A filter device of an oil-gas separator for lubricating oil production

Abstract

The application relates to the air purification technical field, and particularly discloses a filter device of an oil-gas separator for lubricating oil production, which comprises a cylinder body, an annular filter element coaxially arranged in the cylinder body, and a plurality of filter cores with different diameters and coaxially arranged with each other and composed of the annular filter element; a plurality of vertical rods extending in the axial direction are arranged on the inner side and the outer side circumferential surface of each filter core, and the inner side vertical rods and the outer side vertical rods are arranged in a staggered mode in the circumferential direction; the vertical rods are in sliding fit with the cylinder body, so that the vertical rods can move in the radial direction of the cylinder body; a moving device is arranged on the cylinder body and used for driving the vertical rods on the two sides of the filter core to move synchronously, so that an extrusion area and a working area which can move in the circumferential direction are formed on the filter core, a dynamic self-cleaning function is realized, the oil mist and impurities accumulated on the surface of the filter core can be peeled off without stopping the machine, and the problems of easy blockage, high maintenance cost and difficult continuous and stable operation of the existing filter device are effectively solved.

Description

Technical Field

[0001] This invention relates to the field of air purification technology, and more specifically to a filtration device for an oil-gas separator used in lubricating oil production. Background Technology

[0002] During the production, blending, storage, and transportation of lubricating oil, oil-gas mixtures are often generated, especially in processes such as heating, dehydration, degassing, and circulation. These mixtures often carry a large amount of oil mist and tiny droplets. If not effectively separated, this not only leads to lubricating oil loss but also easily causes pollution to subsequent pipelines, vacuum systems, or environmental treatment equipment. Therefore, existing lubricating oil production systems typically include oil-gas separators, which generally contain filtration devices to intercept and separate oil mist from the oil-gas mixture. Existing filtration devices mostly employ a cylindrical structure, with single or multiple filter elements inside the cylinder. These filter elements are generally cylindrical or pleated, and oil mist is trapped by the flow of oil through the filter media. Their structure is relatively fixed, relying on the pore structure of the filter element itself to complete the filtration function.

[0003] Chinese patent document CN118949572B discloses a filter for dust-laden oil and gas, comprising a cylindrical body with a top cover connected to its top and a cone connected to its bottom. A first bypass port and a second bypass port are provided on the top cover and the cylindrical body, which are connected by a pipe to form an external passage. A bypass valve is provided on the pipe. Several filter elements are provided inside the cylindrical body. A first heating component and a second heating component are provided on the outer walls of the cylindrical body and the cone. The filter of this invention, under the combined action of the heating components and the external passage, not only ensures that the interior of the cylindrical body and the cone maintains a high temperature at all times, but also allows for timely drainage of the filter elements during operation. This achieves effective separation of dust and oil and gas, and effectively avoids abnormal phenomena such as negative pressure inside the filter. It has advantages such as high processing efficiency, good filtration effect, low maintenance cost, high safety, and long service life. When used to filter dust-laden oil and gas, it can effectively remove dust from the oil and gas, demonstrating high practical value and promising application prospects.

[0004] However, the filtration devices in existing oil-gas separators still have many technical shortcomings that urgently need to be addressed in practical applications, as follows: First, the static and fixed structure of filter elements makes them prone to clogging, leading to a decrease in separation efficiency. Most filter elements in existing filtration devices are fixedly installed, and the pore structure of the filter media remains unchanged during filtration. As operating time increases, oil mist, tiny droplets, and small amounts of solid impurities in the oil and gas continuously accumulate on the surface and in the internal pores of the filter element, forming a filter cake layer. This significantly increases the filtration resistance of the filter element, reduces the oil and gas throughput, and drastically decreases the separation efficiency. In severe cases, it can even cause partial or complete clogging of the filter element, forcing the production system to shut down for repairs.

