Annular flow coupling separator, oil and water separation and liquid and solid separation apparatus, systems and applications

Abstract

The application discloses a kind of ring flow coupling separators, oil-water separation and liquid-solid separation equipment, system and application, comprising: emulsion separation membrane assembly is located in the flow guide cylinder of flow guide cylinder assembly, is arranged in the vertical direction of flow guide cylinder;The bottom of emulsion separation membrane assembly is communicated with liquid collecting pipe, to collect the oil-water mixture after demulsification in emulsion separation membrane assembly into liquid collecting pipe, porous pipe is located in flow guide cylinder, and is provided with several water inlets, the outer surface of porous pipe is wrapped with hydrophilic oleophobic fiber membrane, water is gathered into porous pipe through water inlet, and separates out separator;Oil collection tank is located in the upper part of flow guide cylinder, and light oil in oil-water mixture is gathered into oil collection tank and separated out ring flow coupling separator;Oily sewage and oil-water mixture in liquid collecting pipe and demulsification gas are mixed, to flush the solid gathered on the surface of emulsion separation membrane assembly and porous pipe, so that solid is gathered to the bottom of ring flow coupling separator and discharged, improve oil-water separation and liquid-solid separation efficiency.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a circulating coupling separator, oil-water separation and liquid-solid separation equipment, system and application. Background Technology

[0002] Most existing industrial projects, such as those in the petroleum and petrochemical industries, involve the separation of oil and water, and liquid and solid components in oily wastewater. While floating and dispersed oil in oily wastewater are relatively easy to treat, emulsified oil in the wastewater often requires chemical treatment. Conventional physical methods such as gravity settling in storage tanks, cyclone separation, inclined plate polymerization, and air flotation are often insufficient to achieve the desired results. This process frequently necessitates the addition of chemical agents, which introduces new pollution, increases operating costs and hazardous waste treatment expenses, and hinders cost reduction, efficiency improvement, environmental protection, and the resource recovery of oil products.

[0003] Achieving oil separation from oily wastewater through efficient physical methods is a challenging problem in the industry and a current research hotspot both domestically and internationally. Summary of the Invention

[0004] In order to improve the demulsification effect of emulsion in the oil-water separation process, thereby improving the oil-water separation efficiency and saving operating costs, and to achieve oil-water separation and liquid-solid separation, this invention provides a circulating coupling separator, oil-water separation and liquid-solid separation equipment, system and application.

[0005] In a first aspect, embodiments of the present invention provide a circulating coupling separator, which may include: a flow guide tube assembly, an emulsion separation membrane assembly, a liquid collection pipe, an oil collection tank, and a porous pipe;

[0006] The emulsion separation membrane assembly is located in the guide tube of the guide tube assembly and is arranged in the vertical direction of the guide tube; the bottom of the emulsion separation membrane assembly is connected to the collection pipe to collect the oil-water mixture after demulsification by the emulsion separation membrane assembly into the collection pipe, and the collection pipe is used as the liquid phase inlet of the external injector;

[0007] The porous tube is located in the guide tube and is arranged at a preset angle with the horizontal direction; the porous tube has several water inlet holes, and the outer surface of the porous tube is wrapped with a hydrophilic and oleophobic fiber membrane. The water in the oil-water mixture is collected in the porous tube through the water inlet holes and separated from the circulating coupling separator.

[0008] The oil collection tank is located at the top of the guide tube. Light oil in the oil-water mixture gathers in the oil collection tank and is separated from the circulating coupling separator.

[0009] The bottom of the circulating coupling separator is used to connect to the ejector outlet of the ejector. Oily wastewater is mixed with the oil-water mixture and demulsifying gas in the collection pipe through the ejector and introduced into the circulating coupling separator to flush the solids that accumulate on the surface of the emulsion separation membrane assembly and the porous tube, so that the solids accumulate at the bottom of the circulating coupling separator and are discharged.

[0010] Optionally, the opening direction of the water inlet is oriented towards the outlet direction of the injector, and the diameter of the water inlet is 10 to 2000 μm; the porosity of the water inlet on the porous tube is 5% to 70%, and the angle between the porous tube and the horizontal direction is 10 to 65°.

[0011] Optionally, the vertical projection length of the porous tube is 10% to 65% of the diameter of the guide tube.

[0012] Optionally, the guide tube assembly may include a guide tube support frame and a guide tube; or, the guide tube assembly may include a guide tube support frame and multiple guide tubes, with multiple guide tubes arranged sequentially at a predetermined interval in the vertical direction; the guide tubes are fixed by the guide tube support frame;

[0013] The ratio of the cross-sectional area of ​​the guide tube to the cross-sectional area of ​​the circulating coupling separator is 0.26 to 0.85:1.

[0014] Optionally, the guide tube has a plurality of guide holes on its wall, the porosity of the guide holes is 30% to 70%, and the diameter of the guide holes is 50 μm to 2 mm; the outer side of the guide tube wall is wrapped with a demulsifying membrane, the pore size of the demulsifying membrane is 30 to 80 μm, and the membrane material of the demulsifying membrane is at least one of the following: polyphenylene sulfide, polyimide, or polyarylene ether nitrile.

[0015] Optionally, the emulsion separation membrane assembly may be one or more, the ratio of the cross-sectional area of ​​the emulsion separation membrane assembly to the cross-sectional area of ​​the guide tube is 0.05 to 0.35:1, and the ratio of the height of the emulsion separation membrane assembly to the height of the guide tube is 0.5 to 1:1.

