the support plate.

[0025] Optionally, a handle is provided in the middle of the upper side of the support frame; the support frame and the hollow plate are injection molded by ABS, PP or PVC material.

[0026] By adopting the above technical solution, the handle is convenient for taking and transferring the entire rigid flat membrane support plate. The support frame and hollow plate made of injection molding of ABS, PP or PVC materials have high strength, light weight, low cost and are easy to install and disassemble.

[0027] In the second aspect, the present application provides a membrane element adopting the following technical solution: A membrane element comprises the above-mentioned rigid flat membrane support plate, and also comprises a double-layer separation membrane and a double-layer flow channel cloth; the double-layer separation membrane and the double-layer flow channel cloth are welded on the welding line of the support frame and covered on the hollow plate.

[0028] In the present application, the rigid flat membrane support plate can be manufactured by injection molding technology, and the separation membrane and the flow channel cloth are tightly welded to the welding lines around the rigid flat membrane support plate by ultrasonic welding or hot melt welding technology. The manufactured flat membrane element has the characteristics of light weight and uniform water production pressure distribution.

[0029] By adopting the above technical solution, the material used for the membrane element is reduced, the weight is reduced, and it is convenient for transportation and installation. The overall manufacturing cost is only 50% or even lower than that of the traditional membrane element, and the service life is longer.

[0030] Optionally, the double-layer separation membrane and the double-layer flow channel cloth are tightly welded to the platform side of the hollow plate by ultrasonic welding or hot-melt welding technology.

[0031] By adopting the above technical solution, the stability and uniformity of force of the separation membrane and the channel cloth installation are guaranteed. The manufactured membrane element has the characteristics of light weight, uniform water production pressure distribution, and resistance to high-pressure backwashing.

[0032] The present invention has the following advantages over the prior art: In summary, the present application includes at least one of the following beneficial technical effects: 1. The support frame of the flat membrane support plate in the present application is solid, which helps to strengthen the overall strength of the entire membrane element; the several intermittent arc surfaces and the internally arranged discontinuous support beams in the present application are similar to the common bridge structure, which can effectively transfer stress to the tangential surface and enhance the mechanical properties inside the flat membrane support plate.

[0033] 2. The membrane element structure in this application uses less material, is light in weight, and has low cost, so that the membrane element has the characteristics of light weight, uniform distribution of water production pressure, and uniform distribution of cleaning liquid.

[0034] 3. The size design of the water collection chamber, water collection port, support beam, and water connection port in this application makes the suction pressure distributed on the membrane surface more uniform, the control of membrane pollution is improved, and the expected life of the flat membrane is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the first three-dimensional structure of the support plate in this application.

[0036] Figure 2 It is a second three-dimensional structural schematic diagram of the support plate in this application.

[0037] Figure 3 It is a front view structural schematic diagram of the support plate in this application.

[0038] Figure 4 It is a schematic diagram of the transverse cross-sectional structure of the support plate in this application.

[0039] Figure 5 yes Figure 4 Schematic diagram of the local enlarged structure in.

[0040] Figure 6 It is a schematic diagram of the longitudinal cross-sectional structure of the support plate in this application.

[0041] Figure 7 yes Figure 6 Schematic diagram of the local enlarged structure in.

[0042] Figure 8 It is a stress distribution cloud diagram of the support plate in this application.

[0043] Fig. 9 It is a deformation distribution cloud diagram of the support plate in this application.

[0044] Fig.10 It is the pressure distribution cloud diagram of the support plate at Y=0mm in this application.

[0045] Fig.11 It is the pressure distribution cloud diagram of the support plate at Y=+2.5mm in this application.

[0046] In the figure: 10. Support frame; 11. Water collecting chamber; 12. Water producing nozzle; 13. Welding line; 14. Water stop line; 20. Hollow plate; 21. Corrugated plate; 211. Arc surface; 212. Platform; 22. Support beam; 221. Water-passing connection port; 23. Water collection cavity; 24. Water collection port; 30. Handle. DETAILED DESCRIPTION

[0047] The following will be combined with the attached Figure 1 -Attached Fig.11 , the technical solutions in the embodiments of the present invention are clearly and completely described. The described embodiments are only possible technical implementations of the present invention, not all possible implementations. Those skilled in the art can completely combine the embodiments of the present invention to obtain other embodiments without creative work, and these embodiments are also within the scope of protection of the present invention.

