Electrostatic lubricating oil efficient filtering device with porous electrode

Abstract

The invention discloses an electrostatic lubricating oil efficient filtering device with a porous electrode, and relates to the technical field of hydraulic lubricating system oil purification, the electrostatic lubricating oil efficient filtering device comprises a shell, a high voltage electrode, a dust collector and a grounding electrode; through innovative porous electrode design, gradient electric field optimization and an intelligent control system, the oil purification efficiency and adaptability are remarkably improved. According to the high-voltage electrode, a honeycomb-shaped porous structure is combined with a BaTiO3-PTFE dielectric coating, and efficient electrification and agglomeration of micron-sized particles are achieved by enhancing corona discharge and dielectrophoresis effects; the dust collector not only strengthens the gradient adsorption effect of an electric field, but also solves the problem of insulation of water-containing oil liquid through winding of multiple layers of dielectric materials and the design of a waterproof film interlayer. The control system monitors the particle concentration and the pressure difference in real time, the voltage and the flow are dynamically adjusted, a high-pressure back flushing mechanism is adopted, and the service life of a filter element is prolonged while the NAS 6-level purification standard is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic lubricating system oil purification, and particularly to an electrostatic high-efficiency lubricating oil filtering device with porous electrodes. Background Art

[0002] In the technical field of lubricating oil purification, mechanical filtration and electrostatic adsorption are mainly used at present. Although traditional mechanical filtration technology can effectively intercept larger particle pollutants, its removal effect on sub-micron particles and colloidal oxides is limited, and there are problems such as easy clogging of the filter element and frequent replacement. Although electrostatic oil purification technology can make particles charged and adsorbed through a high-voltage electric field, the electrode structure design in the existing technology has obvious deficiencies: the electric field generated by parallel plate electrodes is too uniform, resulting in insufficient polarization of small particles; although traditional wire-cylinder electrodes can generate a non-uniform electric field, the field strength distribution is uneven, and the proportion of low-field strength regions is too large, affecting the overall purification effect.

[0003] Existing electrostatic oil purification devices generally have the problem of low purification efficiency. In particular, the purification rate of particles with a size of 0.5 - 5 μm is usually lower than 85%. This is mainly because the electrode surface is too smooth, the corona effect is weak, and it is unable to effectively promote particle charging and agglomeration. At the same time, the oil flow scouring easily causes the adsorbed particles to fall off, resulting in secondary pollution. In terms of the control system, the existing technology lacks the ability to monitor the particle concentration of the oil in real time and adjust adaptively, and it is difficult to achieve the optimal purification effect. Therefore, in view of the above phenomena, an electrostatic high-efficiency lubricating oil filtering device with porous electrodes is proposed to meet the actual use needs. Summary of the Invention

[0004] The present invention provides an electrostatic high-efficiency lubricating oil filtering device with porous electrodes. By adopting a honeycomb porous electrode structure, the non-uniformity of the electric field and the corona effect are significantly enhanced. At the same time, a dust collecting body structure is designed to effectively improve the adsorption stability of particles. In terms of the control system, the present invention realizes adaptive adjustment based on multi-parameter feedback, can optimize the working parameters in real time according to the oil state, and significantly improves the purification efficiency and system reliability.

[0005] To achieve the above object, an electrostatic high-efficiency lubricating oil filtering device with porous electrodes provided by the present invention includes a housing, a high-voltage electrode, a dust collecting body, and a grounding electrode; the housing includes an upper end cover and a lower end cover, both the upper end cover and the lower end cover are provided with an oil inlet and an oil outlet, and the lower end cover is grounded; the grounding electrode is in a cylindrical shape; the upper end cover and the lower end cover are respectively arranged on the upper and lower sides of the grounding electrode; the dust collecting body is in a cylindrical shape and is coaxially arranged with the grounding electrode; the high-voltage electrode adopts a honeycomb porous structure; the high-voltage electrode is arranged at the axial position of the grounding electrode.

