CN212549041U

CN212549041U - Production equipment of reverse osmosis membrane

Info

Publication number: CN212549041U
Application number: CN202020361927.9U
Authority: CN
Inventors: 陈亦力; 赵旭; 裴志强; 况武; 张翠苗
Original assignee: Beijing Originwater Membrane Technology Co Ltd
Current assignee: Beijing Originwater Membrane Technology Co Ltd
Priority date: 2020-03-20
Filing date: 2020-03-20
Publication date: 2021-02-19
Anticipated expiration: 2030-03-20

Abstract

The utility model provides a production facility of reverse osmosis diaphragm. The device comprises an unreeling device, an edge sealing machine, a substrate modification tank, a water phase coating device, a dewatering device, an oil phase coating device, a drying device and a diaphragm post-treatment device which are sequentially arranged. The unwinding device comprises three groups of parallel unwinding machines, and is used for unwinding and edge gluing of the first polyolefin base layer, the pure water runner cloth and the second polyolefin base layer; then fixing, edge sealing and drying the three layers of membranes by an edge sealing machine to obtain a composite base material of the reverse osmosis membrane; carrying out hydrophilic modification and water-phase soaking treatment on the base material by using a base material modification and water-phase coating device, and removing redundant water-phase liquid on the surface of the membrane by using a water removing device; and conveying the membrane coated with the oil phase into a drying device, and conveying the dried membrane to a membrane post-treatment device for cleaning modification and secondary drying. The utility model discloses can realize the application of polyolefin material in reverse osmosis membrane production to production efficiency is high, is twice of traditional reverse osmosis membrane production efficiency.

Description

Production equipment of reverse osmosis membrane

Technical Field

The utility model relates to a technical field is made to the diaphragm, especially relates to a production facility of reverse osmosis diaphragm.

Background

The reverse osmosis technology is the most economical and mature advanced technology with excellent treatment effect in the membrane separation technology, and is widely applied to various fields of sewage treatment, seawater desalination, household drinking water treatment and the like at present.

The reverse osmosis membrane is a core component in the reverse osmosis treatment technology, the traditional reverse osmosis membrane generally consists of polyester non-woven fabric, a polysulfone ultrafiltration support layer and a polyamide desalination layer, and the polyolefin material is used as a base material of the reverse osmosis membrane, which is the development direction of the new generation of reverse osmosis membrane, and the membrane products of the type are published at present. Compared with the traditional polyester non-woven fabric and polysulfone support, the polyolefin material has the advantages of light weight, thin thickness, low cost, mature production process and great advantages for the traditional support material.

Although the polyolefin material has many unique advantages, the application of the polyolefin material in the production of reverse osmosis membranes has more problems. The polyolefin material has the advantages of thin thickness, large deformation amount and high tension control requirement, and the traditional reverse osmosis production equipment cannot directly meet the production requirement.

The reverse osmosis membrane production technology is relatively complex, the traditional process comprises the steps of firstly coating polysulfone solution on polyester non-woven fabric quantitatively, then gelling the polysulfone solution through a phase inversion process, and forming a polysulfone ultrafiltration base membrane with the polyester non-woven fabric, wherein the base membrane can be used as a supporting layer of a reverse osmosis membrane desalting layer. Then entering an interface polymerization process, coating a water phase m-phenylenediamine solution and an oil phase trimesoyl chloride solution on an ultrafiltration supporting layer for reaction, and generating a polyamide desalting layer on the ultrafiltration layer so as to achieve the aim of desalting.

And then, the produced film sheet enters a film rolling process. In the prior art, pure water flow path cloth is usually required to be placed between two pieces of membrane non-woven fabrics made of the above materials, then concentrated water flow path cloth is placed on the membrane surface, then a film rolling machine is used for rolling the multilayer structure into a cylinder, and the membranes are bonded by glue.

It can be seen that the reverse osmosis membrane production process in the prior art is very complex and has low production efficiency. The polyolefin material is thin in thickness and large in deformation, and the coating of the interface polymerization desalting layer cannot be realized on the traditional production process.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a production facility of reverse osmosis membrane piece to overcome prior art's problem.

In order to achieve the purpose, the utility model adopts the following technical scheme.

