A method and device for manufacturing a reverse osmosis membrane

Abstract

The present invention relates to a method and equipment for making a reverse osmosis membrane, comprising the following steps: S1, feeding a non-woven fabric from an unwinder, then coating the non-woven fabric with a water-permeable microporous polysulfone as a support layer, and adding hot air drying after coating; S2, coating the support layer with a polyamide material as a functional layer, and drying the functional layer; S3, slitting the product obtained in step S2 according to the required size, and then winding it up by a winder. The equipment has an unwinder, a first spraying mechanism, a hot air mechanism, a second spraying mechanism, a drying mechanism, and a slitting and winding mechanism arranged in sequence from upstream to downstream, and is suitable for implementing the above-mentioned manufacturing method, so as to achieve streamlined process steps, short process, simple equipment structure, high degree of automation, conform to industrial production, and improve the production efficiency and quality of reverse osmosis membranes.

Description

Technical Field

[0001] The present invention relates to the technical field of membranes, and more particularly to the preparation of reverse osmosis membranes. Background Art

[0002] Osmosis is the phenomenon that a solvent moves from a solution with a low solute concentration to another solution with a high solute concentration through a semipermeable separation membrane that separates the two solutions. In this case, the pressure acting on the solution with a high solute concentration by the movement of the solvent is called osmotic pressure. However, when an external pressure higher than the osmotic pressure level is applied, the solvent moves to the solution with a low solute concentration, and this phenomenon is called reverse osmosis. According to the reverse osmosis principle, various types of salts or organic substances can be separated through a semipermeable membrane using a pressure gradient as a driving force. Reverse osmosis membranes that utilize the reverse osmosis phenomenon have been used to separate substances at the molecular level, remove salt from brine or seawater, and provide water for household, commercial and industrial use.

[0003] Ordinary reverse osmosis membranes are generally composed of non-woven fabrics, a support layer (porous polysulfone layer) sprayed on the non-woven fabric, and a polyamide functional layer arranged on the support layer. The porous polysulfone layer has a low porosity and a fixed structure. The interfacial polymerization reaction is slow when preparing the polyamide layer. The formed polyamide layer is loose and thick, and its water flux and desalination rate are low. The existing reverse osmosis membrane manufacturing method has the defects of high cost, complex process, and limited performance improvement. Therefore, a method and equipment for manufacturing a reverse osmosis membrane that is easy to industrialize and suitable for industrial use is developed. Summary of the invention

[0004] The purpose of the present invention is to provide a method and equipment for manufacturing a reverse osmosis membrane, which can overcome the defects of the prior art and improve production efficiency and quality.

[0005] To achieve the above object, the present invention provides a method for manufacturing a reverse osmosis membrane, wherein the method is to manufacture a reverse osmosis membrane using a non-woven fabric as a substrate in a roll-to-roll production environment, comprising the following steps:

[0006] S1, delivering the non-woven fabric from the unwinder, then coating the non-woven fabric with water-permeable microporous polysulfone as a support layer, and adding hot air drying after coating;

[0007] S2, coating the support layer with a polyamide material as a functional layer, and drying the functional layer;

[0008] S3, the product obtained in step S2 is divided into strips according to the required size, and then rolled up by a winder.

[0009] The above scheme is further that the coating of the water-permeable microporous polysulfone in step S1 and the coating of the polyamide material in step S2 are both carried out in the form of spraying, and the spraying amount is adjusted by the air pressure of the air pump.

[0010] The above solution is further characterized in that the functional layer is dried by rolling and drying with a hot oil internal heating roller.

[0011] In order to achieve the above object, the present invention provides a device for manufacturing a reverse osmosis membrane, which has:

[0012] An unwinder that continuously unwinds nonwoven fabric for use in making a reverse osmosis membrane;

[0013] A first spraying mechanism, which is arranged downstream of the unwinding machine and is used to spray water-permeable microporous polysulfone on the surface of the non-woven fabric;

[0014] A hot air mechanism, which is arranged downstream of the first spray mechanism and sends out hot air to dry the water-permeable microporous polysulfone on the non-woven fabric;

[0015] A second spraying mechanism, which is arranged downstream of the hot air mechanism and is used to spray a polyamide material on the water-permeable microporous polysulfone;

[0016] A drying mechanism, which is arranged downstream of the second spraying mechanism and dries the polyamide material;

[0017] The striping and winding mechanism is arranged downstream of the drying mechanism and is used to strip and wind the product according to the required size.

