A process and equipment for the secondary environmental protection reuse of waste solvents

Abstract

The present application provides a process and equipment for the secondary environmental protection and reuse of waste solvents, which are applied in the field of manufacturing technology. By filtering the waste solvents from enameled wires, sampling the filtered recycled solvents, analyzing the specific proportion of paint resins therein, and then calculating the proportion of high-solid paint resins to be added according to the measurement results, the high-solid paint resins in the calculated proportion are mixed with the recycled solvents. A circulating pump is used to draw the high-solid paint resins from the bottom of the container and mix them with the recycled solvents by spraying from above, so that the two are fully mixed to form low-solid paint resins that can be reused. This process for the secondary environmental protection and reuse of waste solvents not only improves the reuse rate of waste solvents, but also ensures the performance of the reused solvents by precisely controlling the proportion of paint resins, meeting the dual requirements of environmental protection and economic benefits.

Description

Technical Field

[0001] The present application relates to the technical field of manufacturing, and particularly relates to a process and equipment for the secondary environmental protection and reuse of waste solvents. Background Art

[0002] During the production and operation of enamelled wire, situations such as "wire breakage", "gauge change", and "maintenance" are inevitable. When the above situations occur, the inevitable treatment measure is to use solvents for circulating cleaning of molds, paint boxes, paint tanks, etc. The waste solvents after solvent cleaning become hazardous wastes, which not only cannot realize the physical value of the solvents but also require a large amount of money for professional hazardous waste treatment.

[0003] Regarding the treatment of waste solvents in the current enamelled wire industry, there are mainly two ways, both of which have related disadvantages, as follows:

[0004] 1. Entrust a professional hazardous waste company for treatment:

[0005] Enterprises need to invest a large amount of costs for hazardous waste storage and management, such as sites, containers, personnel, safety and environmental protection facilities, etc., and it is difficult to grasp the treatment timeliness; the cost of harmless treatment by professional institutions is high; the physical value of the solvents cannot be utilized, for example, dissolving resins and circulating combustion heat energy.

[0006] 2. Use the solvent recovery equipment on the market that utilizes the distillation principle to conduct secondary distillation recovery of waste solvents:

[0007] However, the recovery and treatment capacity of this method is average; and this solvent recovery equipment is time-consuming and power-consuming to use, and the safety of temperature, pressure, etc. during the distillation process with full electric heating is debatable; moreover, waste solvents are mixtures with different distillation ranges for fractions, and some components of the secondary solvents re-distilled will definitely be missing, and the dissolution quality effect of the solvents after recovery is severely discounted and it is difficult to use directly again, and can only be used as an auxiliary material by blending with new solvents, and it is difficult to make full use of the remaining value of waste solvents.

[0008] Therefore, there is a lack of a device and a treatment process in the prior art that are environmentally friendly, efficient, cost-saving, and can make full use of the combustion calorific value of waste solvents. Summary of the Invention

[0009] In view of the above deficiencies of the prior art, the present application provides a process and equipment for the secondary environmental protection and reuse of waste solvents, which are applied to the technical field of manufacturing. By mixing waste solvents with high-solid-content paint resins, low-solid-content paint resins that can be reused are formed. This kind of low-solid-content paint resin can be directly used in the enamelled wire production process without additional treatment, greatly improving the resource utilization efficiency.

[0010] In a first aspect, a process for the secondary environmental protection and reuse of waste solvents filters particulate impurities from waste solvents of enameled wires to obtain a treated recycled solvent containing paint resin;

[0011] Sample the recycled solvent to obtain the proportion of paint resin in the recycled solvent, and calculate the addition amount of high-solid paint resin according to the proportion of the paint resin;

[0012] Mix the high-solid paint resin and the recycled solvent into a cavity according to the addition amount, and use a circulation pump to draw the high-solid paint resin from the bottom of the cavity and spray it onto the recycled solvent from above, so that the high-solid paint resin is fully mixed with the recycled solvent during the process of penetrating to the bottom, forming a low-solid paint resin that can be reused.

[0013] The process for the secondary environmental protection and reuse of waste solvents provided by this application filters waste solvents of enameled wires to remove particulate impurities therein, thereby obtaining a relatively pure recycled solvent containing paint resin; samples the filtered recycled solvent to analyze the specific proportion of paint resin therein, and then calculates the addition amount of high-solid paint resin to be added according to the measurement results. By accurately calculating the addition amount, the performance of the final product can be ensured to meet the requirements; mixes the high-solid paint resin with the calculated addition amount with the recycled solvent, uses a circulation pump to draw the high-solid paint resin from the bottom of the container, and mixes it with the recycled solvent by spraying from above. The use of the circulation pump helps to achieve full mixing of the high-solid paint resin and the recycled solvent, improving the mixing efficiency and uniformity. During the process of the high-solid paint resin penetrating to the bottom of the recycled solvent, the two are fully mixed to form a low-solid paint resin that can be reused. The beneficial effect of this step is that by reusing waste solvents, the demand for new materials is reduced, and at the same time, the potential impact of waste solvents on the environment is reduced, realizing the recycling of resources. This process for the secondary environmental protection and reuse of waste solvents not only improves the reuse rate of waste solvents, but also ensures the performance of the reused solvent by accurately controlling the proportion of paint resin, meeting the dual requirements of environmental protection and economic benefits.