[0048] In the prior art, each membrane element is generally composed of a support plate, a separation membrane (membrane), and a flow channel cloth (lining cloth). The cost of the support plate accounts for 40% to 60% of the entire membrane element, so reducing the cost of the support plate is directly related to the product profit of the entire membrane element. In the MBR process, frequent aeration and flushing are required, and reverse cleaning is also required, so the support plate requires higher rigidity and strength. Simply saving costs by reducing the thickness of the support plate will cause it to be insufficiently rigid, insufficient to support it upright and maintain a flat surface. In actual use, deformation and warping will inevitably occur, which will cause the distance between two adjacent membrane elements to change and contact at the warping position. In particular, the smaller the distance, the uneven air-water flushing between the membrane elements will produce mud accumulation, which will cause the membrane surface to be blocked, resulting in a decrease in the water flux; therefore, it is necessary to save materials while ensuring its rigidity and strength. This is the focus and difficulty of improving the rigid flat membrane support plate.

[0049] Reference Figure 1 , Figure 2 and Figure 3As shown, the rigid flat membrane support plate provided in the embodiment of the present application includes a support frame 10 and a hollow plate 20. The support frame 10 is a rectangular frame structure, and the hollow plate 20 is a rectangular plate. The hollow plate 20 is fixed in the support frame 10; the left and right sides and the bottom side of the support frame 10 are solid plate structures, and there are welding lines 13 on the surrounding sides of the support frame 10. The welding lines 13 are used for welding and fixing the separation membrane and the flow channel cloth to ensure the stability, reliability and sealing of the connection between the separation membrane and the flow channel cloth and the support plate; two waterstop lines 14 are arranged on the surrounding sides of the support frame 10; the two waterstop lines 14 are respectively located on the inner and outer sides of the welding line 13 to prevent water on both sides from flowing to the welding line 13, thereby facilitating welding and improving the sealing effect of the connection between the separation membrane and the flow channel cloth and the support plate. A handle 30 is provided at the middle position of the top of the support frame 10. A water nozzle 12 is opened at the top of the support frame 10. The water nozzle 12 is located on one side of the handle 30. The handle 30 facilitates the taking and transfer of the entire rigid flat membrane support plate. The water nozzle 12 is used for the outflow of filtered water.

[0050] In this embodiment, the length of the support frame 10 is 600mm to 2500mm, and the width is 300mm to 1000mm. Preferably, the length of the support frame 10 is 2000mm, and the width is 500mm. There is one water-generating nozzle 12, which is arranged at the top of the support frame 10 and located on one side of the handle 30. The support frame 10 and the hollow plate 20 are injection molded by ABS, PP or PVC materials. The entire support plate has high strength, light weight, low cost, and is easy to install and disassemble.

[0051] Reference Figure 2 , Figure 4 and Figure 5 As shown, the hollow plate 20 includes two parallel and spaced corrugated plates 21 arranged opposite to each other, the side surface of the corrugated plate 21 is formed by a plurality of intermittent arc-shaped surfaces 211 to form a corrugated arc-shaped surface, and a platform 212 is provided between two adjacent arc-shaped surfaces 211; Combination Figure 6 and Figure 7 As shown, the platforms 212 between the double-sided corrugated plates 21 are arranged opposite to each other, and a plurality of support beams 22 are arranged between the double-sided corrugated plates 21. The support beams 22 and the platforms 212 are arranged one by one, and the two sides of the support beams 22 are respectively connected to the two opposite platforms 212; the double-sided corrugated plates 21, the platforms 212 and the support beams 22 can be formed as one piece; the relative arc-shaped surfaces 211 and the adjacent support beams 22 and platforms 212 are surrounded to form a water collection cavity 23; a water collection cavity 11 is arranged in the support frame 10, and the water collection cavity 11 is located at the top of the support frame 10 and is arranged along the width direction of the support frame 10; the bottom of the water collection cavity 11 is connected to all the water collection cavities 23 at the same time; the water production nozzle 12 is connected to the water collection cavity 11.

