Spiral-wound membrane assembly capable of synchronously separating oil and water and application of spiral-wound membrane assembly

Abstract

The invention discloses a spiral-wound membrane assembly for synchronously separating oil and water and application thereof. The spiral-wound membrane assembly comprises a central tube, a hydrophilic membrane bag, a hydrophobic membrane bag and a wrapping sealing shell, two ends of the central pipe are opened and are partitioned into a pure water collecting end and a pure oil collecting end by a partition plate; the hydrophilic membrane bags and the hydrophobic membrane bags are spirally wound outside the central tube at intervals; the hydrophilic film bag is formed by sequentially stacking and sealing three edges of a hydrophilic film, a pure water diversion net and a hydrophilic film, an opening is hermetically fixed on the outer wall of the central tube, and a pure water circulating hole is formed in the pure water collecting end wall of the central tube; the hydrophobic membrane bag is formed by sequentially stacking and sealing three sides of a hydrophobic membrane, a pure oil flow guide net and a hydrophobic membrane, an opening is hermetically fixed on the outer wall of the central tube, and a pure oil circulating hole is formed in the pure oil collecting end wall of the central tube; a feeding channel is formed between the adjacent hydrophilic membrane bag and hydrophobic membrane bag, and an emulsion flow guide net is arranged in the feeding channel. The spiral-wound membrane assembly can filter and separate pure water and pure oil at the same time, two-way liquid discharging is achieved, and the water and oil recovery rate is close to 100%.

Description

Technical Field

[0001] The invention relates to the technical field of oil-water emulsion mixture separation, in particular to a roll-type membrane component for synchronously separating oil and water and application thereof. Background Art

[0002] Oil-water separation is currently an important means to reduce environmental pollution and alleviate resource waste. With the rapid development of industry, water resources and fossil resources are becoming increasingly scarce, and oil-water separation technology is receiving more and more attention.

[0003] Compared with traditional technologies, membrane separation technology has the advantages of high efficiency, low energy consumption, easy operation and easy industrialization, so it is widely used in the field of water treatment. Although membrane separation technology is constantly developing, it still faces the problem of being unable to completely separate oil and water. Taking the hydrophilic membrane commonly used in industry as an example, it can only allow water to pass through and intercept other substances, which will inevitably cause the liquid to be separated to be continuously concentrated until it cannot be separated, thus causing secondary pollution. For example, the Japanese patent document with publication number JP2019506292A discloses a conductive composite membrane reactor, which consists of a water inlet system, a power supply system, a membrane reactor, a water outlet control system and a clear water tank. The water inlet system consists of a water inlet tank and a water inlet flow regulating device. The membrane reactor consists of a reaction tank, a composite membrane assembly and a stirring system. Each group of composite membrane assemblies is a flat membrane structure, which consists of a cathode composite membrane, an anode composite membrane and a separation layer. Several composite membrane assemblies located in the reaction tank are respectively connected to the positive and negative electrodes of the power supply system through wires with good conductive properties; the membrane reactor adopts an immersed arrangement, and an agitator is arranged in the reaction tank to mix the reaction liquid in the reaction tank evenly. The reaction tank outlet of the membrane reactor is connected to the water outlet system through a pipe.

[0004] A rolled membrane is a widely used membrane component that has the characteristics of high packing density, high membrane area utilization, and high separation efficiency. However, the traditional rolled membrane component has only one filtrate outlet in the central tube, and can only obtain one product, which cannot solve the problem of secondary pollution. For example, the patent with publication number WO2008 / 013114A1 discloses a polyolefin microporous membrane roll and a method for manufacturing the same. The polyolefin microporous membrane roll is a roll formed by winding a polyolefin microporous membrane on a core, and the absolute value (μm) of the difference between the membrane thickness T (μm) calculated by the following formula and the membrane thickness t (μm) evaluated using a microporous membrane (difference in membrane thickness) is less than 1.5μm. T(μm)=π(D 2 -d 2 ) / 4L (D refers to the outer diameter (mm) of the winding material including the porous membrane wound on the winding core, d refers to the outer diameter (mm) of the winding core, and L refers to the winding length (m) of the winding material).