[0014] Further, the high-solid paint resin, the recycled solvent, and the low-solid paint resin satisfy the relational expression (a% * m + b% * n) / (m + n) = c%, where a% is the proportion of paint resin in the high-solid paint resin, m is the mass of the high-solid paint resin, b% is the proportion of paint resin in the recycled solvent, n is the mass of the recycled solvent, and c% is the proportion of paint resin in the low-solid paint resin.

[0015] A process for the secondary environmental protection and reuse of waste solvents provided by this application calculates the weighted average of the mass percentage concentrations of high-solid paint resins, recycled solvents, and low-solid paint resins through the formula (a% * m + b% * n) / (m + n) = c%, ensuring that the paint resin content in the mixed low-solid paint resin meets the expectations. Through precise calculation and control, the effective reuse of waste solvents is achieved, while ensuring that the performance of the final product meets specific requirements. This method not only improves the utilization efficiency of resources but also reduces environmental pollution, with significant economic and environmental benefits.

[0016] Further, the proportion of paint resin in the high-solid paint resin is 40%, the proportion of paint resin in the recycled solvent is 1%, and the proportion of paint resin in the low-solid paint resin is 30%.

[0017] A process for the secondary environmental protection and reuse of waste solvents provided by this application realizes the effective reuse of waste solvents by precisely calculating and controlling that the proportion of paint resin in the high-solid paint resin is 40%, the proportion of paint resin in the recycled solvent is 1%, and the proportion of paint resin in the low-solid paint resin is 30%, while ensuring that the performance of the final product meets specific requirements. This method not only improves the utilization efficiency of resources but also reduces environmental pollution, with significant economic and environmental benefits.

[0018] Further, the step of filtering particulate impurities from the enameled wire waste solvent to obtain the treated recycled solvent containing paint resin includes: rough filtration and fine filtration;

[0019] The rough filtration includes the steps of: using a circulating pump to pump up the enameled wire waste solvent, passing it through a filter element to intercept large particulate matters with a particle size greater than or equal to the first filtration aperture, and obtaining the roughly filtered waste solvent;

[0020] The fine filtration includes the steps of using a circulating pump to pump the roughly filtered waste solvent, passing it through a filter bag to intercept small particulate matters and flocs with a particle size greater than or equal to the second filtration aperture, and obtaining the treated recycled solvent containing paint resin, where the second filtration aperture is smaller than the first filtration aperture.

[0021] A process for the secondary environmental protection and reuse of waste solvents provided by this application uses a circulation pump to extract waste solvents from enameled wire, and a filter element is used to intercept large particles with a size greater than or equal to the first filtration pore size. This step mainly removes larger solid impurities. Then, the waste solvents that have undergone rough filtration are extracted again using the circulation pump, and a filter bag is used to intercept small particles and floccules with a size greater than or equal to the second filtration pore size. This step further removes finer impurities to ensure the purity of the recycled solvents. Through these two steps, the waste solvents are filtered at two different levels, and finally, recycled solvents with a higher cleanliness level are obtained, which can be used for further reuse or as raw materials for other processes, thereby achieving resource conservation and environmental protection.

[0022] Further, during the rough filtration and the fine filtration processes, the circulation filtration time is 4 hours respectively.

[0023] Further, the steps of mixing the high-solid-content paint resin and the recycled solvent into the cavity according to the addition amount, and using a circulation pump to extract the high-solid-content paint resin from the bottom of the cavity and spray it upward onto the recycled solvent, so that the high-solid-content paint resin is fully mixed with the recycled solvent during the process of penetrating to the bottom to form a low-solid-content paint resin that can be reused include:

[0024] Pour the high-solid-content paint resin into the bottom of the cavity according to the addition amount, and then pour the recycled solvent above the high-solid-content paint resin;

[0025] Insert the inlet of the circulation pump into the high-solid-content paint resin, and connect a spray pipe group to the outlet of the circulation pump. The spray openings of the spray pipe group are located above the cavity;

[0026] After the circulation pump extracts the high-solid-content paint resin from the bottom of the cavity, it sprays it upward onto the recycled solvent through the spray pipe group, so that the high-solid-content paint resin is fully mixed with the recycled solvent during the process of penetrating to the bottom to form a low-solid-content paint resin that can be reused.

[0027] In a second aspect, this application proposes a device for the secondary environmental protection and reuse of waste solvents. The device is applied to the process of any one of the above, and the device includes:

[0028] Filtering device: used to filter particulate impurities from waste solvents of enameled wire to obtain processed recycled solvents containing paint resin;

[0029] Calculation device: used to sample the recycled solvent to obtain the proportion of paint resin in the recycled solvent, and calculate the addition amount of high-solid-content paint resin according to the proportion of the paint resin;

[0030] Processing device: It is used to mix the high-solid paint resin and the recycled solvent into the cavity according to the addition amount, and use a circulation pump to draw out the high-solid paint resin from the bottom of the cavity and spray it onto the recycled solvent from above, so that the high-solid paint resin is fully mixed with the recycled solvent during the process of penetrating to the bottom, forming a low-solid paint resin that can be reused.

[0031] Further, the filtering device includes:

[0032] Coarse filtering device, which is used to filter the waste solvent of enameled wire, intercept large particles with a particle size greater than or equal to the first filtering aperture in the waste solvent of enameled wire, and obtain the coarsely filtered waste solvent;

[0033] Fine filtering device, which is used to filter small particles and flocs with a particle size greater than or equal to the second filtering aperture, and obtain the processed recycled solvent containing paint resin.