[0006] In some embodiments, the high-voltage electrode includes a conductive substrate and a surface dielectric coating; the conductive substrate is stainless steel or conductive ceramic; the surface dielectric coating is a BaTiO3 nanoparticle composite PTFE material with a porosity of 40%-60% and a pore diameter of 10-100 μm.

[0007] In some embodiments, the dust collecting body includes a filter paper and a high-voltage resistant and water-impermeable film. The pores of the filter paper are no more than 40 μm. Epoxy resin is sprayed on the surface of the filter paper. The dust collecting body is formed by winding the filter paper into a cylinder, and the high-voltage resistant and water-impermeable film is sandwiched between the layers of the filter paper.

[0008] In some embodiments, it further includes a control system. The control system includes a pump group, a particle number detector, a high-voltage power amplifier, an oil tank, a PLC control module, and a flow regulating valve; the pump group is connected to the oil inlet of the lower end cover through an oil inlet pipeline, and the oil outlet is connected to the oil tank through an oil return pipeline to form a circulation loop; the particle number detector is installed on the oil return pipeline of the oil outlet and is connected to the PLC control module through a signal line; the high-voltage power amplifier is connected to the high-voltage electrode of the upper end cover through a cable; the bottom of the oil tank is connected to the inlet of the pump group through a suction pipeline; the PLC control module is connected to the high-voltage power amplifier and the pump group motor respectively through control lines, and the flow regulating valve is installed on the oil inlet pipeline at the outlet of the pump group and is electrically connected to the PLC control module.

[0009] In some embodiments, the control system further includes two pressure sensors. The two pressure sensors are respectively installed on the oil inlet pipeline and the oil return pipeline and are connected to the PLC control module through signal lines.

[0010] In some embodiments, the control system further includes four solenoid valves. The four solenoid valves are respectively arranged on the oil inlet and oil outlet pipelines.

[0011] An electrostatic high-efficiency lubricating oil filtering method with a porous electrode provided by the present invention specifically includes the following steps:

[0012] Step S1: Start the pump group, and the oil enters the device from the oil inlet at a flow rate of 3-5 L / min;

[0013] Step S2: The high-voltage power amplifier applies a voltage of 5-15 kV, and the high-voltage electrode generates a non-uniform electric field to charge and polarize the particles;

[0014] Step S3: The charged particles are adsorbed to the dust collecting body under the action of the electric field gradient force, and the colloidal oxides are intercepted after increasing in size through corona agglomeration;

[0015] Step S4: The purified oil returns to the oil tank from the oil outlet, and the particle number detector feeds back data to the PLC control module in real time;

[0016] Step S5: The PLC adjusts the voltage and flow rate according to the feedback until the particle concentration ≤ NAS Class 6.

[0017] In some embodiments, Step S5 specifically includes: when the particle number detector detects that the oil in the oil outlet has particles > 5μm, that is, when the particle concentration > NAS Class 6 standard, the PLC control module adjusts the parameters according to the following formula:

[0018] V new = V0 × (1 + K p × ΔC)

[0019] Q new = Q0 × (1 - K q × ΔC)

[0020] Where: V new is the adjusted output voltage, V0 is the initial set voltage, K p is the voltage adjustment coefficient, ΔC is the exceeded NAS grade number, Q new is the adjusted flow rate, Q0 is the initial set flow rate, K q is the flow rate adjustment coefficient.

[0021] In some embodiments, the PLC control module further includes a backwashing program: when the pressure difference ΔP detected by two pressure sensors at the inlet and outlet is > 0.3MPa:

[0022] Step S601: Cut off the output of the high-voltage power amplifier;

[0023] Step S602: Control the solenoid valve to make the oil in the filter device flow reversely;

[0024] Step S603: Increase the flow rate to 8 - 10 L / min and keep it for 30S;

[0025] Step S604: Control the solenoid valve to resume forward flow and re-apply high voltage;

[0026] Step S605: When ΔP is still > 0.25MPa after three consecutive backwashes, trigger a filter element replacement alarm.

