A cutting fluid purification and recycling device

Abstract

The utility model provides a kind of purification and recycling device of cutting fluid, it is specifically related to cutting fluid recycling technical field, to solve the defect of cutting fluid purification technology in prior art.The device includes the pretreatment unit, demulsification unit and separation unit sequentially communicated along cutting fluid processing path;The inlet of pretreatment unit receives cutting fluid to be handled, and outlet is communicated with the inlet of demulsification unit;Demulsification unit is closed cavity, and the inside of closed cavity is equipped with the flow guide mechanism for forming spiral flow field and the aeration mechanism for introducing gas, and outlet is communicated with the inlet of separation unit;Separation unit includes multiple separation chambers connected in series, and its final outlet is used to output purified cutting fluid;Further including control unit.The device is synergistically designed by staged filtration, intensified demulsification, gradient separation and intelligent control, realizes the efficient removal of metal particles and emulsified oil in cutting fluid, and the oil content and granularity of purified cutting fluid meet the requirements of mechanical processing reuse.

Description

Technical Field

[0001] This utility model relates to the field of cutting fluid recycling technology, and more specifically, to a device for purifying and reusing cutting fluid. Background Technology

[0002] Cutting fluid is a key auxiliary material used in machining processes to cool cutting tools, lubricate machined surfaces, prevent rust, and remove chips. Its performance directly affects machining accuracy, tool life, and production efficiency. With the development of green manufacturing and the circular economy, the recycling and reuse of cutting fluid has become an important means to reduce production costs and environmental pollution. Direct discharge not only wastes resources, but the impurities it contains, such as metal shavings, emulsified oil, and microbial metabolites, can also seriously pollute water bodies and soil.

[0003] Existing cutting fluid purification technologies mainly include physical filtration, chemical demulsification, and gravity separation. However, these methods have the following shortcomings in practical applications: 1. During pretreatment, traditional filtration methods often employ single-stage filters or centrifugal separation, which can only remove large particulate impurities and have poor retention effects on micron-sized fine particles and colloidal contaminants, leading to excessive load on subsequent processing units. 2. For emulsified oils, demulsification often relies on chemical agents. While these can disrupt the stability of the oil-water interface, they introduce new chemical substances, altering the cutting fluid composition and reducing its reusability. Furthermore, agent residues can easily cause secondary pollution. Traditional physical demulsification methods, such as heating and stirring, suffer from high energy consumption and poor demulsification effects. 3. Existing oil-water separation methods often employ single air flotation or membrane filtration technologies. Air flotation is ineffective at removing fine oil droplets, while membrane filtration is prone to membrane fouling due to oil droplet adhesion. Utility Model Content

[0004] The purpose of this invention is to provide a device for purifying and reusing cutting fluid, which can solve the defects of existing cutting fluid purification technologies.

[0005] The embodiments of this utility model are achieved through the following technical solutions:

[0006] A cutting fluid purification and reuse device includes a pretreatment unit, a demulsification unit, and a separation unit connected sequentially along the cutting fluid treatment path. The inlet of the pretreatment unit receives the cutting fluid to be treated, and its outlet is connected to the inlet of the demulsification unit. The demulsification unit is a closed cavity, and the interior of the closed cavity is provided with a flow guiding mechanism for forming a spiral flow field and a venting mechanism for introducing gas. Its outlet is connected to the inlet of the separation unit. The separation unit includes multiple separation chambers connected in series, and its final outlet is used to output the purified cutting fluid. The device also includes a control unit electrically connected to the pretreatment unit, the demulsification unit, and the separation unit respectively.

