Oil and impurity removal device and oil and impurity removal method and application thereof

Abstract

The invention discloses an oil and impurity removal device and an oil and impurity removal method and application thereof, and relates to the field of oil-water separation of petrochemical engineering and sewage treatment.The oil and impurity removal device comprises an overflow section, a rotational flow section, a conical section and a settling section which are sequentially connected from top to bottom and coaxially arranged; the overflow section is a conical pipe barrel with the lower end caliber larger than the upper end caliber, and the top of the overflow section is connected with an overflow pipe. A feeding pipe is arranged on the side wall of the upper part of the cyclone section, and a combined fiber net is mounted at the top end in the cyclone section; the conical section is a conical pipe barrel with the upper end caliber larger than the lower end caliber, a particle settling pipe is arranged on the side wall of the lower portion of the conical section, and an oil guide rotational flow net is installed at the bottom end in the conical section; the settling section is a conical pipe barrel with the upper end caliber larger than the lower end caliber, and a water-phase settling opening is formed in the bottom of the settling section. According to the novel oil and impurity removal device and method, the oil removal effect of the fiber net is improved, the defect that a cyclone is poor in emulsion treatment effect is overcome, and multi-stage separation of solid impurities is achieved.

Description

Technical Field

[0001] This invention relates to the field of oil-water separation in petrochemicals and wastewater treatment, and more specifically, to an oil and impurity removal device, method, and application thereof. Background Technology

[0002] During oil extraction and processing, various types of oily wastewater with significant differences in quality are generated, mainly including produced water, well washing wastewater, and raw water. This wastewater primarily contains suspended solids, colloids, dispersed oil, floating oil, emulsified oil, and other dissolved substances. Currently, the common processes used to treat wastewater from oil production and processing include physical, chemical, physicochemical, and biological methods. Physical methods focus on removing some minerals and most suspended solids and oils from the wastewater. Chemical methods are mainly used to treat colloids and dissolved substances in wastewater that cannot be effectively removed by physical or biological methods alone, especially emulsified oil in oily wastewater. Physicochemical methods typically combine flotation and adsorption. Biological methods utilize the biochemical action of microorganisms to purify wastewater through biological absorption and transformation. Hydrocyclone separators are relatively mature technologies and, as typical equipment utilizing a combined centrifugal and gravitational force field, are widely used in many fields due to their simple structure, small footprint, convenient installation and operation, and low operating costs. Its working principle is based on centrifugal sedimentation. Due to the different sizes and densities of the internal droplets, the lighter liquid flows out from the top and the heavier liquid flows out from the bottom, thus achieving the purpose of separation.

[0003] Currently, the global trend of crude oil deterioration is intensifying, resulting in severe emulsification and increased impurities in wastewater after electrostatic desalination. Traditional hydrocyclones are ineffective at treating emulsions and cannot directly separate wastewater from impurities; furthermore, impurities can cause pipe buildup, affecting treatment efficiency. Therefore, there is an urgent need to develop new methods for removing emulsified oil. Chinese patent CN116764833A, invented by Yang Qiang et al., discloses a method and apparatus for enhanced hydrocyclone oil removal using built-in fiber-induced polymerization, involving technologies such as hydrocyclone separation and fiber coalescence. While it exhibits good oil removal performance, it struggles with emulsified oil treatment, its effectiveness is unstable, and its separation of particulate impurities is weak, easily causing blockage in downstream coalescers, affecting treatment efficiency, and making equipment maintenance difficult. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides an oil and impurity removal device, method, and application thereof. This invention organically combines media coalescing technology with cyclone separation technology. On one hand, it utilizes the oil-water separation characteristics of the combined fiber nodes; on the other hand, the fine pore size of the woven material can isolate particulate impurities, thereby improving separation efficiency and achieving multi-stage separation.

[0005] One of the objectives of this invention is to provide an oil and impurity removal device.

[0006] The oil and impurity removal device of the present invention comprises, from top to bottom, an overflow section, a swirling section, a conical section, and a settling section, which are connected sequentially and coaxially arranged, wherein:

[0007] The overflow section is a tapered tube with a lower port diameter larger than the upper port diameter, and its top is connected to an overflow pipe;

[0008] The swirl section is a cylindrical tube with a feed pipe on its upper side wall and a combined fiber mesh installed at the top inside.

[0009] The conical section is a conical tube with an upper port diameter larger than a lower port diameter, with a particle settling pipe installed on its lower side wall and an oil cyclone screen installed at the bottom inside.