[0005] Therefore, it is necessary to improve the structure of the roll membrane and achieve simultaneous separation and recovery of oil and water through technological innovation. Summary of the invention

[0006] The present invention provides a roll membrane assembly for synchronously separating oil and water. The roll membrane assembly can filter and separate pure water and pure oil at the same time, has two-way liquid outlet, and the water and oil recovery rate is close to 100%, which is expected to achieve "zero liquid discharge" in industry.

[0007] The technical solution of the present invention is as follows:

[0008] A roll-type membrane assembly for synchronously separating oil and water, comprising a central tube, a hydrophilic membrane bag, a hydrophobic membrane bag, and a wrapping sealing shell;

[0009] Both ends of the central tube are open and divided into a pure water collecting end and a pure oil collecting end by a partition plate. The pure water collecting end collects pure water and outputs it from the opening, and the pure oil collecting end collects pure oil and outputs it from the opening.

[0010] A plurality of the hydrophilic membrane bags and the hydrophobic membrane bags are spirally wound at intervals outside the central tube to form a hydrophilic spiral channel and a lipophilic spiral channel respectively; the outer side is sealed by a wrapping sealing shell;

[0011] The hydrophilic membrane bag is formed by stacking a hydrophilic membrane, a pure water guide net, and a hydrophilic membrane in sequence and sealing on three sides. The opening of the hydrophilic membrane bag is sealed and fixed on the outer wall of the central tube along the axial direction. The wall of the pure water collection end of the central tube is provided with a plurality of pure water flow holes connecting the hydrophilic membrane bag and the tube cavity of the pure water collection end of the central tube.

[0012] The hydrophobic membrane bag is formed by stacking a hydrophobic membrane, a pure oil guide net, and a hydrophobic membrane in sequence and sealing on three sides. The opening of the hydrophobic membrane bag is sealed and fixed on the outer wall of the central tube along the axial direction. A plurality of pure oil flow holes connecting the hydrophobic membrane bag and the tube cavity of the pure oil collection end of the central tube are opened on the tube wall of the pure oil collection end of the central tube.

[0013] A feed channel is formed between adjacent hydrophilic membrane bags and hydrophobic membrane bags, and an emulsion guide net is arranged in the feed channel.

[0014] The oil-water mixture to be separated enters from the feed channel, and the oil and water in the oil-water mixture to be separated are separated due to the different wettability of the oil and water on the membrane surface, and then enter different membrane bags. Water enters the hydrophilic spiral channel through the hydrophilic membrane and is collected along with the pure water diversion net through the pure water flow hole into the tube cavity of the pure water collection end of the central tube. The oil enters the hydrophobic spiral channel through the hydrophobic membrane and is collected along with the pure oil diversion net through the pure oil flow hole into the tube cavity of the pure oil collection end of the central tube.

[0015] The present invention designs two membrane groups with different wettability to be wound around the central tube, which subverts the principle that the traditional roll membrane has only one type of membrane component. By introducing multiple membrane group elements, the hydrophilic membrane bag is used to separate pure water, and the hydrophobic membrane bag is used to separate pure oil, so as to achieve the synchronous separation of oil and water. The central tube is opened at both ends and the middle is partitioned, and its two ends are divided into water channels and oil channels, so that the oil and water can be continuously and quickly exported from the roll membrane component after being separated. Such a roll membrane component with both hydrophilic and hydrophobic membrane groups and pure water and pure oil outlets can achieve the synchronous separation of various oil-water mixtures, has a high water and oil recovery rate, greatly reduces the generation of industrial secondary pollution, and is beneficial to environmental protection and resource recovery.

[0016] Preferably, the material of the central tube is a metal material or alloy material made of one or more metal materials such as stainless steel, iron, copper, aluminum, etc.; a polymer material or composite material made of one or more polymer materials such as polyethylene, polypropylene, polyvinyl chloride, polybutylene, polytetrafluoroethylene, etc.

[0017] Preferably, the cross-sectional diameter of the central tube is 1 to 1000 mm; and the pure water flow holes are circular, square or rectangular.

[0018] The partitions cannot be wetted by oil or water.