[0005] Secondly, filter element cleaning is cumbersome, costly, and disrupts continuous production. Currently, there are two main cleaning methods commonly used to address filter element clogging: one is to stop production to disassemble, clean, or replace the filter element. This requires interrupting the entire production process, and the disassembly, cleaning, and installation processes are time-consuming and labor-intensive, reducing production efficiency and increasing labor costs and filter element wear. The other is online backflushing cleaning, which involves blowing gas or liquid back into the filter element to remove accumulated impurities. However, backflushing cleaning has significant limitations. On the one hand, the backflushing pressure is difficult to control precisely; excessive pressure may damage the filter media, while insufficient pressure will not achieve the desired cleaning effect. On the other hand, backflushing can cause partial filtration interruptions, affecting the stability of separation efficiency. Furthermore, backflushing is often ineffective for highly viscous oil mist deposits.

[0006] Third, the multi-layer filter design suffers from insufficient synergy. Some existing devices employ a multi-layer filter structure to improve separation accuracy, but each layer operates independently, lacking an effective collaborative mechanism. Clogging of the outer filter layer directly affects the working state of the inner filter layer, leading to uneven resistance distribution throughout the filtration system and further exacerbating the risk of localized clogging. Furthermore, multi-layer filters are more difficult to clean, requiring layer-by-layer maintenance, making the operation more complex. Summary of the Invention

[0007] This invention provides a filtration device for an oil-gas separator used in lubricating oil production, aiming to solve the problem that the filter element cleaning methods in related technologies mostly rely on shutdown disassembly or backflushing, which not only has high maintenance costs but also makes it difficult to achieve continuous and stable operation.

[0008] A filtration device for an oil-gas separator used in lubricating oil production includes a cylindrical body, in which an annular filter element is coaxially arranged, the filter element being composed of multiple filter elements of different diameters that are coaxially arranged with each other. Each filter element has multiple vertical rods extending axially on its inner and outer circumferential surfaces, with the inner and outer vertical rods staggered in the circumferential direction. The vertical rod is slidably engaged with the cylinder body, so that the vertical rod can move along the radial direction of the cylinder body; The cylinder is equipped with a motion device to drive the vertical rods on the inner and outer sides of the filter element to move synchronously, thereby forming a compression area and a working area on the filter element that can move in the circumferential direction.

[0009] Its effect is as follows: by setting up an annular filter element composed of multiple filter elements of different diameters and coaxially nested, a multi-stage oil-gas filtration structure is formed, which can perform step-by-step fine filtration of the oil-gas mixture in the lubricating oil production process, significantly improving the separation efficiency of oil mist and tiny droplets. Axially extending vertical rods are arranged on the inner and outer circumferential surfaces of the filter element, staggered in the circumferential direction. When the motion device drives these vertical rods to move synchronously along the radial direction of the cylinder, a squeezing area and a working area that can move in the circumferential direction are formed on the filter element. This design allows different positions on the circumference of the filter element to alternately be in a filtration working state and a squeezing cleaning state during operation. When the extrusion zone moves to a certain position, the filter element at that position undergoes radial elastic deformation under the pressure of the staggered vertical rods on the inner and outer sides. Utilizing the elastic restoring force of the filter media itself, it squeezes out the oil mist condensates and impurities accumulated inside and on the surface of the filter pores, achieving online dynamic cleaning of the filter element. Meanwhile, the other circumferential positions of the filter element remain in the working area, ensuring the continuity of the filtration process. This effectively avoids the problems of increased filtration resistance and decreased separation efficiency caused by clogging in traditional static filter elements. Furthermore, cleaning can be completed without stopping the machine for disassembly, reducing maintenance costs and meeting the requirements of stable equipment operation for continuous lubricant production. The staggered arrangement of the inner and outer vertical rods creates an asymmetrical radial force on the filter element during extrusion. This asymmetrical extrusion generates a more complex stress distribution, causing minute relative displacements and friction within the filter media, further enhancing the removal of clogging material from the filter pores. The sliding fit between the vertical rods and the cylinder, along with the control of the motion device, ensures that the extrusion zone can move smoothly, continuously, or intermittently along the circumference of the filter element, thereby achieving uniform cleaning of the entire filter element surface.