[0034] Furthermore, the coarse filtering device at least includes a circulation pump and a filter core connected to the circulation pump. The filter core is provided with a first filtering hole, and the aperture of the first filtering hole is the first filtering aperture; the fine filtering device at least includes a circulation pump and a filter bag connected to the circulation pump. The filter bag is provided with a second filtering hole, and the aperture of the second filtering hole is the second filtering aperture.

[0035] Furthermore, the processing device at least includes a cavity, a circulation pump arranged in the cavity, and a spray pipe group connected to the circulation pump. The feed port of the circulation pump extends into the bottom of the cavity, and the spray ports of the spray pipe group are located in the upper part of the cavity.

[0036] Beneficial effects: A process and equipment for the secondary environmental protection and reuse of waste solvents provided by this application filter the enameled wire waste solvent to remove particulate impurities therein, thereby obtaining a relatively pure recycled solvent containing paint resin; sample the filtered recycled solvent, analyze the specific proportion of the paint resin therein, and then calculate the proportion of the high-solid-content paint resin to be added according to the measurement results. By accurately calculating the addition amount, the performance of the final product can be ensured to meet the requirements; mix the high-solid-content paint resin in the calculated proportion with the recycled solvent, use a circulation pump to draw the high-solid-content paint resin from the bottom of the container, and mix it with the recycled solvent by spraying from above. The use of the circulation pump helps to achieve the full mixing of the high-solid-content paint resin and the recycled solvent, improve the mixing efficiency and uniformity. During the process of the high-solid-content paint resin penetrating to the bottom of the recycled solvent, the two are fully mixed to form a low-solid-content paint resin that can be reused. The beneficial effect of this step is that by reusing waste solvents, the demand for new materials is reduced, and at the same time, the potential impact of waste solvents on the environment is reduced, realizing the recycling of resources. This process for the secondary environmental protection and reuse of waste solvents not only improves the reuse rate of waste solvents, but also ensures the performance of the reused solvent by precisely controlling the proportion of the paint resin, meeting the dual requirements of environmental protection and economic benefits. Description of the Drawings

[0037] Figure 1 It is a flowchart of a process for the secondary environmental protection and reuse of waste solvents provided by this application.

[0038] Figure 2 It is the coarse filtration device of a device for the secondary environmental protection and reuse of waste solvents provided by this application.

[0039] Figure 3 It is the fine filtration device of a device for the secondary environmental protection and reuse of waste solvents provided by this application.

[0040] Figure 4 It is the treatment device of a device for the secondary environmental protection and reuse of waste solvents provided by this application.

[0041] Figure 5 It is a component diagram of an enameled wire waste solvent provided by this application.

[0042] Label description: 1. Coarse filtration device; 2. Fine filtration device; 3. Treatment device; 11. Circulation pump; 12. Filter element; 21. Filter bag; 31. Spray pipe group; 32. Cavity; 4. Enameled wire waste solvent; 41. Particulate matter; 42. Paint resin; 5. Recycled solvent; 6. High-solid-content paint resin. Detailed Embodiments

[0043] Next, in combination with the accompanying drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Components of the embodiments of the present application described and marked in the accompanying drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application to be protected, but only represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0044] It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, terms such as "first" and "second" are only used for differential description and cannot be understood as indicating or implying relative importance.

[0045] The following discloses many different implementation manners or examples to achieve the purpose of the present invention. In the production of enameled wires, situations such as wire breakage, track switching, and maintenance often occur. In these situations, solvents are required to clean the molds, paint tanks, and paint troughs. However, the waste solvents after cleaning become hazardous wastes, which not only cannot exert the actual value of the solvents but also require a large amount of funds for professional treatment. Currently, there are mainly two treatment methods in the industry: one is to entrust a professional hazardous waste company for treatment, and the other is to use a solvent recovery device based on the principle of distillation for secondary distillation and recovery. However, both of these methods have obvious defects and cannot meet the actual needs of enterprises. To solve this problem, the present application proposes a process and equipment for the secondary environmental protection and reuse of waste solvents.

[0046] Specifically, please refer to Figures 1 to 5 , a process for the secondary environmental protection and reuse of waste solvents,

[0047] S1: Filter the enameled wire waste solvent 4 to remove particulate impurities, and obtain a recovered solvent 5 containing paint resin 42 after treatment;

[0048] S2: Sample the recovered solvent 5 to obtain the proportion of the paint resin 42 in the recovered solvent 5, and calculate the addition amount of the high-solid content paint resin 6 according to the proportion of the paint resin 42;

[0049] S3: Mix the high-solid content paint resin 6 and the recovered solvent 5 into the cavity 32 according to the addition amount, and use the circulation pump 11 to draw the high-solid content paint resin 6 from the bottom of the cavity 32 and spray it onto the recovered solvent 5 from above, so that the high-solid content paint resin 6 is fully mixed with the recovered solvent 5 during the process of penetrating to the bottom, forming a low-solid content paint resin that can be reused.

[0050] Among them, in step S1, the enameled wire waste solvent 4 contains at least solid impurities, dissolved paint resin 42, and solvent components. Only the solid impurities are harmful components that need to be removed. The solid impurities at least include oxide films, mud and sand, and paint scale, specifically referring to Figure 5 .