[0010] The settling section is a conical tube with an upper port diameter larger than the lower port diameter, and a water phase settling port is provided at its bottom.

[0011] The connection methods for the overflow section, swirl section, conical section and settling section can adopt the fixed connection methods commonly used in this field, such as, but not limited to, bolt connection.

[0012] The oil-water mixture enters through the feed pipe in the swirling section and flows and rotates along the wall under high velocity and pressure, generating centrifugal force. Under the action of centrifugal force, large oil droplets with low density move towards the center of the swirling flow and coalesce to form an oil core, which flows out through the overflow pipe above. High-density water droplets and impurities flow along the outer side of the swirling flow. In the swirling section, due to the internal installation of a composite fiber mesh, when the liquid rotates, the emulsified oil collides with and adheres to the composite fiber mesh, coalescing into large oil droplets. The stability of oil-in-water or water-in-oil emulsions is disrupted near the fiber nodes, achieving the effect of oil-water separation. In the conical section, an oil-guiding swirling mesh is installed inside the tube. As the tube diameter decreases, impurities are isolated, and the oil-guiding fibers also adsorb and encapsulate oil droplets that are wrapped in particles, allowing them to flow upwards through the spiral fibers and coalesce. The isolated particulate impurities flow out through the particle settling pipe on one side, while wastewater flows out from the aqueous phase settling port at the bottom.

[0013] In a preferred embodiment of the present invention:

[0014] The composite fiber web is woven from hydrophilic and oleophobic fibers and hydrophilic and oleophobic fibers. Preferably, the hydrophilic and oleophobic fibers are at least one of polyacrylonitrile hydrophilic fibers, glass fibers, regenerated cellulose fibers, bamboo fibers, and soybean protein fibers, and more preferably glass fibers; and / or, the hydrophilic and oleophobic fibers are at least one of polytetrafluoroethylene fibers, polypropylene fibers, and polyvinyl chloride fibers, and more preferably polytetrafluoroethylene fibers.

[0015] The weaving method of the composite fiber web is not special or limited; hydrophilic and oleophobic fibers can be interwoven.

[0016] In a preferred embodiment of the present invention:

[0017] The composite fiber web has a tubular structure, preferably one of the following: cylindrical, conical or frustum-shaped (contracting from top to bottom), or conical or frustum-shaped (contracting from bottom to top); and / or,

[0018] The height of the composite fiber web is 1 / 2 to 3 / 4 of the height of the swirl section; and / or,

[0019] The composite fiber web has at least two layers. Preferably, each layer has no fewer than 11 fibers. More preferably, the diameter of each fiber is no more than 200 micrometers, and even more preferably 20 to 50 micrometers.

[0020] The mesh size of the composite fiber web is no greater than 1400 micrometers, preferably 400 to 1100 micrometers.

[0021] In a preferred embodiment of the present invention:

[0022] The oil-guiding swirl mesh is woven from oleophilic fibers; preferably, the oil-guiding swirl mesh is formed by interlacing oleophilic fibers into a spiral shape; more preferably, the oleophilic fibers are at least one of polytetrafluoroethylene fibers, polypropylene fibers, and polyvinyl chloride fibers, and even more preferably polytetrafluoroethylene fibers.

[0023] In a preferred embodiment of the present invention:

[0024] The oil swirl mesh is a conical or frustum-shaped structure that tapers from bottom to top; and / or,

[0025] The height of the oil swirl screen is 1 / 4 to 1 / 2 of the height of the conical section; and / or,

[0026] The oil-guiding swirl mesh has at least two layers. Preferably, each layer has no fewer than 11 fibers. More preferably, the diameter of each fiber is no greater than 200 micrometers, and even more preferably, it is 20 to 50 micrometers. And / or,

[0027] The mesh size of the oil swirl net is no greater than 900 micrometers, preferably 300 to 800 micrometers.

[0028] In a preferred embodiment of the present invention:

[0029] The composite fiber web is fixedly installed or rotatably installed inside the swirl section; and / or

[0030] The oil swirl net is either fixedly installed or rotatably installed inside the conical section;

[0031] The above-mentioned fixed installation can adopt common installation methods in the field, such as bolt fixing connection; the above-mentioned rotatable installation can adopt common installation methods in the field, such as bearing connection, so as to achieve the effect of the combined fiber mesh and / or oil vortex mesh rotating with the fluid.