[0007] In some embodiments, the pretreatment unit includes at least two stages of filtration components, each stage of which is connected in series along the flow direction of the cutting fluid and has progressively increasing filtration accuracy. It includes a coarse filter and a fine filter arranged sequentially along the flow direction of the cutting fluid. The coarse filter is a magnetic filtration structure, which includes a cylindrical shell with a uniformly distributed array of magnets circumferentially surrounding its inner wall. The fine filter is a membrane filtration structure, which includes a cylindrical body with several ceramic membrane tubes arranged parallel to each other along the axial direction inside. The top of the cylindrical body has a raw liquid inlet communicating with the cylindrical shell, and the bottom has a filtrate outlet communicating with the demulsification unit inlet.

[0008] In some embodiments, the pretreatment unit further includes a backwashing assembly, which includes a backwashing pipeline disposed below the membrane filtration structure. The inlet end of the backwashing pipeline is connected to the cleaning liquid output end of the separation unit via a control valve, and the outlet end of the backwashing pipeline is connected to the bottom of the cylinder. The control valve is electrically connected to the control unit.

[0009] In some embodiments, the demulsifying unit's flow guiding mechanism includes spiral guide vanes distributed circumferentially along the inner wall of the enclosed cavity, the spiral guide vanes extending downward along the axial direction of the enclosed cavity; a power assembly is connected to the upper end of the spiral guide vanes, the power assembly is fixed to the top outer side of the enclosed cavity, and its output shaft passes through the top wall of the enclosed cavity and is drively connected to the spiral guide vanes; the top wall of the enclosed cavity is detachably connected to the cylindrical section of the enclosed cavity.

[0010] In some embodiments, the flow guiding mechanism further includes a flow guiding cylinder located at the center of the enclosed cavity. The flow guiding cylinder is a cylindrical body with open ends and is vertically fixed at the center of the enclosed cavity. Its upper end extends and is fixed to the inner side of the hollow output shaft of the power assembly, and its lower end extends into the contraction section at the bottom of the enclosed cavity. The lower end of the flow guiding cylinder maintains a preset distance from the bottom of the contraction section to form a vortex zone. The contraction section is a variable diameter structure, which includes an upper conical section and a lower conical section from top to bottom. The taper of the upper conical section is greater than that of the lower conical section. The large-diameter end of the upper conical section is connected to the cylindrical section of the enclosed cavity, and the small-diameter end of the upper conical section smoothly transitions to the large-diameter end of the lower conical section.

[0011] In some embodiments, the ventilation mechanism includes a ventilation pipe that penetrates the center of the bottom of the enclosed cavity. The outlet end of the ventilation pipe is located inside the guide tube and is correspondingly positioned below a perforated plate inside the guide tube. The perforated plate is horizontally fixed to the inner wall of the guide tube, and its surface is uniformly distributed with multiple through holes for dispersing gas to form microbubbles. The inlet end of the ventilation pipe is connected to a gas regulating component. The gas regulating component includes an air compressor, a flow controller, and a proportional valve connected in sequence via pipelines. The proportional valve is connected to the inlet end of the ventilation pipe via a pipeline. The gas regulating component is electrically connected to a control unit.

[0012] In some embodiments, the series-connected separation chambers of the separation unit include an air flotation chamber, a coalescing chamber, and a membrane separation chamber that are connected sequentially in the horizontal direction. A partition with adjustable height by an electric push rod is vertically arranged between the air flotation chamber and the coalescing chamber, and between the coalescing chamber and the membrane separation chamber. A flow passage is formed between the bottom of the partition and the inner bottom of the separation chamber. The electric push rod is electrically connected to the control unit.

[0013] In some embodiments, the top of the flotation chamber is provided with a purging assembly and an oil skimming assembly. The purging assembly includes a porous air pipe embedded in the inner wall of the flotation chamber. One end of the porous air pipe is connected to an external air pump station, and the air outlet direction of the porous air pipe is parallel to the liquid surface. The scraper of the oil skimming assembly moves horizontally along the liquid surface to scrape the floating oil into a first oil collection tank inside the chamber. The bottom of the first oil collection tank is connected to the oil drain pipe outside the separation chamber. The coalescence chamber is filled with oleophilic and hydrophobic filler. The top of the inner side of the coalescence chamber is provided with a second oil collection tank whose bottom is connected to the oil drain pipe. The membrane separation chamber is equipped with a separation membrane assembly, which is located above the flow channel. The final outlet is located on the side wall of the membrane separation chamber and above the separation membrane assembly.