[0016] The membrane material of the emulsion separation membrane assembly is a porous membrane material composed of graphene aerogel and / or polyimide aerogel, and the porosity of the porous membrane material is 70% to 98%.

[0017] Optionally, the oil collection trough is inverted conical, and the angle between the generatrix of the cone containing the oil collection trough and the horizontal line is 10 to 65°.

[0018] The fluid collection section of the oil collection tank has several through holes, and the porosity of the fluid collection section is 10% to 30%. The outer surface of the fluid collection section is covered with a hydrophilic and oleophobic fiber membrane. The fluid collection section is used to connect with the oil discharge pipe so that the separated light oil can be discharged from the circulating coupling separator through the oil discharge pipe.

[0019] In a second aspect, embodiments of the present invention provide an oil-water separation and liquid-solid separation device, which may include: a housing, and an ejector, a gas-liquid separator, and the aforementioned circulating coupling separator located inside a cavity enclosed by the housing;

[0020] The bottom of the shell is provided with a solids discharge port for discharging solids separated from oily wastewater;

[0021] The injector is located in the lower part of the chamber and is used to mix the oily wastewater with gas and the demulsified oil-water mixture to form microbubbles, which are then injected into the circulating coupling separator for oil-water separation and liquid-solid separation.

[0022] The gas-liquid separator is located in the upper part of the chamber, and an exhaust port is provided in the upper part of the shell. The gas phase outlet of the gas-liquid separator is connected to the exhaust port. The gas-liquid separator is used to separate the separated gas and discharge it outside the equipment through the exhaust port.

[0023] The circulating coupling separator is located between the ejector and the gas-liquid separator. The liquid collection pipe of the circulating coupling separator is connected to the liquid phase inlet of the ejector to supply the demulsified oil-water mixture to the ejector. The housing is provided with a purified water outlet and an oil phase outlet, which are used to install the purified water outlet pipe and the oil phase outlet pipe, respectively. The purified water outlet pipe is connected to the porous pipe, and the oil phase outlet pipe is connected to the fluid collection part of the oil collection tank.

[0024] Optionally, the ejector may include: an ejector inlet, an ejector outlet, a liquid phase inlet, and a gas phase inlet; the ejector inlet is used to connect with the oily wastewater supply equipment, the ejector outlet is connected to the circulating coupling separator, the liquid phase inlet is connected to the liquid collection pipe of the circulating coupling separator, and the gas phase inlet is used to connect with the gas supply equipment.

[0025] Optionally, the above-mentioned oil-water separation and liquid-solid separation equipment may further include: a skirt plate located inside the chamber, the skirt plate being conical in shape;

[0026] The skirt is located between the guide tube of the circulating coupling separator and the injector.

[0027] Thirdly, embodiments of the present invention provide an oil-water separation system, which may include a first aspect of a circulating coupling separator.

[0028] Fourthly, embodiments of the present invention provide another oil-water separation system, which may include: an oily wastewater supply device, a gas supply device, an oil phase collection device, and the oil-water separation and liquid-solid separation device described in the second aspect;

[0029] The oily wastewater supply device is connected to the injector inlet of the injector in the oil-water separation and liquid-solid separation device, the gas supply device is connected to the gas phase inlet of the injector, and the oil phase collection device is connected to the oil phase discharge pipe installed on the oil phase discharge outlet.

[0030] Fifthly, embodiments of the present invention provide an application of the circulating coupling separator described in the first aspect in an oil-water separation system.

[0031] In a sixth aspect, embodiments of the present invention provide an application of the oil-water separation and liquid-solid separation equipment described in the second aspect in an oil-water separation system; wherein the fluid velocity at the ejector outlet of the ejector is 2 to 15 m / s.

[0032] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0033] This invention provides a circulating coupled separator, an oil-water separation and liquid-solid separation device, system, and application. In this circulating coupled separator, the oil-water emulsion, after membrane separation, is not directly discharged from the system but is instead introduced into the system via an injector using microbubbles. This allows the oil droplets after membrane separation to circulate and coalesce further through the microbubbles, thus combining the advantages of circulating flotation and membrane separation technologies to achieve oil and solid removal. This circulating coupled separator increases the fluid residence time, improves the gas-liquid collision efficiency during flotation, and integrates the advantages of emulsion membrane separation demulsification, microbubble-enhanced circulating coalescence of demulsified oil droplets, and microbubble-enhanced cleaning of insoluble substances on the membrane surface. This not only significantly improves the separation effect of emulsified oil but also prevents clogging during the separation process, greatly extending the operating cycle and improving the overall liquid-solid separation efficiency.

[0034] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings.