[0019] Preferably, the wrapping seal may be made of a metal material or alloy material made of one or more metal materials such as stainless steel, copper, etc.; a polymer material or composite material made of one or more polymer materials such as EPDM rubber, silicone rubber, polytetrafluoroethylene, polyacrylic acid, polyvinyl chloride, polyphenylene sulfide, etc.

[0020] Preferably, the cross-sectional diameter of the wrapped sealing shell is 10 to 10,000 mm; and the pure oil circulation hole is elliptical or rectangular.

[0021] Preferably, the material of the emulsion guide net is a polymer material or a composite material made of one or more polymer materials such as polypropylene resin, unsaturated polyester resin, vinyl resin, epoxy resin, etc.; a metal material or an alloy material made of one or more metal materials such as stainless steel, copper, etc.; an inorganic material or a composite material made of one or more inorganic materials such as glass fiber, carbon fiber, etc.; a composite material made of two or three of polymer materials, metal materials and inorganic materials.

[0022] Preferably, the emulsion diversion net has a thickness of 0.1 to 10 mm, a mesh width of 0.1 to 50 mm, and a mesh wire radius of 0.1 to 5 mm, and can be prepared by extrusion, weaving, and the like.

[0023] The thickness, mesh width, mesh radius and preparation method of the pure water guide net and the pure oil guide net are similar to those of the emulsion guide net, and are determined according to the size of the wound membrane module and the properties of the mixture to be separated.

[0024] Preferably, the pure water guide net is made of a polymer material or a composite material made of one or more hydrophilic polymer materials such as polyethylene terephthalate, polycarbonate, hydrophilic modified polypropylene, cloth, etc.; a metal material or an alloy material made of one or more metal materials such as stainless steel, copper, etc.; an inorganic material or a composite material made of one or more hydrophilic inorganic materials such as hydrophilic glass fiber, carbon fiber, etc.; a composite material made of two or three of polymer materials, metal materials and inorganic materials;

[0025] The material of the pure oil guide net is a polymer material or a composite material made of one or more hydrophobic polymer materials such as polytetrafluoroethylene, hydrophobic polyvinylidene fluoride, polydimethylsiloxane, polypropylene, polyester, etc.; a metal material or an alloy material made of one or more metal materials such as stainless steel, copper, etc.; an inorganic material or a composite material made of one or more hydrophobic inorganic materials such as hydrophobic glass fiber; a composite material made of two or three of polymer materials, metal materials and inorganic materials.

[0026] Preferably, the pure water guide net is aligned with the pure water flow hole; and the pure oil guide net is aligned with the pure oil flow hole.

[0027] The hydrophilic membrane is made of hydrophilic material.

[0028] Preferably, the hydrophilic membrane is a hydrophilic ceramic membrane such as silicon carbide ceramic membrane, Al2O3 ceramic membrane; a hydrophilic molecular sieve membrane; a hydrophilic metal membrane such as an aluminum alloy membrane, a copper membrane; a hydrophilic natural polymer membrane such as a cellulose membrane, a chitin membrane; a hydrophilic modified natural polymer membrane such as a cellulose acetate membrane, a cellulose nitrate membrane, a nanocellulose membrane; a hydrophilic synthetic polymer membrane such as a hydrophilic polyvinylidene fluoride, a polyether sulfone, a polylactic acid, a polyamide, a polyurethane, a polycarbonate; a hydrophilic composite membrane made of the above materials; a hydrophilic membrane modified by hydrophilic molecules such as dopamine and polyethylene glycol; a hydrophilic membrane obtained by plasma treatment, surface etching, etc.

[0029] Preferably, the hydrophilic membrane is a microfiltration membrane with an average pore size of 0.02-10 μm or an ultrafiltration membrane with an average pore size of 2-20 nm.

[0030] The hydrophobic membrane is made of hydrophobic material.