[0014] In some embodiments, the oil scraping assembly includes two parallel annular chains; the annular chains are arranged on both sides of the liquid surface along the length of the air flotation cavity, and a plurality of scrapers are fixedly arranged laterally between the two annular chains, with the bottom edge of the scrapers contacting the liquid surface inside the air flotation cavity; the inner ends of the air flotation cavity are respectively rotatably connected to a drive sprocket and a driven sprocket via a bracket, and each annular chain is sleeved on the corresponding drive sprocket and driven sprocket, and a motor is driven by the drive sprocket to drive the chain to circulate.

[0015] In some embodiments, a reflux pipeline is provided between the separation unit and the pretreatment unit. One end of the reflux pipeline is connected to the separation chamber located at the end of the separation unit, and the other end is connected to the inlet of the pretreatment unit. A turbidity sensor is provided on the reflux pipeline, and the turbidity sensor is electrically connected to the control unit.

[0016] The technical solution of this utility model embodiment has at least the following advantages and beneficial effects:

[0017] 1. This device employs a two-stage filtration system in its pretreatment unit. The coarse filter uses a magnetic array to adsorb large ferromagnetic particles, while the fine filter utilizes ceramic membrane tubes to trap micron-sized particles, achieving graded filtration from macro to micro. Furthermore, a backwashing assembly is incorporated, using the purified liquid output from the separation unit to backwash the ceramic membrane tubes. When a differential pressure sensor detects membrane fouling, the backwashing assembly automatically activates, resolving membrane clogging issues, maintaining filtration efficiency, and extending service life. This overcomes the technical limitations of traditional single-stage filtration, which can only remove large particles while exhibiting poor fine particle retention and clogging.

[0018] 2. In this device, the demulsification unit achieves synergistic demulsification through mechanical shearing and air flotation. The spiral guide vanes rotate under the drive of a servo motor, causing the cutting fluid to form a spiral flow. After acceleration in the contraction section, strong shearing force is generated in the vortex region, disrupting the interfacial stability of the emulsified oil droplets. The vent pipe releases microbubbles through a perforated plate. These bubbles carry oil droplets to the surface, and the localized high pressure during bubble bursting further assists in demulsification, eliminating the need for chemical agents. Furthermore, the contraction section employs a double-tapered variable-diameter structure; the larger taper at the top accelerates the fluid, while the smaller taper at the bottom maintains the vortex intensity, ensuring efficient demulsification of emulsions of varying viscosities. This results in lower energy consumption compared to traditional physical heating demulsification methods.

[0019] 3. In this device, the separation unit uses the air flotation chamber, coalescence chamber and membrane separation chamber in the separation chamber to carry out gradient purification, thereby taking into account the removal of floating oil, fine oil droplets and particles. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of a cutting fluid purification and reuse device provided in an embodiment of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the coarse filter element in the pretreatment unit provided in the embodiment of this utility model;

[0023] Figure 3 This is a top view of the internal structure of the coarse filter element in the pretreatment unit provided in the embodiment of this utility model;

[0024] Figure 4This is a schematic diagram of the structure of the fine filter element in the pretreatment unit provided in the embodiment of this utility model;

[0025] Figure 5 This is a top view of the internal structure of the fine filter element in the pretreatment unit provided in the embodiment of this utility model;

[0026] Figure 6 This is a schematic diagram of the demulsifying unit provided in an embodiment of the present invention;

[0027] Figure 7 This is a top view of the perforated plate provided in an embodiment of the present invention;

[0028] Figure 8 This is a schematic diagram of the separation unit provided in an embodiment of the present invention;

[0029] Figure 9 Top view of the structure of the first and second oil collecting tanks provided in the embodiments of this utility model;

[0030] Figure 10 This is a schematic diagram of the oil scraping assembly provided in an embodiment of the present invention.

