Medium and micro channel demulsification device with flow field-electric field coordinated regulation and control and demulsification method with flow field-electric field coordinated regulation and control

Abstract

The invention discloses a flow field-electric field coordinated regulation and control dielectric and microchannel demulsification device and a flow field-electric field coordinated regulation and control demulsification method. The demulsification device comprises an outer cylinder electrode, an inner cylinder, a flow channel regulation assembly and a central electrode, the inner cylinder is sleeved in the outer cylinder electrode; the flow channel adjusting assembly comprises a plurality of sub-structures which are arranged in the first direction. The central electrode is arranged in the flow channel adjusting assembly; a second cavity for the fluid to pass through is formed between the inner surface of the inner cylinder and the outer surface of the flow channel adjusting assembly; and an electric field is formed between the outer cylinder electrode and the central electrode. According to the invention, the balance between the flow flux and the control precision is established by utilizing flow field-electric field coordinated regulation and control and the size effect of a fluid channel, so that the relatively large flow flux is ensured, the flow field-electric field can be precisely regulated and controlled, the collision and coalescence of emulsion droplets are effectively regulated and controlled, and the problem of high-efficiency separation of two phases after emulsification and extraction is solved.

Description

Technical Field

[0001] The present application belongs to the field of extraction, specifically to the field of demulsification of extraction emulsions, and relates to a microchannel demulsification device with coordinated flow field-electric field control and a method for demulsification with coordinated flow field-electric field control. Background Art

[0002] The extraction process has the problem of low mass transfer and phase separation efficiency of liquid-liquid phases, which seriously restricts its industrial expansion. In this regard, the emulsification-demulsification combined technology utilizes the high-speed mass transfer of liquid-liquid phases in the emulsified state, which can effectively reduce the equipment size and break through the limitation of industrial expansion. However, the low phase separation efficiency of demulsification has become a difficult problem that needs to be solved urgently in the emulsification-demulsification combined technology.

[0003] Effective coalescence of droplets after collision is the key to demulsification technology. The oil-water interface of the droplets in the emulsion adsorbs surface charges. The electric field induces non-uniform redistribution of surface charges, resulting in surface anisotropy, which is an effective way to regulate droplet collision and coalescence. At present, most of the research on droplet collision and coalescence under electric fields focuses on driving the motion and migration of stationary droplets to collide through the effects of electric fields on droplets such as dipole, electrophoresis and dielectrophoresis. Electric field-driven droplet collisions occur in the direction of the electric field lines, resulting in a single droplet collision form, making it difficult to achieve efficient demulsification.

[0004] Therefore, there is an urgent need to find an effective way to regulate the collision and coalescence of emulsion droplets, so as to improve the demulsification efficiency and achieve efficient demulsification of large quantities of emulsions, and solve the problem of industrial re-scaling of solvent extraction technology for purifying wet-process phosphoric acid. Summary of the invention

[0005] The purpose of the present application is to overcome the shortcomings of the prior art and to provide a microchannel demulsification device with coordinated flow field and electric field regulation and a demulsification method with coordinated flow field and electric field regulation, which utilizes the coordinated flow-electric field regulation and the size effect of the fluid channel to effectively regulate the collision and coalescence of emulsion droplets, and has the advantages of high demulsification efficiency and large processing capacity.

[0006] In order to achieve its purpose, the technical solution adopted by this application is as follows:

[0007] In order to achieve the above-mentioned purpose, in the first aspect, the embodiment of the present application discloses a microchannel demulsification device with coordinated control of flow field and electric field, the demulsification device comprises an outer cylinder electrode, an inner cylinder, a flow channel adjustment component and a central electrode; the inner cylinder is sleeved in the outer cylinder electrode and extends along a first direction, and the inner cylinder is provided with a liquid inlet and a liquid outlet;

[0008] The flow channel regulating component is arranged inside the inner cylinder and extends along the first direction, and the outer surface of the flow channel regulating component includes a plurality of substructures, and the substructures are arranged in an array along the first direction;

[0009] The flow channel regulating component is provided with a first cavity, in which the central electrode is provided, and the axis of the central electrode is parallel to or coincides with the axis of the flow channel regulating component; the second cavity is formed between the inner surface of the inner cylinder and the outer surface of the flow channel regulating component, the second cavity is for fluid to pass through, and the second cavity is connected with the liquid inlet and the liquid outlet; an electric field is formed between the outer cylinder electrode and the central electrode.

[0010] As an optional implementation, the inner diameter R1 of the inner cylinder is 2-75 mm, and the length L1 is 200-300 mm; and / or the length of the outer cylinder electrode is less than or equal to the length of the inner cylinder.

[0011] And / or, when the length of the outer cylinder electrode is smaller than the length of the inner cylinder (2), the minimum distance between the outer cylinder electrode and the liquid inlet is 0 to 75 mm, and the length of the outer cylinder electrode is 150 to 300 mm.