[0035] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0036] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0037] Figure 1 This is a schematic diagram of the circulating coupling separator provided in an embodiment of the present invention;

[0038] Figure 2 for Figure 1 AA-direction cross section;

[0039] Figure 3 This is a schematic diagram of the structure of the oil-water separation and liquid-solid separation equipment provided in the embodiments of the present invention;

[0040] Among them, 1-circulating coupling separator; 2-ejector; 3-gas-liquid separator; 4-shell; 5-chamber; 6-skirt; 7-purified water discharge pipe; 8-oil phase discharge pipe;

[0041] 11-Flow guide tube assembly; 12-Emulsion separation membrane assembly; 13-Collection pipe; 14-Oil collection tank; 15-Porous pipe;

[0042] 111-Guide tube; 112-Guide tube support frame; 21-Ejector inlet; 22-Ejector outlet; 23-Liquid phase inlet; 24-Gas phase inlet;

[0043] 41-Solid discharge port; 42-Exhaust port; 43-Purified water discharge port; 44-Oil phase discharge port. Detailed Implementation

[0044] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] The inventors have discovered that existing methods for treating oily wastewater from crude oil electrostatic desalination suffer from the following challenges: crude oil has a high specific gravity, making oil-water separation difficult; oil content is high and fluctuates significantly; it contains colloids and asphaltenes, resulting in stable emulsions but making demulsification difficult; and it has high salt content and contains a certain amount of silt, easily causing equipment blockage and corrosion. In particular, hydrocyclone technology is only suitable for wastewater with a large density difference between oil and water, and its treatment effect is poor for wastewater with a small density difference; it has poor resistance to fluctuations and is not suitable for operating conditions with drastic fluctuations; at the same time, the equipment is prone to scaling and blockage, and it does not have a demulsification effect, resulting in high oil content in the effluent, requiring secondary treatment. In view of the above problems, this invention is proposed to provide a circulating coupling separator, oil-water separation and liquid-solid separation equipment, system, and application that overcomes or at least partially solves the above problems.

[0048] This invention provides a circulating coupling separator 1, referring to... Figure 1 As shown, the circulating coupling separator 1 may include: a guide tube assembly 11, an emulsion separation membrane assembly 12, a collection pipe 13, an oil collection tank 14, and a porous pipe 15; wherein, the emulsion separation membrane assembly 12 is located in the guide tube 111 of the guide tube assembly 11 and is arranged in the vertical direction of the guide tube 111; the bottom of the emulsion separation membrane assembly 12 is connected to the collection pipe 13 to collect the oil-water coupling material after demulsification by the emulsion separation membrane assembly 12 into the collection pipe 13, and the collection pipe 13 is used to connect the liquid phase inlet 133 of the external injector 2; the porous pipe 15 is located in the guide tube 111 and is arranged at a preset angle with the horizontal direction; the porous pipe 15 has several water inlet holes, and multiple The outer surface of the porous tube 15 is wrapped with a hydrophilic and oleophobic fiber membrane (not shown in the figure). Water in the oil-water mixture is collected in the porous tube 15 through the water inlet and separated out of the circulating coupling separator 1. The oil collection tank 14 is located above the guide tube 111. Light oil in the oil-water mixture is collected in the oil collection tank 14 and separated out of the circulating coupling separator 1. The bottom of the circulating coupling separator 1 is used to connect the outlet of the ejector 2 of the external ejector 2. Oily wastewater is mixed with the oil-water mixture and demulsifying gas in the collection pipe 13 through the ejector 2 and introduced into the circulating coupling separator 1 to flush the solids collected in the emulsion separation membrane assembly 12 and the porous tube 15 so that the solids are collected at the bottom of the circulating coupling separator 1 and discharged.

[0049] It should be noted that, when used alone, the circulating coupling separator in this embodiment of the invention has an outer shell, and the guide tube assembly, emulsion separation membrane assembly, liquid collection pipe, oil collection tank, and perforated pipe are all disposed inside the outer shell to form an independent device unit. If the circulating coupling separator is combined with other devices, such as the ejector and gas-liquid separator mentioned later in this embodiment of the invention, to form an integrated device, the entire device can be provided with a housing, and the circulating separator, ejector, and gas-liquid separator are all located within the housing. This embodiment of the invention does not specifically limit this. It should also be noted that the guide tube and other components involved in this embodiment can be made of metal. To improve their corrosion resistance and wear prevention performance, an anti-corrosion and wear-resistant coating can be sprayed on the surface. This embodiment of the invention does not specifically limit this.

[0050] In this embodiment, the circulating coupling separator is a gas-liquid circulation center airlift type circulating device. The aforementioned guide tube is open at both the top and bottom, and its diameter is smaller than that of the circulating coupling separator. An annular channel is formed between the outer wall of the guide tube and the inner wall of the circulating coupling separator. The overall direction of fluid movement is upward from the center and downward from the top in the annular channel. The guide tube and the outer shell together form an upper and lower circulation system. The porous tube is wrapped with a hydrophilic and oleophobic fiber membrane, which can enhance the demulsification and stratification of oil-water emulsions, and block oil and insoluble substances in the stratified oil-water liquid, so as to achieve the continuous discharge of purified water free of oil and suspended solids.

[0051] In the above-mentioned circulating coupled separator provided in this embodiment of the invention, the oil-water emulsion is not directly discharged from the system after membrane separation. Instead, microbubbles are introduced through an injector, so that the oil droplets after membrane separation are further enhanced and coalesced by microbubble circulation. This coupling and integrating the advantages of circulating air flotation and membrane separation technologies achieves oil and solid removal. This circulating coupled separator increases the fluid residence time, improves the gas-liquid collision efficiency during air flotation, and integrates the advantages of emulsion membrane separation demulsification, microbubble circulation enhancement of oil droplet coalescence after demulsification, and microbubble enhanced cleaning of insoluble substances on the membrane surface. It not only significantly improves the separation effect of emulsified oil, but also prevents clogging during the separation process, which can greatly extend the operating cycle and improve the overall liquid-solid separation efficiency.