[0032] In a preferred embodiment of the present invention:

[0033] The inclination angle of the conical tube in the overflow section is 10–75 degrees, preferably 20–45 degrees; and / or,

[0034] The ratio of the height to the diameter of the cylindrical tube in the swirl section is (2-4):1; and / or,

[0035] The inclination angle of the conical tube in the conical section is 10–75 degrees, preferably 10–35 degrees; and / or,

[0036] The inclination angle of the conical tube in the settling section is 10–75 degrees, preferably 10–35 degrees; and / or,

[0037] The conical section and the overflow section of the oil removal and impurity removal device of the present invention have a small inclination angle, which can make the liquid flow smoothly and reduce the problem of secondary emulsification of oil droplets caused by centrifugal shear force.

[0038] The port diameter of each of the overflow section, swirl section, conical section, and settling section is the same as the port diameter at the connection point of the adjacent section; and / or,

[0039] The overflow section, swirl section, conical section, and settling section are directly connected by a detachable, sealed connection, preferably including flange or threaded connections; and / or,

[0040] The overflow pipe is threadedly connected to the overflow section. Preferably, the length of the overflow pipe extending into the overflow section is 1 / 2 to 4 / 5 of the height of the tapered tube of the overflow section; and / or,

[0041] The overflow pipe and the water phase settling port of the oil and impurity removal device of the present invention are connected by a threaded connection, which can control the depth of the pipe and thus stabilize the treatment effect.

[0042] The aqueous phase settling inlet is threadedly connected to the settling section; and / or

[0043] The feed pipe is a straight pipe, tangentially arranged to the cylindrical tube of the swirl section; preferably, the ratio of the diameter of the feed pipe to the diameter of the cylindrical tube of the swirl section is 1:(4-7); and / or, the installation position of the feed pipe is not particularly restricted, as long as the bottom of the feed pipe is not lower than the bottom of the composite fiber web; and / or,

[0044] The top of the composite fiber web is parallel to or coincides with the top of the vortex section. Preferably, the distance between the top of the composite fiber web and the top of the vortex section is no greater than 1 / 3 of the height of the vortex section; and / or,

[0045] The particle settling pipe is a straight pipe, tangentially arranged to the conical section of the conical tube; preferably, the ratio of the diameter of the particle settling pipe to the maximum diameter of the conical section is 1:(6-8); and / or, the top of the particle settling pipe is not higher than the top of the oil swirl screen, more preferably, the top of the particle settling pipe is not higher than 1 / 2 of the height of the oil swirl screen; and / or,

[0046] The bottom of the oil vortex guide net is parallel to or coincides with the bottom of the conical section. Preferably, the distance between the bottom of the oil vortex guide net and the bottom of the conical section is not greater than 1 / 3 of the height of the conical section. More preferably, when the oil vortex guide net is frustum-shaped, the ratio of the maximum diameter to the minimum diameter of the oil vortex guide net is (2-5):1, and / or the ratio of the maximum diameter to the height of the oil vortex guide net is 1:(2-5).

[0047] The second objective of this invention is to provide a method for removing oil and impurities using the oil and impurity removal device described in the first objective of this invention.

[0048] The oil and impurity removal method of the oil and impurity removal device of the present invention includes:

[0049] The oil-water mixture enters the device through the feed pipe. Under the action of centrifugal force, the large oil droplets with low density move towards the center of the vortex and coalesce to form an oil core, which overflows and is discharged through the upper overflow pipe. The water droplets with high density and impurities flow along the outer side of the vortex.

[0050] The outer side of the vortex center is provided with a combined fiber network made of hydrophilic and oleophobic fibers. During centrifugation, the emulsified oil between the vortex center and the outer side of the vortex adheres and coalesces on the combined fiber network, and oil-water separation occurs at the fiber nodes of the hydrophilic and oleophobic fibers. The oil droplets continue to move towards the vortex center and coalesce under the centrifugal force, while the water droplets fall under the action of gravity.

[0051] As the dense water droplets and impurities flow along the outer side of the vortex, they fall under the influence of gravity. An oil-guiding vortex net is set at the lower outlet, and the particulate impurities are separated by the oil-guiding vortex net and discharged separately through the particle settling pipe. The water is discharged from the water phase settling port of the settling section under the influence of gravity. At the same time, the oil droplets on the particulate impurities are adsorbed and aggregated by the oil-guiding vortex net and flow upward along the oil-guiding vortex net and move towards the center of the vortex with centrifugal force.