A production device of a reverse osmosis membrane comprises an unreeling device, an edge sealing machine, a base material modification tank, a water phase coating device, a dewatering device, an oil phase coating device, a drying device and a membrane post-treatment device which are sequentially arranged, wherein all the devices are connected through a conveying belt;

the unwinding device comprises at least three groups of unwinding machines which are arranged in parallel and are sequentially used for unwinding and edge gluing of the first polyolefin base layer, the pure water runner cloth and the second polyolefin base layer;

the edge sealing machine is used for fixing, edge sealing and drying the three-layer polyolefin composite base material to obtain a double-sided polyolefin composite base material;

the substrate modification and water phase coating device is used for carrying out hydrophilic modification and dipping water phase treatment on the double-sided polyolefin composite substrate;

the water removing device removes redundant aqueous phase liquid on the surface of the double-sided polyolefin composite substrate;

the oil phase coating device extrudes and coats oil phase to two sides of the double-sided polyolefin composite substrate through a slit;

conveying the double-sided polyolefin composite base material coated with the oil phase into a drying device, and generating a reverse osmosis desalting layer by an interfacial polymerization process in the process of the double-sided polyolefin composite base material; and conveying the dried double-sided polyolefin composite base material to a membrane post-treatment device for cleaning modification and secondary drying to obtain the reverse osmosis membrane.

Preferably, a glue applicator is arranged between the unreeling device and the edge sealing machine, and glue is coated on the edges between the first polyolefin base layer and the pure water flow passage cloth and between the pure water flow passage cloth and the second polyolefin base layer through the glue applicator.

Preferably, the edge sealing machine with a three-layer structure is formed by the first polyolefin base layer, the pure water runner cloth and the second polyolefin base layer, and the edge sealing machine is used for fixing, edge sealing and drying the reverse osmosis base material with the three-layer structure to obtain a double-sided polyolefin composite base material supported by the pure water runner cloth, wherein the double-sided polyolefin composite base material is the support layer of the reverse osmosis membrane.

Preferably, an electrostatic dust removal brush and a diaphragm leveling device are further arranged between the edge sealing machine and the film coating device, the diaphragm leveling device comprises one or more pairs of leveling rollers which are arranged in pairs, residual flock on the diaphragm is swept by the electrostatic dust removal brush, and the surface of the diaphragm is leveled under the action of the diaphragm leveling rollers.

Preferably, convey the diaphragm through modified groove of polyolefin, dewatering roller, aqueous phase flooding groove and water trap in proper order through the conveyer belt, water trap is including the dewatering roller or the air knife that set up in pairs, and each pair of dewatering roller or air knife is including setting up respectively at each roll body or the air knife of diaphragm both sides, the crack interval between the paired dewatering roller or air knife with the thickness phase-match of the three layer construction of polyolefin composite substrate.

Preferably, the oil phase coating device is a double-faced roller slit coating device and comprises a left slit coating head and a right slit coating head which are respectively arranged on the left side and the right side of the three-layer structure, and the left slit coating head and the right slit coating head are respectively communicated with the oil phase material tank.

Preferably, the drying device is a suspension oven, and the suspension oven comprises a membrane channel arranged in the middle of the oven, and a heating mechanism and an air outlet mechanism which are respectively arranged on the upper side and the lower side of the membrane channel.

Preferably, the membrane post-treatment device comprises a cleaning modification tank, a glycerol impregnation tank and a secondary drying device.

Preferably, the equipment further comprises a winding machine arranged at the downstream of the drying device, and the dried membrane enters the winding machine through a conveyor belt to be wound to form a double-layer composite reverse osmosis membrane product.

Preferably, the conveyor belt is arranged in the interval from the downstream of the edge sealing machine to the upstream of the winding machine, and the conveyor belt is driven by a motor and a driving shaft;

the conveying belt is composed of a pair of conveying belts and is arranged on one side of the film surface, and the conveying belts do not contact with the main body part of the film surface and only contact with the edge of the film surface; alternatively, the conveyor belts are composed of two pairs of conveyor belts, are arranged on the upper side and the lower side of the film surface, and convey the film surface in a clamping mode, do not contact with the main body part of the film surface, and only contact with the edge of the film surface.