[0052] Reference Figure 2and Figure 5 As shown, each arc surface 211 is provided with a plurality of water collection ports 24 penetrating into the corresponding water collection cavity 23, wherein at least one water collection port 24 is located at the top of the arc surface 211, and the other water collection ports 24 are distributed on both sides of the top of the arc surface 211, which can effectively ensure that the water production pressure is more evenly distributed on the entire membrane surface, reducing the pressure difference between the various areas of the membrane surface, thereby reducing the risk of membrane contamination. In addition, the reasonable layout of the water collection ports 24 also helps to improve the water production efficiency, accelerate the flow rate of the produced water, and thus increase the service life of the entire membrane element. As a preferred solution, in this embodiment, there are three water collection ports 24 on each arc surface 211, and the three water collection ports 24 are arranged along the horizontal direction of the arc surface 211, wherein the first water collection port 24 is arranged at the top of the arc surface 211, and the other two water collection ports 24 are distributed at equal angles on both sides of the first water collection port 24 along the center of the arc surface 211, and the angle formed by the line between the center of the two adjacent water collection ports 24 and the center of the arc surface 211 is in the range of 15 degrees to 30 degrees, for example, it can be 20 degrees, so that the layout of the water collection ports 24 on the arc surface 211 is more reasonable, which can effectively balance the suction pressure on the membrane surface, prevent the acceleration of membrane pollution caused by excessive local pressure, and extend the service life of the membrane element. At the same time, this layout method can also ensure that the flow speed of the produced water is faster, improve the water production efficiency, and achieve uniform distribution of the produced water.

[0053] In this embodiment, the aperture of the water collection port 24 is 1mm to 2mm, the distribution distance is 5mm to 10mm, and the cross-sectional flow rate can be 0.18 to 0.22mm / s. For example, the aperture of the water collection port 24 can be 1.5mm, the distribution distance is 8mm, and the cross-sectional flow rate can be 0.2mm / s; the aperture, distribution distance and cross-sectional flow rate of the water collection port 24 are reasonably designed, which can effectively improve the water production efficiency. The smaller aperture and moderate distribution distance ensure that the water collection port 24 will not cause the structural strength of the support plate to decrease due to being too large, nor will it increase the processing difficulty due to being too dense. At the same time, the appropriate cross-sectional flow rate ensures the smoothness of the water flow, reduces the water flow resistance, makes the water production more uniform, and avoids the uneven distribution of the water flow on the membrane surface, reducing the risk of membrane pollution.

[0054] Reference Figure 6 and Figure 7 As shown, the support beam 22 is also provided with a plurality of water-passing connection ports 221, which are arranged at intervals on the support beam 22, and the height of the water-passing connection ports 221 is 1mm to 2mm, the width is 5mm to 8mm, and the center distance between two adjacent water-passing connection ports 221 is 10mm to 20mm. The water-passing connection ports 221 are used to balance the water production pressure inside the multiple water collection chambers 23, so that the water production pressure distribution is more uniform, avoiding the problem of accelerated membrane pollution caused by excessive pressure near the suction port of the traditional support plate, and extending the service life of the membrane element.

[0055] As a preferred solution, in this embodiment, the height of the water-passing connection opening 221 is 1.5 mm, the width is 6 mm, and the center distance between two adjacent water-passing connection openings 221 is 15 mm.

[0056] In this embodiment, the width of the platform 212 is 2mm to 5mm; the height of the support beam 22 is 3mm to 5mm, and the width is 2mm to 3mm; the thickness of the arc surface 211 of the corrugated plate 21 is 1mm to 2mm, and the side length of the arc surface 211 corresponding to the water collection cavity 23 is 5mm to 8mm; the overall opening rate of each arc surface 211 on the hollow plate 20 is not less than 10% and not higher than 30%. As a preferred solution, in this embodiment, the width of the platform 212 can be 3mm; the height of the support beam 22 can be 4mm, and the width can be 2.5mm; the thickness of the arc surface 211 of the corrugated plate 21 can be 1.5mm, and the side length of the arc surface 211 corresponding to the water collection cavity 23 can be 6mm; the overall opening rate of each arc surface 211 is 13%.

[0057] The implementation principle is as follows: the support frame 10 in the present application is used to strengthen the strength of the entire membrane element; the hollow plate 20 has an arc-shaped side structure for each water collection cavity 23, which is combined with the discontinuous support beam 22 arranged inside to form a common bridge structure, which can effectively transfer stress to the tangential surface and strengthen the mechanical properties inside the flat membrane support plate. The porous cavity structure of the rigid flat membrane support plate in the present application has a sufficient number and sufficient space of water collection cavities 23, which ensures the smoothness of the flow channel and accelerates the flow rate of the produced water, thereby increasing the water production flux per unit time and improving the water production efficiency. Moreover, while ensuring the strength of the structure, less materials are used, which overcomes the problems of high material cost, complex preparation method, low water production efficiency, and poor membrane pollution control in the prior art.