[0012] As an optional implementation, the ratio of the inner diameter R1 of the inner cylinder to the maximum outer diameter R2 of the flow channel regulating component substructure is R1:R2=(1.5-4):1, and the one-dimensional size of the second cavity is R3=R1-R2=1-25mm.

[0013] As an optional embodiment, at least two identical substructures are arranged continuously or at intervals along the first direction to form a repeating unit;

[0014] And / or, the flow channel regulating component (3) comprises at least one of the repeating units.

[0015] As an optional embodiment, the shape of the substructure is selected from one or more of a twisted rope shape, an ellipse shape, a teardrop shape, a prism shape or a gyroscope shape;

[0016] and / or, when the number of the repeating units is greater than 1, the shapes of the substructures constituting each of the repeating units may be the same or different;

[0017] And / or, when the substructures are spaced apart, the spacing between the substructures is 0 <L3≤5mm;

[0018] And / or, the total extension length L4 of all the repeating units along the first direction is 15-100 mm.

[0019] As an optional embodiment, the outer surface material of the flow channel regulating component is selected from insulating hydrophilic materials;

[0020] And / or, the inner surface material of the inner cylinder is selected from insulating oleophilic materials;

[0021] and / or, the insulating oleophilic material is selected from one or more of polyurethane foam, porous silica gel, polytetrafluoroethylene or polypropylene;

[0022] And / or, the insulating hydrophilic material is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyamide (PA, nylon) modified materials, ceramics, glass, etc.;

[0023] As an optional implementation, the outer cylindrical electrode is grounded, and the central electrode is connected to a power generator, which provides direct current or alternating current;

[0024] And / or, the electric field is in the form of a uniform electric field or a non-uniform electric field;

[0025] And / or, the voltage provided by the power generating device is 1-15 kV.

[0026] In a second aspect, the embodiment of the present application discloses a demulsification method of flow field-electric field coordinated regulation, characterized in that the operation steps of the demulsification method include:

[0027] 1) Start the power generating device, adjust the power voltage and frequency, and generate an electric field in the fluid channel;

[0028] 2) injecting the emulsion into the fluid channel in the demulsification device at a certain flow rate, wherein at least one flow channel regulating component is provided in the fluid channel in the demulsification device;

[0029] 3) The emulsion flows through the flow channel regulating component along the fluid channel, undergoes a demulsification process under the coordinated regulation of the electric field and the flow field, and obtains a demulsified liquid after a certain period of time.

[0030] As an optional embodiment, the demulsification device adopts the demulsification device disclosed in the first aspect of the present application, the central electrode is connected to a power generator, and the power generator provides direct current or alternating current; the electric field is in the form of a uniform electric field or a non-uniform electric field; the voltage provided by the power generator is 1-15kV.

[0031] As an optional embodiment, the emulsion has a first temperature before being injected into the liquid inlet, and the first temperature is 18-35° C.; the demulsification time is 2-10 min.

[0032] Compared with the prior art, this application has the following beneficial effects:

[0033] 1) The present application adjusts the shape of the flow channel regulating component substructure and the wettability of the surface material, and sets the electric field at the appropriate position to induce the droplets to produce surface anisotropy and control the droplets to collide, effectively regulating the droplet collision rate and coalescence efficiency, thereby achieving efficient demulsification.

[0034] 2) The fluid channel size of the present application is between that of the microchannel and that of the traditional large chemical industry, that is, the microchannel size is used to establish a balance between flow flux and control accuracy, which not only ensures a large flow flux, but also can more accurately control the flow field-electric field, and can achieve industrial large-scale emulsion demulsification.

[0035] 3) By using the demulsification device of the present application, under the coordinated regulation of flow field-electric field, the demulsification rate of the organic extraction system emulsion (such as phosphoric acid-water / TBP-kerosene emulsion system) can reach 88% within 10 minutes, and the demulsification efficiency is significantly improved, solving the problem that the two phases cannot be efficiently separated after emulsification extraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Schematic diagram of the structure of a microchannel demulsification device with coordinated flow field and electric field control in one embodiment of the present application.

[0037] Figure 2 for Figure 1 Side view of.

[0038] Figure 3 Schematic diagram of the repeating unit of the twisted rope flow regulation component substructure.

[0039] Figure 4 Schematic diagram of the repeating unit of the prismatic flow regulation component substructure.

[0040] Figure 5 Schematic diagram of the repetitive unit of the gyro-shaped flow channel regulation component substructure.

[0041] In the figure, 1-outer cylinder electrode, 2-inner cylinder, 3-flow channel adjustment component, 4-center electrode, 5-liquid inlet, 6-liquid outlet. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] In the present application, the terms "upper", "lower", "left", "right", "top", "bottom", "inner", "outer", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0044] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0045] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0046] In addition, the terms "first", "second", etc. are mainly used to distinguish different devices, elements or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance and quantity of the indicated devices, elements or components. Unless otherwise specified, "plurality" means two or more.