By the aforesaid the embodiment of the utility model provides a technical scheme can see out, the utility model discloses a reverse osmosis membrane production facility can realize the application of polyolefin material in reverse osmosis membrane production to production efficiency is high, is twice of traditional reverse osmosis membrane production efficiency. Adopt the utility model discloses equipment and technology can effectively solve the problem that polyolefin material was applied to reverse osmosis membrane production, also can be according to this patent on conventional reverse osmosis membrane production line the technology is reformed transform, and production efficiency can reach more than the twice of preceding production technology.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is a schematic structural diagram of a production facility of a reverse osmosis membrane provided by the present invention;

fig. 2 is the utility model provides a pair of two-sided from roller slot type film coating device schematic structure:

fig. 3 is a schematic structural view of a suspension oven provided by the present invention;

fig. 4 is a schematic structural diagram of a conveyor belt provided by the present invention;

fig. 5 is a schematic view of the advancing state of the diaphragm according to the present invention.

Wherein; 1. an unwinding device; 2. an edge sealing machine; 3. an electrostatic dust removal brush; 4. a membrane flattening roller; 5. a polyolefin modification tank; 6. a dewatering roll; 7. a water phase impregnation tank; 8. a water removal device; 9. an oil phase slit extrusion coating device; 10. suspending the oven; 11. a membrane cleaning and modifying tank; 12. a glycerol impregnation tank; 13. suspending the oven; 14. a winding device; 15. a first polyolefin based film; 16. gluing machine; 17, pure water flow channel cloth; 18. a second polyolefin based film; 19. an oil phase; 20. a drive shaft; 21. a motor; 22. and (4) a conveyor belt.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention, and should not be construed as limiting the present invention.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element or intervening elements may also be present. Further, "connected" or "coupled" as used herein may include wirelessly connected or coupled. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the description of this patent, it is to be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for the convenience of describing the patent and for the simplicity of description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the patent.

In the description of this patent, it is noted that unless otherwise specifically stated or limited, the terms "mounted," "connected," and "disposed" are to be construed broadly and can include, for example, fixedly connected, disposed, detachably connected, disposed, or integrally connected and disposed. The specific meaning of the above terms in this patent may be understood by those of ordinary skill in the art as appropriate.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

For the convenience of understanding the embodiments of the present invention, the following description will be given by way of example only with reference to the accompanying drawings, and the embodiments are not limited thereto.

The utility model discloses an overcome the application problem of polyolefin material on as the reverse osmosis supporting layer, improved again on traditional production technology, promoted more than one time for traditional technology production efficiency.

In order to achieve the above object, the utility model provides a reverse osmosis membrane's production facility's structure is as shown in fig. 1, including unwinding device 1, edge sealing machine 2, substrate modification tank 5 and aqueous phase coating device 7, water trap 8, oil phase coating device 9, drying device 10 and the diaphragm aftertreatment device that set up according to the preface, link through conveyer belt 22 between each device. The membrane post-treatment device comprises a cleaning modification tank 11, a glycerol impregnation tank 12 and a secondary drying device 13.

The unreeling device 1 comprises at least three sets of unreeling machines arranged in parallel, and the unreeling machines are sequentially used for unreeling and edge gluing of a first polyolefin base layer, pure water runner cloth and a second polyolefin base layer.

The three-layer polyolefin composite base material after being glued is fixed and dried through an edge sealing machine, the edge sealing machine 2 is arranged between the unreeling device 1 and the base material modification and water phase coating device, the polyolefin base material and the pure water runner cloth are fixed through the edge sealing machine 2 in a hot melting or high-frequency welding mode, and glue coated on the edge of the polyolefin composite base material can also be fixed through a heating mode, so that the three-layer polyolefin composite base material is bonded.

And a membrane flattening device 4 is arranged between the edge sealing machine and the film coating device, and the membrane flattening device 4 is composed of one or more pairs of flattening rollers which are arranged in pairs.

According to a preferred embodiment, an electrostatic precipitation brush 3 is arranged between the edge sealing machine 2 and the film sheet leveling device 4, and the electrostatic precipitation brush 3 is used for removing fine flock carried by the film sheets on the conveyor belt 4.