[0031] Preferably, the hydrophobic membrane is a ceramic membrane, a molecular sieve membrane, a metal membrane, a modified natural polymer membrane obtained by hydrophobic modification; a hydrophobic synthetic polymer membrane such as polytetrafluoroethylene, polydimethylsiloxane, hydrophobic polyvinylidene fluoride, polypropylene, polyethylene, polybutene, polyester, fluorosilicone resin, polystyrene, vinyl acetate copolymer, polyphenylene sulfide, etc.; a hydrophobic composite membrane made of the above materials; a hydrophobic membrane modified by low surface energy elements such as fluorine and silicon.

[0032] Preferably, the hydrophobic membrane is a microfiltration membrane with an average pore size of 0.02-10 μm or an ultrafiltration membrane with an average pore size of 2-20 nm.

[0033] Preferably, the number of the hydrophilic membrane bags is 1 to 100; the number of the hydrophobic membrane bags is 1 to 100.

[0034] Preferably, the aspect ratio of the hydrophilic membrane bag or the hydrophobic membrane bag is (0.01-1):1; the packing density of the roll-type membrane assembly is 10-1000m 2 / m 3 .

[0035] The packing density is the ratio of the total area of ​​the hydrophilic membrane and the hydrophobic membrane in the spiral membrane module to the total volume of the spiral membrane module.

[0036] The method for preparing the spiral membrane assembly comprises:

[0037] The hydrophilic membrane, the pure water guide net and the hydrophilic membrane are stacked in sequence, and the three sides of the hydrophilic membrane are sealed to form a hydrophilic membrane bag. The opening side of the hydrophilic membrane bag is sealed and connected to the outer wall of the central tube, and the pure water flow hole on the central tube wall is located on the inner side of the hydrophilic membrane bag;

[0038] The hydrophobic membrane, the pure oil guide net and the hydrophobic membrane are stacked in sequence, and the three sides of the hydrophobic membrane are sealed to form a hydrophobic membrane bag. The opening side of the hydrophobic membrane bag is sealed and connected to the outer wall of the central tube, and the pure oil flow hole on the central tube wall is located on the inner side of the hydrophobic membrane bag;

[0039] The hydrophilic membrane bag, the emulsion guide net and the hydrophobic membrane bag are spirally wound around the central tube in sequence to form a rolled membrane assembly.

[0040] The invention also provides application of the rolled membrane assembly in separating oil-water mixture.

[0041] The oil-water mixture is a free oil-water mixture, a dispersed oil-water mixture or an emulsified oil-water mixture. The oil-water mixture is synchronously separated into pure water and pure oil by the spiral membrane assembly.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) When the oil-water mixture enters the roll-type membrane assembly for simultaneous separation of oil and water at a certain flow rate, water passes through the hydrophilic membrane to form pure water and enters the hydrophilic spiral channel, and reaches the pure water flow hole on the wall of the pure water collection end of the central tube along the pure water guide net, and then enters the pure water collection end of the central tube and flows out from the pure water outlet; oil passes through the hydrophobic membrane to form pure oil and enters the hydrophobic spiral channel, and reaches the pure oil flow hole on the wall of the pure oil collection end of the central tube along the pure oil guide net, and then enters the pure oil collection end of the central tube and flows out from the pure oil outlet, and then is exported from the roll-type membrane assembly. The above asymmetric component design provides transmission channels and outlets for water and oil at the same time, realizing the simultaneous separation and recovery of oil and water.

[0044] (2) Thanks to the unique structure of the spiral membrane, there is a narrow confined space between the hydrophilic membrane and the hydrophobic membrane, which is conducive to the extrusion and collision of the emulsion droplets in the oil-water emulsion to break the emulsion. In this way, the spiral membrane is endowed with a demulsification function in addition to the basic separation function, so free oil-water mixture, dispersed oil-water mixture and emulsified oil-water mixture can all be separated using the spiral membrane assembly of the present invention.

[0045] (3) The present invention can also efficiently extract the oil phase when extracting the water phase in the oil-water mixture, thereby reducing the oil concentration in the emulsion, reducing the degree of oil contamination of the hydrophilic membrane, maintaining the performance of the hydrophilic membrane, and increasing the service life of the hydrophilic membrane.

[0046] (4) When the present invention is operated in the cross-flow filtration mode, the water and oil recovery rate is close to 100%, which is expected to achieve "zero liquid discharge" in industry, reduce process costs, and is conducive to the development of a circular economy and the promotion of sustainable development road construction.