[0058] This embodiment also discloses a membrane element, including a double-layer separation membrane and a double-layer flow channel cloth and the above-mentioned rigid flat membrane support plate. The double-layer separation membrane and the double-layer flow channel cloth are welded on the welding line 13 of the support frame 10 by ultrasonic welding or hot melt welding technology, and covered on the hollow plate 20. The flow channel cloth is located between the separation membrane and the support frame 10, and the length and width of the flow channel cloth are smaller than the length and width of the separation membrane and the length and width of the support frame 10. Furthermore, the double-layer separation membrane and the double-layer flow channel cloth are also tightly welded to the side of the platform 212 of the hollow plate 20 by ultrasonic welding or hot melt welding technology.

[0059] The implementation principle is as follows: the welded membrane element is immersed in the activated sludge pool, and the sewage initially purified by the activated sludge is filtered through the separation membrane outside the membrane element, flows into the water collection chamber 23 through the water collection port 24, and finally collects into the water collection chamber 11 and is sucked out through the water production nozzle 12. The membrane element in this application uses less material and is lighter, which is convenient for transportation and installation. The overall manufacturing cost is only 50% or even lower than that of the traditional membrane element, and the service life is longer. It is also light and has uniform water production pressure distribution.

[0060] The mechanical strength of the rigid flat membrane support plate and membrane element provided in this embodiment can be verified and designed using static analysis software, and the steps are as follows: (1) Use statics analysis software to import the designed three-dimensional model of the rigid flat membrane support plate, create a new statics case, and apply the required verification materials; (2) Select the support frame 10 as the fixture, select the arc surface 211 of the hollow plate 20 as the force-bearing surface, set the values ​​to be verified, and then perform mesh segmentation and run the calculation example; (3) Obtain simulation results of the internal stress and deformation of the model according to design requirements.

[0061] In this embodiment, the static analysis software is Soildworks, and the force applied to the hollow plate 20 is 50N. Figure 8 and Fig. 9 As shown in the figure, the simulation results show that the stress distribution of the rigid flat membrane is relatively dispersed, and the stress distribution value range is 2.5~7.6×10 -4 N / m 2 The flat membrane support plate did not experience significant extrusion displacement, and the larger displacement deformation was concentrated at the water-passing connection port 221, with a force displacement range of 7 to 8×10 -3 mm, indicating that the flat membrane support plate has good rigidity and the compressive strength can be guaranteed.

[0062] The water production uniformity of the membrane element provided in this embodiment can be verified and designed using CFD software, and the steps are as follows: (1) Use Space Claim to extract and model the fluid domain and use Ansys Mesh to divide the mesh; (2) Using Ansys Fluent to discretize the solution process using numerical methods, the standard K-ε model and standard wall function were selected; the pressure-velocity coupling solution method: PISO; The discretization settings of other equations are as follows: pressure discretization: Second order, momentum discretization: Second orderUpwind.

[0063] (3) The water production flux of a single membrane element under a negative pressure of -10 kPa is set to 30 LMH, the membrane element contains single-phase liquid water, and the gravity acceleration is -9.81 m / s 2 ,refer to Fig.10 and Fig.11 The XZ plane is divided as the basic viewing plane, and the internal pressure distribution is divided into multiple layers in the Y direction. The Y=0mm position of the model is the plane where the center of gravity of the model is located, which can display the pressure distribution of the internal water collection chamber 11, the water connection port 221 and the water collection chamber 23 section; the Y=+2.5mm position is the plane where the model water collection port 24 is located, which can display the pressure distribution of the water collection port 24. It can be seen that the pressure distribution of the internal water collection chamber 11, the water connection port 221 and the water collection chamber 23 section is consistent, and the pressure distribution of the water collection port 24 is consistent, without obvious turbulence. The porous cavity structure of the rigid flat membrane support plate balances the internal pressure distribution of the flat membrane support plate, thereby accelerating the flow rate of the produced water and improving the water production efficiency.