[0052] The specific steps include: Large oil droplets coalesce towards the center under centrifugal force, forming an oil core that flows out from the overflow port. The composite fiber mesh attracts small oil droplets, causing them to coalesce into larger droplets. Oil-in-water or water-in-oil separation occurs when passing through the nodes of the composite fiber mesh. Particulate impurities, due to their inherent characteristics, are located on the outer side of the vortex and flow out through the settling port on one side of the steady flow section. The oil-guiding fiber mesh adsorbs oil droplets from impurity particles and isolates the particles, improving the purity of the wastewater. Oil droplets adsorbed by the oil-guiding vortex mesh coalesce and flow upwards along the fibers.

[0053] A third objective of this invention is to provide an application of an oil and impurity removal device as described in one objective of this invention or an oil and impurity removal method as described in another objective of this invention in the field of oil-water separation.

[0054] In a preferred embodiment of the present invention:

[0055] The petroleum compounds in the oil and water to be separated are less than 1000 mg / L, and / or the COD content is less than 2000 mg / L, and / or the suspended solids content is less than 500 mg / L, and / or the Reynolds coefficient of the inlet fluid is 15000 to 30000, and / or the cross-sectional velocity of the inlet fluid is 0.001 to 0.005 m / s.

[0056] This invention combines a hydrocyclone device with fiber coalescing technology to provide a new oil and impurity removal device and method. By utilizing the oil-water separation characteristics of the combined fiber nodes, it not only improves the oil removal effect of the fiber web and solves the defect of poor emulsion treatment by hydrocyclones, but also isolates particulate impurities through the fine pore size of the fiber web, realizing the impurity removal function for solid impurities and enabling multi-stage separation, thereby improving separation efficiency and extending the service life of the equipment.

[0057] The oil and impurity removal device of this invention has a compact and three-dimensional structure, occupies a small area, and its service life can be extended by replacing the combined fiber mesh and oil-guiding cyclone mesh. Furthermore, the wastewater treatment capacity and flexibility can be increased through series and parallel connection, improving wastewater treatment efficiency and making it suitable for situations with unstable flow rates. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the oil and impurity removal device in Example 1;

[0059] Figure 2 This is a cross-sectional view of the oil and impurity removal device of Example 1;

[0060] Figure 3 This is a schematic diagram of the combined fiber web structure of the oil and impurity removal device in Example 1;

[0061] Figure 4 This is a schematic diagram of the structure of the oil-guiding cyclone screen of the oil removal and impurity removal device in Example 1;

[0062] Figure 5 This is a schematic diagram of the interface distribution of droplets of different sizes in a swirling flow field.

[0063] Figure 6 This is a schematic diagram illustrating the process of oil droplets coalescing on oleophilic fibers.

[0064] Figure 7 This is a schematic diagram of the swirling separation of water-in-oil droplets under the action of polar forces at the nodes of a composite fiber network;

[0065] Among them, 1-1 water phase settling port, 1-2 settling section, 1-3 particle settling pipe, 1-4 conical section, 1-5 swirl section, 1-6 feed pipe, 1-7 overflow section, 1-8 overflow pipe, 1-9 oil outlet, 1-10 oil guide swirl net, and 1-11 combined fiber net. Detailed Implementation

[0066] The present invention will now be described in detail with reference to specific accompanying drawings and embodiments. It is important to note that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made to the present invention by those skilled in the art based on its content are still within the scope of protection of the present invention. In this invention, unless explicitly stated as limiting, specific, necessary, or essential, all terms are to be interpreted broadly. Those skilled in the art can interpret these terms based on relevant industry terminology or characteristics.

[0067]

Example 1

[0068] like Figure 1 and 2 As shown, an oil and impurity removal device is a radial hydrocyclone, comprising, from top to bottom, an overflow section 1-7, a vortex section 1-5, a conical section 1-4, and a settling section 1-2, which are coaxially arranged and fixed together by bolts.

[0069] Overflow section 1-7 is a tapered tube with a lower port diameter larger than the upper port diameter. The inclination angle of the tapered tube of overflow section 1-7 is 25 degrees. The top of the tube is connected to overflow pipe 1-8 by thread. The length of the overflow pipe extending into the overflow section is 3 / 4 of the height of the tapered tube of the overflow section.