[0031] Icons: 1. Enclosed cavity; 2. Cylindrical shell; 3. Magnet array; 4. Cylinder; 5. Ceramic membrane tube; 6. Raw material inlet; 7. Filtrate outlet; 8. Backflushing pipeline; 9. Control valve; 10. Spiral guide vane; 11. Power assembly; 12. Top wall; 13. Cylindrical section; 14. Guide tube; 15. Upper conical section; 16. Lower conical section; 17. Vent pipe; 18. Perforated plate; 19. Through hole; 20. Air compressor; 21. Flow controller; 22. Specific ratio Example valve; 23. Air flotation chamber; 24. Coalescing chamber; 25. Membrane separation chamber; 26. Baffle; 27. Electric actuator; 28. Porous air pipe; 29. ​​Air pump station; 30. First oil collection tank; 31. Oil discharge pipe; 32. Oleophilic and hydrophobic packing; 33. Second oil collection tank; 34. Separation membrane module; 35. Final outlet; 36. Annular chain; 37. Scraper; 38. Drive sprocket; 39. Driven sprocket; 40. Motor; 41. Return pipeline; 42. Turbidity sensor. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0035] In the description of this utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0036] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0037] Please see Figures 1-10 As shown, the main body of this embodiment is a cutting fluid purification and reuse device. Along the cutting fluid treatment path, it sequentially includes a pretreatment unit, a demulsification unit, a separation unit, and a control unit electrically connected to the above units. After the pretreatment unit removes solid impurities of different particle sizes, the cutting fluid enters the demulsification unit for emulsification treatment of the emulsified oil. Then, the separation unit achieves deep separation of oil and water and fine particles through multiple chambers. Finally, the purified cutting fluid is reused through the final outlet 35 of the separation unit. The control unit monitors the operating parameters of each unit in real time and regulates the coordinated operation of the execution components to form a closed-loop purification system.

[0038] Furthermore, the pretreatment unit is used to remove solid particulate impurities from the cutting fluid in stages. Its inlet is connected to the cutting fluid collection tank through a pipeline, and its outlet is connected to the inlet of the demulsification unit through a pipeline. Specifically, it includes a filtration assembly, in which coarse filter elements and fine filter elements are connected in series along the flow direction of the cutting fluid, with the filtration accuracy increasing sequentially.

[0039] The coarse filter element is a magnetic filtration structure, including a cylindrical shell 2 with a uniformly distributed array of magnets around its inner wall. The magnet array is made of neodymium iron boron material and is used to adsorb ferromagnetic metal debris in the cutting fluid. The cutting fluid flows in from the top inlet of the shell, is adsorbed by the magnet array, and then flows into the fine filter element from the bottom outlet.

[0040] The fine filter element is a membrane filtration structure, including a cylindrical body 4, inside which several ceramic membrane tubes 5 are fixedly arranged in parallel along the axial direction; the top of the cylindrical body 4 is provided with a raw liquid inlet 6, which is connected to the bottom outlet of the coarse filter element through a pipeline; the bottom of the cylindrical body 4 is provided with a filtrate outlet 7, which is connected to the inlet of the demulsification unit through a pipeline; after the cutting fluid is filtered by the ceramic membrane tubes 5, micron-sized fine particles such as aluminum and copper powder are retained, and the clear liquid is discharged from the filtrate outlet 7.