[0018] The above scheme is further that the first spraying mechanism has multiple first feed tubes, one end of which is provided with a first nozzle, and the first nozzle sprays permeable microporous polysulfone toward the non-woven fabric; and the other end of the first feed tube is connected to a distributor; the second spraying mechanism has multiple second feed tubes, one end of which is provided with a second nozzle, and the second nozzle sprays polyamide material toward the non-woven fabric; and the other end of the second feed tube is also connected to a distributor; a multi-channel flow channel is provided inside the distributor, and the distributor cooperates with the corresponding air pump to respectively control the spraying amount of the first nozzle and the second nozzle.

[0019] The above solution is further that the distributor is assembled on a lifting and adjusting seat, and the lifting and adjusting seat synchronously adjusts the first nozzle and the second nozzle away from or close to the non-woven fabric.

[0020] The above scheme is further that the drying mechanism is composed of three parallel hot oil internal heating rollers, the surface of the hot oil internal heating rollers is smooth, the spacing between the three hot oil internal heating rollers is sufficient for the non-woven fabric sprayed with polyamide material to pass through and bypass, and the adjacent hot oil internal heating rollers roll the non-woven fabric sprayed with polyamide material with a certain pressure.

[0021] The above scheme is further that the lifting and adjusting seat is driven to rise and fall by a worm gear lifting structure, and the worm gear lifting structure drives the lifting and falling of the lifting and adjusting seat according to a signal provided by a thickness sensor arranged at the drying mechanism.

[0022] The process steps of the invention are simplified, the process is short, the equipment structure is simple, the degree of automation is high, and the invention is suitable for industrial production, thereby improving the production efficiency and quality of the reverse osmosis membrane. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 It is a schematic diagram of the structure of a preferred embodiment of the present invention;

[0024] Attached Figure 2 for Figure 1 Another structural diagram of the embodiment from another perspective;

[0025] Attached Figure 3 for Figure 1 An enlarged schematic diagram of a local structure of an embodiment;

[0026] Attached Figure 4 for Figure 1 An enlarged schematic diagram of the drying mechanism structure of the embodiment;

[0027] Attached Figure 5 for Figure 4 A schematic diagram of the local structural connection of the drying mechanism of the embodiment. DETAILED DESCRIPTION

[0028] The concept, specific structure and technical effects of the present invention will be further described below in conjunction with the accompanying drawings to fully understand the purpose, characteristics and effects of the present invention.

[0029] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0030] See also Figure 1 , 2 3 is a schematic diagram of a preferred embodiment of the present invention. The present invention provides a method for manufacturing a reverse osmosis membrane, wherein the method uses a non-woven fabric as a substrate to manufacture the reverse osmosis membrane in a roll-to-roll production environment, thereby achieving continuous production and processing, with simplified process steps and a short flow. Specifically, the following steps are included:

[0031] S1. The non-woven fabric is fed out from the unwinder, and then the water-permeable microporous polysulfone is coated on the non-woven fabric as a support layer, and hot air drying is added immediately after coating to achieve rapid drying of the water-permeable microporous polysulfone and to bond it to the non-woven fabric, which helps to shorten the interval time between processes and obtain a stable support structure system.

[0032] S2. Coating a polyamide material as a functional layer on the support layer, and then drying the functional layer. Preferably, the functional layer is dried by rolling and drying with a hot oil internal heating roller, which not only achieves the drying effect, but also increases the rolling, making the product tighter, the polyamide material adheres more firmly and more evenly, the fixing effect is better, and the use efficiency and life are improved.

[0033] S3. The product obtained in step S2 is divided into strips according to the required size, and then rolled up by a winder to achieve automated continuous production.

[0034] In the above-mentioned production method, this embodiment further adopts spraying for coating the water-permeable microporous polysulfone in step S1 and coating the polyamide material in step S2, and the spraying amount is adjusted by the air pressure of the air pump to achieve intelligent control of the spraying, and the spraying quality is stable and reliable.