[0070] The swirl section 1-5 is a cylindrical tube with a diameter-to-height ratio of 1:2. A feed pipe 1-6 is installed on its upper sidewall, and a combined fiber mesh 1-11 is installed at its inner top. The feed pipe 1-6 is tangent to the cylindrical tube, and the ratio of the feed pipe 1-6's diameter to the diameter of the cylindrical tube in the swirl section 1-5 is 1:4. Figure 3As shown, the composite fiber mesh 1-11 is made of interwoven glass fiber and polytetrafluoroethylene fiber. Each fiber has a diameter of 45 mm, with 12 fibers per layer, 6 glass fibers and 6 polytetrafluoroethylene fibers, for a total of 3 layers. The pore size is 800-1100 micrometers. The height of the composite fiber mesh 1-11 is 3 / 5 of the height of the swirl section 1-5. The composite fiber mesh 1-11 is installed inside the swirl section 1-5 using a bearing connection, allowing it to rotate within the hydrocyclone.

[0071] Conical section 1-4 is a conical tube with an upper port diameter larger than the lower port diameter, and the inclination angle of the conical tube is 15 degrees. A particle settling pipe 1-3 is installed on its bottom sidewall, and an oil swirl screen 1-10 is installed at the inner bottom end. The particle settling pipe 1-3 is tangent to the contraction tube of conical section 1-4, and the ratio of the diameter of the particle settling pipe 1-3 to the maximum diameter of the conical section is 1:6. Figure 4 As shown, the oil cyclone separator 1-10 is made of polytetrafluoroethylene fibers interwoven into a spiral shape. Each fiber has a diameter of 45 mm, and there are two layers with 11 fibers per layer. The mesh size of the oil cyclone separator 1-10 is 900 micrometers. The oil cyclone separator 1-10 is frustum-shaped, and its minimum diameter, maximum diameter, and height ratio is 1:4:8. The height is 2 / 5 of the height of the conical section 1-4. The oil cyclone separator 1-10 is installed inside the conical section 1-4 using a bearing connection, allowing it to rotate within the cyclone separator.

[0072] Settling section 1-2 is a conical tube with an upper port diameter larger than the lower port diameter. The inclination angle of the conical tube is 15 degrees, and its bottom is threadedly connected to the water phase settling port 1-1.

[0073] The process for treating oily wastewater is as follows: The oily wastewater to be treated enters the cyclone through the feed pipe 1-6. Under the strong flow velocity, a huge centrifugal force is generated. Affected by the centrifugal force, oil droplets coalesce towards the center to form an oil core. In addition, small oil droplets are gradually enlarged by the adsorption and coalescence effect of the combined fiber mesh 1-11 and participate in the separation process. The oil phase is discharged from the oil outlet 1-9 of the overflow pipe 1-8. The remaining wastewater enters the conical section 1-4. In this stage, impurities are squeezed towards the center by the wall and isolated outside the oil-guiding cyclone mesh 1-10, and discharged from the particle settling pipe 1-3. Subsequently, the remaining wastewater is discharged from the aqueous phase settling outlet 1-1.

[0074] The above-mentioned device is used to treat oily wastewater. The wastewater to be treated contains petroleum compounds below 1000 mg / L, COD below 2000 mg / L, and suspended solids below 500 mg / L. The Reynolds coefficient of the inlet fluid is between 15000 and 30000, and the cross-sectional flow velocity is between 0.001 and 0.005 m / s.

[0075] Experimental results show that the treated wastewater has an oil content below 20 mg / L, suspended solids below 20 mg / L, and COD content below 40 mg / L. The device achieves an oil removal rate of 95%–98%, a dirt removal rate of 92%–96%, and a COD removal rate of 95%–98%. These results demonstrate that the oil and dirt removal device of this invention has excellent oil and dirt removal performance.

[0076]

Example 2

[0077] A method for removing oil and impurities, the specific steps of which are as follows:

[0078] The oil-water mixture to be treated enters the hydrocyclone section through the feed pipe. Under high flow velocity and pressure, the fluid flows along the wall, forming a vortex and generating strong centrifugal force. Under this centrifugal force, larger, less dense oil droplets aggregate and merge towards the center, forming an oil core that flows out from the overflow port. Larger, less dense particles are thrown to the outside by the centrifugal force and flow along the wall. At this point, the centrifugal force alone is insufficient to effectively separate oil droplets of different diameters within the hydrocyclone. Figure 5 It can be seen that large oil droplets are more concentrated on the inner side due to centrifugal force, while small oil droplets have a smaller diameter and are less affected by centrifugal force, thus being distributed throughout the plane. Furthermore, oil droplets containing particulate impurities are more affected by centrifugal force and flow along the wall.