[0041] Furthermore, the backwashing assembly includes a backwash line 8 and a control valve 9. The inlet end of the backwash line 8 is connected to the cleaning liquid output end of the separation unit, i.e., the final outlet 35 of the membrane separation chamber 25, via the control valve 9. The outlet end of the backwash line 8 is connected to the bottom of the cylinder 4 of the fine filter element. The control valve 9 is a solenoid directional valve and is electrically connected to the control unit. When the pressure difference between the inlet and outlet of the fine filter element reaches a preset threshold, the control unit drives the control valve 9 to open. The purified liquid output by the separation unit backwashes the ceramic membrane tube 5 through the backwash line 8 to remove membrane pore blockages. The flushing wastewater is discharged from the drain valve between the coarse filter element and the fine filter element.

[0042] Furthermore, the demulsification unit is a closed cavity 1 made of 304 stainless steel. Its inlet is connected to the filtrate outlet 7 of the pretreatment unit, and the outlet is connected to the inlet of the air flotation chamber 23 of the separation unit through a pipe. The interior is equipped with a flow guiding mechanism and a ventilation mechanism.

[0043] The flow guiding mechanism includes a spiral guide vane 10, a flow guiding cylinder 14, and a contraction section.

[0044] The spiral guide vanes 10 are distributed circumferentially along the inner wall of the enclosed cavity 1 and extend downward in a spiral shape along the axial direction of the cavity. The upper end of the spiral guide vanes 10 is connected to the power assembly 11, which is a servo motor. The power assembly 11 is fixed on the outer side of the top of the cavity, and its output shaft passes through the top wall 12 of the cavity and is connected to the spiral guide vanes 10 for transmission. The output shaft and the top wall 12 of the enclosed cavity 1 are sealed by a mechanical seal, which can drive the guide vanes to rotate. The top wall 12 of the enclosed cavity 1 is detachably connected to the cylindrical section 13 by a flange, which facilitates the maintenance of internal components.

[0045] The guide tube 14 is a cylindrical body with openings at both ends, vertically fixed at the center of the cavity, with the upper end extending and fixed to the inner side of the hollow output shaft of the power assembly 11, and the lower end extending into the contraction section at the bottom of the cavity; the lower end of the guide tube 14 maintains a preset distance from the bottom of the contraction section to form a vortex zone.

[0046] The contraction section is a variable diameter structure, consisting of an upper conical section 15 with a taper of 60° and a lower conical section 16 with a taper of 30° from top to bottom. The large diameter end of the upper conical section 15 is welded to the cylindrical section 13 of the cavity, and its small diameter end smoothly transitions to the large diameter end of the lower conical section 16, ensuring that the fluid forms a stable spiral flow during the contraction process.

[0047] The ventilation mechanism includes a ventilation pipe 17, a perforated plate 18, and a gas conditioning component.

[0048] The vent pipe 17 passes through the center of the bottom of the cavity, and the air outlet is located inside the guide tube 14 and is correspondingly positioned below the perforated plate 18. The perforated plate 18 is horizontally welded to the inner wall of the guide tube 14, and its surface is evenly distributed with through holes 19 for dispersing gas to form microbubbles.

[0049] The gas regulating component includes an air compressor 20, a flow controller 21, and a proportional valve 22 connected in sequence via pipelines. The proportional valve 22 is connected to the air inlet end of the vent pipe 17 via a pipeline. The gas regulating component is electrically connected to the control unit and can dynamically adjust the air intake according to the cutting fluid flow rate.

[0050] Furthermore, the separation unit includes a separation chamber comprising a flotation chamber 23, a coalescing chamber 24, and a membrane separation chamber 25 connected sequentially in a horizontal direction. Adjacent chambers are separated by a vertical partition 26, and the final outlet 35 is located on the side wall of the membrane separation chamber 25. A flow channel is formed between the bottom of the partition 26 and the bottom of the inner side of the chamber; an electric push rod 27 is connected to the top of the partition 26, and the top of the electric push rod 27 is fixedly connected to the top of the separation chamber and electrically connected to the control unit, thereby changing the cross-sectional area of ​​the flow channel by adjusting the height of the partition 26.