[0027] Compared with the related technology, an electrostatic high-efficiency lubricating oil filtering device with porous electrodes provided by the present invention has the following beneficial effects:

[0028] The present invention provides an electrostatic high-efficiency lubricating oil filtering device with a porous electrode. Through innovative porous electrode design, gradient electric field optimization, and an intelligent control system, the oil purification efficiency and adaptability have been significantly improved. The high-voltage electrode adopts a honeycomb porous structure combined with a BaTiO3-PTFE dielectric coating. By enhancing the corona discharge and dielectrophoresis effects, efficient charging and agglomeration of micron-sized particles are achieved. The dust collector is designed with multiple layers of dielectric materials wound and a waterproof film interlayer, which not only strengthens the electric field gradient adsorption effect but also solves the insulation problem of water-containing oil. The control system dynamically adjusts the voltage and flow rate by real-time monitoring of the particle concentration and pressure difference, and adopts a high-voltage reverse flushing mechanism, which extends the filter element life while ensuring the NAS 6-level purification standard. This device is especially suitable for high-precision lubrication systems, can simultaneously handle metal abrasives, gums, and trace moisture, reduces energy consumption by more than 30% compared with traditional filtering technologies, and extends the maintenance cycle by 2-3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of the filtering device of the present invention;

[0030] Figure 2 is a schematic overall connection structure diagram of the present invention.

[0031] Reference numerals in the figure: 1, high-voltage electrode; 2, grounding electrode; 3, dust collector; 4, upper end cover; 5, lower end cover; 6, first oil outlet; 7, second oil outlet; 8, first oil inlet; 9, second oil outlet; 101, first solenoid valve; 102, second solenoid valve; 103, third solenoid valve; 104, fourth solenoid valve; 105, first pressure sensor; 106, second pressure sensor; 107, waste oil collector; 100, filtering device; 200, high-voltage power amplifier; 300, pump group; 400, fuel tank; 500, particle number detector; 600, flow regulating valve; 700, return oil pipeline; 800, oil inlet pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Embodiment 1

[0033] This embodiment provides an electrostatic high-efficiency lubricating oil filtering device with a porous electrode. As Figure 1 shown, the present invention includes a housing, a high-voltage electrode 1, a dust collector 3, and a grounding electrode 2; the housing includes an upper end cover 4 and a lower end cover 5. The upper end cover 4 is provided with a first oil outlet 6 and a second oil outlet 9. The lower end cover 5 is provided with a first oil inlet 8 and a second oil outlet 7. The lower end cover 5 is grounded; the grounding electrode 2 is cylindrical; the upper end cover 4 and the lower end cover 5 are respectively arranged on the upper and lower sides of the grounding electrode 2; the dust collector 3 is cylindrical and coaxially arranged with the grounding electrode 2; the high-voltage electrode 1 adopts a honeycomb porous structure; the high-voltage electrode 1 is arranged at the axial position of the grounding electrode 3.

[0034] In this embodiment, the honeycomb porous structure of the high-voltage electrode 1 is irregular. On the one hand, it can increase the electric field strength, and the electric field gradient makes non-charged impurity particles move directionally and adsorb on the dielectric dust collector 3, improving the purification efficiency. On the other hand, it promotes the generation of electron avalanche phenomenon. The corona principle makes the impurity particles charged and agglomerate together, increasing in size, and improving the efficiency of electrostatic oil purification.

[0035] Embodiment Two

[0036] On the basis of Embodiment One, the high-voltage electrode includes a conductive matrix and a surface dielectric coating; the conductive matrix is stainless steel or conductive ceramic; the surface dielectric coating is a BaTiO3 nanoparticle composite PTFE material with a porosity of 40%-60% and a pore diameter of 10-100 μm.

