A method and system for purifying a mold release agent

Abstract

This invention discloses a method and system for purifying and treating release agents, belonging to the field of release agent purification and treatment. The treatment method is as follows: S1, raw release agent wastewater is introduced into a treatment tank for hydraulic cavitation treatment, while ozone is simultaneously introduced. Floating oil, waste wax, and solid particulate matter in the wastewater float to the surface of the treatment tank and overflow into a scum tank; S2, after cavitation treatment, when there is very little scum on the surface of the treatment tank, the treated liquid in the treatment tank is introduced into a media filter for further filtration. The filtered clean liquid is then transported to a supply tank; S3, when the media packing adsorbs a thick wax layer, the pressure in the filter tank reaches a threshold. Water from the circulating water tank is introduced into the filter tank to backwash the wax layer. The water containing wax after backwashing enters the circulating water tank; S4, when the wax content in the circulating water in the circulating water tank reaches a threshold, a low-temperature steel roller is used to cool the water, causing wax to precipitate onto the steel roller. The wax is scraped off and collected, and the water is reused. This invention uses hydraulic cavitation to break out and remove oil and wax from waste liquid, and further removes residual waste wax from the treated liquid through media filtration, ensuring the cleanliness of the recycled mold release agent liquid.

Description

Technical Field

[0001] This invention relates to the field of mold release agent purification, treatment, recycling and reuse, and particularly to the field of mold release agent purification based on deep dewaxing. Background Technology

[0002] Existing mold release agent recycling processes are complex, requiring the separation of oil, wax, and solid particles. The separated liquid must then be diluted to the appropriate concentration before being supplied to machine tools. Because oil and wax sometimes exist in an emulsified state, they are difficult to remove completely in one step. Often, a precision filtration system is used at the end. Precision filtration utilizes cartridge filters, which have a limited lifespan and dirt-holding capacity, often requiring frequent replacement and resulting in high maintenance costs. Furthermore, existing mold release agent waste liquid purification and recycling systems typically treat the waste liquid in a treatment tank, and then supply the treated liquid to a mixing tank for further proportioning. This requires an additional mixing tank, and the extra tank and related equipment contribute to the high overall equipment cost.

[0003] Currently, when using existing treatment equipment to recycle release fluid, the high temperature of the release process and the cavitation of the recycling equipment break down some of the emulsified wax in the release agent, causing some of the emulsified wax to precipitate as solid wax particles. These solid wax particles adhere to the pipes and inner walls of the equipment, forming a wax layer that leads to pipe blockage, reduces treatment efficiency, and lowers the quality of the workpiece. To solve the problem of solid wax accumulation, a cavitation-flotation-wax scraping technology was developed, resulting in a preliminary on-site wax removal process. However, this process can only remove large waste wax particles that float to the surface; if small waste wax particles are not removed, they will still cause blockage in the fluid supply pipes.

[0004] To further reduce investment in dewaxing equipment, decrease equipment usage and maintenance costs, and improve dewaxing efficiency, it is necessary to continue developing low-cost, simple-to-operate filtration processes for dewaxing treated release fluids. This will maintain a low concentration of solid wax, preventing significant wax accumulation and ensuring the quality of reuse. Media filtration is highly efficient at removing small particles, petroleum hydrocarbons, and waxy sludge from water. However, once the media adsorbs a large amount of contaminants, regeneration becomes difficult, requiring the removal and cleaning of the filter media. This limits the application of media filtration in release agent applications. Summary of the Invention

[0005] To address the issue of residual wax in existing mold release agent purification and reuse systems, this invention proposes a mold release agent purification method and system. The method utilizes hydraulic cavitation to break up and remove oil and wax from the waste liquid. Further filtration using a medium removes residual wax from the treated liquid, ensuring the cleanliness of the recycled mold release agent liquid. Additionally, the medium packing material can be cleaned and regenerated.

[0006] Based on the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A method for purifying a mold release agent, the method comprising the following steps:

[0008] S1. The raw wastewater of the release agent is introduced into the treatment tank and undergoes hydraulic cavitation treatment in the treatment tank. At the same time, ozone is introduced. The floating oil, waste wax and solid small particles in the wastewater float on the surface of the treatment tank and overflow into the scum tank through the overflow plate.