[0051] Among them, the process first filters the particulate impurities in the enameled wire waste solvent 4 to obtain the recycled solvent 5 containing the paint resin 42 after treatment. The purpose of this step is to remove the solid impurities in the waste solvent and lay the foundation for subsequent treatment. The filtration process can adopt a multi-stage filtration system, including coarse filtration and fine filtration, to ensure the purity of the recycled solvent 5.

[0052] In step S2, after obtaining the recycled solvent 5, by sampling the recycled solvent 5, the proportion of the paint resin 42 in the recycled solvent 5 can be accurately measured. This data is a key parameter for subsequent treatment because it determines the addition amount of the high-solid-content paint resin 6 to be added. The sampling process can use high-precision analytical instruments, such as gas chromatographs or liquid chromatographs, to ensure the accuracy of the measurement results. Specifically, multiple samplings can be carried out during sampling, and the average content of the paint resin 42 contained in the recycled solvent 5 can be calculated to reduce the error caused by accidental situations to the calculation results.

[0053] Based on the sampling results, the process of this application uses a specific calculation method to determine the addition amount of the high-solid-content paint resin 6. This calculation process takes into account the existing content of the paint resin 42 in the recycled solvent 5 and the resin content required for the final target product (low-solid-content paint resin). Through precise calculation, it can be ensured that the amount of the high-solid-content paint resin 6 added is neither excessive and wasteful nor insufficient to reach the target concentration. In step S3, according to the calculated addition amount, the high-solid-content paint resin 6 and the recycled solvent 5 are mixed into the cavity 32, and the mixing process adopts an innovative circulating pump spraying technology. Utilizing the characteristic that the high-solid-content paint resin 6 has a high density, the circulating pump 11 pumps the high-solid-content paint resin 6 out from the bottom of the cavity 32, and then sprays it evenly onto the surface of the recycled solvent 5 through a spraying device located above the cavity 32. This top-down spraying method utilizes the gravitational force, enabling the high-solid-content paint resin 6 to be fully mixed with the recycled solvent 5 during the downward penetration process. This method can not only ensure the uniformity of mixing but also significantly improve the mixing efficiency.

[0054] Among them, in order to ensure that the high-solid-content paint resin 6 and the recycled solvent 5 can be fully mixed, the flow rate of the circulating pump 11 should match the size of the cavity 32 and the mixing requirements, the pressure should be sufficient to spray the high-solid-content paint resin 6 evenly, and the material needs to be resistant to solvent corrosion. Among them, when spraying, porous nozzles or rotating spray arms can be used to ensure a wide and uniform spraying coverage area.

[0055] The process of this application not only solves the problem of waste solvent treatment but also realizes the efficient utilization of resources. By mixing waste solvent with high-solid paint resin 6, a low-solid paint resin that can be reused is formed. This low-solid paint resin can be directly used in the enameled wire production process without additional treatment, greatly improving the resource utilization efficiency. Compared with the prior art, the process of this application has significant advantages. Compared with the method of entrusting a professional hazardous waste company for treatment, this process greatly reduces the treatment cost and avoids the complexity of hazardous waste storage and management. Compared with the method of recycling using distillation equipment, this process not only has lower energy consumption and higher safety but also can retain all components of the solvent to ensure the quality of the recycled product.

[0056] Furthermore, the high-solid paint resin 6, the recycled solvent 5, and the low-solid paint resin satisfy the relational expression (a% * m + b% * n) / (m + n) = c%, where a% is the proportion of paint resin 42 in the high-solid paint resin 6, m is the mass of the high-solid paint resin 6, b% is the proportion of paint resin 42 in the recycled solvent 5, n is the mass of the recycled solvent 5, and c% is the proportion of paint resin 42 in the low-solid paint resin.

[0057] Among them, in actual operation, the composition of the recycled solvent 5 can be accurately analyzed first to determine the proportion of paint resin 42 therein. This can be achieved through analytical methods such as gas chromatography or liquid chromatography; then, according to production requirements, the concentration of the target low-solid paint resin is determined, which may vary according to different application scenarios; next, a high-solid paint resin 6 with a suitable concentration is selected. Usually, a concentration of about 40% is selected, which can ensure sufficient resin content without causing too high viscosity to be difficult to handle; finally, substituting these data into the formula can calculate the specific amount of the high-solid paint resin 6 to be added. Through this formula, the amount of the high-solid paint resin 6 to be added can be accurately calculated to achieve the concentration of the target low-solid paint resin. This accurate calculation method effectively avoids the common problems of over-addition or under-addition in traditional processes, thus greatly improving the resource utilization efficiency and reducing the production cost.

[0058] Furthermore, the proportion of paint resin 42 in the high-solid paint resin 6 is 40%, the proportion of paint resin 42 in the recycled solvent 5 is 1%, and the proportion of paint resin 42 in the low-solid paint resin is 30%.

[0059] Among them, in some specific embodiments, an enameled wire manufacturing enterprise generates 500 kg of waste solvent every day. After preliminary analysis, the content of paint resin 42 in it is 1%. The enterprise hopes to process these waste solvents into low-solids paint resin with a concentration of 30% for use in other production processes. According to the formula, it can be calculated that approximately 273.3 kg of high-solids paint resin 6 with a concentration of 40% needs to be added. In this way, not only is the waste solvent fully utilized, but also approximately 730 kg of directly usable low-solids paint resin is produced, greatly improving the resource utilization efficiency.