[0047] The extraction process has the problem of low mass transfer and phase separation efficiency of liquid-liquid phases, which seriously restricts its industrial expansion. In this regard, the emulsification-demulsification combined technology utilizes the high-speed mass transfer of liquid-liquid phases in the emulsified state, which can effectively reduce the equipment size and break through the limitation of industrial expansion. However, the low phase separation efficiency of demulsification has become a difficult problem that needs to be solved urgently in the emulsification-demulsification combined technology.

[0048] Effective coalescence of droplets after collision is the key to demulsification technology. The oil-water interface of the droplets in the emulsion adsorbs surface charges. The electric field induces non-uniform redistribution of surface charges, resulting in surface anisotropy, which is an effective way to regulate droplet collision and coalescence. At present, most of the research on droplet collision and coalescence under electric fields focuses on driving the motion and migration of stationary droplets to collide through the effects of electric fields on droplets such as dipole, electrophoresis and dielectrophoresis. Electric field-driven droplet collisions occur in the direction of the electric field lines, resulting in a single droplet collision form, making it difficult to achieve efficient demulsification.

[0049] Therefore, there is an urgent need to find an effective way to regulate the collision and coalescence of emulsion droplets, so as to improve the demulsification efficiency and achieve efficient demulsification of large quantities of emulsions, and solve the problem of industrial scale-up of the emulsification-demulsification combined technology.

[0050] Based on this, the present application provides a microchannel demulsification device with coordinated flow field and electric field regulation.

[0051] See also Figure 1 and Figure 2 The demulsification device provided in one embodiment of the present application comprises an outer cylinder electrode 1, an inner cylinder 2, a flow channel adjustment component 3 and a central electrode 4; the inner cylinder 2 is sleeved in the outer cylinder electrode 1 and extends along a first direction, and the first direction is the length direction of the outer cylinder electrode 1 and the inner cylinder 2;

[0052] See also Figure 1 In some embodiments, the flow channel regulating component 3 is arranged inside the inner cylinder and extends along the first direction, and the outer surface of the flow channel regulating component 3 includes a plurality of substructures, and the substructures are arranged along the first direction. By utilizing the continuous change of the surface shape of the substructure of the flow channel regulating component, the flow field distribution in the fluid channel is changed, and then the collision of the droplets of the emulsion is regulated, which is conducive to obtaining a higher demulsification efficiency and a better demulsification rate.

[0053] In some embodiments, the flow channel regulating component 3 is provided with a first cavity, in which a central electrode 4 is provided, and the central electrode 4 extends in a straight line along a first direction. In some specific embodiments, the axis of the central electrode 4 is parallel to or coincides with the axis of the flow channel regulating component 3. Optionally, the axes of the central electrode 4, the flow channel regulating component 3 and the inner cylinder 2 coincide, and such a setting can make each point in the fluid channel equidistant from the central electrode 4 have the same electric field strength, and the fluid channel has a symmetrical electric field distribution centered on the central electrode 4.

[0054] In some embodiments, a second cavity is formed between the inner surface of the inner cylinder 2 and the outer surface of the flow channel adjustment component 3, and the second cavity is used for the emulsion or demulsified liquid to pass through.

[0055] In some embodiments, the inner cylinder 2 is provided with a liquid inlet 5 and a liquid outlet 6, which are respectively arranged at both ends of the inner cylinder 2, and the liquid inlet 5 and the liquid outlet 6 are respectively connected to the second cavity, and the emulsion enters the second cavity through the liquid inlet 5, and the demulsified liquid flows out of the second cavity through the liquid outlet 6. The specific setting positions and sizes of the liquid inlet 5 and the liquid outlet 6 can be set according to actual needs and are not specifically limited here.

[0056] In some embodiments, an electric field is formed between the outer cylindrical electrode 1 and the central electrode 4. The oil-water interface of the droplets in the emulsion adsorbs surface charges. In the absence of an external electric field, the adsorbed charges will be evenly distributed on the surface of the droplets, thereby hindering the coalescence of the droplets after collision. The surface charge of the droplets is not in a fixed state, and non-uniform redistribution may occur under the induction of the electric field. The uneven surface properties of the droplets will affect the coalescence effect of their different collision contact surfaces, thereby improving the demulsification effect. The present application forms an electric field between the outer cylindrical electrode 1 and the central electrode 4, inducing non-uniform redistribution of the surface charge of the droplets, thereby obtaining the surface charge distribution and collision mode that are most conducive to droplet coalescence, thereby achieving efficient demulsification.

[0057] In some embodiments, the cross-sectional profile of the inner cylinder along the direction perpendicular to the axis can be circular, elliptical, square, regular polygonal, etc., and those skilled in the art can flexibly adjust and set it according to actual needs. Figure 2 The cross-sectional profile of the inner cylinder along the direction perpendicular to the axis is circular, which is conducive to batch processing and manufacturing.