[0051] The top of the flotation chamber 23 is equipped with a purging assembly and an oil scraping assembly. The purging assembly includes a porous air pipe 28 embedded in the inner wall of the flotation chamber 23. One end of the air pipe is connected to an external air pump station 29. Air outlets are evenly distributed along the length of the pipe wall, with the air outlet direction parallel to the liquid surface, used to blow floating oil towards the first oil collection tank 30. The oil scraping assembly includes two parallel annular chains 36, arranged along the length of the flotation chamber 23 on both sides of the liquid surface. Several oil-resistant rubber scrapers 37 are horizontally fixed between the two chains, with the bottom edge of the scrapers 37 in contact with the liquid surface. The two ends of the inner side of the flotation chamber 23 are rotatably connected to a drive sprocket 38 and a driven sprocket 39 through a bracket. The chain is sleeved on the sprocket. The drive sprocket 38 is connected to a motor 40 for transmission, driving the chain to circulate. The scrapers 37 move with the chain, scraping the floating oil to the first oil collection tank 30 inside the chamber. The bottom of the first oil collection tank 30 is connected to an external oil drain pipe 31 through a pipeline, thereby discharging the floating oil.

[0052] The bottom of the coalescence chamber 24 is filled with an oleophilic and hydrophobic filler 32, such as a polypropylene fiber layer; a second oil collection trough 33 is provided on the top of the inner side of the chamber, and the bottom of the second oil collection trough 33 is connected to the oil discharge pipe 31 of the air flotation chamber 23 through a pipeline to collect the oil droplets that float after coalescence.

[0053] The membrane separation chamber 25 is equipped with a separation membrane assembly 34, which is made of polytetrafluoroethylene hollow fiber membrane. The separation membrane assembly 34 is arranged vertically above the flow channel. The final outlet 35 is located on the side wall of the membrane separation chamber 25, above the membrane assembly, and is connected to the cutting fluid recovery tank for outputting purified cutting fluid.

[0054] It is worth mentioning that the control unit includes a PLC controller, such as a Siemens S7-1200 PLC processor, which is electrically connected to the differential pressure sensor installed at the inlet and outlet of the fine filter element, the flow controller 21 of the demulsification unit, the electric push rod 27 of the separation unit, and the turbidity sensor 42, respectively, and can realize parameter monitoring and automatic adjustment functions.

[0055] One end of the return pipeline 41 is connected to the bottom of the membrane separation chamber 25, and the other end is connected to the inlet of the pretreatment unit. The pipeline is equipped with a turbidity sensor 42 and an electric ball valve that are electrically connected to the control unit. When the turbidity of the liquid at the bottom of the membrane separation chamber 25 exceeds a preset threshold, the control unit opens the electric ball valve to return the substandard liquid to the pretreatment unit for reprocessing, ensuring the quality of the reused cutting fluid.

[0056] The working process of this device

[0057] The cutting fluid to be treated first enters the pretreatment unit, where ferromagnetic particles are adsorbed by the magnetic array of the coarse filter, and fine particles are intercepted by the ceramic membrane tube 5 of the fine filter. The backwashing component periodically cleans the membrane tube blockage. The pretreated clear liquid enters the demulsification unit, where a spiral flow is formed under the drive of the spiral guide plate 10. After being accelerated in the contraction section, strong shear force is generated in the vortex zone. At the same time, gas is introduced by the ventilation mechanism and dispersed into microbubbles by the porous plate 18, which synergistically destroys the emulsion structure. The demulsified mixture enters the air flotation chamber 23 of the separation unit, where the purging component and oil scraping component remove floating oil. The lower layer liquid enters the coalescence chamber 24 through the flow channel at the bottom of the partition 26, where residual oil droplets coalesce through the oleophilic and hydrophobic packing 32. The treated liquid flows into the membrane separation chamber 25, where it is filtered by the membrane module. The purified liquid is reused from the final outlet 35, and the unqualified liquid is returned to the pretreatment unit through the return pipeline 41. The control unit monitors the parameters of each link throughout the process and dynamically adjusts the actuators to ensure stable system operation.