[0047] (5) The roll-type membrane assembly of the present invention has a simple structure and is easy to operate, which is conducive to practical industrial applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the structure of the hydrophilic and hydrophobic membrane sheets in the spiral membrane assembly for simultaneous separation of oil and water before winding;

[0049] Figure 2 A cross-sectional view of the central tube of a spiral membrane module for simultaneous separation of oil and water;

[0050] Figure 3 A schematic diagram of the winding of the emulsion guide net, the hydrophilic membrane sheet, the pure water guide net, the hydrophobic membrane sheet, and the pure oil guide net outside the central tube of a spiral membrane assembly for simultaneous separation of oil and water;

[0051] Figure 4 Flow chart of treating oil-water mixture for spiral wound membrane module for simultaneous separation of oil and water;

[0052] In the figure: 1-central tube; 101-pure water flow hole; 102-pure water outlet; 103-pure oil flow hole; 104-pure oil outlet; 105-partition; 301-hydrophilic membrane; 302-pure water guide net; 401-hydrophobic membrane; 402-pure oil guide net; 5-emulsion guide net. DETAILED DESCRIPTION

[0053] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0054] Example 1

[0055] This embodiment provides a method for preparing a spiral membrane module, the preparation method comprising the following steps:

[0056] The two ends of the central tube are open and divided into a pure water collecting end and a pure oil collecting end by a partition 105. The pure water collecting end collects pure water and outputs it to a pure water outlet 102, and the pure oil collecting end collects pure oil and outputs it to a pure oil outlet 104;

[0057] The hydrophilic membrane 301, the pure water guide net 302, and the hydrophilic membrane 301 are stacked in sequence, and three sides are sealed to form a hydrophilic membrane bag, and the other side is sealed and connected to the outer wall of the central tube 1. A pure water flow hole 101 is opened on the side wall of the pure water collection end of the central tube 1, and the pure water flow hole 101 is located inside the hydrophilic membrane bag to form a hydrophilic membrane sheet group; the hydrophobic membrane 401, the pure oil guide net 402, and the hydrophobic membrane 401 are stacked in sequence, and three sides are tightly sealed to form a hydrophobic membrane bag, and the other side is sealed and connected to the outer wall of the central tube 1. A pure oil flow hole 103 is opened on the side wall of the pure oil collection end of the central tube 1, and the pure oil flow hole 103 is located inside the hydrophobic membrane bag to form a hydrophobic membrane sheet group. An emulsion guide net 5 is arranged between adjacent hydrophilic membrane sheets 301 and hydrophobic membrane sheets 401.

[0058] Figure 1 The structure diagram of the hydrophilic and hydrophobic membrane groups in the wound membrane assembly before winding is shown in FIG. The hydrophilic membrane group, the hydrophobic membrane group and the emulsion guide net 5 are wound around the central tube 1 at the same time to obtain the following Figure 3 The spiral membrane module shown.

[0059] The material of the central tube 1 is polytetrafluoroethylene, the cross-sectional diameter of the central tube 1 is 25 mm, and 20 circular pure water flow holes 101 are arranged on the tube wall, and the diameter of the circular pure water flow holes 101 is 15 mm.

[0060] The material of the wrapping sealing layer 2 is oil-resistant polyphenylene sulfide, and the cross-sectional diameter of the wrapping sealing layer 2 is 500 mm.

[0061] The material of the emulsion diversion net 5 is a mixed woven net of glass fiber and polypropylene. The thickness of the emulsion diversion net 5 is 1.5 mm, the mesh density is 200 meshes, and the mesh radius is 0.2 mm.

[0062] The material of the pure water diversion net 302 is non-woven fabric; the material of the pure oil diversion net 402 is polypropylene woven net.

[0063] The material of the hydrophilic membrane 301 is cellulose acetate microfiltration membrane with a pore size of 220nm and a porosity of 80%; the hydrophobic membrane 401 is polypropylene microfiltration membrane with a pore size of 220nm and a porosity of 75%; the number of hydrophilic membrane groups and hydrophobic membrane groups are both 2, the aspect ratio of the membrane group is 0.05:1, and the final packing density is 100m 2 / m 3 .