[0009] S2. After cavitation treatment, when there is very little scum on the surface of the treatment tank, the treatment liquid in the treatment tank is introduced into the media filter for further filtration, and the filtered clean liquid is transported to the supply tank.

[0010] S3. When the media packing adsorbs a thick wax layer, the pressure in the filter tank reaches the threshold. Close the outlet valve and open the second inlet pump to introduce water from the circulating water tank into the filter tank to backwash the wax layer. After backwashing, the water containing wax enters the circulating water tank.

[0011] S4. When the wax content in the circulating water in the circulating water tank reaches the threshold, the water is cooled by using a low-temperature steel roller, and the wax precipitates on the steel roller; the wax is scraped off and collected, and the water is reused.

[0012] Furthermore, in step S1, the raw water of the release agent wastewater is initially filtered by a pre-filter, then pumped out by the first inlet pump, filtered by a paper tape filter, and introduced into the treatment tank.

[0013] Further, in step S1, the scum containing some liquid in the scum tank is pumped by the first inlet pump through the first circuit to the paper belt filter for further filtration, and the filtrate enters the treatment tank.

[0014] Further, in step S2, the treatment liquid enters the media filter via a swirling flow, passes through the media packing from bottom to top, and the filtrate is introduced into the supply tank; the concentrated liquid is introduced into the paper tape filter for further filtration.

[0015] Furthermore, in step S3, the circulating water in the circulating water tank is hot water, and the circulating water tank uses a heater or heat exchanger to heat the circulating water.

[0016] Furthermore, in step S3, the circulating water draws in gas through the ejector to form a gas-liquid mixture, which sprays and cleans the media packing material, and the rinsing water enters the circulating water tank.

[0017] The present invention also aims to provide a mold release agent purification system, which applies the above-mentioned mold release agent purification method, and the system includes:

[0018] Raw water collection tank, used to store release agent waste liquid discharged from machine tools;

[0019] The treatment tank is connected to the raw water collection tank; the treatment tank is connected to a hydraulic cavitation system; the treatment tank is equipped with an overflow plate, which separates the treatment tank into a scum tank;

[0020] The treatment tank and the raw water collection tank are connected in sequence by an inlet pump and a paper tape filter.

[0021] A media filter is connected to the treatment tank;

[0022] A circulating water tank is connected to the media filter; the circulating water tank is connected to a heater or heat exchanger.

[0023] A first circuit is provided between the scum tank and the liquid inlet pump.

[0024] Preferably, the media filter includes: a filter tank and media packing material disposed inside the filter tank.

[0025] Preferably, the media filter further includes:

[0026] A media mesh is used to intercept the media packing material;

[0027] A hydrocyclone is disposed below the medium mesh;

[0028] The liquid is tangentially introduced into the hydrocyclone through the inlet.

[0029] The clean liquid outlet is located above the medium packing material;

[0030] An exhaust port is located below the hydrocyclone; the exhaust port is connected to the paper tape filter.

[0031] Preferably, the filter tanks are arranged in parallel, and each filter tank is connected to a circulating water tank; an ejector is provided between the circulating water tank and the filter tank; the ejector is provided with an air inlet.

[0032] Preferably, a low-temperature steel roller is provided above the circulating water tank. The low-temperature steel roller slides up and down through the circulating water tank, and when it rises, it leaves the liquid surface; when it descends to the liquid surface, it rotates at a low speed.

[0033] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0034] 1. The raw wastewater from the release agent is treated in a treatment tank using hydraulic cavitation. This breaks down the oil and solid wax in the water-in-oil state, causing them to float to the surface and overflow into a scum tank. The scum containing some liquid in the scum tank is then pumped to a paper belt filter for further filtration, achieving continuous removal of surface waste wax and oil, resulting in a high liquid reuse rate.

[0035] 2. First, remove the oil and some solid wax from the wastewater in the treatment tank through a scum tank, and then filter it through a media filter to separate the remaining wax, so that the liquid entering the supply tank has a higher purity.