[0058] In some embodiments, the inner diameter R1 of the inner cylinder is 2-75 mm. The inner diameter R1 of the inner cylinder is defined as the farthest distance from any point on the cross-sectional profile of the inner cylinder along the direction perpendicular to the axis to the center of the cross-sectional profile. In some specific examples, the inner diameter R1 of the inner cylinder is 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 60 mm, 70 mm, 75 mm.

[0059] In some embodiments, the length L1 of the inner cylinder is 200-300 mm. In some specific examples, the length L1 of the inner cylinder is 200 mm, 210 mm, 220 mm, 230 mm, 240 mm, 250 mm, 260 mm, 270 mm, 280 mm, 290 mm, 300 mm. The length of the inner cylinder affects the residence time of the emulsion, and thus affects the demulsification effect. If the length of the inner cylinder is short, the residence time of the emulsion is insufficient, and sufficient demulsification cannot be achieved; if the length of the inner cylinder is too long, the momentum loss of the demulsified liquid is caused, and the processing efficiency of the demulsification device is reduced.

[0060] In some embodiments, the length of the outer cylinder electrode is less than or equal to the length of the inner cylinder. When the length of the outer cylinder electrode is less than the length of the inner cylinder, the outer cylinder electrode is partially sleeved on the outside of the inner cylinder, so that an electric field is generated only in the area where the outer cylinder electrode is set, inducing non-uniform redistribution of the surface charge of the droplets, thereby regulating the droplet coalescence behavior in the electric field area; no electric field is generated in the area where the outer cylinder electrode is not set, and the flow field distribution is adjusted by using the surface structure of the flow channel adjustment component and the wettability of the surface material, thereby regulating the droplet collision mode. In some specific embodiments, when the length of the outer cylinder electrode is equal to the length of the inner cylinder, an electric field is generated in the entire micro-space through which the emulsion passes, and the electric field and flow field can be used to coordinately regulate the droplet collision and coalescence process. In some specific embodiments, when the length of the outer cylinder electrode is smaller than the length of the inner cylinder, the minimum distance between the outer cylinder electrode and the liquid inlet is 0-75 mm, and the length of the outer cylinder electrode is 150-300 mm; in this way, after the emulsion enters the micro-space, it first undergoes a suitable flow field to regulate the droplet collision, and on the basis of ensuring the collision rate, the coalescence efficiency is improved through electric field induction, thereby achieving efficient demulsification.

[0061] In some embodiments, the ratio of the inner diameter of the inner cylinder to the maximum outer diameter of the flow channel regulating component substructure is R1:R2=(1.5-4):1. Further, the ratio of the inner diameter of the inner cylinder to the maximum outer diameter of the flow channel regulating component substructure is R1:R2=(2-3.5):1; further, the ratio of the inner diameter of the inner cylinder to the maximum outer diameter of the flow channel regulating component substructure is R1:R2=(2.5-3):1. In some specific examples, the ratio of the inner diameter of the inner cylinder to the maximum outer diameter of the flow channel regulating component substructure is 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1. In the present application, the inner diameter of the inner cylinder and the outer diameter of the flow channel regulating component substructure refer to the diameter or equivalent diameter of the cross section of the inner cylinder and the substructure along the direction perpendicular to the axis. The outer surface shape of the flow channel regulating component presents a certain regular change due to the existence of the substructure. Therefore, the maximum outer diameter of the flow channel regulating component substructure refers to the maximum diameter or maximum equivalent diameter of the cross section of the flow channel regulating component in the direction perpendicular to the axis. By setting the ratio of the inner diameter of the inner cylinder to the maximum outer diameter of the flow channel regulating component substructure within the above range, a larger emulsion flow flux can be ensured and the processing efficiency can be improved, while taking into account the control accuracy of the flow field-electric field, thereby achieving a higher demulsification rate.

[0062] The second cavity formed between the inner cylinder 2 and the flow channel regulating component 3 corresponds to the meso-micro space where the emulsion flows, so the inner diameter of the inner cylinder 2 and the outer diameter of the flow channel regulating component 3 jointly determine the size of the meso-micro space. In this application, "meso-micro" means that the fluid channel size is larger than the micro channel size and smaller than the conventional industrial channel size; in actual production, the micro channel size is usually micron-level, for example, 10 to 1000 μμm, and the conventional industrial channel size is usually 25-1000 mm.

[0063] In some specific embodiments, the one-dimensional dimension R3 of the second cavity is R3 = R1 - R2 = 1 - 25 mm. Further, the one-dimensional dimension R3 of the second cavity is R3 = R1 - R2 = 3 - 15 mm. In some specific examples, the one-dimensional dimension of the second cavity can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, etc. The inventors of the present application found through research that when the fluid flow space is a microchannel, the collision and coalescence of droplets mostly concentrate at a certain node in the microchannel. If the one-dimensional dimension of the second cavity is less than 1 mm, the fluid channel for the emulsion to pass through is too small, and the flow flux is low, resulting in low utilization rate of the overall device; if the one-dimensional dimension of the second cavity is greater than 25 mm, the fluid channel for the emulsion to pass through is too large, and it is difficult to achieve precise regulation of the electric field, thereby increasing the control requirements for the equipment and causing an increase in equipment cost.