[0052] In an optional embodiment, the opening direction of the water inlet is toward the ejector outlet direction of the ejector 2, and the diameter of the water inlet is 10 to 2000 μm; the porosity of the water inlet on the porous tube 15 is 5% to 70%, and the angle between the porous tube 15 and the horizontal direction is 10 to 65°.

[0053] In this embodiment, the opening direction of the water inlet is towards the ejector outlet direction, that is, the fluid direction is vertically upward in the central circulation zone, and the opening direction of the water inlet is at an angle of 0 to 90° with the fluid direction. This ensures that the water in the mixed fluid can be maximized to converge into the porous pipe through the water inlet. Furthermore, the water inlet direction is at an angle of 0 to 90° with the upward direction of the circulation zone. In the upward direction of the water flow, that is, on the back side (slanted upward) of the water-facing surface of the porous pipe, it is conducive to the flushing effect of the water flow, and timely and effectively flush away the solid insoluble matter and oil phase blocked by the water inlet of the porous pipe.

[0054] In another optional embodiment, the vertical projection length of the porous tube 15 is 10% to 65% of the diameter of the guide tube 111. In this embodiment, the angle is set to maximize the length of the porous tube, thereby increasing the area of ​​the hydrophilic and oleophobic fiber membrane wrapped around the surface of the porous tube to enhance the oil-water separation effect. However, the angle should not be too large to avoid the porous tube being far from the circulation center region of the guide tube. In this embodiment, there may be one or more porous tubes, and the present invention does not specifically limit this.

[0055] In this embodiment, during the operation of the porous tube, the gas-liquid fluid flowing upward from the center of the guide tube enters the purified water drain pipe through the water inlet (micropores) on the porous tube. The hydrophilic and oleophobic fibers wrapped around the surface of the porous tube intercept oil droplets and suspended solids and other insoluble substances in the water entering the porous tube. Under the continuous blowing action of microbubbles, the oil droplets and suspended solids on the surface of the hydrophilic and oleophobic fibers are removed from the surface of the porous tube. The microbubbles continuously and intensify the washing of the hydrophilic and oleophobic fibers on the surface of the porous tube, avoiding the clogging problems of conventional oil-water and liquid-solid separation technologies. The purified water, after oil and suspended solids removal, is discharged from the purified water drain pipe.

[0056] In another alternative embodiment, refer to Figure 1 and Figure 3 As shown, the guide tube assembly 11 may include a guide tube support frame 112 and a guide tube 111; or, the guide tube assembly 11 may include a guide tube support frame 112 and multiple guide tubes 111, with multiple guide tubes 111 arranged sequentially at a preset interval in the vertical direction; the guide tubes 111 are fixed by the guide tube support frame 112; the ratio of the cross-sectional area of ​​the guide tube 111 to the cross-sectional area of ​​the circulating coupling separator 1 is 0.26 to 0.85:1.

[0057] In this embodiment, at least one guide tube is used. If multiple guide tubes are used to form a guide tube assembly, they are arranged in a multi-level sequence at predetermined intervals in the vertical direction. The height of the guide tubes used in this embodiment is 300–2200 mm. The purpose of the guide tubes is to guide the fluid to form a circulation from bottom to top, thus guiding the fluid. The cross-sectional area occupied by the guide tubes in the circulation coupling separator cannot be too large or too small; that is, it must provide space for both the fluid ascending channel and the fluid descending channel.

[0058] In another optional embodiment, the guide tube 111 has a plurality of guide holes (not shown in the figure) on its wall, the porosity of the guide holes is 30% to 70%, and the diameter of the guide holes is 50 μm to 2 mm; the outer side of the guide tube 111 is wrapped with a demulsifying membrane, the pore size of the demulsifying membrane is 30 to 80 μm, and the membrane material of the demulsifying membrane is at least one of the following: polyphenylene sulfide, polyimide or polyarylether nitrile.

[0059] In this embodiment of the invention, the guide holes in the cylinder wall and the demulsifying film wrapped around the outer side of the cylinder wall can further enhance the demulsification effect of the emulsion. In specific implementation, small holes are provided on the guide cylinder as guide holes, allowing a portion of the oil-water mixture to flow out through these holes to the outer side of the cylinder wall. Because the outer side is wrapped with a demulsifying film, the demulsification effect is further achieved. A support frame can be provided on the outer side of the cylinder wall, with a certain distance between the support frame and the cylinder wall, and the demulsifying film covers the support frame. The parameters of the porosity of the guide holes, the pore diameter of the guide holes, and the pore diameter of the demulsifying film are all beneficial to the effective demulsification of the emulsion formed by emulsifying light oil and water.

[0060] In another optional embodiment, there are one or more emulsion separation membrane modules 12, the ratio of the cross-sectional area of ​​the emulsion separation membrane module 12 to the cross-sectional area of ​​the guide tube 111 is 0.05 to 0.35:1, and the ratio of the height of the emulsion separation membrane module 12 to the height of the guide tube 111 is 0.5 to 1:1; the membrane material of the emulsion separation membrane module 12 is a porous membrane material composed of graphene aerogel and / or polyimide aerogel, and the porosity of the porous membrane material is 70% to 98%.