[0036] 3. The release agent treatment solution is introduced into a media filter. The media filler is ceramsite. After filtration through the ceramsite, due to the porous nature of the ceramsite, it has a strong adsorption capacity for wax. The maximum adsorption capacity of each gram of ceramsite can reach 0.24g of wax. Under normal circumstances, the amount of wax adsorbed by each gram of ceramsite is 0.06-0.12g. If the water exits from the top, it has a good interception effect on the residual wax and oil in the treatment solution. If the water exits from the bottom, the ceramsite can be dispersed during backwashing, which is conducive to cleaning the ceramsite.

[0037] 4. Ceramsite can also be recycled and reused by hot water washing; in the circulating water tank, wax is further recovered by low temperature steel rollers, so that the circulating water is purified and reused, saving water; wax can also be recovered; compared with precision filters, media filters have no consumables and have very low usage and maintenance costs. Attached Figure Description

[0038] Figure 1 This is a system flow diagram of the mold release agent purification system of the present invention.

[0039] Figure 2 This is a structural flow diagram of the hydraulic cavitation treatment section of the mold release agent purification system.

[0040] Figure 3 This is a structural flow diagram of the media filter section of the mold release agent purification system in Example 1.

[0041] Figure 4 This is a structural flowchart of another embodiment of the media filter section of the mold release agent purification system in Example 1.

[0042] Figure 5 This is a structural flow diagram of the media filter section of the mold release agent purification system in Example 2.

[0043] In the diagram: 1. Raw water tank for release agent wastewater; 10. Floating suction port; 11. Valve; 12. Pre-filter; 13. First inlet pump; 2. Treatment tank; 20. Waste residue tank; 201. Valve; 21. Overflow plate; 22. Discharge pipe; 202. Valve; 23. Ozone generator; 3. Hydraulic cavitation generator; 30. High-pressure pump; 4. Paper tape filter; 5. Media filter; 51. Filter tank; 52. Media packing; 520. Media mesh; 6. Media filter; 60. Hydrocyclone; 61. Filter tank; 62. Media packing; 620. Media mesh; 63. Inlet pipe; 64. Clean liquid outlet; 65. Drain outlet; 65. Valve; 650. Valve; 651. Air outlet; 66. Supply tank; 7. Circulating water tank; 8. Second inlet pump; 80. Ejector; 81. Heater; 82. Low-temperature steel roller; 83. Proportional pump; 9. Valve; 90. Detailed Implementation

[0044] The present invention will now be further described with reference to the accompanying drawings and specific embodiments.

[0045] This invention also provides a method for deep dewaxing and purification of mold release agents, such as... Figure 1-3 As shown, the method includes the following steps:

[0046] S1. The raw wastewater of the release agent is initially filtered by a pre-filter, then pumped out by the first inlet pump, filtered by a paper belt filter, and introduced into the treatment tank. The raw wastewater of the release agent is introduced into the treatment tank and undergoes hydraulic cavitation treatment while ozone is introduced. The floating oil, waste wax, and solid small particles in the wastewater float on the surface of the treatment tank and overflow into the scum tank through the overflow plate. The scum in the scum tank with some liquid is pumped by the inlet pump through the first loop to the paper belt filter for further filtration, and the filtrate enters the treatment tank.

[0047] S2. After cavitation treatment, when there is very little scum on the surface of the treatment tank, the treatment liquid in the treatment tank is further filtered by the media filter, and the filtered clean liquid is transported to the supply tank; or the treatment liquid enters the media filter by swirling flow, passes through the media packing from bottom to top, and the filtrate is introduced into the supply tank; the concentrated liquid is introduced into the paper belt filter for further filtration.

[0048] S3. When a thick wax layer is adsorbed on the media packing, the pressure in the filter tank reaches the threshold. The outlet valve is closed, and the second inlet pump and valve are opened to introduce water from the circulating water tank into the filter tank to backwash the wax layer. The water containing wax after backwashing enters the circulating water tank. The circulating water in the circulating water tank is hot water, and the circulating water tank uses a heater or heat exchanger to heat the circulating water. The circulating water draws in gas through the ejector to form a gas-liquid mixture to spray and clean the media packing. The rinsing water enters the circulating water tank.

[0049] S4. When the wax content in the circulating water in the circulating water tank reaches the threshold, a low-temperature steel roller is used to descend to the surface of the circulating water tank to cool the water. The wax precipitates on the steel roller, is scraped off and collected, and the water is reused.