[0064] In some embodiments, at least 2 of the sub-structures are arranged continuously or at intervals along the first direction to form a repeating unit.

[0065] In some specific embodiments, the flow channel adjusting assembly 3 includes at least 1 of the repeating units.

[0066] Please refer to Figure 3 to Figure 5 , in some embodiments, the shape of the sub-structure can be selected from one or more of an elliptical shape, a prismatic shape, a gyroscopic shape, a twisted rope shape, a water droplet shape, etc.; for a water-oil two-phase mixed system, parameters such as the properties of the organic phase, the mass concentration of the water phase, the oil-water volume ratio, and the emulsion temperature will comprehensively affect the fluidity of the emulsion. Selecting the sub-structure shape according to the fluidity of the emulsion is beneficial to fully increase the turbulence of the emulsion, strengthen droplet collision, and thus accelerate the demulsification process.

[0067] In some embodiments, when the number of the repeating units is greater than 1, the shapes of the sub-structures in the repeating units can be the same or different. By setting repeating units with different shapes from each other, the local regulation of the flow field distribution in the fluid channel can be achieved, thereby precisely adjusting the droplet collision rate and effectively improving the demulsification rate and demulsification efficiency.

[0068] In some embodiments, when the sub-structures are arranged at intervals, the distance L3 between the sub-structures satisfies 0 < L3 ≤ 5 mm; in some specific examples, when the sub-structures are arranged at intervals, the distance L3 between the sub-structures is 1 mm, 2 mm, 3 mm, 4 mm, 5 mm.

[0069] In some embodiments, the sum of the extension lengths of all the repeating units along the first direction L4=15-100mm. In some specific examples, the sum of the extension lengths of all the repeating units along the first direction L4 can be 15mm, 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm. The inventors found through research that if the total extension length of the repeating unit is set to be less than 15mm, the total extension length of the repeating unit is too short to effectively regulate the flow field distribution, and thus cannot fully affect the collision process of the droplets; when the sum of the extension lengths of the repeating units is greater than 100mm, it is easy to cause the emulsion or demulsified liquid to lose too much kinetic energy in the flow channel, resulting in increased flow resistance and reduced demulsification efficiency.

[0070] In the present application, the position of the repeating unit on the flow channel regulating component can be set according to the actual needs of flow field regulation. For example, the starting repeating unit can be adjacent to the liquid inlet, or at a certain distance from the liquid inlet; the repeating units can be concentrated and continuously distributed within a certain length range of the flow channel regulating component, or can be evenly or unevenly distributed on the surface of the flow channel regulating component. The specific setting can be based on the actual needs of flow field regulation and is not limited here.

[0071] In some embodiments, the outer surface material of the flow channel regulating component 3 is selected from an insulating hydrophilic material, and the inner surface material of the inner cylinder 2 is selected from an insulating oleophilic material. The inventors have found through research that when the surface material of the flow channel regulating component 3 is an insulating hydrophilic material, and the inner surface material of the inner cylinder 2 is an insulating oleophilic material, it can promote the water droplets in the emulsion to gather toward the flow channel regulating component 3, and at the same time promote the oil droplets to gather toward the inner surface of the inner cylinder 2, which is conducive to promoting the directional movement of the droplets under the non-uniform electric field and gathering to the central area of ​​the meso-micro space, preventing some of the droplets from being adsorbed on the inner surface of the inner cylinder 2 and unable to collide with other droplets, resulting in a decrease in the demulsification rate and demulsification efficiency.

[0072] In some specific embodiments, the insulating oleophilic material is selected from one or more of polyurethane foam, porous silica gel, polytetrafluoroethylene or polypropylene; the insulating hydrophilic material is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyamide (PA, nylon) modified materials, ceramics, glass, etc. Those skilled in the art can select the type of material within the above range according to the properties of the emulsion system and the material, and no specific limitation is made here.

[0073] See also Figure 1 In some embodiments, the outer tube electrode 1 is grounded, and the central electrode 4 is connected to a power generator (not shown in the figure), which provides direct current or alternating current; the electric field is in the form of a uniform electric field or a non-uniform electric field.

[0074] In some specific embodiments, the voltage provided by the power generator is 1-15kV. Specifically, the voltage provided by the power generator can be 1 kV, 2kV, 3kV, 4kV, 5kV, 6kV, 7kV, 8kV, 9kV, 10kV, 11kV, 12kV, 13kV, 14kV, 15kV. Setting a higher voltage can increase the electric field strength, which is beneficial to enhancing the aggregation effect of the droplets. In the range of 1-15kV, as the voltage increases, the aggregation efficiency of the droplets will increase rapidly. When the voltage is greater than 15kV, the voltage is too large, the demulsification effect is not significantly improved, and even a downward trend appears.