[0064] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A rigid flat membrane support plate, comprising a support frame (10) and a hollow plate (20), wherein the hollow plate (20) is fixedly arranged in the support frame (10); It is characterized in that The hollow plate (20) comprises two parallel corrugated plates (21) arranged opposite to each other at intervals, the side surfaces of the corrugated plates (21) are formed of a plurality of intermittent arcuate surfaces (211) to form a corrugated arcuate surface, and a platform (212) is arranged between two adjacent arcuate surfaces (211); the platforms (212) on the corrugated plates (21) on both sides are arranged in a one-to-one correspondence, and a plurality of support beams (22) are arranged between the corrugated plates (21) on both sides, and the two sides of each support beam (22) are respectively fixed on two opposite platforms (212); the opposite arcuate surfaces (211) and the adjacent support beams (22) and platforms (212) together form a water collection cavity (23); A water collecting chamber (11) is provided in the supporting frame (10), and the water collecting chamber (11) is connected to the water collecting chamber (23); and a water producing nozzle (12) connected to the water collecting chamber (11) is provided on the supporting frame (10).

2. The rigid flat membrane support plate according to claim 1, characterized in that: Each of the arc-shaped surfaces (211) is provided with a plurality of water collection ports (24) penetrating into the corresponding water collection cavity (23), wherein at least one of the water collection ports (24) is located at the top of the arc-shaped surface (211), and the other water collection ports (24) are distributed at both sides of the top of the arc-shaped surface (211).

3. The rigid flat membrane support plate according to claim 2, characterized in that: There are three water collection ports (24) on each of the arc-shaped surfaces (211), and the three water collection ports (24) are arranged along the horizontal direction of the arc-shaped surface (211), wherein the first water collection port (24) is arranged at the top of the arc-shaped surface (211), and the other two water collection ports (24) are distributed at equal angles on both sides of the first water collection port (24) along the center of the arc-shaped surface (211), and the angle formed by the line between the centers of two adjacent water collection ports (24) and the center of the arc-shaped surface (211) is in the range of 15 degrees to 30 degrees.

4. The rigid flat membrane support plate according to claim 2 or 3, characterized in that: The water collection port (24) has an aperture of 1 mm to 2 mm, a distribution distance of 5 mm to 10 mm, and a cross-sectional flow rate of 0.18 to 0.22 mm / s.

5. The rigid flat membrane support plate according to claim 1, 2 or 3, characterized in that: The support beam (22) is also provided with a plurality of water-passing connection openings (221), which are arranged at intervals on the support beam (22), the water-passing connection openings (221) are 1 mm to 2 mm in height, 5 mm to 8 mm in width, and the center distance between two adjacent water-passing connection openings (221) is 10 mm to 20 mm.

6. The rigid flat membrane support plate according to claim 3, characterized in that: The width of the platform (212) is 2 mm to 5 mm; the height of the support beam (22) is 3 mm to 5 mm, and the width is 2 mm to 3 mm; the thickness of the arc surface (211) of the corrugated plate (21) is 1 mm to 2 mm, and the side length of the arc surface (211) corresponding to the water collection cavity (23) is 5 mm to 8 mm; The overall opening rate of each arc-shaped surface (211) on the hollow plate (20) is not less than 10% and not more than 30%.

7. The rigid flat membrane support plate according to claim 1, 2 or 3, characterized in that: The hollow plate (20) is rectangular, the supporting frame (10) is a rectangular frame structure, the left and right sides and the bottom side of the supporting frame (10) are all solid plate structures, the water collection chamber (11) is located on the top side of the supporting frame (10) and is arranged along the width direction of the supporting frame (10); the bottom of the water collection chamber (11) is connected to all the water collection chambers (23) at the same time; the length of the supporting frame (10) is 600 mm to 2500 mm, and the width is 300 mm to 1000 mm.

8. The rigid flat membrane support plate according to claim 1, 2 or 3, characterized in that: The supporting frame (10) has welding lines (13) on the four sides of the side surface; the supporting frame (10) has water stop lines (14) on both sides of the welding lines (13); A handle (30) is provided at the middle of the upper side of the support frame (10); the support frame (10) and the hollow plate (20) are injection molded using ABS, PP or PVC materials.

9. A membrane element comprising the rigid flat membrane support plate according to any one of claims 1 to 8, characterized in that: The membrane element further comprises a double-layer separation membrane and a double-layer flow channel cloth; the double-layer separation membrane and the double-layer flow channel cloth are welded on the supporting frame (10) around their peripheries and covered on the hollow plate (20).

10. The membrane element according to claim 9, characterized in that The double-layer separation membrane and the double-layer flow channel cloth are tightly welded to the side surface of the platform (212) of the hollow plate (20) by ultrasonic welding or hot-melt welding technology.

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