[0010] Preferably, the filter element includes at least an inner filter element and an outer filter element, and multiple filter elements are nested sequentially from the inside out to form a multi-stage oil-gas filtration structure. This multi-stage filtration structure enables graded interception of oil mist and impurities of different particle sizes in the oil-gas mixture. The inner filter element intercepts smaller oil mist and impurities, while the outer filter element intercepts larger oil mist and impurities, significantly improving overall separation accuracy. Simultaneously, the coaxial structure of the multi-stage nesting ensures a uniform flow path for the oil-gas mixture within the cylinder, avoiding a decrease in separation efficiency due to excessively high local flow velocities. The reasonable flow channel gaps between each filter element facilitate smooth oil-gas flow and the return of lubricating oil after separation.

[0011] Preferably, the filter element is made of sintered metal fiber material, porous metal material, or composite metal mesh material, and possesses radial elastic deformation capability. Sintered metal fiber material features high porosity, good air permeability, and high filtration accuracy. Its three-dimensional mesh structure can effectively intercept oil mist and micro-droplets, while also possessing good mechanical strength and corrosion resistance. Porous metal material has the advantages of uniform pore size, stable structure, and resistance to high temperature and pressure, making it suitable for oil-gas separation under harsh working conditions. Composite metal mesh material is composed of multiple layers of metal mesh, combining high filtration accuracy and mechanical strength, and can withstand repeated elastic deformation without easily being damaged. All of the above materials possess good radial elastic deformation capability, capable of radial contraction when subjected to compression from a vertical rod, and able to elastically return to their original shape after the compression is released.

[0012] Preferably, one side of the vertical rod is fixedly connected to the corresponding filter element, and both ends are slidably disposed within the inner wall of the cylinder. The fixed connection between the vertical rod and the filter element can be achieved by welding, threaded connection, or snap-fit ​​connection to ensure a firm and reliable connection and prevent relative displacement when the filter element is deformed.

[0013] Preferably, the inner wall of the cylinder is provided with multiple axially extending guide grooves or guide rails to limit the radial movement direction of the vertical rods. The number of guide grooves or guide rails matches the number of vertical rods and is evenly distributed on the circumferential direction of the upper and lower walls of the cylinder to ensure that each vertical rod can obtain independent guiding action.

[0014] Preferably, the inner and outer vertical rods are staggered in the circumferential direction, creating an asymmetric radial force on the filter element during compression. This staggered distribution results in an asymmetric force distribution in the circumferential direction when the filter element is compressed, generating localized shearing and kneading effects. This more effectively removes oil mist deposits and impurities accumulated on the filter element surface and in its internal pores. Compared to symmetrical compression, asymmetric compression prevents deposits from forming a uniform compacted layer on the filter element surface, significantly improving cleaning efficiency. It also reduces fatigue damage during compression, extending the filter element's service life.

[0015] Preferably, the motion device includes a drive member and a pusher for pushing the vertical rod, the pusher moving in a circular motion along a circular trajectory. This ensures that the pusher can move smoothly in the circumferential direction.

[0016] Preferably, the vertical rod is provided with a wedge-shaped block that can abut against the pushing part. When the pushing part moves along a circular trajectory, its end contacts the inclined surface of the wedge-shaped block. Through the guiding effect of the inclined surface, the circular motion of the pushing part is converted into the radial motion of the vertical rod, thereby achieving the compression of the filter element.

[0017] Preferably, the pushing part acts simultaneously on the inner and outer vertical rods located at the same circumferential position during the movement to achieve synchronous radial pushing. This synchronous radial pushing method causes both the inner and outer sides of the filter element to be compressed simultaneously, resulting in bidirectional radial contraction. This allows for more comprehensive removal of deposits from the inner and outer surfaces of the filter element, while avoiding uneven deformation or damage caused by excessive force on one side.

[0018] Preferably, the squeezing area moves continuously or intermittently along the circumference of the filter element under the drive of the motion device, so that different circumferential positions of the filter element are squeezed and cleaned sequentially. When the motion device adopts a continuous drive mode, the squeezing area moves at a uniform speed along the circumference of the filter element, which can continuously and uninterruptedly clean the filter element. This is suitable for working conditions where the oil mist content in the oil and gas is high and the filter element is easily clogged. When the intermittent drive mode is adopted, the squeezing area stays at each circumferential position for a certain period of time before moving to the next position. The residence time can be adjusted according to the viscosity and thickness of the deposit. This is suitable for working conditions where the impurity content in the oil and gas is low and the cleaning requirement is relatively less urgent.