[0079] A composite fiber mesh is installed inside the swirl section. The fiber mesh is a downward-contracting frustum shape, and its built-in oleophilic fibers can capture oil droplets at various points on the plane. The principle is as follows: Figure 6 As shown: oil droplets are captured and attached to oleophilic fibers during flow, and then connect with subsequent oil droplets to form oil bridges, along which the oil droplets flow. As more oil droplets attach, they gradually increase in size. When they reach a certain size, they detach from the fibers and merge into the oil core under the influence of fluid drag. And as... Figure 7 As shown: the composite fiber web separates emulsified oil droplets from water droplets under the action of polar forces, thus improving the separation efficiency.

[0080] An oil swirl screen is installed below the conical section. The screen can adsorb oil droplets and isolate particulate impurities. Particulate impurities are separated and discharged separately by the screen, while oil droplets are adsorbed and aggregated by the screen and flow upwards along it.

[0081] The above examples are all applications of the present invention. All applications within the scope of the present invention without innovative improvements are within the scope of the present invention. It should be understood that the above examples are only a detailed description of the present invention and should not be construed as limiting the present invention.

Claims

1. An oil and impurity removal device, characterized in that... The device includes an overflow section, a swirling section, a conical section, and a settling section, which are connected sequentially from top to bottom and arranged coaxially, wherein: The overflow section is a tapered tube with a lower port diameter larger than the upper port diameter, and its top is connected to an overflow pipe; The swirl section is a cylindrical tube with a feed pipe on its upper side wall and a combined fiber mesh installed at the top inside. The conical section is a conical tube with an upper port diameter larger than a lower port diameter, with a particle settling pipe installed on its lower side wall and an oil cyclone screen installed at the bottom inside. The settling section is a conical tube with an upper port diameter larger than the lower port diameter, and a water phase settling port is provided at its bottom.

2. The apparatus according to claim 1, characterized in that: The composite fiber web is woven from hydrophilic and oleophobic fibers and hydrophilic and oleophobic fibers. Preferably, the hydrophilic and oleophobic fibers are at least one of polyacrylonitrile hydrophilic fibers, glass fibers, regenerated cellulose fibers, bamboo fibers, and soybean protein fibers, and more preferably glass fibers; and / or, the hydrophilic and oleophobic fibers are at least one of polytetrafluoroethylene fibers, polypropylene fibers, and polyvinyl chloride fibers, and more preferably polytetrafluoroethylene fibers.

3. The apparatus according to claim 1, characterized in that: The composite fiber web has a tubular structure, preferably one of the following: cylindrical, conical or frustum-shaped (contracting from top to bottom), or conical or frustum-shaped (contracting from bottom to top); and / or, The height of the composite fiber web is 1 / 2 to 3 / 4 of the height of the swirl section; and / or, The composite fiber web has at least two layers, preferably with no fewer than 11 fibers in each layer, more preferably with each fiber having a diameter of no more than 200 micrometers, and even more preferably 20 to 50 micrometers; and / or, The mesh size of the composite fiber web is no greater than 1400 micrometers, preferably 400 to 1100 micrometers.

4. The apparatus according to claim 1, characterized in that: The oil-guiding swirl mesh is woven from oleophilic fibers; preferably, the oil-guiding swirl mesh is formed by interlacing oleophilic fibers into a spiral shape; more preferably, the oleophilic fibers are at least one of polytetrafluoroethylene fibers, polypropylene fibers, and polyvinyl chloride fibers, and even more preferably polytetrafluoroethylene fibers.

5. The apparatus according to claim 1, characterized in that: The oil swirl mesh is a conical or frustum-shaped structure that tapers from bottom to top; and / or, The height of the oil swirl screen is 1 / 4 to 1 / 2 of the height of the conical section; and / or, The oil-guiding swirl mesh has at least two layers. Preferably, each layer has no fewer than 11 fibers. More preferably, the diameter of each fiber is no greater than 200 micrometers, and even more preferably, it is 20 to 50 micrometers. And / or, The mesh size of the oil swirl net is no greater than 900 micrometers, preferably 300 to 800 micrometers.