[0064] The oil-water emulsion enters the wound membrane module from the side through the emulsion guide net, and is then separated by the hydrophilic membrane and the hydrophobic membrane according to their different wettability.

[0065] like Figure 4 As shown in the figure, the separation process of oil-water mixture: the oil-water mixture is pumped into the roll membrane assembly and transported through the emulsion diversion net. The two sides of the emulsion diversion net are hydrophilic membrane bags and hydrophobic membrane bags respectively. Water and oil enter the hydrophilic membrane bag and the hydrophobic membrane bag respectively according to their wettability. Water is guided to the central tube by the pure water diversion net in the hydrophilic membrane bag, and is collected at the pure water flow holes on the upper half of the central tube and discharged through the pure water outlet, and then pumped into the pure water collection tank; oil is guided to the pure oil flow holes on the other half of the central tube by the pure oil diversion net in the hydrophobic membrane bag, and is collected and discharged through the pure oil outlet on the other side, and then pumped into the pure oil collection tank. The unseparated feed liquid flows out of the membrane assembly and is pumped back to the stock liquid storage tank for circulation separation until the feed liquid is completely separated.

[0066] The emulsion used in Example 1 has an oil:water volume ratio of 1:9, the oil phase used is n-hexadecane, the emulsifier is sodium dodecyl sulfate, the emulsifier concentration is 10 mg / mL, and the total volume of the emulsion is 1m 3 .

[0067] When the wound membrane assembly for synchronously separating oil and water prepared by the present invention is used in the field of oil-water separation, the water and oil recovery rates are calculated by the following formula:

[0068]

[0069] Among them, R w is the water recovery rate, m w is the mass of pure water obtained after separation, m "w is the mass of water in the emulsion to be separated; R o is the oil recovery rate, mo is the mass of pure oil obtained after separation, m "o It is the mass of oil contained in the emulsion to be separated.

[0070] The specific separation performance parameters are shown in Table 1:

[0071] Table 1

[0072] Separation time (h) Water recovery rate (%) Oil recovery rate (%) Water purity (%) Oil purity (%) 5 96.35 98.32 99.22 99.32

[0073] Example 2-3

[0074] The spiral membrane modules of Examples 2-3 were prepared in the same manner as in Example 1, and the emulsion to be separated in Example 1 was replaced with a free oil-water mixture without an emulsifier and a dispersed oil-water mixture dispersed by ultrasound, respectively, and the oil-water ratio was still 1:9. The test results are shown in Table 2:

[0075] Table 2

[0076]

[0077] Embodiment 4-7

[0078] The hydrophilic membrane of the wound membrane assembly in Example 1 was replaced by Al2O3 ceramic microfiltration membrane (Example 4), with a pore size of 100nm and a porosity of 50%; aluminum alloy microfiltration membrane (Example 5), with a pore size of 50nm and a porosity of 30%; polyethersulfone microfiltration membrane (Example 6), with a pore size of 450nm and a porosity of 85%; hydrophilic modified polypropylene microfiltration membrane (Example 7), with a pore size of 220nm and a porosity of 75%, respectively, Examples 4-7. The emulsion to be separated is the same as in Example 1, and the test results are shown in Table 3:

[0079] Table 3

[0080]

[0081] Examples 8-12

[0082] The hydrophobic membrane of the wound membrane assembly in Example 1 was replaced with octadecyltrichlorosilane-modified silicon carbide ceramic microfiltration membrane (Example 8), with a pore size of 300nm and a porosity of 50%; n-dodecyl mercaptan-modified aluminum alloy microfiltration membrane (Example 9), with a pore size of 50nm and a porosity of 30%; polytetrafluoroethylene microfiltration membrane (Example 10), with a pore size of 450nm and a porosity of 80%; polyvinylidene fluoride microfiltration membrane (Example 11), with a pore size of 450nm and a porosity of 85%; polyethylene terephthalate microfiltration membrane (Example 12), with a pore size of 400nm and a porosity of 70%, respectively, Examples 8-12. The emulsion to be separated is the same as in Example 1, and the test results are shown in Table 4:

[0083] Table 4:

[0084]

[0085] Examples 13-20

[0086] The same method as in Example 1 was used to prepare the wound membrane modules of Examples 13-20, and the oil phase in the emulsion to be separated in Example 1 was replaced with dichloromethane, petroleum ether, n-hexane, cyclohexane, diesel, gasoline, low-viscosity silicone oil (viscosity ~10 mPa.s), and soybean oil, respectively, which are Examples 13-20. The test results are shown in Table 5:

[0087] Table 5

[0088]

[0089] Examples 21-25

[0090] The spiral membrane modules of Examples 21-25 were prepared in the same manner as in Example 1, and the oil-water ratio in the emulsion to be separated in Example 1 was replaced with 0.5:9.5, 1.5:8.5, 2:8, 3:7, and 4:6, respectively, which are Examples 21-25. The test results are shown in Table 6:

[0091] Table 6

[0092]

[0093] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A spiral membrane assembly for simultaneous separation of oil and water, characterized in that: It includes a central tube, a hydrophilic membrane bag, a hydrophobic membrane bag, and a wrapped sealing shell; Both ends of the central tube are open and divided into a pure water collecting end and a pure oil collecting end by a partition plate. The pure water collecting end collects pure water and outputs it from the opening, and the pure oil collecting end collects pure oil and outputs it from the opening. A plurality of the hydrophilic membrane bags and the hydrophobic membrane bags are spirally wound at intervals outside the central tube to form a hydrophilic spiral channel and a lipophilic spiral channel respectively; the outer side is sealed by a wrapping sealing shell; The hydrophilic membrane bag is formed by stacking a hydrophilic membrane, a pure water guide net, and a hydrophilic membrane in sequence and sealing on three sides. The opening of the hydrophilic membrane bag is sealed and fixed on the outer wall of the central tube along the axial direction. The wall of the pure water collection end of the central tube is provided with a plurality of pure water flow holes connecting the hydrophilic membrane bag and the tube cavity of the pure water collection end of the central tube. The hydrophobic membrane bag is formed by stacking a hydrophobic membrane, a pure oil guide net, and a hydrophobic membrane in sequence and sealing on three sides. The opening of the hydrophobic membrane bag is sealed and fixed on the outer wall of the central tube along the axial direction. A plurality of pure oil flow holes connecting the hydrophobic membrane bag and the tube cavity of the pure oil collection end of the central tube are opened on the tube wall of the pure oil collection end of the central tube. A feed channel is formed between adjacent hydrophilic membrane bags and hydrophobic membrane bags, and an emulsion guide net is arranged in the feed channel.

2. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The cross-sectional diameter of the central tube is 1-1000 mm; the pure water flow hole is circular, square or rectangular.

3. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The cross-sectional diameter of the wrapped sealing shell is 10-10000 mm; the pure oil circulation hole is elliptical or rectangular.

4. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The thickness of the emulsion guide net is 0.1-10 mm, the mesh width is 0.1-50 mm, and the mesh wire radius is 0.1-5 mm.

5. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The pure water guide net is aligned with the pure water flow hole; the pure oil guide net is aligned with the pure oil flow hole.

6. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The hydrophilic membrane is made of hydrophilic material; the hydrophilic membrane is a microfiltration membrane with an average pore size of 0.02-10 μm or an ultrafiltration membrane with an average pore size of 2-20 nm.

7. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The hydrophobic membrane is made of hydrophobic material; the hydrophobic membrane is a microfiltration membrane with an average pore size of 0.02-10 μm or an ultrafiltration membrane with an average pore size of 2-20 nm.

8. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The number of the hydrophilic membrane bags is 1 to 100; the number of the hydrophobic membrane bags is 1 to 100.

9. The spiral membrane assembly for synchronously separating oil and water according to claim 1, characterized in that: The aspect ratio of the hydrophilic membrane bag or the hydrophobic membrane bag is (0.01-1):1; the packing density of the roll membrane assembly is 10-1000m 2 / m 3 .

10. Use of the spiral membrane module according to any one of claims 1 to 9 in separating oil-water mixtures.

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