[0061] In this embodiment, the function of the emulsion separation membrane module is to demulsify the emulsion. Therefore, when the fluid passes through the membrane module, it enters from the outside and exits from the inside, with the fluid inlet direction perpendicular to the apparent flow direction of the bubbles (bubbles rising from bottom to top). The cross-sectional area of ​​the guide tube occupied by the membrane module is between 0.05 and 0.35. If the area is too small, fewer membrane modules will be deployed, failing to achieve the overall demulsification effect; if the area is too large, more membrane modules will be deployed, occupying too much of the upward flow channel of the mixture, affecting the overall circulation of the entire circulating coupling separator. The above-mentioned ratio of membrane module height to guide tube height ensures that the membrane module is completely located inside the guide tube while also ensuring a sufficient quantity of membrane modules to maximize the demulsification effect.

[0062] In another alternative embodiment, refer to Figure 1 and Figure 3 As shown, the oil collection tank 14 is inverted conical in shape, and the angle between the generatrix of the cone containing the oil collection tank 14 and the horizontal line is 10 to 65°. Several through holes (not shown in the figure) are opened on the fluid collection part of the oil collection tank 14, and the porosity of the fluid collection part is 10% to 30%. The outer surface of the fluid collection part is covered with a hydrophilic and oleophobic fiber membrane. The fluid collection part is used to connect with the oil discharge pipe so that the separated light oil can be discharged from the circulating coupling separator 1 through the oil discharge pipe.

[0063] In this embodiment, the oil collection tank collects light oil from the oil-water mixture. A fluid collection section is located at the bottom of the oil collection tank, and the light oil collected in the fluid collection section is discharged through the oil phase discharge pipe. In this embodiment, the angle between the generatrix of the cone containing the oil collection tank and the horizontal line is 10-65°. This avoids the oil phase (light oil) entering the inverted cone-shaped oil collection tank from easily overflowing if the angle is too small, and also avoids the inverted cone-shaped oil collection tank from having too small a storage space if the angle is too large. In this embodiment, the outer surface of the fluid collection section is wrapped with a hydrophilic and oleophobic fiber membrane. Larger oil droplets are agglomerated through the circulating air flotation effect. At the same time, due to the density difference, as they float to the oil collection tank, some air bubbles coalesce, and the oil phase is collected in the oil collection tank. A small amount of water permeates through the hydrophilic and oleophobic membrane layer on the surface of the oil collection tank due to gravity and falls into the guide tube. The oil phase is concentrated to a certain level and discharged from the separator through the oil phase discharge pipe connected to the oil collection tank.

[0064] Based on the same inventive concept, this invention provides an oil-water separation and liquid-solid separation device, referring to... Figure 3As shown, the device may include: a housing 4, and an injector 2, a gas-liquid separator 3, and the aforementioned circulating coupling separator 1 located inside a chamber 5 enclosed by the housing 4; a solid discharge port 41 is provided at the bottom of the housing 4 for discharging solids separated from the oily wastewater; the injector 2 is located at the lower part of the chamber 5 for mixing the oily wastewater with gas and the demulsified oil-water mixture to form microbubbles, which are then injected into the circulating coupling separator 1 for oil-water separation and liquid-solid separation; the gas-liquid separator 3 is located at the upper part of the chamber 5, and an exhaust port 42 is provided at the upper part of the housing 4; the gas phase outlet of the gas-liquid separator 3 (not shown in the figure) (Shown) It is connected to the exhaust port 42. The gas-liquid separator 3 is used to separate the separated gas and discharge it outside the equipment through the exhaust port 42. The circulating coupling separator 1 is located between the ejector 2 and the gas-liquid separator 3. The liquid collection pipe 13 of the circulating coupling separator 1 is connected to the liquid phase inlet 133 of the ejector 2 to supply the oil-water mixture after demulsification to the ejector 2. The housing 4 is provided with a purified water outlet 43 and an oil phase outlet 44, which are used to install the purified water outlet pipe 7 and the oil phase outlet pipe 8, respectively. The purified water outlet pipe 7 is connected to the porous pipe 15, and the oil phase outlet pipe 8 is connected to the fluid collection part of the oil collection tank 14.

[0065] It should be noted that the gas-liquid separator in this embodiment can separate the gas phase carrying a small amount of liquid phase into gas phase and liquid phase. The gas phase is discharged from the system through the top exhaust pipe, and the liquid phase settles into the gas-liquid circulation zone, thus ensuring the stable pressure balance inside the equipment.

[0066] The oil-water and liquid-solid separation equipment provided in this embodiment, through the coupling and integration of a circulating coupled separator, a membrane oil removal component, hydrophilic and oleophobic fibers, and a jet bubble generator, offers a rationally structured, easy-to-operate, highly efficient, and low-cost oil-water and liquid-solid separation device for oily wastewater. This overcomes the problems of poor oil-water demulsification, low oil removal efficiency, high cost, and easy clogging of separation equipment in existing technologies. Furthermore, this equipment integrates and couples physical oil-water separation methods such as circulating air flotation, fiber liquid membrane mass transfer separation (a unit operation based on mass transfer theory for separating various homogeneous mixtures), demulsification membrane component separation, and packing adsorption. The introduction of a circulating flow field increases liquid residence time, resulting in advantages such as high gas holdup, large bubble specific surface area, high mass and heat transfer efficiency, uniform flow field distribution, and rapid mixing.