[0058] This embodiment achieves efficient removal of metal particles and emulsified oil from cutting fluid through a synergistic design of graded filtration, enhanced demulsification, gradient separation, and intelligent control. The oil content and particle size of the purified cutting fluid meet the requirements for reuse in machining, significantly reducing production costs and environmental pollution.

[0059] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A device for purifying and reusing cutting fluid, characterized in that, The system includes a pretreatment unit, a demulsification unit, and a separation unit connected sequentially along the cutting fluid treatment path; the inlet of the pretreatment unit receives the cutting fluid to be treated, and the outlet is connected to the inlet of the demulsification unit; the demulsification unit is a closed cavity (1), and the interior of the closed cavity (1) is provided with a flow guiding mechanism for forming a spiral flow field and a venting mechanism for introducing gas, and the outlet is connected to the inlet of the separation unit; the separation unit includes multiple separation chambers connected in series, and its final outlet (35) is used to output the purified cutting fluid; it also includes a control unit that is electrically connected to the pretreatment unit, the demulsification unit, and the separation unit respectively.

2. The cutting fluid purification and reuse device according to claim 1, characterized in that, The pretreatment unit includes at least two stages of filtration components. Each stage of the filtration components is connected in series along the flow direction of the cutting fluid, and the filtration accuracy increases sequentially. It includes a coarse filter and a fine filter arranged sequentially along the flow direction of the cutting fluid. The coarse filter is a magnetic filtration structure, which includes a cylindrical shell (2). The inner wall of the cylindrical shell (2) is circumferentially surrounded by a magnet array (3). The fine filter is a membrane filtration structure. The membrane filtration structure includes a cylinder (4). Several ceramic membrane tubes (5) are fixedly arranged in parallel along the axial direction inside the cylinder (4). The top of the cylinder (4) is provided with a raw liquid inlet (6) that communicates with the cylindrical shell (2), and the bottom is provided with a filtrate outlet (7) that communicates with the demulsification unit inlet.

3. The cutting fluid purification and reuse device according to claim 2, characterized in that, The pretreatment unit also includes a backwashing assembly, which includes a backwashing pipe (8) disposed below the membrane filtration structure. The inlet end of the backwashing pipe (8) is connected to the cleaning liquid output end of the separation unit via a control valve (9). The outlet end of the backwashing pipe (8) is connected to the bottom of the cylinder (4). The control valve (9) is electrically connected to the control unit.

4. The cutting fluid purification and reuse device according to claim 1, characterized in that, The demulsifying unit includes a spiral guide vane (10) distributed circumferentially along the inner wall of the closed cavity (1). The spiral guide vane (10) extends downward along the axial direction of the closed cavity (1). A power assembly (11) is connected to the upper end of the spiral guide vane (10). The power assembly (11) is fixed on the top outer side of the closed cavity (1), and its output shaft passes through the top wall (12) of the closed cavity (1) and is connected to the spiral guide vane (10) in a transmission connection. The top wall (12) of the closed cavity (1) is detachably connected to the cylindrical section (13) of the closed cavity (1).

5. The cutting fluid purification and reuse device according to claim 4, characterized in that, The flow guiding mechanism also includes a flow guiding cylinder (14) located at the center of the closed cavity (1). The flow guiding cylinder (14) is a cylindrical body with open ends and is vertically fixed at the center of the closed cavity (1). Its upper end extends and is fixed to the inner side of the hollow output shaft of the power assembly (11), and its lower end extends into the contraction section at the bottom of the closed cavity (1). The lower end of the flow guiding cylinder (14) maintains a preset distance from the bottom of the contraction section to form a vortex zone. The contraction section is a variable diameter structure, which includes an upper conical section (15) and a lower conical section (16) from top to bottom. The taper of the upper conical section (15) is greater than that of the lower conical section (16). The large diameter end of the upper conical section (15) is connected to the cylindrical section (13) of the closed cavity (1), and the small diameter end of the upper conical section (15) smoothly transitions to the large diameter end of the lower conical section (16).