6. The apparatus according to claim 1, characterized in that: The composite fiber web is fixedly installed or rotatably installed inside the swirl section; and / or The oil swirl net is either fixedly installed or rotatably installed inside the conical section.

7. The apparatus according to claim 1, characterized in that: The inclination angle of the conical tube in the overflow section is 10–75 degrees, preferably 20–45 degrees; and / or, The ratio of the height to the diameter of the cylindrical tube in the swirl section is (2-4):1; and / or, The inclination angle of the conical tube in the conical section is 10–75 degrees, preferably 10–35 degrees; and / or, The inclination angle of the conical tube in the settling section is 10–75 degrees, preferably 10–35 degrees; and / or, The port diameter of each of the overflow section, swirl section, conical section, and settling section is the same as the port diameter at the connection point of the adjacent section; and / or, The overflow section, swirl section, conical section, and settling section are directly connected by a detachable, sealed connection, preferably including flange or threaded connections; and / or, The overflow pipe is threadedly connected to the overflow section. Preferably, the length of the overflow pipe extending into the overflow section is 1 / 2 to 4 / 5 of the height of the tapered tube of the overflow section; and / or, The aqueous phase settling inlet is threadedly connected to the settling section; and / or The feed pipe is a straight pipe, which is tangentially arranged to the cylindrical tube of the swirl section; preferably, the ratio of the diameter of the feed pipe to the diameter of the cylindrical tube of the swirl section is 1:(4-7); and / or, the bottom of the feed pipe is not lower than the bottom of the composite fiber web; and / or, The top of the composite fiber web is parallel to or coincides with the top of the vortex section. Preferably, the distance between the top of the composite fiber web and the top of the vortex section is no greater than 1 / 3 of the height of the vortex section; and / or, The particle settling pipe is a straight pipe, tangentially arranged to the conical section of the conical tube; preferably, the ratio of the diameter of the particle settling pipe to the maximum diameter of the conical section is 1:(6-8); and / or, the top of the particle settling pipe is not higher than the top of the oil swirl screen, more preferably, the top of the particle settling pipe is not higher than 1 / 2 of the height of the oil swirl screen; and / or, The bottom of the oil vortex guide net is parallel to or coincides with the bottom of the conical section. Preferably, the distance between the bottom of the oil vortex guide net and the bottom of the conical section is not greater than 1 / 3 of the height of the conical section. More preferably, when the oil vortex guide net is frustum-shaped, the ratio of the maximum diameter to the minimum diameter of the oil vortex guide net is (2-5):1, and / or the ratio of the maximum diameter to the height of the oil vortex guide net is 1:(2-5).

8. A method for removing oil and impurities using the oil and impurity removal apparatus as described in any one of claims 1-7, characterized in that... The method includes: The oil-water mixture enters the device through the feed pipe. Under the action of centrifugal force, the large oil droplets with low density move towards the center of the vortex and coalesce to form an oil core, which overflows and is discharged through the upper overflow pipe. The water droplets with high density and impurities flow along the outer side of the vortex. The outer side of the vortex center is provided with a combined fiber network made of hydrophilic and oleophobic fibers. During centrifugation, the emulsified oil between the vortex center and the outer side of the vortex adheres and coalesces on the combined fiber network, and oil-water separation occurs at the fiber nodes of the hydrophilic and oleophobic fibers. The oil droplets continue to move towards the vortex center and coalesce under the centrifugal force, while the water droplets fall under the action of gravity. As the dense water droplets and impurities flow along the outer side of the vortex, they fall under the influence of gravity. An oil-guiding vortex net is set at the lower outlet, and the particulate impurities are separated by the oil-guiding vortex net and discharged separately through the particle settling pipe. The water is discharged from the water phase settling port of the settling section under the influence of gravity. At the same time, the oil droplets on the particulate impurities are adsorbed and aggregated by the oil-guiding vortex net and flow upward along the oil-guiding vortex net and move towards the center of the vortex with centrifugal force.

9. The application of an oil and impurity removal device as described in any one of claims 1-7 or an oil and impurity removal method as described in claim 8 in the field of oil-water separation.

10. The application according to claim 9, characterized in that: The petroleum compounds in the oil and water to be separated are less than 1000 mg / L, and / or the COD content is less than 2000 mg / L, and / or the suspended solids content is less than 500 mg / L, and / or the Reynolds coefficient of the inlet fluid is 15000 to 30000, and / or the cross-sectional velocity of the inlet fluid is 0.001 to 0.005 m / s.

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