[0067] Furthermore, since the fluid ejected from the ejector outlet is an oil-water emulsion with a certain flow rate, it enters the ejector through the ejector inlet. The gas phase (which can be nitrogen, etc.) and the liquid after separation by the emulsion film are introduced into the ejector through the gas phase inlet and the liquid phase inlet, respectively. After thorough mixing, microbubbles are generated and enter the gas-liquid circulation mixing zone. Under the action of the ejection kinetic energy carried by the injected oily wastewater, the liquid after separation by the emulsion film, and the gas phase, and the density difference in the circulator, a regular gas-liquid circulation flow is formed. At the same time, under the enhanced mixing and micro-disturbance action of the microbubbles, the oil in the water layer and the water in the oil layer are carried to the oil-water interface, increasing the probability of collision between oil droplets and water droplets, and small oil droplets are gradually coalesced into large oil droplets.

[0068] In another alternative embodiment, refer to Figure 3 As shown, the ejector 2 may include: an ejector inlet 21, an ejector outlet 22, a liquid phase inlet 23, and a gas phase inlet 24; the ejector inlet 21 is used to connect with the oily wastewater supply equipment, the ejector outlet 22 is connected to the circulating coupling separator 1, the liquid phase inlet 23 is connected to the liquid collection pipe 13 of the circulating coupling separator 1, and the gas phase inlet 24 is used to connect with the gas supply equipment.

[0069] In this embodiment of the invention, the ejector outlet is configured as a micropore with a pore size of 50–1500 μm. This micropore structure, combined with the gas introduced through the gas phase inlet, forms microbubbles inside the chamber, effectively demulsifying the emulsion. It should be noted that in this embodiment, the liquid phase inlet and gas phase inlet introduce the oil-water mixture and gas (nitrogen can be used in this embodiment) into the ejector under negative pressure for mixing. The gas mixing forms microbubbles, thereby achieving bubble demulsification. In the aforementioned guide tube of this embodiment, the oily wastewater entering through the ejector inlet, the oil-water mixture after demulsification introduced through the liquid phase inlet of the ejector, and the gas introduced through the gas phase inlet form a regular gas-liquid circulation flow under the action of the kinetic energy carried by the gas and the fluid density difference in the circulating coupling separator. Microbubbles promote the aggregation and merging of small oil droplets into large oil droplets, and the mixture has a certain kinetic energy, which washes away insoluble substances such as suspended matter on the surface of the emulsion separation membrane component and porous tube in the circulating coupling separator. Solids fall to the bottom and converge, realizing liquid-solid separation.

[0070] In this embodiment, the oil-water mixture in the collection pipe is introduced through the liquid phase inlet. On the one hand, the oil-water mixture undergoes demulsification by the components of the circulating coupling separator; on the other hand, it undergoes further demulsification by bubbles, resulting in better demulsification of the emulsified oil through multiple processes; thirdly, the oil-water mixture introduced into the collection pipe through the liquid phase inlet forms a large circulation in the entire device, with multiple cycles and multiple demulsifications, resulting in more thorough oil-water separation.

[0071] In another alternative embodiment, refer to Figure 3 As shown, the device may further include: a skirt 6 located inside the chamber 5, the skirt 6 being conical in shape; the skirt 6 is located between the guide tube 111 and the ejector 2 of the circulating coupling separator 1. The skirt can effectively guide the flow direction of the fluid, so that the fluid flow direction at the center of the oil-water separation and liquid-solid separation equipment is from bottom to top, and the fluid flow direction at the periphery is from top to bottom, thereby forming a large overall circulation.

[0072] The working process of the water separation and liquid-solid separation equipment described above in this embodiment of the invention is as follows:

[0073] 1) An oil-water emulsion with a certain flow rate enters the ejector through the ejector inlet. The gas phase (which can be nitrogen, etc.) and the liquid (oil-water mixture) after separation by the emulsion separation membrane module are introduced into the ejector through the ejector gas phase inlet and the ejector liquid phase inlet, respectively. After thorough mixing and generation of microbubbles, the mixture enters the gas-liquid circulation mixing zone of the circulation coupling separator. Under the action of the jetting kinetic energy carried by the injected oily wastewater, the liquid after separation by the emulsion membrane, and the gas phase, as well as the density difference in the circulation device, a regular gas-liquid circulation flow is formed. At the same time, under the enhanced mixing and micro-disturbance action of the microbubbles, the oil in the water layer and the water in the oil layer are carried to the oil-water interface, increasing the collision probability between oil droplets and water droplets, and small oil droplets are gradually coalesced into large oil droplets.

[0074] 2) The mainstream direction of the oil-water emulsion in the guide tube is vertical flow from bottom to top. The oil-water emulsion enters the membrane module vertically from the outside of the emulsion separation membrane module through the spray force of the ejector. The mainstream direction of the oil-water emulsion entering the membrane module is horizontal flow. During the process, the oil-water emulsion that is not easy to separate and has an unclear oil-water interface becomes an oil-water system that is easy to separate and has a clear oil-water interface. After being collected by the liquid collection pipe at the bottom of the membrane module, it enters the ejector through the liquid phase inlet of the ejector. In the ejector, it mixes with the gas phase and the raw oily wastewater to form a mixed fluid. The mixed fluid then generates a mixed fluid with microbubbles as the gas phase through the microporous component at the ejector outlet.