[0019] By adopting the above technical solution, the beneficial effects of the present invention are as follows: 1. Achieve dynamic self-cleaning of the filter element without downtime maintenance, ensuring continuous production: A motion device drives the pusher in a circular motion. The pusher engages with a wedge block on the vertical rod, converting the circular motion into radial motion of the vertical rod, thus forming a circumferentially movable compression zone on the filter element. The continuous or intermittent movement of this compression zone sequentially cleans different circumferential positions of the filter element, simultaneously completing self-cleaning without interrupting the filtration process. This dynamic self-cleaning method completely changes the existing technology's reliance on downtime disassembly or backflushing for cleaning, effectively solving the problem of frequent filter maintenance and reduced production efficiency in continuous lubricant production, ensuring long-term stable operation of the production system.

[0020] 2. Asymmetric bidirectional extrusion cleaning significantly improves cleaning effectiveness: This invention utilizes an alternating design of inner and outer vertical rods, creating asymmetric radial force on the filter element during extrusion. This generates shearing and kneading effects, more effectively removing oil mist deposits and impurities accumulated on the filter element's surface and within its pores. Simultaneously, the pushing unit acts on both the inner and outer vertical rods, achieving bidirectional radial pushing, ensuring that both the inner and outer sides of the filter element are simultaneously compressed, resulting in a more comprehensive and thorough cleaning. Compared to existing backflushing or symmetrical extrusion cleaning technologies, this invention avoids the formation of a compacted deposit layer, significantly improving cleaning effectiveness, reducing filtration resistance, and ensuring the filter element maintains consistently good filtration performance.

[0021] 3. Multi-stage filtration structure design, high separation efficiency, and avoidance of filter element damage: The filter element of this invention consists of multiple filter elements of different diameters arranged coaxially, forming a multi-stage oil-gas filtration structure. This multi-stage filtration structure enables graded interception of oil mist and impurities of different particle sizes in the oil and gas. The outer filter element intercepts larger particles of oil mist and impurities, while the inner filter element intercepts smaller particles, significantly improving overall separation accuracy. Simultaneously, a reasonable flow channel gap is formed between each filter element layer, which, together with the oil-gas guiding device, ensures a uniform flow path for oil and gas within the cylinder, avoiding excessively high local flow velocities that could lead to a decrease in separation efficiency, further enhancing the oil-gas separation effect. Because each filter element is relatively thin, it avoids excessive deformation of the packing material within the filter element during compression, preventing damage or breakage. Attached Figure Description

[0022] Figure 1 This is a front view of the present invention.

[0023] Figure 2 This is a cross-sectional view of the present invention.

[0024] Figure 3 This is a schematic diagram of the structure of the present invention after the cylinder body is removed.

[0025] Figure 4 This is a top view of the pushing part in this invention.

[0026] Figure 5 for Figure 4 A magnified structural diagram of point A in the middle.

[0027] Figure 6 This is a schematic diagram of the vertical rod in this invention.

[0028] Figure 7 This is a schematic diagram of the structure of the cylinder in this invention.

[0029] Figure label: 1. Cylinder; 11. Guide groove; 2. Filter element; 21. Vertical rod; 211. Wedge block; 3. Motion device; 31. Pushing part; 32. Driving component; 33. Drive shaft; 331. Air outlet; 332. Rotary docking plate. Detailed Implementation

[0030] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0031] like Figures 1-7As shown, the present invention discloses a filtration device for an oil-gas separator used in lubricating oil production, comprising a cylinder 1, a filter element, a motion device 3, and a control system (not shown in the control system diagram). An annular filter element is coaxially arranged inside the cylinder 1. The filter element consists of multiple filter elements 2 of different diameters arranged coaxially. Multiple axially extending vertical rods 21 are provided on the inner and outer circumferential surfaces of each filter element 2. The inner and outer vertical rods 21 are staggered in the circumferential direction. The vertical rods 21 slide against the cylinder 1, allowing them to move radially along the cylinder 1. The motion device 3 is provided on the cylinder 1 to drive the synchronous movement of the vertical rods 21 on both the inner and outer sides of the filter element 2, thereby forming a compression area and a working area on the filter element 2 that can move circumferentially.