According to another preferred embodiment, a glue applying machine is arranged between the unwinding device 1 and the edge sealing machine 2, and the glue applying machine is used for coating glue on the edges between the first polyolefin base layer and the pure water runner cloth and between the pure water runner cloth and the second polyolefin base layer, so that the three-layer structure can be fixed in the subsequent process.

The utility model discloses in, be provided with water trap 8 between water phase steeping vat 7 and the oil phase coating device 9, water trap 8 can adopt one pair or many to remove the water roller or air knife and constitute, and every to remove water roller or air knife including setting up respectively at each roll body or air knife of diaphragm both sides, the crack interval between mated removal water roller or air knife with the three layer construction's of polyolefin substrate thickness phase-match. The gap between the roll body cracks should not be too narrow to prevent the three-layer structure film from being crushed, as long as the base film is ensured to have no obvious water drops after passing through the dewatering roll.

The oil phase coating device 9 is a double-faced roller slit coating device and comprises a left slit coating head and a right slit coating head which are respectively arranged on the left side and the right side of the three-layer structure, and the left slit coating head and the right slit coating head are respectively communicated with an oil phase material tank.

Preferably, the drying device 10 is a suspension oven, and the suspension oven includes a membrane channel disposed in the middle of the oven, and a heating mechanism and an air outlet mechanism respectively disposed on the upper and lower sides of the membrane channel.

Preferably, the membrane post-treatment device comprises a cleaning modification tank 11 and a glycerin dipping tank 12. The membrane cleaning modification tank 11 can modify the membrane in a chemical or physical mode according to the performance of the required membrane, so that the performance of the membrane is better improved, and chemical substances remained on the surface of the membrane can be cleaned, so that the membrane meets the sanitary requirement.

After the membrane passes through the glycerol dipping tank 12, the membrane is dipped in glycerol solution, and other humectants can be used for replacing glycerol to prevent the membrane from being damaged in the subsequent secondary drying process.

The utility model discloses in, the conveyer belt sets up in the low reaches of edge sealing machine to the upstream interval of rolling machine, the conveyer belt is by motor and driving shaft transmission.

In the present invention, the conveyor belt may be formed by a pair of relatively narrow conveyor belts disposed on one side of the film surface, and the narrow conveyor belts are designed so that the conveyor belts do not contact the main body of the film surface, but only contact the edge of the film surface. The driving shaft for guiding is not contacted with the film surface through the isolation effect of the conveyor belt, so that the film surface is prevented from being damaged.

Alternatively, the conveyor may be formed of two pairs of relatively narrow conveyors disposed on both upper and lower sides of the film surface for conveying the film surface by sandwiching the film surface, and similarly, the conveyor is secured so as not to contact the main body of the film surface but to contact only the edge of the film surface.

The utility model discloses a reverse osmosis membrane's production facility's use includes:

three unreeling machines 1 which are arranged in parallel are arranged to unreel a first polyolefin base layer 15, a pure water runner cloth 17 and a second polyolefin base layer 18 respectively, so that a polyolefin base material with a three-layer structure is obtained. Injecting glue at the edges of two sides of the base material through a glue applicator 16, and then sending the base material into a high-speed edge sealing machine 2 to carry out edge sealing and drying on the base material to obtain a double-sided polyolefin composite base layer supported by pure water runner cloth, wherein the double-sided polyolefin composite base layer is a supporting material membrane of the reverse osmosis membrane. Traditional reverse osmosis membrane itself divide into three-layer composite structure, is non-woven fabrics layer, polysulfone ultrafiltration layer, polyamide desalination layer respectively, the utility model discloses an adopt polyolefin material, replace non-woven fabrics and polysulfone layer, directly carry out interfacial polymerization on the polyolefin substrate, reach the purpose of replacing two kinds of raw and other materials. Meanwhile, a double-sided coating process is adopted to compound with the pure water flow passage cloth, a three-layer composite base material of polyolefin-flow passage cloth-polyolefin is formed at first, and a composite structure of a polyamide desalting layer-a polyolefin supporting layer-the pure water flow passage cloth-the polyolefin supporting layer-the polyamide desalting layer is carried out by carrying out double-sided interfacial polymerization, so that the productivity is doubled.