[0050] Based on the above method and process, the present invention also provides a mold release agent purification system, which is implemented according to the following embodiments.

[0051] Example 1:

[0052] like Figure 2 A mold release agent purification and treatment system includes a mold release agent waste liquid raw water collection tank 1 and a treatment tank 2. A floating suction port 10 is provided on the surface of the raw water collection tank 1. A paper tape filter 4 is connected between the raw water collection tank 1 and the treatment tank 2. A valve 11, a pre-filter 12, and an inlet pump 13 are sequentially arranged between the raw water collection tank 1 and the paper tape filter 4. An overflow plate 21 is provided in the treatment tank 2, dividing the treatment tank 2 into a scum tank 20, which has a scum outlet 22. A first loop is provided between the scum tank 20 and the inlet pump 13, and a valve 201 is provided on the first loop. Treatment tank 2 is connected to a hydraulic cavitation system. The treatment tank 2 has an inlet and an outlet for the hydraulic cavitation system. The hydraulic cavitation system includes a high-pressure pump 30 and a hydraulic cavitation generator 3 connected in sequence. The inlet is connected to the high-pressure pump 30, and the outlet is connected to the hydraulic cavitation generator. A second circuit is also provided between the inlet and the inlet pump 13, and a valve 202 is installed on the second circuit. Treatment tank 2 is also connected to an ozone generator 23, which purifies the treatment tank 2 with ozone. A proportioning pump 9 for mixing is also connected between the inlet pump 13 and the treatment tank 2, and a valve 90 is installed between the inlet pump 3 and the proportioning pump 9.

[0053] like Figure 3 The treatment tank 2 is connected to the media filter 5. A liquid discharge pump 21 and a valve are provided between the treatment tank 2 and the media filter 5. The media filter 5 includes a filter tank 51 and a media packing 52 installed in the filter tank 51. The media packing is ceramsite. A media mesh 520 for intercepting ceramsite is provided in the filter tank. The mesh pores of the media mesh are slightly smaller than the ceramsite particle size. A flow meter is installed at the outlet of the filter tank and a pressure gauge is installed at the inlet. The height of the filter media does not exceed 75% of the height of the tank.

[0054] Multiple filter tanks are connected in series. The first-stage filter tank is connected to the treatment tank 2, and the outlet of the final-stage filter tank is connected to the supply tank 7. The filter tanks are connected in series from the first-stage to the final-stage filter tank, and valves are installed between each filter tank. The system also includes a circulating water tank 8 for backwashing the filter tank packing. In backwashing mode, the filter tanks are connected in parallel. The inlet and outlet of each filter tank are connected to the main pipe of the circulating water tank 8. A second inlet pump 80 is connected between the inlet of each filter tank and the circulating water tank 8. Valves are installed between the circulating water tank 8 and the inlet of each filter tank, and valves are installed between the outlet of each filter tank and the circulating water tank 8.

[0055] During filtration, all backwash valves are closed. The treated liquid drawn from treatment tank 2 can only be filtered sequentially through the series of filter tanks, and the purified liquid is discharged to supply tank 7. During backwashing, the valves of the series filter tanks, the valve at the outlet pump 21, and the valve connecting to supply tank 7 are all closed. The backwash valves are opened, and each filter tank is flushed in the opposite direction to the filtration flow path. The flushing wastewater enters the circulating water tank 8. Backwashing each filter tank from bottom to top can disperse the ceramsite, which is beneficial for cleaning the ceramsite.

[0056] like Figure 4 An ejector 81 is provided between the circulating water tank 8 and each filter tank 51. The ejector 81 is also provided with an air inlet. The gas-liquid mixture generated by the ejector sprays the ceramic particles in the filter tank 51 from bottom to top, with a greater impact force, which is conducive to cleaning the ceramic particles.

[0057] like Figure 3 The circulating water tank 8 is also connected to a heater 82 or a heat exchanger. The heater 82 heats the circulating water tank; the heating temperature exceeds the melting point of wax (greater than 65℃), and a certain temperature is maintained to continuously rinse the ceramic particles. Due to the high water temperature, the wax layer adsorbed on the ceramic particles melts, and the wax is carried out by the hot water and returns to the circulating water tank. When the water temperature rises from 20℃ to 100℃, the surface tension drops from 72.75 to 58.6 mN / m. Utilizing the lower surface tension of the hot water, most of the wax adsorbed on the filter media can be desorbed into the water. After several rounds of circulating spraying in the filter tank, the ceramic particles are cleaned and regenerated.