[0075] In some embodiments, the present application also provides a flow field-electric field coordinated regulation demulsification method, and the operation steps of the demulsification method include:

[0076] 1) Start the power generating device, adjust the power voltage and frequency, and generate an electric field in the fluid channel;

[0077] 2) injecting the emulsion into the fluid channel in the demulsification device at a certain flow rate, wherein at least one flow channel regulating component is provided in the fluid channel in the demulsification device;

[0078] 3) The emulsion flows through the flow channel regulating component along the fluid channel, undergoes a demulsification process under the coordinated regulation of the electric field and the flow field, and obtains a demulsified liquid after a certain period of time.

[0079] In some embodiments, the central electrode 4 is connected to a power generator, which provides direct current or alternating current; the electric field is in the form of a uniform electric field or a non-uniform electric field; and the voltage provided by the power generator is 1-15 kV.

[0080] In some embodiments, the emulsion has a first temperature before being injected into the liquid inlet, and the first temperature is 18-35° C.; the demulsification time is 2-10 min.

[0081] The specific implementation methods of the present application are described in detail below in combination with Examples 1-4 and Comparative Examples 1-5.

[0082] Example 1

[0083] In this embodiment, a microchannel demulsification device with coordinated flow field and electric field regulation is provided. The demulsification device is composed of an outer cylinder electrode 1, an inner cylinder 2, a flow channel adjustment component 3, and a central electrode 4.

[0084] The central axes of the outer cylinder electrode 1, the inner cylinder 2, the flow channel adjustment component 3 and the central electrode 4 coincide. The outer cylinder electrode 1 is a 316L stainless steel tube, the inner surface of the inner cylinder 2 is made of polytetrafluoroethylene, the outer diameter is 22mm, the inner diameter is 20mm, and the length is 200mm. The inner cylinder 2 is sleeved in the outer cylinder electrode 1, and the two are arranged adjacently; the outer cylinder electrode is 200mm long.

[0085] Both ends of the inner cylinder 2 are sealed and provided with a central electrode 4 through hole; a liquid inlet 5 for injecting emulsion is provided at one end of the inner cylinder 2, and a liquid outlet 6 for discharging demulsified liquid is provided at the other end;

[0086] A flow channel regulating component 3 is arranged at the central axis of the inner cylinder 2, and the two ends of the flow channel regulating component 3 are respectively fixedly connected to the two ends of the inner cylinder 2, and a fluid channel for the emulsion / demulsified liquid to pass through is formed between the outer surface of the flow channel regulating component 3 and the inner surface of the inner cylinder 2; the ratio of the inner diameter of the inner cylinder 2 to the maximum outer diameter of the substructure of the flow channel regulating component 3 is 3:1; the surface of the flow channel regulating component 3 includes a twisted rope-shaped substructure, a single substructure is 5 mm long, and the substructures are continuously arranged. The flow channel regulating component 3 includes 20 substructures in total, and the total extended length of all substructures is 100 mm. The starting substructure is arranged at a distance of 50 mm from the liquid inlet of the inner cylinder; the outer surface material of the flow channel regulating component 3 is polyvinyl alcohol; the central electrode 4 is inserted in the flow channel regulating component 3.

[0087] In this embodiment, the emulsion formed by emulsification extraction of phosphoric acid-water / TBP-kerosene system is taken as the research object, wherein, before emulsification extraction, the concentration of phosphoric acid solution is 50%, the volume ratio of TBP / kerosene is 3:1, the ratio of aqueous phase to organic phase is 1:4 (that is, the volume ratio of aqueous phase in the initial emulsion is 1:5), and the emulsification extraction is carried out for 1 minute at a shear emulsifier speed of 5000 rpm to form an emulsion.

[0088] Turn on the power generator, the current is in the form of AC, the voltage is adjusted to 10kV, and the electric field frequency is 50Hz. The emulsion is injected into the demulsification device through the liquid inlet 5 at a flow rate of 25mL / min, and the emulsion contacts the flow channel adjustment component 3 and fills the fluid channel along it. Under the coordinated regulation of flow-electric field, the emulsion completes the demulsification process after 2 minutes to form a demulsified liquid, which flows out of the demulsification device through the liquid outlet 6. After the demulsified liquid is collected, take an appropriate volume of the demulsified liquid and transfer it to a 100mL measuring cylinder. After the liquid level is stable, measure the volume of the water phase immediately. According to the total volume of the demulsified liquid and the volume of the water phase, calculate the volume ratio of the water phase in the demulsified liquid.

[0089] The two-phase separation effect of the emulsion after demulsification operation is expressed by the demulsification rate P:

[0090]

[0091] Where V wis the volume ratio of water phase in the initial emulsion before demulsification operation, V d It is the volume ratio of water phase in the demulsified liquid after demulsification.