[0037] In this embodiment, to prepare a porous BaTiO3 nanoparticle composite PTFE coating on the surface of the conductive matrix, first, the matrix needs to be sandblasted and roughened and treated by plasma activation to enhance the coating adhesion. Mix BaTiO3 nanoparticles and PTFE emulsion in a mass ratio of 3:7, and add 30%-40% of a pore-forming agent (such as NH4HCO3 or NaCl), and prepare a uniform slurry by ball milling. Use electrostatic spraying or dip-coating process to coat the slurry on the surface of the matrix, and control the wet film thickness within the range of 200-300 μm. Subsequently, perform stepwise sintering treatment. First, make PTFE melt at 280°C, then raise the temperature to 360°C to decompose the pore-forming agent, and finally complete densification at 400°C. To optimize the coating performance, a post-treatment process of plasma etching and secondary impregnation with BaTiO3 sol is also required. This process can finally obtain a porous coating with a porosity of 40-60% and a pore diameter of 10-100 μm. A dielectric constant gradient change (ε = 100 to 10) is formed from the surface to the interface of the coating, and the breakdown field strength reaches more than 30 kV / mm, while maintaining excellent bonding strength (critical load ≥ 30 N). This porous structure design not only ensures the gradient characteristics of the electric field distribution but also improves the particle adsorption capacity, significantly enhancing the purification efficiency of the electrostatic oil purification device.

[0038] Embodiment Three

[0039] On the basis of Embodiment One, the dust collector 3 includes filter paper and a high-voltage resistant and water-impermeable film. The pores of the filter paper are not larger than 40 μm, epoxy resin is sprayed on the surface of the filter paper, the dust collector is wound into a cylinder by the filter paper, and the high-voltage resistant and water-impermeable film is sandwiched between the layers of the filter paper.

[0040] In this embodiment, the dust collector 3 is made of filter paper of fiber material, the surface is treated by spraying epoxy resin, a high-voltage-resistant and water-impermeable thin film is sandwiched in the middle, and after being folded, it is tightly rolled into a cylinder. There are four dielectric thin layers with different dielectric constants in the radial direction. Since there is a water-impermeable and high-voltage-resistant insulating film sandwiched between the dust collection layers, once the filter paper absorbs water, the water cannot connect between the entire dust collectors. In this way, the insulation resistance between the electrodes remains very large, and the conduction current cannot rise significantly. It can purify the oil containing a certain amount of moisture, expanding the applicable range of oil products for electrostatic oil purification. By spraying epoxy resin, the electric field in the electrostatic oil purification area is strengthened, and the radial gradient of the electric field is enhanced to increase the adsorption force. Without increasing the applied voltage, the actual electric field in the oil purification area is doubled. Among them, the dust collector 3 can be removed and cleaned and replaced by removing the upper end cover 4.

[0041] Embodiment 4

[0042] Based on Embodiments 1 to 3, as Figure 2 shown, it further includes a control system. The control system includes a pump group 300, a particle number detector 500, a high-voltage power amplifier 200, a fuel tank 400, a PLC control module, and a flow regulating valve 600;

[0043] The pump group 300 is connected to the oil inlet of the lower end cover 5 through an oil inlet pipeline 800, and the oil outlet is connected to the fuel tank 400 through an oil return pipeline 700 to form a circulation loop; the particle number detector 500 is installed on the oil return pipeline 700 at the oil outlet and is connected to the PLC control module through a signal line; the high-voltage power amplifier 200 is connected to the high-voltage electrode 1 of the upper end cover 4 through a cable; the bottom of the fuel tank 400 is connected to the inlet of the pump group 300 through a suction pipeline; the PLC control module is respectively connected to the high-voltage power amplifier 200 and the motor of the pump group 300 through control lines, and the flow regulating valve 600 is installed on the oil inlet pipeline at the outlet of the pump group 300 and is electrically connected to the PLC control module.

[0044] The control system further includes a first pressure sensor 105 and a second pressure sensor 106. The two pressure sensors are respectively installed on the oil inlet pipeline 800 and the oil return pipeline 700 and are connected to the PLC control module through signal lines.

[0045] The control system further includes a first solenoid valve 101, a second solenoid valve 102, a third solenoid valve 103, and a fourth solenoid valve 104. The first solenoid valve 101 is connected to the first oil inlet 8, the second solenoid valve 102 is connected to the second oil inlet 7, the third solenoid valve 103 is connected to the first oil outlet 6 and then connected to the waste oil collector 107, and the fourth solenoid valve 104 is connected to the second oil outlet 9.