[0060] In another specific embodiment, the application of this formula under different concentration requirements can be demonstrated. For example, a coating manufacturing enterprise needs paint resins 42 with different concentrations for different product lines. They may need to process recycled solvent 5 into three different low-solids paint resins with concentrations of 20%, 25%, and 35%. By adjusting the c% value in the formula, we can quickly calculate the amount of high-solids paint resin 6 to be added in each case, thus flexibly meeting different production requirements.

[0061] Specifically, this application stipulates that the proportion of paint resin 42 in high-solids paint resin 6 is 40%. When filtering particulate impurities from enameled wire waste solvent 4, a detection instrument can be used to detect the solvent in real time until after filtration, so that the proportion of paint resin 42 in recycled solvent 5 is 1%. The proportion of paint resin 42 in the finally formed low-solids paint resin is 30%. This precise ratio can not only ensure the quality of the final product, but also maximize the utilization of waste solvents while reducing the use of new materials. The advantage of this ratio method lies in that it takes into account the material balance of the entire system. The 40% high-solids paint resin 6 provides sufficient resin content to effectively increase the resin content of the 1% low-concentration recycled solvent 5. The final 30% low-solids paint resin is an ideal concentration, which can not only meet the subsequent production requirements but also avoid resource waste.

[0062] Furthermore, the step of filtering particulate impurities from enameled wire waste solvent 4 to obtain the processed recycled solvent 5 containing paint resin 42 includes: coarse filtration and fine filtration;

[0063] Coarse filtration includes the steps of using a circulation pump 11 to pump up enameled wire waste solvent 4, passing it through a filter element 12 to intercept large particles 41 with a particle size of the particulate matter 41 greater than or equal to the first filtration aperture, and obtaining the coarsely filtered waste solvent;

[0064] Fine filtration includes the steps of using a circulation pump 11 to pump the coarsely filtered waste solvent, passing it through a filter bag 21 to intercept small particles 41 with a particle size of the particulate matter 41 greater than or equal to the second filtration aperture and flocs, and obtaining the processed recycled solvent 5 containing paint resin 42.

[0065] Among them, in the process of secondary environmentally friendly reuse of waste solvents in the present application, filtering the waste solvent 4 of enameled wire for particulate impurities can not only remove solid impurities in the waste solvent, but also lay the foundation for subsequent treatment. However, in actual operation, a single filtering method may be difficult to meet the requirements for the purity of the recovered solvent 5. In order to further improve the filtering effect, the present application proposes a multi-stage filtering system, including two stages of coarse filtration and fine filtration.

[0066] The coarse filtration stage mainly targets larger particles 41 in the waste solvent. In this stage, the circulating pump 11 is used to pump up the waste solvent 4 of the enameled wire, and then pass it through the filter element 12. The filter element 12 is provided with filter holes of a specific aperture, which can effectively intercept large particles 41 with a size greater than or equal to the first filter aperture. This process can not only remove obvious impurities, but also protect the subsequent fine filtration equipment and extend its service life.

[0067] After the coarse filtration, the waste solvent enters the fine filtration stage. In this stage, the circulating pump 11 is also used, but the waste solvent after the coarse filtration is passed through the filter bag 21. The second filter aperture on the filter bag 21 is smaller than the first filter aperture, and can intercept finer particles 41 and flocs. Through these two stages of filtration, a higher purity recovered solvent 5 can be obtained, providing better raw materials for the subsequent reuse process.

[0068] The multi-stage filtration system of the present application is flexible in design and can be adjusted according to actual needs. For example, filter cores 12 and filter bags 21 of different materials and pore sizes can be selected to adapt to different types of waste solvents. The filter core 12 can be made of metal mesh, ceramic or polymer materials, while the filter bag 21 can be made of nylon, polypropylene or polyester fiber. This flexibility allows the process to adapt to the needs of different industries and different production scales.

[0069] Furthermore, during the coarse filtration and fine filtration processes, the circulating filtration time is 4 hours respectively.

[0070] Among them, in order to ensure the filtering effect, the circulating filtration time in the coarse filtration and fine filtration processes of this application is 4 hours. This time setting is based on a large amount of experimental data verification, which can take into account the processing efficiency while ensuring the filtering effect. However, in actual operation, the filtration time can be appropriately adjusted according to the specific situation of the waste solvent. For example, for waste solvents with a lighter degree of pollution, the filtration time can be appropriately shortened; for waste solvents with severe pollution, it may be necessary to extend the filtration time or increase the number of filtrations.

[0071] Further, the steps of mixing the high-solid paint resin 6 and the recycled solvent 5 into the cavity 32 according to the addition amount, and using the circulation pump 11 to extract the high-solid paint resin 6 from the bottom of the cavity 32 and spray it onto the recycled solvent 5 from above, so that the high-solid paint resin 6 is fully mixed with the recycled solvent 5 during the process of penetrating to the bottom to form a low-solid paint resin that can be reused include:

[0072] Pour the high-solid paint resin 6 into the bottom of the cavity 32 according to the addition amount, and then pour the recycled solvent 5 above the high-solid paint resin 6;

[0073] Insert the inlet of the circulation pump 11 into the high-solid paint resin 6, and connect a spray pipe group 31 to the outlet of the circulation pump 11. The spray nozzles of the spray pipe group 31 are located above the cavity 32;

[0074] After the circulation pump 11 extracts the high-solid paint resin 6 from the bottom of the cavity 32, it sprays it onto the recycled solvent 5 from above through the spray pipe group 31, so that the high-solid paint resin 6 is fully mixed with the recycled solvent 5 during the process of penetrating to the bottom to form a low-solid paint resin that can be reused.