[0032] The cylinder 1, serving as the main supporting structure of the filtration device, is made of high-strength carbon steel or stainless steel, such as Q345B carbon steel or 304 stainless steel, ensuring sufficient mechanical strength and corrosion resistance to withstand pressure and temperature changes during the oil-gas separation process. The cylinder 1 is designed in a cylindrical shape, with its diameter and length determined based on the required gas volume, oil mist content, and separation efficiency. Typically, the diameter of the cylinder 1 ranges from 300mm to 1000mm, and the length ranges from 300mm to 1500mm, meeting the needs of different production scales. An air inlet and an air outlet are respectively located at both ends of the cylinder 1; the air inlet is located at the bottom of the cylinder 1, and the air outlet is located on the side of the cylinder 1.

[0033] Multiple axially extending guide grooves 11 are provided on the inner top and bottom walls of the cylinder 1. The number of guide grooves 11 matches the number of vertical rods 21 and is evenly distributed along the circumference of the inner wall of the cylinder 1. The cross-sectional shape of the guide grooves 11 is designed as a dovetail shape, which can effectively prevent the vertical rods 21 from coming out of the groove, improving the stability and reliability of the structure. The length of the guide grooves 11 covers the maximum radial travel of the vertical rods 21, and is usually set to 40mm-100mm, ensuring that the vertical rods 21 are effectively guided and supported throughout the entire range of motion. The surface of the guide grooves 11 is precision machined to reduce the sliding friction resistance between the guide grooves and the vertical rods 21.

[0034] An oil collecting tank is integrally formed with the cylinder body 1 at its bottom. Its volume is determined by the amount of lubricating oil separated, typically capable of storing at least 24 hours' worth of separated oil. An oil drain valve, either a ball valve or a gate valve, is installed at the bottom of the oil collecting tank to facilitate the periodic return of the separated lubricating oil to the production system. A return flow channel is provided between the oil collecting tank and the filter element 2. The number of return flow channels matches the number of filter elements 2. Each return flow channel contains a filter screen with a pore size of 5μm-10μm to further filter out minute impurities in the lubricating oil, ensuring the quality of the recovered lubricating oil.

[0035] The top cover of cylinder 1 is removable, facilitating the inspection and replacement of components such as filter element 2 and moving device 3 inside cylinder 1 by operators. An oil-resistant rubber gasket is installed between the top cover and cylinder 1 to ensure sealing performance. The flange cover is fixed with bolts.

[0036] The filter element consists of multiple filter elements 2 of different diameters, arranged coaxially. The number of filter elements 2 can be set to 2-5 stages according to the separation accuracy requirements. Usually, a 2-stage or 3-stage filter element 2 structure is adopted, which can meet the separation accuracy requirements while avoiding maintenance difficulties caused by an overly complex structure. The distance between each filter element 2 is set to 100mm-150mm to form a reasonable flow channel gap, ensuring smooth flow of oil and gas, and facilitating the return of lubricating oil after separation.

[0037] Filter element 2 is made of sintered metal fiber material, porous metal material, or composite metal mesh material. These materials possess good radial elastic deformation capacity, high mechanical strength, and corrosion resistance. Among them, sintered metal fiber material has a porosity of 60%-80% and a filtration accuracy of 1μm-5μm, making it suitable for applications requiring high separation precision. Porous metal material has a porosity of 40%-60% and a filtration accuracy of 5μm-10μm, making it suitable for harsher operating conditions. Composite metal mesh material is composed of 3-5 layers of metal mesh, with a porosity of 50%-70% and a filtration accuracy of 3μm-8μm, combining high filtration accuracy and mechanical strength, making it a versatile material for filter element 2.

[0038] The filter element 2 is cylindrical, and its diameter is designed according to the diameter of the cylinder 1 and the number of filter elements 2. The diameter of the inner filter element 2 is usually 200mm-500mm, and the diameter of the outer filter element 2 increases sequentially according to the diameter and spacing of the inner filter elements 2. The length of the filter element 2 matches the length of the cylinder 1 to ensure that there is sufficient installation space between the two ends of the filter element 2 and the cylinder 1.