6. The cutting fluid purification and reuse device according to claim 5, characterized in that, The ventilation mechanism includes a ventilation pipe (17) that passes through the center of the bottom of the closed cavity (1). The outlet end of the ventilation pipe (17) is located inside the guide tube (14) and is correspondingly arranged below the perforated plate (18) inside the guide tube (14). The perforated plate (18) is horizontally fixed to the inner wall of the guide tube (14). The surface of the perforated plate (18) is evenly distributed with multiple through holes (19) for dispersing gas to form microbubbles. The inlet end of the ventilation pipe (17) is connected to a gas regulating component. The gas regulating component includes an air compressor (20), a flow controller (21), and a proportional valve (22) connected in sequence through a pipeline. The proportional valve (22) is connected to the inlet end of the ventilation pipe (17) through a pipeline. The gas regulating component is electrically connected to the control unit.

7. The cutting fluid purification and reuse device according to claim 1, characterized in that, The separation unit comprises a series of separation chambers including an air flotation chamber (23), a coalescing chamber (24), and a membrane separation chamber (25) connected in sequence in the horizontal direction. A partition (26) with adjustable height by an electric push rod (27) is vertically arranged between the air flotation chamber (23) and the coalescing chamber (24), and between the coalescing chamber (24) and the membrane separation chamber (25). A flow passage is formed between the bottom of the partition (26) and the inner bottom of the separation chamber. The electric push rod (27) is electrically connected to the control unit.

8. The cutting fluid purification and reuse device according to claim 7, characterized in that, The air flotation chamber (23) is equipped with a purging assembly and an oil scraping assembly at its top. The purging assembly includes a porous air pipe (28) embedded in the inner wall of the air flotation chamber (23). One end of the porous air pipe (28) is connected to an external air pump station (29), and the air outlet direction of the porous air pipe (28) is parallel to the liquid surface. The scraper (37) of the oil scraping assembly moves horizontally along the liquid surface to scrape the floating oil into the first oil collection tank (30) inside the chamber. The bottom of the first oil collection tank (30) is connected to the outlet outside the separation chamber. The oil pipe (31) is connected; the coalescence chamber (24) is filled with oleophilic and hydrophobic filler (32), and the top of the inner side of the coalescence chamber (24) is provided with a second oil collection tank (33) whose bottom is connected to the oil drain pipe (31); the membrane separation chamber (25) is equipped with a separation membrane assembly (34), the separation membrane assembly (34) is located above the flow channel, and the final outlet (35) is located on the side wall of the membrane separation chamber (25) and above the separation membrane assembly (34).

9. A cutting fluid purification and reuse device according to claim 8, characterized in that, The oil scraping assembly includes two parallel annular chains (36); the annular chains (36) are arranged on both sides of the liquid surface along the length direction of the air flotation cavity (23), and several scrapers (37) are fixedly arranged laterally between the two annular chains (36). The bottom edge of the scraper (37) is in contact with the liquid surface inside the air flotation cavity (23); the two ends of the inner side of the air flotation cavity (23) are respectively rotatably connected to the drive sprocket (38) and the driven sprocket (39) through the bracket. Each annular chain (36) is sleeved on the corresponding drive sprocket (38) and the driven sprocket (39). The motor (40) is connected to the drive sprocket (38) to drive the chain to circulate.

10. A cutting fluid purification and reuse device according to claim 1, characterized in that, A reflux pipeline (41) is provided between the separation unit and the pretreatment unit. One end of the reflux pipeline (41) is connected to the separation chamber located at the end of the separation unit, and the other end is connected to the inlet of the pretreatment unit. A turbidity sensor (42) is provided on the reflux pipeline (41), and the turbidity sensor (42) is electrically connected to the control unit.

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