[0075] 3) The gas phase carrying a small amount of liquid phase is separated into gas phase and liquid phase by the gas-liquid separator (cyclone separator) at the top of the equipment. The gas phase is discharged from the equipment through the top exhaust pipe, and the liquid phase settles into the gas-liquid circulation mixing zone of the circulation coupling separator.

[0076] 4) The gas-liquid fluid flowing upward from the center of the guide tube enters the purified water drain pipe through the water inlet (micropores) of the porous tube. The hydrophilic and oleophobic fibers wrapped around the surface of the porous tube intercept oil droplets and suspended solids and other insoluble substances in the water entering the porous tube. Under the continuous blowing action of microbubbles, the oil droplets and suspended solids on the surface of the hydrophilic and oleophobic fibers are removed from the surface of the porous tube. The microbubbles continuously and intensify the washing of the hydrophilic and oleophobic fibers on the surface of the porous tube, avoiding the clogging problems of conventional oil-water and liquid-solid separation technologies. The purified water after oil and suspended solids removal is discharged from the purified water drain pipe.

[0077] 5) Larger oil droplets undergo agglomeration through the circulating air flotation process. Simultaneously, due to the density difference, as they rise to the oil collection tank, some air bubbles coalesce, and the oil phase is collected in the oil collection tank. A small amount of water, due to gravity, permeates through the hydrophilic and oleophobic film layer on the surface of the oil collection tank and falls into the guide tube of the circulating coupling separator. The oil phase is concentrated to a certain level and discharged from the equipment through the oil phase discharge pipe connected to the oil collection tank.

[0078] The processes of circulating air flotation, emulsion film separation, and microbubble generation in the water separation and liquid-solid separation equipment proposed in the embodiments of the present invention are not independent and simple superpositions, but rather organic couplings that integrate many factors. For example, the jet velocity of the jet mixer, the amount of gas phase introduced, the amount of liquid introduced after emulsion film separation, and the height of the guide tube of the circulating coupling separator, the ratio of its effective area to the effective cross-sectional area of ​​the circulating coupling separator, all vary according to different process conditions, the oil content of the oily wastewater, and the degree of emulsification.

[0079] Based on the same inventive concept, this invention also provides an oil-water separation system, which may include the above-mentioned circulating coupling separator.

[0080] Based on the same inventive concept, another oil-water separation system is also provided in this embodiment of the invention, which may include: an oily wastewater supply device (refer to...). Figure 3 As shown, the oily wastewater is pumped into an ejector, a gas supply device, an oil phase collection device, and the aforementioned oil-water separation and liquid-solid separation device; wherein, the oily wastewater supply device is connected to the ejector inlet of the ejector in the oil-water separation and liquid-solid separation device, the gas supply device is connected to the gas phase inlet of the ejector, and the oil phase collection device is connected to the oil phase discharge pipe installed on the oil phase outlet.

[0081] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned circulating coupling separator in an oil-water separation system.

[0082] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned oil-water separation and liquid-solid separation equipment in an oil-water separation system; wherein, the fluid velocity at the ejector outlet of the ejector is 2 to 15 m / s.

[0083] In this embodiment of the invention, the fluid velocity at the outlet of the ejector is 2–15 m / s. This velocity setting is intended to more effectively demulsify the emulsion. If the velocity is below 2 m / s, the ejector provides insufficient kinetic energy, resulting in low gas (nitrogen) and liquid flow rates, weakening the coupled demulsification effect of bubble demulsification and emulsion separation membrane component demulsification. If the velocity is above 15 m / s, it can easily cause secondary mixing and emulsification of the already demulsified oil-water two phases, leading to a reduction in the overall demulsification effect.

[0084] The detailed description and beneficial effects of the oil-water separation system, the application of the circulating coupling separator in the oil-water separation system, and the application of the oil-water separation and liquid-solid separation equipment in the oil-water separation system provided in the embodiments of the present invention can be found in the relevant records and descriptions of the circulating coupling separator and the oil-water separation and liquid-solid separation equipment. The embodiments of the present invention will not be repeated here.

[0085] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A circulating coupling separator, characterized in that, include: Flow guide tube assembly, emulsion separation membrane assembly, liquid collection pipe, oil collection tank and porous pipe; The emulsion separation membrane assembly is located in the guide tube of the guide tube assembly and is arranged in the vertical direction of the guide tube; the bottom of the emulsion separation membrane assembly is connected to the collection pipe to collect the oil-water mixture after demulsification by the emulsion separation membrane assembly into the collection pipe, and the collection pipe is used as the liquid phase inlet of the external injector; The porous tube is located in the guide tube and is arranged at a preset angle with the horizontal direction; the porous tube has several water inlet holes, and the outer surface of the porous tube is wrapped with a hydrophilic and oleophobic fiber membrane. The water in the oil-water mixture is collected in the porous tube through the water inlet holes and separated from the circulating coupling separator. The oil collection tank is located at the top of the guide tube. Light oil in the oil-water mixture gathers in the oil collection tank and is separated from the circulating coupling separator. The bottom of the circulating coupling separator is used to connect to the ejector outlet of the ejector. Oily wastewater is mixed with the oil-water mixture and demulsifying gas in the collection pipe through the ejector and introduced into the circulating coupling separator to flush the solids that accumulate on the surface of the emulsion separation membrane assembly and the porous tube, so that the solids accumulate at the bottom of the circulating coupling separator and are discharged.