The downstream of the edge sealing machine 2 is provided with electrostatic dust removing brushes 3 which are formed in pairs, and the electrostatic dust removing brushes 3 are used for sweeping residual flock on the membrane. Subsequently, make the diaphragm through the diaphragm levelling roll 4 that sets up in pairs through the conveyer belt, make the surface of diaphragm more level and more smooth through the effect of diaphragm levelling roll 4, be convenient for carry on subsequent handling. Subsequently, the membrane enters a base material modification tank 5 for hydrophilic modification, and then excess solvent is removed through a dewatering roll 6.

After the water removing roller 6 is removed, the composite membrane enters a water phase impregnation tank 7 to be impregnated with water phase, and one or more groups of water phase impregnation tanks 7 can be arranged.

Two sets of water removal devices 8 are arranged downstream of the aqueous phase impregnation tank 7, each set of water removal devices 8 comprising pairs of roller bodies or air knives. When the composite web is guided by the conveyor belt through the dewatering device 8, excess liquid on the surface of the web is removed, and the web is subsequently fed to the oil phase coating device 9.

Fig. 2 is the utility model provides a two-sided from roller slot type coating device structure sketch map. The oil phase coating device 9 adopts a slit type structure, oil phase is uniformly discharged from a slit under the action of pressure in a slit cavity, and then is quantitatively coated on two surfaces of the composite membrane, so that oil phase coating operation on two sides of the composite body can be completed in one process.

In the oil phase coated diaphragm was conveyed into the suspension oven, fig. 3 is the utility model provides a structural schematic diagram of suspension oven, the diaphragm is further dried in the suspension oven. Multiple sets of levitation ovens 10 can be provided as desired. The suspension oven is composed of an air duct, air nozzles, a box body and the like, air is conveyed to heating facilities such as an electric heating furnace or an oil furnace by a fan to be heated, then conveyed into the air duct of the suspension oven, and blown to the reverse osmosis membrane by the air nozzles, the oven is divided into an upper part and a lower part, the membrane is dried in the middle of the oven in an advancing mode, and hot air blown by the upper air nozzles and the lower air nozzles floats, so that the suspension oven is called.

Membrane post-treatment devices such as a membrane cleaning modification tank 11 and a glycerin dipping tank 12 may be provided between the

suspension ovens

10 and 13 according to the production process requirements of the membrane.

Finally, the dried membrane enters a winding machine 14 through a conveyor belt to be wound to form a double-layer composite reverse osmosis membrane product, and the double-layer composite reverse osmosis membrane product can be applied to the winding of reverse osmosis membrane elements.

Fig. 4 is the structural schematic diagram of the conveying belt provided by the present invention, and fig. 5 is the schematic diagram of the advancing state of the membrane provided by the present invention. In the conveying process of the working procedures, particularly, the conveying devices shown in fig. 4 and 5 are used in the membrane cleaning modification tank 11, the glycerol impregnation tank 12 and other tank bodies to ensure that no membrane surface contacts with the shaft, and the membrane is driven by the conveying belt during operation.

The utility model discloses in, the conveyer belt that the data send process all adopted narrower setting in pairs, and the conveyer belt passes through driving shaft 20 to be connected with motor 21, by motor control axle rotational speed, each turn has an axle to make the conveyer belt turn, so whole equipment does not have the diaphragm axle to need not tension control system, solved the problem of polyolefin material receipts power deformation on the one hand, on the other hand has reduced the friction and the fish tail influence of roller to the diaphragm.

To sum up, the utility model discloses a reverse osmosis membrane production facility can realize the application of polyolefin material in reverse osmosis membrane production to production efficiency is high, is twice of traditional reverse osmosis membrane production efficiency. Adopt the utility model discloses equipment and technology can effectively solve the problem that polyolefin material was applied to reverse osmosis membrane production, also can be according to this patent on conventional reverse osmosis membrane production line the technology is reformed transform, and production efficiency can reach more than the twice of preceding production technology.

The embodiment of the utility model provides a can make production speed promote more than one time through two-sided coating technology, improve production efficiency greatly.