[0075] Among them, in the process of secondary environmental protection and reuse of waste solvents in this application, the mixing process of the high-solid paint resin 6 and the recycled solvent 5 is a key step. To further optimize this process, this application proposes an improved mixing method. This method can not only ensure the uniformity of mixing, but also improve the mixing efficiency, so as to obtain a higher-quality low-solid paint resin.

[0076] Specifically, the mixing method of this application includes the following steps: First, pour the high-solid paint resin 6 into the bottom of the cavity 32 according to the pre-calculated addition amount. The design of this cavity 32 takes into account the special requirements of the mixing process, including the appropriate height and diameter ratio, as well as the special internal structure, to promote the mixing effect. After the high-solid paint resin 6 is poured, then pour the recycled solvent 5 above the high-solid paint resin 6. This way of layered pouring helps the subsequent mixing process.

[0077] Next, insert the inlet of the circulation pump 11 into the high-solid paint resin 6. The selection of the circulation pump 11 is crucial, and factors such as its flow rate, pressure, and material need to be considered. The flow rate of the pump should match the size of the cavity 32 and the mixing requirements, the pressure should be sufficient to spray the high-solid paint resin 6 evenly, and the material needs to be resistant to solvent corrosion. Connect a spray pipe group 31 to the outlet of the circulation pump 11. The design of the spray pipe group 31 is a key point, and forms such as porous nozzles or rotating spray arms can be used to ensure a wide and uniform spraying coverage area.

[0078] After starting the circulation pump 11, the high-solid paint resin 6 is drawn out from the bottom of the cavity 32 and evenly sprayed onto the recycled solvent 5 from above through the spray pipe group 31. This top-down spraying method utilizes the gravitational force, enabling the high-solid paint resin 6 to be fully mixed with the recycled solvent 5 during the downward penetration process. This method not only ensures the uniformity of mixing but also significantly improves the mixing efficiency.

[0079] During the mixing process, the viscosity of the high-solid paint resin 6 and the fluidity of the recycled solvent 5 are parameters that require special attention. To ensure sufficient mixing, the mixing effect can be optimized by adjusting the speed of the circulation pump 11 and the spraying time. For example, variable frequency control technology can be used to adjust the rotation speed of the circulation pump 11 to adapt to high-solid paint resins 6 with different viscosities. Additionally, multiple spraying cycles can be set, with a certain interval time between each cycle, allowing the mixture sufficient time for natural diffusion and homogenization.

[0080] This method realizes an efficient and uniform mixing process by designing a circulating spray system and precisely controlling the quality of each mixed solvent, providing a reliable guarantee for obtaining high-quality low-solid paint resin. This method not only improves the resource utilization efficiency but also reduces the production cost, providing strong support for the sustainable development of the enameled wire industry.

[0081] Please refer to Figures 2 to 5 , this application proposes an equipment for the secondary environmental protection reuse of waste solvents. The equipment is applied to the process of any one of the above, and the equipment includes:

[0082] Filtering device: used to filter particulate impurities from the enameled wire waste solvent 4 to obtain the treated recycled solvent 5 containing the paint resin 42;

[0083] Calculation device: used to sample the recycled solvent 5 to obtain the proportion of the paint resin 42 in the recycled solvent 5, and calculate the addition amount of the high-solid paint resin 6 based on the proportion of the paint resin 42;

[0084] Treatment device 3: used to mix the high-solid paint resin 6 and the recycled solvent 5 into the cavity 32 according to the addition amount, and use the circulation pump 11 to draw the high-solid paint resin 6 out from the bottom of the cavity 32 and spray it onto the recycled solvent 5 from above, so that the high-solid paint resin 6 is fully mixed with the recycled solvent 5 during the process of penetrating to the bottom, forming a low-solid paint resin that can be reused twice.

[0085] Among them, the equipment for the secondary environmental protection reuse of waste solvents in this application mainly includes three core parts: a filtering device, a calculation device, and a treatment device 3. These three parts respectively correspond to the three main steps in the process, forming a complete treatment system.

[0086] The filtration device is the first step in the entire treatment process. Its main function is to filter particulate impurities from the waste solvent 4 of enameled wire to obtain the treated recycled solvent 5 containing paint resin 42. This filtration device can adopt a multi-stage filtration system, including coarse filtration and fine filtration. Coarse filtration can use a filter screen with a large pore size or a centrifugal separator to remove large particulate impurities. Fine filtration can adopt a filter element provided with activated carbon to further remove fine particles and some soluble impurities. The design of the filtration device needs to consider the characteristics of different types of waste solvents, and replaceable filter elements can be used to adapt to different filtration requirements.

[0087] The calculation device is responsible for sampling the recycled solvent 5 to obtain the proportion of paint resin 42 in the recycled solvent 5, and calculating the addition amount of high-solid paint resin 6 based on this proportion. This calculation device can integrate high-precision analytical instruments, such as near-infrared spectrometers or gas chromatographs, for quickly and accurately determining the content of paint resin 42 in the solvent. At the same time, it also needs to be equipped with a powerful calculation unit and a dedicated algorithm, which can quickly calculate the required addition amount of high-solid paint resin 6 according to the measurement results and the preset target product parameters. To improve flexibility, the calculation device can be set with multiple formulation modes to adapt to different production requirements.