[0092] The results show that the demulsification rate of Example 1 of the present application is 88%, and the processing capacity of the demulsification device is 25 mL / min.

[0093] Example 2

[0094] In this embodiment, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the flow channel adjustment component is prismatic in shape, such as Figure 4 The results show that the demulsification rate of Example 2 is 78%, and the processing capacity of the demulsification device is 25 mL / min.

[0095] Example 3

[0096] In this embodiment, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the shape of the flow channel adjustment component is a gyro shape, such as Figure 5 The results show that the demulsification rate of Example 3 is 80%, and the processing capacity of the demulsification device is 25 mL / min.

[0097] Example 4

[0098] In this embodiment, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the outer surface material of the flow channel adjustment component is polyethylene glycol. The results show that the demulsification rate of Example 4 is 75%, and the processing capacity of the demulsification device is 25 mL / min.

[0099] Comparative Example 1

[0100] In this comparative example, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that no substructure is provided on the surface of the flow channel adjustment component 3. The results show that the demulsification rate of Comparative Example 1 is 43%, and the processing capacity of the demulsification device is 25 mL / min.

[0101] Comparative Example 2

[0102] In this comparative example, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the power generation device is not turned on. The results show that the demulsification rate of Comparative Example 2 is 15%, and the processing capacity of the demulsification device is 25 mL / min.

[0103] Comparative Example 3

[0104] In this comparative example, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that no substructure is set on the surface of the flow channel adjustment component 3 and the power generation device is not turned on. The results show that the demulsification rate of Comparative Example 1 is 7%, and the processing capacity of the demulsification device is 25mL / min.

[0105] Comparative Example 4

[0106] In this comparative example, the emulsion parameters, the arrangement of the demulsifier, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the inner diameter of the inner cylinder is 5 mm, that is, the fluid channel in the demulsifier is set to a microchannel scale. The results show that the demulsification rate of Comparative Example 3 is 50%, and the processing capacity of the demulsifier is 10 mL / min.

[0107] Comparative Example 5

[0108] In this embodiment, the emulsion parameters, the arrangement of the demulsification device, the operation steps and the process parameters used are the same as those in Example 1. The difference from Example 1 is that the outer surface material of the flow channel adjustment component is polytetrafluoroethylene. The results show that the demulsification rate of Example 4 is 67%, and the processing capacity of the demulsification device is 25 mL / min.

[0109] Comparison of demulsification effects between the embodiment and the comparative example

[0110] Serial number Demulsification rate / % <![CDATA[Throughput / (mL min -1 )]]> Example 1 88 25 Example 2 78 25 Example 3 80 25 Example 4 75 25 Comparative Example 1 43 25 Comparative Example 2 15 25 Comparative Example 3 7 25 Comparative Example 4 50 10 Comparative Example 5 67 25

[0111] Comparing the test data of Example 1 and Comparative Examples 1 to 3, the results show that compared with the case where only a single electric field is set to regulate demulsification in Comparative Example 1, the flow channel regulating component is set in the demulsification device to change the flow field distribution and regulate the droplet collision mode. In the same demulsification time, the demulsification rate is significantly increased from 43% in Comparative Example 1 to 88% in Example 1; and the test results of Example 1 and Comparative Example 2 show that the setting of the electric field can regulate the surface charge distribution of the emulsion droplets, so that the droplet surface produces anisotropy, thereby promoting effective coalescence after the droplet collision. In the same demulsification time, the demulsification rate is significantly increased from 15% in Comparative Example 2 to 88% in Example 1. Comparative Example 3 has no flow field and electric field to coordinately regulate the demulsification process, and the demulsification rate is only 7% in the same time.

[0112] By comparing the test data of Example 1 and Comparative Example 4, the reasons are analyzed. Under the condition of the same initial flow rate of the emulsion, the droplet collision and coalescence in the microchannel are mostly concentrated at a certain node, the utilization rate of the overall device is low, and the flow flux is low, only 10mLmin -1 Setting the fluid channel to a meso-micro size can ensure a larger flow flux while taking into account the control accuracy of the flow field-electric field, thereby achieving a higher demulsification rate and processing efficiency.

[0113] Comparing the test data of Examples 1 to 4, the results show that when other conditions are the same, the flow channel regulating component is in the shape of a twisted rope, a prism, or a gyro, and the surface material is selected from polyvinyl alcohol or polyethylene glycol materials with hydrophilic insulation, which can achieve the technical purpose of demulsification by coordinated regulation of flow field-electric field in the fluid channel, and the demulsification rate in 2 minutes can be as high as 88%, thereby achieving a better demulsification effect and meeting the industrial scale-up needs of solvent extraction purification.