[0035] See also Figure 1 , 2, 3, 4, and 5 are schematic diagrams of preferred embodiments of the present invention. In view of the above-mentioned manufacturing method, the present invention also provides an apparatus for manufacturing a reverse osmosis membrane, which comprises an unwinder 1, a first spraying mechanism 2, a hot air mechanism 3, a second spraying mechanism 4, a drying mechanism 5, a strip winding mechanism 6, and a stable machine base 100 for assembling the mechanisms. The unwinder 1 continuously unwinds non-woven fabrics for use in manufacturing reverse osmosis membranes. The unwinder 1 realizes automatic unwinding and self-adjustment of tension to achieve continuous unwinding production. The first spraying mechanism 2 is arranged downstream of the unwinder 1, and the first spraying mechanism 2 is used to spray water-permeable microporous polysulfone on the surface of the non-woven fabric to form a support layer. The hot air mechanism 3 is arranged downstream of the first spraying mechanism 2, and the hot air mechanism 3 sends out hot air to dry the water-permeable microporous polysulfone on the non-woven fabric, thereby achieving rapid drying and obtaining a stable and reliable support layer. The hot air mechanism 3 can realize self-heating and temperature control to obtain dry hot air of a certain temperature. Of course, it can also be heated by recycled heat. The specific hot air mechanism 3 can adopt existing technology, which will not be repeated here. The second spraying mechanism 4 is arranged downstream of the hot air mechanism 3. The second spraying mechanism 4 is used to spray polyamide material on the water-permeable microporous polysulfone to obtain a functional layer; the drying mechanism 5 is arranged downstream of the second spraying mechanism 4. The drying mechanism 5 dries the polyamide material to make the polyamide material dry, adhere and fix. The striping and winding mechanism 6 is arranged downstream of the drying mechanism 5. The striping and winding mechanism 6 is used to strip and wind the product according to the required size. In this embodiment, the striping and winding mechanism 6 adopts a rolling cutting method to strip, which is convenient, fast, and simple in structure. The striping and winding mechanism 6 realizes the rolling and storage of the produced reverse osmosis membrane. The whole equipment has a simple structure and a high degree of automation, and is suitable for industrial production.

[0036] See also Figure 1 , 2As shown in Figure 3, in this embodiment, the first spraying mechanism 2 has a plurality of first feed tubes 21, one end of which is provided with a first nozzle 22, and the first nozzle 22 sprays water-permeable microporous polysulfone toward the non-woven fabric; and the other end of the first feed tube 21 is connected to the distributor 7; the second spraying mechanism 4 has a plurality of second feed tubes 41, one end of which is provided with a second nozzle 42, and the second nozzle 42 sprays polyamide material toward the non-woven fabric; and the other end of the second feed tube 41 is also connected to the distributor 7, so that the first feed tube 21 and the second feed tube 41 are cantilevered at the front and rear ends of the distributor 7. The distributor 7 is provided with multiple flow channels inside, and the distributor 7 also cooperates with the corresponding air pump to control the spraying amount of the first nozzle 22 and the second nozzle 42 respectively. The specific air pressure control of the air pump is a prior art and will not be repeated here. The above structure realizes compact equipment structure integration, optimized assembly and control implementation. The present embodiment is further characterized in that the distributor 7 is assembled on a lifting and adjusting seat 8, and the lifting and adjusting seat 8 synchronously adjusts the distance between the first nozzle 22 and the second nozzle 42 and the non-woven fabric, and cooperates with the traction speed of the non-woven fabric to adjust the thickness of the coating after spraying, which is conducive to controlling production and obtaining a reverse osmosis membrane of excellent quality. The present embodiment is further characterized in that the lifting and adjusting seat 8 is arranged at the gantry provided by the machine base 100 and is driven to rise and fall by a worm gear lifting structure 81, and the worm gear lifting structure 81 drives the lifting and falling of the lifting and adjusting seat 8 according to the signal provided by the thickness sensor arranged at the drying mechanism 5. The thickness sensor can be an infrared sensor or a pressure sensor, etc., and can be purchased and configured from the market according to the actual situation. The principle of thickness sensing will not be repeated here.