[0039] The surface of filter element 2 is coated with a hydrophobic and oleophobic coating, using a polytetrafluoroethylene (PTFE) coating or a superhydrophobic nano-coating. The coating is applied using a spraying or dipping process to ensure uniform coverage of the inner and outer surfaces and pores of filter element 2. This hydrophobic and oleophobic coating reduces the adhesion of oil mist and lubricating oil to the filter media surface, minimizing deposit accumulation. It also facilitates the removal of deposits with the returning lubricating oil after stripping, further improving the self-cleaning ability and separation efficiency of filter element 2.

[0040] The thickness of filter element 2 is set from 5mm to 20mm depending on the different material properties and filtration accuracy requirements. Metal fiber sintered material filter elements are typically 8mm-15mm thick, achieving high porosity and air permeability while ensuring sufficient filtration area and mechanical strength. Porous metal material filter elements are generally 10mm-20mm thick; their thicker structure helps maintain pore size uniformity and structural stability, adapting to high-temperature and high-pressure conditions. Composite metal mesh material filter elements are relatively thin, mostly 5mm-12mm thick, balancing filtration accuracy, air permeability, and mechanical strength through the stacking of multiple metal mesh layers. The appropriate selection of filter element thickness ensures effective oil and gas interception and separation while also guaranteeing good radial elastic deformation performance, meeting the compression and recovery requirements during dynamic cleaning processes.

[0041] The vertical rod 21 is made of high-strength alloy steel, such as 40Cr or 35CrMo, possessing high mechanical strength and wear resistance. It can withstand repeated extrusion forces without easily deforming or being damaged. The diameter of the vertical rod 21 is set to 10mm-20mm, and its length matches the length of the filter element 2, ensuring complete coverage of the axial length of the filter element 2. One side of the vertical rod 21 is fixed to the filter element 2. The vertical rod 21 slides up and down within the guide groove 11 on the inner wall of the cylinder 1. A sliding block is inserted at its end. The sliding block is made of wear-resistant alloy material, such as copper alloy or engineering plastic. The shape of the sliding block matches the cross-sectional shape of the guide groove 11, ensuring smooth sliding along the guide groove 11.

[0042] A wedge-shaped block 211 is fixedly mounted on the sliding block, capable of abutting against the pushing part 31. The wedge-shaped block 211 is integrally formed or welded to the sliding block, and its material is the same as that of the vertical rod 21. The slope angle of the wedge-shaped block 211 is set to 20°-45°, and is optimized according to the movement direction of the pushing part 31 and the radial movement requirements of the vertical rod 21. The surface of the wedge-shaped block 211 is hardened, such as by nitriding or chrome plating, to achieve a hardness of HRC50 or higher, thereby improving surface hardness and wear resistance and reducing frictional loss between it and the pushing part 31.

[0043] The inner and outer vertical rods 21 are staggered in the circumferential direction, causing the filter element 2 to be subjected to asymmetrical radial force during the extrusion process. This staggered distribution results in an asymmetrical distribution of force in the circumferential direction when the filter element 2 is subjected to extrusion, forming local shear force and kneading action, which can more effectively remove oil mist deposits and impurities accumulated on the surface and in the internal pores of the filter element 2.

[0044] The motion device 3 includes a drive component 32 and two sets of push parts 31 for pushing the vertical rod 21. The push parts 31 move in a circular motion along a circular trajectory. The drive component 32 is a servo motor. A reducer is installed at the output end of the servo motor. A connecting rod is fixedly connected to the output end of the reducer. The connecting rod is fixedly connected to the push part 31, and the rotation axis of the connecting rod is coaxial with the filter element 2. The servo motor drives the connecting rod to rotate, so that the push part 31 can move in a circular direction. The upper and lower connecting rods are connected by a drive shaft 33, so that the upper and lower sets of push parts 31 can move synchronously through one drive component 32. The drive shaft 33 is a hollow structure. Multiple air outlets 331 are opened on the side of the drive shaft 33 inside the filter element 2. A rotating docking plate 332 is set at the bottom of the drive shaft 33. The rotating docking plate 332 is used to connect other equipment pipes, so that oily exhaust gas enters the drive shaft 33 through the docking plate and then enters the filter element 2 through the air outlets 331. Because the drive shaft 33 rotates, the gas can be evenly distributed.