[0088] The treatment device 3 at least includes a circulation pump 11 extending into the bottom of the cavity 32 and a spray pipe group 31 connected to the circulation pump 11. According to the addition amount given by the calculation device, the high-solid paint resin 6 and the recycled solvent 5 are mixed into the cavity 32. The material of this cavity 32 needs to consider corrosion resistance, and stainless steel or special composite materials can be selected. The circulation pump 11 in the treatment device 3 is a key component, and it needs to be able to precisely control the flow rate and pressure to ensure the uniformity of the mixing process. The selection of the pump needs to consider the high-viscosity characteristics of the high-solid paint resin 6, and screw pumps or gear pumps and other pump types suitable for transporting high-viscosity liquids can be used.

[0089] The spray pipe group 31 is another important part of the treatment device 3. It needs to be able to evenly spray the high-solid paint resin 6 onto the surface of the recycled solvent 5. The spray pipe group 31 can adopt a multi-point injection design to ensure coverage of the entire cross-section of the cavity 32. The selection of the nozzle needs to consider the characteristics of the high-solid paint resin 6, and specially designed atomizing nozzles can be used to improve the uniformity of spraying.

[0090] The equipment for the secondary environmental protection reuse of waste solvents proposed in this application realizes the efficient reuse of waste solvents through precise filtration, intelligent calculation, and efficient mixing treatment. This kind of equipment can not only greatly improve the efficiency and quality of waste solvent treatment, but also significantly reduce the treatment cost and reduce environmental pollution.

[0091] Furthermore, the filtration device includes:

[0092] The coarse filtration device 1 is used to filter the waste solvent 4 of enameled wire, intercepting large particles 41 in the waste solvent 4 of enameled wire with a particle size greater than or equal to the first filtration aperture, to obtain the waste solvent after coarse filtration;

[0093] The fine filtration device 2 is used to filter small particles 41 with a particle size greater than or equal to the second filtration aperture and flocs, to obtain the treated recycled solvent 5 containing paint resin 42.

[0094] Among them, please refer to Figure 2 , the design of the coarse filtration device 1 can adopt various forms. For example, a metal mesh filter can be used, which has a large surface area and high durability. Another option is to use a multi-layer fiber filtration material, which can have a lower pressure loss while ensuring the filtration effect. In addition, a centrifugal separator can also be considered as part of the coarse filtration device 1, especially when the waste solvent contains a large amount of suspended particles.

[0095] Please refer to Figure 3 , after coarse filtration, the waste solvent enters the fine filtration device 2. The main goal of this stage is to remove small particles 41 with a particle size greater than or equal to the second filtration aperture and flocs. The design of the fine filtration device 2 needs to be more precise to ensure that it can capture the fine impurities that were not removed in the coarse filtration stage. This step is crucial for ensuring the quality of the final recycled solvent 5, because these tiny impurities may affect the subsequent reuse process.

[0096] To further improve the filtration effect, the filtration device of the present application uses a circulation pump 11 in both the coarse filtration and fine filtration stages. In the coarse filtration stage, the circulation pump 11 is connected to the filter core 12, and in the fine filtration stage, the circulation pump 11 is connected to the filter bag 21. This design can not only ensure a stable flow rate of the waste solvent during the filtration process, but also improve the filtration efficiency through repeated circulation.

[0097] Furthermore, the coarse filtration device 1 at least includes a circulation pump 11 and a filter core 12 connected to the circulation pump 11. The filter core 12 is provided with a first filtration hole, and the aperture of the first filtration hole is the first filtration aperture; the fine filtration device 2 at least includes a circulation pump 11 and a filter bag 21 connected to the circulation pump 11. The filter bag 21 is provided with a second filtration hole, and the aperture of the second filtration hole is the second filtration aperture.

[0098] Among them, the filter element 12 is provided with first filter holes, and the aperture size thereof determines the precision of coarse filtration. The filter bag 21 is provided with second filter holes, the aperture of which is smaller than that of the first filter holes, and is used for finer filtration. The filter bag 21 can be made of polymer materials and has good chemical stability and mechanical strength. In practical applications, the filter aperture can be adjusted according to the specific composition of the waste solvent and the requirements of the target product. For example, for waste solvents containing a large amount of paint particles, the first filter aperture can be set to 100 microns, and the second filter aperture can be set to 10 microns. For relatively clean waste solvents, the filter aperture can be reduced accordingly to obtain a higher purity of the recovered solvent 5.

[0099] Furthermore, the processing device 3 at least includes a cavity 32, a circulation pump 11 disposed in the cavity 32, and a spray pipe group 31 connected to the circulation pump 11. The feed port of the circulation pump 11 extends into the bottom of the cavity 32, and the spray ports of the spray pipe group 31 are located in the upper part of the cavity 32.

[0100] Among them, please refer to Figure 4 , the feed port of the circulation pump 11 is designed to extend into the bottom of the cavity 32, so as to ensure that the high-solid paint resin 6 can be continuously extracted, even when the liquid level of the high-solid paint resin 6 gradually decreases during the mixing process. This design avoids the problems of pump idling or reduced extraction efficiency, and ensures the continuity and stability of the entire mixing process.