[0037] See also Figure 1 , 2 As shown in Figure 3, in this embodiment, the drying mechanism 5 is composed of three parallel hot oil internal heating rollers 51. The surface of the hot oil internal heating rollers 51 is smooth. The spacing between the three hot oil internal heating rollers 51 allows the non-woven fabric sprayed with polyamide material to pass through and around, so that the product is attached to the surface of the hot oil internal heating rollers 51 for drying, and the non-woven fabric sprayed with polyamide material is pressed with a certain pressure between adjacent hot oil internal heating rollers 51, so that the product structure is tighter, the polyamide material adheres more firmly and more evenly, the fixing effect is better, and the use efficiency and life are improved. Figure 4 , 5As shown, in this embodiment, the reverse osmosis membrane is defined as the first hot oil internal heating roller 51A, the second hot oil internal heating roller 51B and the third hot oil internal heating roller 51C according to the movement sequence of the reverse osmosis membrane on the three hot oil internal heating rollers 51. The first hot oil internal heating roller is guided to move closer to or away from the second hot oil internal heating roller in the horizontal direction by the first adjustment mechanism 52; the third hot oil internal heating roller is guided to move closer to or away from the second hot oil internal heating roller in the horizontal direction by the second adjustment mechanism 53. Further, the first adjustment mechanism 52 includes a first sliding seat 521 and a cylinder 522. The first sliding seat 521 is assembled on the machine base 100 through a guide rail structure and connected to the end of the first hot oil internal heating roller. In this embodiment, the two ends of the first hot oil internal heating roller are driven and adjusted by two sets of first adjustment mechanisms 52, which is convenient for assembly and adjustment. The cylinder 522 is fixed on the machine base, and the telescopic end of the cylinder 522 is connected to the first sliding seat 521, so that the cylinder 522 drives the first sliding seat 521 to move back and forth, thereby adjusting the gap between the first hot oil internal heating type heating roller and the second hot oil internal heating type heating roller, obtaining the corresponding rolling force, and improving the drying and pressing effect. In this embodiment, the first sliding seat 521 is arranged sideways, and a side of the first sliding seat 521 close to the second hot oil internal heating type heating roller is provided with a leaning inclined surface 5211, and the leaning inclined surface 5211 abuts against the adjusting inclined block 54, and the adjusting inclined block 54 is assembled on the machine base and can move relatively. The working gap between the first hot oil internal heating type heating roller and the second hot oil internal heating type heating roller is determined by adjusting the inclined block 54, which has a simple structure, is convenient to adjust, and has a stable and accurate gap. In this embodiment, in order to improve the stable movement of the first sliding seat 521 on the machine base, a sliding limit groove 5212 is further provided on the first sliding seat 521, and the sliding limit block 101 preset on the machine base extends into the sliding limit groove 5212, and the two work together to effectively assist the movement of the first sliding seat 521 and improve the adjustment stability and accuracy. In this embodiment, the adjustment bevel block 54 is assembled on the machine base and forms a vertical shape, and the upper end of the adjustment bevel block 54 is provided with an adjustment screw rod 541, and the adjustment screw rod 541 passes through the preset through hole of the machine base and is connected to the adjustment nut 542, so that the adjustment nut 542 is rotated to drive the adjustment bevel block 54 to rise and fall. The structure is simple, easy to manufacture and assemble, and also easy to use and maintain. The second adjustment mechanism 53 includes a second sliding seat 531 and an adjusting bolt 532. The second sliding seat 531 is assembled on the machine base through a guide rail structure and connected to the end of the third hot oil internal heating roller. The adjusting bolt 532 is assembled on the machine base, and one end of the adjusting bolt 532 is connected to the second sliding seat 531. The second sliding seat 531 is moved by screwing the adjusting bolt 532 in or out, and the assembly and adjustment are convenient.

[0038] In this embodiment, the product after the drying mechanism 5 is cooled by the air cooling mechanism 9 for subsequent stripping and winding. The air cooling mechanism 9 of this embodiment is composed of a plurality of staggered guide rollers, which increases the product moving path and obtains better air cooling time.