[0045] The number of pushing parts 31 in each group is one more than the number of layers in the filter element 2. That is, when the filter element 2 has two layers, there are three pushing parts 31. This ensures that there are pushing parts 31 on corresponding parts on both the inner and outer sides of the filter element 2, so that they can abut against the wedge blocks 211 on different vertical rod groups 21. This allows for simultaneous squeezing and cleaning of different circumferential positions of the filter element 2, improving cleaning efficiency. Furthermore, rollers (not shown in the figure) can be provided on both sides of the pushing blocks. By abutting against the wedge blocks 211 with the rollers, sliding friction is converted into rolling friction, significantly reducing frictional resistance and energy loss.

[0046] During its movement, the pushing part 31 simultaneously acts on the inner vertical rod 21 and the outer vertical rod 21 located at the same circumferential position to achieve synchronous radial pushing. It can simultaneously contact the wedge-shaped blocks 211 on both the inner and outer vertical rods 21, applying equal and opposite thrusts. When the pushing part 31 moves along a circular trajectory, it contacts the inclined surface of the wedge-shaped blocks 211. Through the guiding effect of the inclined surfaces, the circular motion of the pushing part 31 is converted into the radial motion of the vertical rods 21. The inner vertical rod 21 receives an inward thrust, and the outer vertical rod 21 receives an outward thrust, achieving bidirectional radial compression of the filter element 2.

[0047] The control system is electrically connected to the drive component 32 of the motion device 3, and can automatically adjust the operating parameters of the motion device 3 according to the filtration resistance of the filter element 2. The control system includes a pressure sensor, a controller, and an actuator. The pressure sensor is a differential pressure transmitter, which is installed at the inlet and outlet ends of the cylinder 1 to detect the pressure difference (i.e., filtration resistance) of oil and gas passing through the filter element 2 in real time. The signal output terminal of the pressure sensor is electrically connected to the signal input terminal of the controller, and can transmit the detected pressure difference signal to the controller in real time.

[0048] The controller uses a PLC controller, which stores a preset threshold for filter resistance. When the filter resistance detected by the pressure sensor reaches the preset threshold, the controller automatically sends a control signal to start the motion device 3 and adjust the rotation speed of the drive component 32, changing the movement speed of the pusher 31 to increase the cleaning intensity. When the filter resistance drops to the normal range, the controller automatically reduces the operating power of the motion device 3 or stops the motion device 3, achieving on-demand cleaning.

[0049] The controller typically features a manual control mode, allowing for manual operation via a touchscreen or push-button switches. Operators can manually start or stop the motion device 3, and adjust the speed and frequency of the pushing unit 31 to meet cleaning needs under specific conditions. The control system also includes a fault alarm function. When the pressure sensor, drive unit 32, or motion device 3 malfunctions, the controller promptly issues an alarm signal and displays the fault type on the touchscreen, facilitating timely troubleshooting and resolution by the operator.

[0050] A position sensor, which is either a photoelectric sensor or a Hall effect sensor, is installed along the movement path of the push unit 31 to detect the position information of the push unit 31 in real time and feed the position information back to the control system. Based on the information fed back by the position sensor, the control system controls the operation of the drive component 32 to ensure that the push unit 31 can move smoothly along the circular trajectory and avoid jamming or position deviation.

[0051] Working principle: In the operation of the oil-gas separator for lubricating oil production of the present invention, the oil-gas mixture enters the cylinder 1 through the air inlet of the cylinder 1. First, it is guided by the oil-gas guiding device, forming a spiral flow, and centrifugal force is used to pre-separate some of the larger-diameter oil mist and impurities. Subsequently, the oil-gas mixture flows axially through each stage of filter element 2. The filter element 2 intercepts and separates the oil mist and tiny droplets in the oil-gas through mechanisms such as inertial collision, direct interception, and diffusion sedimentation.

[0052] During the filtration process, the separated lubricating oil flows downwards along the surface of filter element 2 under gravity, flows into the oil collection tank through the return channel, and is periodically recovered to the production system through the drain valve. The purified gas is discharged through the gas outlet of cylinder 1, achieving compliant emissions or recycling.