2. The circulating coupling separator according to claim 1, characterized in that, The opening direction of the water inlet is towards the outlet direction of the injector, and the diameter of the water inlet is 10 to 2000 μm; the porosity of the water inlet on the porous tube is 5% to 70%, and the angle between the porous tube and the horizontal direction is 10 to 65°.

3. The circulating coupling separator according to claim 2, characterized in that, The vertical projection length of the porous tube is 10% to 65% of the diameter of the guide tube.

4. The circulating coupling separator according to claim 1, characterized in that, The guide tube assembly includes a guide tube support frame and a guide tube; or, the guide tube assembly includes a guide tube support frame and multiple guide tubes, with multiple guide tubes arranged sequentially at a predetermined interval in the vertical direction; the guide tubes are fixed by the guide tube support frame; The ratio of the cross-sectional area of ​​the guide tube to the cross-sectional area of ​​the circulating coupling separator is 0.26 to 0.85:

1.

5. The circulating coupling separator according to claim 4, characterized in that, The guide tube has several guide holes on its wall, the porosity of which is 30% to 70% and the diameter of which is 50 μm to 2 mm. The outer side of the guide tube wall is wrapped with a demulsifying membrane, the pore size of which is 30 to 80 μm, and the membrane material of which is at least one of the following: polyphenylene sulfide, polyimide or polyarylene ether nitrile.

6. The circulating coupling separator according to any one of claims 1 to 5, characterized in that, The emulsion separation membrane assembly is one or more, the ratio of the cross-sectional area of ​​the emulsion separation membrane assembly to the cross-sectional area of ​​the guide tube is 0.05 to 0.35:1, and the ratio of the height of the emulsion separation membrane assembly to the height of the guide tube is 0.5 to 1:

1. The membrane material of the emulsion separation membrane assembly is a porous membrane material composed of graphene aerogel and / or polyimide aerogel, and the porosity of the porous membrane material is 70% to 98%.

7. The circulating coupling separator according to any one of claims 1 to 5, characterized in that, The oil collection trough is inverted cone shape, and the angle between the generatrix of the cone containing the oil collection trough and the horizontal line is 10 to 65°. The fluid collection section of the oil collection tank has several through holes, and the porosity of the fluid collection section is 10% to 30%. The outer surface of the fluid collection section is covered with a hydrophilic and oleophobic fiber membrane. The fluid collection section is used to connect with the oil discharge pipe so that the separated light oil can be discharged from the circulating coupling separator through the oil discharge pipe.

8. An oil-water separation and liquid-solid separation device, characterized in that, include: The housing, and the ejector, gas-liquid separator and circulating coupling separator located inside the chamber enclosed by the housing as described in any one of claims 1 to 7; The bottom of the shell is provided with a solids discharge port for discharging solids separated from oily wastewater; The injector is located in the lower part of the chamber and is used to mix the oily wastewater with gas and the demulsified oil-water mixture to form microbubbles, which are then injected into the circulating coupling separator for oil-water separation and liquid-solid separation. The gas-liquid separator is located in the upper part of the chamber, and an exhaust port is provided in the upper part of the shell. The gas phase outlet of the gas-liquid separator is connected to the exhaust port. The gas-liquid separator is used to separate the separated gas and discharge it outside the equipment through the exhaust port. The circulating coupling separator is located between the ejector and the gas-liquid separator. The liquid collection pipe of the circulating coupling separator is connected to the liquid phase inlet of the ejector to supply the demulsified oil-water mixture to the ejector. The housing is provided with a purified water outlet and an oil phase outlet, which are used to install the purified water outlet pipe and the oil phase outlet pipe, respectively. The purified water outlet pipe is connected to the porous pipe, and the oil phase outlet pipe is connected to the fluid collection part of the oil collection tank.

9. The device according to claim 8, characterized in that, The ejector includes an ejector inlet, an ejector outlet, a liquid phase inlet, and a gas phase inlet; the ejector inlet is used to connect with an oily wastewater supply device, the ejector outlet is connected to the circulating coupling separator, the liquid phase inlet is connected to the liquid collection pipe of the circulating coupling separator, and the gas phase inlet is used to connect with a gas supply device.

10. The device according to claim 8 or 9, characterized in that, Also includes: A skirt plate located inside the cavity, the skirt plate being conical in shape; The skirt is located between the guide tube of the circulating coupling separator and the injector.

11. An oil-water separation system, characterized in that, Includes the circulating coupling separator as described in any one of claims 1 to 7.

12. An oil-water separation system, characterized in that, include: Oily wastewater supply equipment, gas supply equipment, oil phase collection equipment, and oil-water separation and liquid-solid separation equipment as described in any one of claims 8 to 10; The oily wastewater supply device is connected to the injector inlet of the injector in the oil-water separation and liquid-solid separation device, the gas supply device is connected to the gas phase inlet of the injector, and the oil phase collection device is connected to the oil phase discharge pipe installed on the oil phase discharge outlet.

13. The application of a circulating coupling separator as described in any one of claims 1 to 7 in an oil-water separation system.

14. The application of an oil-water separation and liquid-solid separation device as described in any one of claims 8 to 10 in an oil-water separation system; wherein, The fluid velocity at the ejector outlet of the ejector is 2–15 m / s.

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