[0039] The process steps of the invention are simplified, the process is short, the equipment structure is simple, the degree of automation is high, and the invention is suitable for industrial production, thereby improving the production efficiency and quality of the reverse osmosis membrane.

[0040] Of course, the above detailed description of the present invention in combination with the implementation method is only for illustrating the technical concept and features of the present invention, and its purpose is to allow people familiar with this technology to understand the content of the present invention and implement it. Therefore, all equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for making a reverse osmosis membrane, characterized in that: It comprises: an unwinding machine (1), a first spraying mechanism (2), a hot air mechanism (3), a second spraying mechanism (4), a drying mechanism (5) and a slitting and winding mechanism (6); The unwinding machine (1) continuously unwinds nonwoven fabric for use in making reverse osmosis membranes; The first spraying mechanism (2) is arranged downstream of the unwinding machine (1), and the first spraying mechanism (2) is used to spray water-permeable microporous polysulfone on the surface of the non-woven fabric; The hot air mechanism (3) is arranged downstream of the first spray mechanism (2), and the hot air mechanism (3) sends out hot air to dry the water-permeable microporous polysulfone on the non-woven fabric; The second spraying mechanism (4) is arranged downstream of the hot air mechanism (3), and the second spraying mechanism (4) is used to spray the polyamide material on the water-permeable microporous polysulfone; The first spraying mechanism (2) comprises a plurality of first feed tubes (21), one end of each of the first feed tubes (21) being provided with a first nozzle (22), the first nozzle (22) spraying water-permeable microporous polysulfone toward the non-woven fabric; and the other end of each of the first feed tubes (21) being connected to a distributor (7); the second spraying mechanism (4) comprises a plurality of second feed tubes (41), one end of each of the second feed tubes (41) being provided with a second nozzle (42), the second nozzle (42) spraying polyamide material toward the non-woven fabric; and the other end of each of the second feed tubes (41) being connected to a distributor (7); A plurality of flow channels are provided inside the material distributor (7), and the distributor (7) cooperates with a corresponding air pump to control the spraying amount of the first nozzle (22) and the second nozzle (42) respectively; the distributor (7) is assembled on a lifting and adjusting seat (8), and the lifting and adjusting seat (8) synchronously adjusts the first nozzle (22) and the second nozzle (42) away from or close to the non-woven fabric; the lifting and adjusting seat (8) is driven to rise and fall by a worm gear lifting structure (81), and the worm gear lifting structure (81) drives the lifting and falling of the lifting and adjusting seat (8) according to a signal provided by a thickness sensor arranged at the drying mechanism (5); The drying mechanism (5) is arranged downstream of the second spraying mechanism (4), and the drying mechanism (5) dries the polyamide material; the drying mechanism (5) is composed of three hot oil internal heating rollers (51) arranged in parallel, the surfaces of the hot oil internal heating rollers (51) are smooth, the spacing between the three hot oil internal heating rollers (51) is sufficient for the non-woven fabric sprayed with the polyamide material to pass through and bypass, and the adjacent hot oil internal heating rollers (51) roll the non-woven fabric sprayed with the polyamide material with a certain pressure; The slitting and winding mechanism (6) is arranged downstream of the drying mechanism (5), and is used to slitting and winding the product according to required sizes.

2. A method for producing a reverse osmosis membrane using the device according to claim 1, characterized in that: The method is to manufacture a reverse osmosis membrane using a non-woven fabric as a substrate in a roll-to-roll production environment, comprising the following steps: S1, delivering the non-woven fabric from the unwinder, then coating the non-woven fabric with water-permeable microporous polysulfone as a support layer, and adding hot air drying after coating; S2, coating the support layer with a polyamide material as a functional layer, and drying the functional layer; S3, the product obtained in step S2 is divided into strips according to the required size, and then rolled up by a winder.

3. The method according to claim 2, characterized in that: The coating of the water-permeable microporous polysulfone in step S1 and the coating of the polyamide material in step S2 are both carried out in the form of spraying, and the spraying amount is adjusted by the air pressure of the air pump.

4. The method according to claim 2, characterized in that: The functional layer is dried by hot oil internal heating roller rolling drying.

Images