[0114] By comparing the test data of Example 1, Example 4 and Comparative Example 5, the results show that for the phosphoric acid-water / TBP-kerosene system, when other conditions are the same, the surface material of the flow channel regulating component is selected with hydrophilic insulating polyvinyl alcohol or polyethylene glycol material, which is beneficial to the droplets to the flow channel regulating component to gather and accelerate the demulsification process, while when the surface material of the flow channel regulating component is selected with lipophilic insulating polytetrafluoroethylene material, there is a part of the droplet dispersed phase adsorbed on the inner surface of the inner cylinder and unable to collide with other droplets, resulting in a decrease in the demulsification rate and demulsification efficiency.

[0115] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A microchannel demulsification device with coordinated flow field and electric field control, characterized in that: The demulsification device comprises an outer cylinder electrode (1), an inner cylinder (2), a flow channel adjustment component (3) and a central electrode (4); the inner cylinder (2) is sleeved inside the outer cylinder electrode (1) and extends along a first direction, and the inner cylinder (2) is provided with a liquid inlet (5) and a liquid outlet (6); The flow channel regulating component (3) is arranged inside the inner cylinder and extends along a first direction, and the outer surface of the flow channel regulating component (3) comprises a plurality of substructures, and the substructures are arranged in an array along the first direction; The flow channel regulating component (3) is provided with a first cavity, in which the central electrode (4) is provided, and the axis of the central electrode (4) is parallel to or coincides with the axis of the flow channel regulating component (3); the second cavity is formed between the inner surface of the inner cylinder (2) and the outer surface of the flow channel regulating component (3), the second cavity is for fluid to pass through, and the second cavity is connected with the liquid inlet (5) and the liquid outlet (6); an electric field is formed between the outer cylinder electrode (1) and the central electrode (4).

2. The demulsification device according to claim 1, wherein the inner diameter R1 of the inner cylinder (2) is 2-75 mm, and the length L1 is 200-300 mm; And / or, the length of the outer tube electrode (1) is less than or equal to the length of the inner tube (2); And / or, when the length of the outer cylinder electrode (1) is smaller than the length of the inner cylinder (2), the minimum distance between the outer cylinder electrode (1) and the liquid inlet (5) is 0 to 75 mm, and the length of the outer cylinder electrode (1) is 150 to 300 mm.

3. The demulsification device according to claim 1, wherein the ratio of the inner diameter R1 of the inner cylinder (2) to the maximum outer diameter R2 of the flow channel adjustment component (3) substructure is R1:R2=(1.5-4):1, and the one-dimensional size of the second cavity is R3=R1-R2=1-25 mm.

4. The demulsification device according to claim 1, characterized in that: At least two identical substructures are arranged continuously or at intervals along the first direction to form a repeating unit; And / or, the flow channel regulating component (3) comprises at least one of the repeating units.

5. The demulsification device according to claim 4, characterized in that: The shape of the substructure is selected from one or more of a twisted rope shape, an ellipse shape, a teardrop shape, a prism shape or a gyroscope shape; and / or, when the number of the repeating units is greater than 1, the shapes of the substructures constituting each of the repeating units may be the same or different; And / or, when the substructures are spaced apart, the spacing between the substructures is 0 <L3≤5mm; And / or, the total extension length L4 of all the repeating units along the first direction is 15-100 mm.

6. The demulsification device according to claim 1, characterized in that: The outer surface material of the flow channel regulating component (3) is selected from insulating hydrophilic materials; and / or, the inner surface material of the inner cylinder (2) is selected from insulating oleophilic materials; and / or, the insulating oleophilic material is selected from one or more of polyurethane foam, porous silica gel, polytetrafluoroethylene or polypropylene; And / or, the insulating hydrophilic material is selected from one or more of polyvinyl alcohol, polyethylene glycol, polyamide modified material, ceramic, glass and the like.

7. The demulsification device according to claim 1, characterized in that: The outer cylindrical electrode (1) is grounded, and the central electrode (4) is connected to a power generator, which provides direct current or alternating current; And / or, the electric field is in the form of a uniform electric field or a non-uniform electric field; And / or, the voltage provided by the power generating device is 1-15 kV.

8. A demulsification method using coordinated flow field and electric field control, characterized in that: The operation steps of the demulsification method include: 1) Start the power generating device, adjust the power voltage and frequency, and generate an electric field in the fluid channel; 2) injecting the emulsion into the fluid channel in the demulsification device at a certain flow rate, wherein at least one flow channel regulating component is provided in the fluid channel in the demulsification device; 3) The emulsion flows through the flow channel regulating component along the fluid channel, undergoes a demulsification process under the coordinated regulation of the electric field and the flow field, and obtains a demulsified liquid after a certain period of time.

9. The demulsification method according to claim 8, characterized in that: The demulsification device is the demulsification device according to any one of claims 1 to 7, the central electrode (4) is connected to a power generator, and the power generator provides direct current or alternating current; the electric field is in the form of a uniform electric field or a non-uniform electric field; the voltage provided by the power generator is 1-15 kV.

10. The demulsification method according to claim 8, characterized in that: The emulsion has a first temperature before being injected into the liquid inlet (5), the first temperature being 18-35°C; and the demulsification time is 2-10 minutes.

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