[0058] like Figure 3 A low-temperature steel roller 83 is installed above the circulating water tank. The low-temperature steel roller 83 passes through the circulating water tank body and can slide up and down a certain distance. When it rises, it detaches from the liquid surface; when it descends to the liquid surface, it rotates at a low speed. When the wax content in the circulating water tank reaches a threshold, the melted wax in the water is recovered by the low-speed rotation of the low-temperature steel roller 83.

[0059] Example 2:

[0060] like Figure 5 The difference between Example 2 and Example 1 lies in the structure of the media filter. The media filter includes a filter tank 61, media packing 62 disposed within the filter tank 61, a hydrocyclone 60 at the lower part of the filter tank 61 with a tangentially directed inlet 63, a clean liquid outlet 64 above the media packing 62, and an vent 65 below the hydrocyclone 60. A media mesh 620 is disposed below the media packing 62 to intercept the media packing; the inlet 63 is located below the media mesh 620. The media mesh 620 is funnel-shaped with a downward convex center. An exhaust port 66 is also provided above the filter tank 61.

[0061] like Figure 5 The inlet 63 is connected to the treatment tank 2, and the outlet pump 21 and valve are connected between the inlet 63 and the treatment tank 2; the clean liquid outlet 64 is connected to the supply tank 7, and the drain port 65 is connected to the paper tape filter 4; a valve 650 is provided between the drain port 65 and the paper tape filter 4.

[0062] The filter utilizes a media filter filled with ceramsite. Due to the porous nature of ceramsite, it has a strong adsorption capacity for wax, with a maximum adsorption capacity of 0.24g wax per gram of ceramsite. Under normal circumstances, the amount of wax adsorbed per gram of ceramsite is 0.06-0.12g. The water exits from the top, and the filtration rate is generally 2-12 m / h. This filter effectively traps residual wax and oil in the treated liquid.

[0063] like Figure 5 The system also includes a circulating water tank 8 for backwashing the media packing. The circulating water tank 8 is connected to the clean liquid outlet 64, and the drain port 65 is connected to the circulating water tank 8. A second inlet pump 80 and a valve are installed between the circulating water tank 8 and the clean liquid outlet 64. A valve 651 is connected between the drain port 65 and the circulating water tank 8. The flushing water washes the media packing from top to bottom.

[0064] How it works in Example 2:

[0065] like Figure 5 The treated liquid, after cavitation treatment in treatment tank 2, is introduced into media filter 6. The media filter contains ceramic particles. During media filtration, valves 650 and 651 can be closed, allowing liquid to pass only through the clean liquid outlet 64, maximizing filtration. The clean liquid is then introduced into supply tank 7. Valve 650 is opened periodically to discharge the concentrated liquid above the paper belt filter 4, where it is filtered again before entering treatment tank 2. When a certain thickness of wax layer is adsorbed on the ceramic particles in filter tank 62, the flow rate at the clean liquid outlet 64 decreases, indicating blockage of the ceramic particle packing. The outlet pump 21 is closed, valve 650 is opened to empty the filter tank, then valve 650 is closed again, and valve 651 is opened. The second inlet pump 80 introduces circulating water from the circulating water tank into the filter tank 61 to rinse the ceramic particles. The wax-containing wastewater is returned to the circulating water tank, and the filter tank can be rinsed repeatedly.

[0066] A heater is installed in the circulating water tank 8 to heat the circulating water to a temperature exceeding the melting point of wax (greater than 65℃). Maintaining this temperature, the water continuously washes the ceramic particles. Due to the high water temperature, the wax layer adsorbed on the ceramic particles melts and is carried away by the hot water, returning to the circulating water tank. This process of repeated spraying and rinsing of the filter tank cleans the ceramic particles and regenerates them.