[0046] In this embodiment, during the normal filtration process, the first solenoid valve 101 and the fourth solenoid valve 104 are opened, and the second solenoid valve 102 and the third solenoid valve 103 are closed. The turbid oil enters from the first oil inlet 8, and after electrostatic filtration, it flows out from the second oil outlet 9. During the backwashing process, the first solenoid valve 101 and the fourth solenoid valve 104 are closed, and the second solenoid valve 102 and the third solenoid valve 103 are opened. The oil enters from the second oil inlet 7 and is discharged from the first oil outlet 6 into the waste oil collector 107.

[0047] Implementation steps:

[0048] Step S1: Start the pump group 300, and the oil enters the filtration device 100 from the first oil inlet 8 at a flow rate of 3 - 5 L / min.

[0049] Step S2: The high - voltage power amplifier 200 applies a voltage of 5 - 15 kV, and the high - voltage electrode 1 generates a non - uniform electric field to charge and polarize the particles.

[0050] Step S3: The charged particles are adsorbed onto the dust collector 3 under the action of the electric field gradient force, and the colloidal oxides are intercepted after increasing in size through corona agglomeration.

[0051] Step S4: The purified oil returns to the fuel tank 400 from the second oil outlet 9, and the particle number detector 500 feeds back data to the PLC control module in real - time.

[0052] Step S5: The PLC adjusts the voltage and flow rate according to the feedback until the particle concentration ≤ NAS 6 level.

[0053] Among them, when the particle number detector detects that the oil at the oil outlet has particles > 5 μm, that is, the particle concentration > the NAS 6 - level standard, the PLC control module adjusts the parameters according to the following formula:

[0054] V new = V0×(1 + K p ×ΔC)

[0055] Q new = Q0×(1 - K q ×ΔC)

[0056] Where: V new is the adjusted output voltage, V0 is the initial set voltage, K p is the voltage adjustment coefficient, ΔC is the exceeded NAS level number, Q new is the adjusted flow rate, Q0 is the initial set flow rate, K q is the flow rate adjustment coefficient.

[0057] When the differential pressure sensors at the inlet and outlet detect that the differential pressure ΔP > 0.3 MPa, the PLC control module executes the backwashing program:

[0058] Step S601: Cut off the output of the high-voltage power amplifier 200;

[0059] Step S602: Close the first solenoid valve 101 and the fourth solenoid valve 104, open the second solenoid valve 102 and the third solenoid valve 103, so that the oil in the filtering device flows reversely, the oil enters from the second oil inlet 7 and is discharged from the first oil outlet 6 into the waste oil collector 107;

[0060] Step S603: Increase the flow rate to 8 - 10 L / min and last for 30 s;

[0061] Step S604: Then open the first solenoid valve 101 and the fourth solenoid valve 104, close the second solenoid valve 102 and the third solenoid valve 103, resume the forward flow and re-apply the high voltage;

[0062] Step S605: When ΔP is still > 0.25 MPa after three consecutive backwashes, trigger the filter element replacement alarm, and at this time, the detachable dust collector 3 can be removed for cleaning and replacement.

Claims

1. An electrostatic high-efficiency lubricating oil filtering device with a porous electrode, characterized in that: It includes a housing, a high-voltage electrode, a dust collecting body and a grounding electrode; the housing includes an upper end cover and a lower end cover, both the upper end cover and the lower end cover are provided with an oil inlet and an oil outlet, and the lower end cover is grounded; the grounding electrode is cylindrical; the upper end cover and the lower end cover are respectively arranged on the upper and lower sides of the grounding electrode; the dust collecting body is cylindrical and coaxially arranged with the grounding electrode; the high-voltage electrode adopts a honeycomb porous structure; the high-voltage electrode is arranged at the axial position of the grounding electrode.

2. The electrostatic high-efficiency lubricating oil filtering device with a porous electrode according to claim 1, characterized in that, The high-voltage electrode includes a conductive matrix and a surface dielectric coating; the conductive matrix is stainless steel or conductive ceramic; the surface dielectric coating is a BaTiO3 nanoparticle composite PTFE material with a porosity of 40%-60% and a pore diameter of 10-100μm.