The cost of the used polyolefin material is far lower than that of the traditional non-woven fabric and polysulfone base material in the aspect of raw material cost, and the polyolefin material is a mature batch production product, so that the non-woven fabric and polysulfone are not required to be secondarily processed, and a large amount of processing cost is saved. Meanwhile, the thickness of the polyolefin material is only one fifth of that of the traditional material, and if membrane elements with the same volume are rolled in the subsequent rolling process of the membrane elements, the effective area of the membrane elements can be greatly increased, the integral water yield of the membrane elements is increased, the volume of the membrane elements can be greatly reduced on the premise of ensuring the same water yield, and the floor area or the volume of a water purifier is saved. Moreover, the existing production capacity can be doubled through a double-sided coating process, and the production cost is greatly reduced.

Those of ordinary skill in the art will understand that: the figures are schematic representations of one embodiment, and the blocks or processes in the figures are not necessarily required to practice the present invention.

Those of ordinary skill in the art will understand that: the components in the devices in the embodiments may be distributed in the devices in the embodiments according to the description of the embodiments, or may be correspondingly changed in one or more devices different from the embodiments. The components of the above embodiments may be combined into one component, or may be further divided into a plurality of sub-components.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. The production equipment of the reverse osmosis membrane is characterized by comprising an unreeling device, an edge sealing machine, a base material modification tank, a water phase coating device, a dewatering device, an oil phase coating device, a drying device and a membrane post-treatment device which are sequentially arranged, wherein all the devices are connected through a conveying belt;

2. The apparatus of claim 1, wherein a glue applicator is disposed between the unwinding device and the edge sealing machine, and glue is applied to the edges between the first polyolefin base layer and the pure water flow path cloth and between the pure water flow path cloth and the second polyolefin base layer through the glue applicator.

3. The apparatus of claim 2, wherein the first polyolefin base layer, the pure water flow path cloth and the second polyolefin base layer form a three-layer edge sealing machine, the three-layer reverse osmosis substrate is fixed and edge sealed and dried by the edge sealing machine, and a double-sided polyolefin composite substrate supported by the pure water flow path cloth is obtained, and the double-sided polyolefin composite substrate is a support layer of the reverse osmosis membrane.

4. The apparatus of claim 1, wherein an electrostatic dust removing brush and a membrane leveling device are further disposed between the edge sealing machine and the film coating device, the membrane leveling device comprises one or more pairs of leveling rollers disposed in pairs, the electrostatic dust removing brush is used for sweeping the remaining flocks on the membrane, and the membrane leveling roller is used for leveling the surface of the membrane.

5. The apparatus of claim 1, wherein the membrane is sequentially conveyed by a conveyor belt through the polyolefin modification tank, the water removal roller, the water phase impregnation tank and the water removal device, the water removal device comprises water removal rollers or air knives arranged in pairs, each pair of water removal rollers or air knives comprises a roller body or an air knife arranged on each side of the membrane, and the gap distance between the water removal rollers or the air knives in pairs is matched with the thickness of the three-layer structure of the polyolefin composite substrate.

6. The apparatus according to claim 3, wherein the oil phase coating device is a double-sided off-roll slit coating device, and comprises a left slit coating head and a right slit coating head which are respectively arranged at the left side and the right side of the three-layer structure, and the left slit coating head and the right slit coating head are respectively communicated with the oil phase material tank.

7. The device according to claim 1, wherein the drying device is a suspension oven, and the suspension oven comprises a membrane channel arranged in the middle of the oven, and a heating mechanism and an air outlet mechanism respectively arranged at the upper side and the lower side of the membrane channel.

8. The apparatus of claim 1, wherein the membrane post-treatment device comprises a cleaning modification tank, a glycerin impregnation tank and a secondary drying device.

9. The apparatus according to claim 1, further comprising a winding machine arranged at the downstream of the drying device, wherein the dried membrane enters the winding machine through a conveyor belt to be wound to form a double-layer composite reverse osmosis membrane product.

10. The apparatus according to claim 9, characterized in that said conveyor belt is arranged downstream of the edge-sealing machine up-stream of the winder, said conveyor belt being driven by a motor and a drive shaft;