[0067] Once the wax content in the circulating water tank reaches a threshold, the low-temperature steel roller descends to the liquid surface to recover the molten wax in the water. The low-temperature steel roller rotates slowly, making full contact with the circulating water containing wax. The solid wax in the water is adsorbed onto the low-temperature steel roller and solidified by cooling. Then, the low-temperature steel roller is raised to scrape off the solid wax.

[0068] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for purifying and treating a release agent, characterized in that, The processing method includes the following steps: S1. The raw wastewater of the release agent is introduced into the treatment tank and undergoes hydraulic cavitation treatment in the treatment tank. At the same time, ozone is introduced. The floating oil, waste wax and solid small particles in the wastewater float on the surface of the treatment tank and overflow into the scum tank. S2. After cavitation treatment, when there is very little scum on the surface of the treatment tank, the treatment liquid in the treatment tank is introduced into the media filter for further filtration, and the filtered clean liquid is transported to the supply tank. S3. When the media packing adsorbs a thick wax layer, the pressure in the filter tank reaches the threshold. Close the outlet valve and open the second inlet pump to introduce water from the circulating water tank into the filter tank to backwash the wax layer. After backwashing, the water containing wax enters the circulating water tank. S4. When the wax content in the circulating water in the circulating water tank reaches the threshold, the water is cooled by using a low-temperature steel roller, and the wax precipitates on the steel roller; the wax is scraped off and collected, and the water is reused.

2. The method for purifying and treating a release agent according to claim 1, characterized in that, In step S1, the raw water of the release agent wastewater is initially filtered by a pre-filter, then pumped out by the first inlet pump, filtered by a paper tape filter, and introduced into the treatment tank.

3. The method for purifying and treating a release agent according to claim 1, characterized in that, In step S1, the scum containing some liquid in the scum tank passes through the first circuit and is pumped by the first inlet pump to the paper tape filter for further filtration, and the filtrate enters the treatment tank.

4. The method for purifying and treating a release agent according to claim 1, characterized in that, In step S2, the treatment liquid enters the media filter via a swirling flow, passes through the media packing from bottom to top, and the filtrate is introduced into the supply tank; the concentrated liquid is introduced into the paper tape filter for further filtration.

5. The method for purifying and treating a release agent according to claim 1, characterized in that, In step S3, the circulating water in the circulating water tank is hot water, and the circulating water tank uses a heater or heat exchanger to heat the circulating water.

6. The method for purifying and treating a release agent according to claim 1, characterized in that, In step S3, circulating water draws in gas through an ejector to form a gas-liquid mixture, which sprays and cleans the media packing material. The rinsing water then enters the circulating water tank.

7. A mold release agent purification system, employing the mold release agent purification method according to any one of claims 1-6, characterized in that, The processing system includes: Raw water collection tank, used to store release agent waste liquid discharged from machine tools; The treatment tank is connected to the raw water collection tank; the treatment tank is connected to a hydraulic cavitation system; the treatment tank is equipped with an overflow plate, which separates the treatment tank into a scum tank; The treatment tank and the raw water collection tank are connected in sequence by an inlet pump and a paper tape filter. A media filter is connected to the treatment tank; A circulating water tank is connected to the media filter; the circulating water tank is connected to a heater or heat exchanger. A first circuit is provided between the scum tank and the liquid inlet pump.

8. The mold release agent purification system according to claim 7, characterized in that, The media filter includes: a filter tank and media packing material disposed inside the filter tank.

9. The mold release agent purification system according to claim 8, characterized in that, The media filter further includes: A media mesh is used to intercept the media packing material; A hydrocyclone is disposed below the medium mesh; The liquid is tangentially introduced into the hydrocyclone through the inlet. The clean liquid outlet is located above the medium packing material; An exhaust port is located below the hydrocyclone; the exhaust port is connected to the paper tape filter.

10. The mold release agent purification system according to claim 8, characterized in that, The filter tanks are arranged in parallel, and each filter tank is connected to a circulating water tank; an ejector is provided between the circulating water tank and the filter tank; the ejector is provided with an air inlet.

11. The mold release agent purification system according to claim 7, characterized in that, A low-temperature steel roller is provided above the circulating water tank. The low-temperature steel roller slides up and down through the circulating water tank, and when it rises, it leaves the liquid surface; when it descends to the liquid surface, it rotates at a low speed.

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