3. An electrostatic high-efficiency lubricating oil filtering device with a porous electrode according to claim 1, characterized in that, The dust collecting body includes a filter paper and a high-voltage resistant water-impermeable film. The pores of the filter paper are not greater than 40μm. Epoxy resin is sprayed on the surface of the filter paper. The dust collecting body is wound into a cylinder by the filter paper, and the high-voltage resistant water-impermeable film is sandwiched between the layers of the filter paper.

4. An electrostatic high-efficiency lubricating oil filtering device with a porous electrode according to any one of claims 1-3, characterized in that, It also includes a control system, which includes a pump group, a particle number detector, a high-voltage power amplifier, an oil tank, a PLC control module and a flow regulating valve; the pump group is connected to the oil inlet of the lower end cover through an oil inlet pipeline, and the oil outlet is connected to the oil tank through a return oil pipeline to form a circulation loop; the particle number detector is installed on the return oil pipeline of the oil outlet and is connected to the PLC control module through a signal line; the high-voltage power amplifier is connected to the high-voltage electrode of the upper end cover through a cable; the bottom of the oil tank is connected to the inlet of the pump group through a suction oil pipeline; the PLC control module is respectively connected to the high-voltage power amplifier and the pump group motor through control lines, and the flow regulating valve is installed on the inlet pipeline of the pump group outlet and is electrically connected to the PLC control module.

5. The electrostatic high-efficiency lubricating oil filtering device with a porous electrode according to claim 4, characterized in that, The control system also includes two pressure sensors, and the two pressure sensors are respectively installed on the oil inlet pipeline and the return oil pipeline and are connected to the PLC control module through signal lines.

6. The electrostatic high-efficiency lubricating oil filtering device with a porous electrode according to claim 4, characterized in that, The control system also includes four solenoid valves, and the four solenoid valves are respectively arranged on the oil inlet and oil outlet pipelines.

7. A filtering method using an electrostatic high-efficiency lubricating oil filtering device with a porous electrode as described in any one of claims 1 to 6, characterized in that, Specifically, it includes the following steps: Step S1: Start the pump group, and the oil enters the device from the oil inlet at a flow rate of 3-5L / min; Step S2: The high-voltage power amplifier applies a voltage of 5-15kV, and the high-voltage electrode generates a non-uniform electric field to charge and polarize the particles; Step S3: The charged particles are adsorbed to the dust collecting body under the action of the electric field gradient force, and the colloidal oxides are intercepted after increasing in size through corona agglomeration; Step S4: The purified oil returns to the oil tank from the oil outlet, and the particle number detector feeds back data to the PLC control module in real time; Step S5: The PLC adjusts the voltage and flow rate according to the feedback until the particle concentration ≤ NAS 6 level.

8. A high-efficiency electrostatic lubricating oil filtering method with a porous electrode according to claim 7, characterized in that, Step S5 specifically includes: when the particle number detector detects that the oil in the oil outlet is >5μm, that is, when the particle concentration > the NAS 6 level standard, the PLC control module adjusts the parameters according to the following formula: V new = V0×(1 + K p ×ΔC) Q new = Q0×(1 - K q ×ΔC) Where: V new is the adjusted output voltage, V0 is the initial set voltage, K p is the voltage regulation coefficient, ΔC is the number of NAS levels exceeding the standard, Q new is the adjusted flow rate, Q0 is the initial set flow rate, K q is the flow rate regulation coefficient.

9. A high-efficiency electrostatic lubricating oil filtration method with a porous electrode according to claim 7, characterized in that The PLC control module also includes a backwashing program: when the pressure difference ΔP > 0.3MPa is detected by the two pressure sensors at the oil inlet and oil outlet: Step S601: Cut off the output of the high-voltage power amplifier; Step S602: Control the solenoid valve to make the oil in the filtering device flow reversely; Step S603: Increase the flow rate to 8 - 10 L / min and maintain for 30 s; Step S604: Control the solenoid valve to resume forward flow and reapply high pressure; Step S605: When ΔP is still > 0.25 MPa after three consecutive backwashes, trigger the filter element replacement alarm.

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