[0053] As the filtration process continues, oil mist deposits and impurities gradually accumulate on the surface and in the internal pores of filter element 2, leading to increased filtration resistance. When the filtration resistance detected by the pressure sensor reaches a preset threshold, the control system automatically activates motion device 3, and drive component 32 drives push unit 31 to perform circular motion along a ring trajectory.

[0054] During its movement, the pushing part 31 contacts the wedge block 211 on the vertical rod 21. Through the guiding effect of the inclined surface, the circular motion is converted into the radial motion of the vertical rod 21. Since the inner and outer vertical rods 21 are staggered in the circumferential direction, and the pushing part 31 acts on both the inner and outer vertical rods 21 simultaneously, the filter element 2 is subjected to asymmetrical bidirectional radial force during the extrusion process, generating shear force and kneading action. This effectively removes deposits and impurities from the surface and internal pores of the filter element 2. Furthermore, the filter element 2 is designed with multiple layers to reduce the thickness of each layer, preventing excessive deformation during extrusion that could lead to fiber breakage in the filter element 2.

[0055] Driven by the motion device 3, the squeezing zone moves continuously or intermittently along the circumference of the filter element 2, sequentially squeezing and cleaning different circumferential positions of the filter element 2. The stripped deposits and impurities flow into the oil collection tank along with the lubricating oil, achieving dynamic self-cleaning of the filter element 2. When the filtration resistance drops to the normal range, the control system automatically reduces the operating power of the motion device 3 or pauses the motion device 3, completing the cleaning process.

[0056] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A filtration device for an oil-gas separator used in lubricating oil production, comprising a cylindrical body, characterized in that: The cylinder is coaxially arranged with an annular filter element, which is composed of multiple filter elements of different diameters that are coaxially arranged with each other. Each filter element has multiple vertical rods extending axially on its inner and outer circumferential surfaces. The inner and outer vertical rods are staggered in the circumferential direction, so that the filter element is subjected to asymmetrical radial force during the extrusion process. The vertical rod is slidably engaged with the cylinder body, so that the vertical rod can move along the radial direction of the cylinder body; The cylinder is equipped with a motion device to drive the vertical rods on the inner and outer sides of the filter element to move synchronously, thereby forming a squeezing area and a working area on the filter element that can move in the circumferential direction. The motion device includes a drive component and a pusher for pushing a vertical rod, the pusher moving in a circular motion along a circular trajectory; The vertical rod is provided with a wedge-shaped block that can abut against the pushing part; The driving component uses a servo motor. A reducer is installed at the output end of the servo motor. A connecting rod is fixedly connected to the output end of the reducer. The connecting rod is fixedly connected to the pushing part, and the rotation axis of the connecting rod is coaxial with the filter element. The connecting rod is driven to rotate by the servo motor, so that the pushing part can move in the circumferential direction. The upper and lower connecting rods are connected by a drive shaft. The drive shaft has a hollow structure, and multiple air outlets are opened on the side of the drive shaft inside the filter element. A rotating docking plate is set at the bottom of the drive shaft. One side of the vertical rod is fixedly connected to the corresponding filter element, and both ends are slidably disposed in the cylinder; The inner wall of the cylinder is provided with multiple axially extending guide grooves or guide rails to limit the radial movement direction of the vertical rod. During the movement, the pushing part acts simultaneously on the inner vertical rod and the outer vertical rod located at the same circumferential position to achieve synchronous radial pushing; The squeezing area moves continuously or intermittently along the circumference of the filter element under the drive of the motion device, so that different circumferential positions of the filter element are squeezed and cleaned in sequence.

2. The filtration device for an oil-gas separator in lubricating oil production according to claim 1, characterized in that, The filter element includes at least an inner filter element and an outer filter element, and multiple filter elements are nested from the inside to the outside to form a multi-stage oil and gas filtration structure.

3. The filtration device for an oil-gas separator in lubricating oil production according to claim 1 or 2, characterized in that, The filter element is made of sintered metal fiber material, porous metal material or composite metal mesh material, and has radial elastic deformation capability.

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