[0101] The spray ports of the spray pipe group 31 are cleverly arranged in the upper part of the cavity 32. This layout makes full use of the gravity effect, so that the sprayed high-solid paint resin 6 can evenly cover the entire surface of the recovered solvent 5 and fully contact and mix with the recovered solvent 5 during the falling process. By adjusting the height, angle and distribution of the spray ports, the mixing effect can be further optimized to ensure that the high-solid paint resin 6 can be evenly dispersed in the recovered solvent 5.

[0102] To achieve this design, the circulation pump 11 can be selected from corrosion-resistant centrifugal pumps or gear pumps, and its flow rate and pressure need to be accurately calculated and selected according to the size of the cavity 32 and the mixing requirements. The feed pipe of the pump can adopt a telescopic pipe with adjustable length to adapt to the requirements of cavities 32 with different heights and different liquid levels.

[0103] The spray pipe group 31 can be designed into a multi-arm structure, with multiple nozzles evenly distributed on each arm to achieve full coverage of the upper space of the entire cavity 32. Or other forms, such as using a fixed grid-shaped spray pipe to form a uniform spraying network in the upper part of the cavity 32. The nozzles can be selected from atomizing or fan-shaped nozzles to obtain better atomization effects and coverage areas.

[0104] In this document, relational terms such as first and second are used solely to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0105] The above description is only for the embodiments of the present application and is not intended to limit the protection scope of the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for secondary environmentally friendly recycling of waste solvents, used for treating waste solvents (4) of enameled wires, wherein the waste solvents (4) of enameled wires contain at least solid impurities, dissolved paint resin (42) and solvent components, and only the solid impurities are harmful components that need to be removed, characterized in that: The following steps are involved: S1: filtering the waste solvent (4) of the enameled wire for particulate impurities to obtain a treated recovered solvent (5) containing a paint resin (42), the step comprising: coarse filtration and fine filtration; The coarse filtration comprises the steps of: using a circulation pump (11) to pump up the enameled wire waste solvent (4), passing through a filter element (12), intercepting large particles with a particle size greater than or equal to a first filter aperture, and obtaining a waste solvent after coarse filtration; The fine filtration comprises the steps of: using a circulation pump (11) to pump up the waste solvent after the coarse filtration, passing it through a filter bag (21), intercepting small particles and floccules whose particle size is greater than or equal to a second filter aperture, and obtaining a processed recovered solvent (5) containing a paint resin (42), wherein the second filter aperture is smaller than the first filter aperture; S2: sampling the recovered solvent (5) to obtain the proportion of the paint resin (42) in the recovered solvent (5), and calculating the amount of the high-solid paint resin (6) to be added according to the proportion of the paint resin (42); S3: pouring the high-solid paint resin (6) into the bottom of the cavity (32) according to the added amount, and then pouring the recovery solvent (5) onto the high-solid paint resin (6); S4: inserting the feed port of the circulation pump (11) into the high-solid paint resin (6), and connecting the discharge port of the circulation pump (11) to a spray pipe group (31), wherein the spray port of the spray pipe group (31) is located above the cavity (32); S5: After the circulation pump (11) extracts the high-solid paint resin (6) from the bottom of the chamber (32), it is sprayed from above to the recovery solvent (5) through the spray pipe group (31), so that the high-solid paint resin (6) is fully mixed with the recovery solvent (5) in the process of penetrating to the bottom, thereby forming a low-solid paint resin that can be reused.

2. The process for secondary environmentally friendly recycling of waste solvents according to claim 1, characterized in that: The high-solid paint resin (6), the recovery solvent (5) and the low-solid paint resin satisfy the relationship (a%*m+b%*n) / (m+n)=c%, wherein a% is the proportion of the paint resin (42) in the high-solid paint resin (6), m is the mass of the high-solid paint resin (6), b% is the proportion of the paint resin (42) in the recovery solvent (5), n is the mass of the recovery solvent (5), and c% is the proportion of the paint resin (42) in the low-solid paint resin.

3. The process for secondary environmentally friendly recycling of waste solvents according to claim 2, characterized in that: The proportion of the paint resin (42) in the high-solid paint resin (6) is 40%, the proportion of the paint resin (42) in the recovery solvent (5) is 1%, and the proportion of the paint resin (42) in the low-solid paint resin is 30%.

4. The process for secondary environmentally friendly recycling of waste solvents according to claim 1, characterized in that: During the coarse filtration and the fine filtration, the circulating filtration time is 4 hours respectively.

5. A device for secondary environmentally friendly recycling of waste solvents, characterized in that: The device is applied to the process described in any one of claims 1 to 4 above, and the device comprises: A filtering device: used for filtering particulate impurities from the waste solvent (4) of the enameled wire to obtain a processed recovered solvent (5) containing the paint resin (42); A calculation device is used for sampling the recovery solvent (5), obtaining the proportion of the paint resin (42) in the recovery solvent (5), and calculating the addition amount of the high-solid paint resin (6) according to the proportion of the paint resin (42); The processing device (3) is used to mix the high-solid paint resin (6) and the recovery solvent (5) into the chamber (32) according to the added amount, and use a circulation pump (11) to extract the high-solid paint resin (6) from the bottom of the chamber (32) and spray it onto the recovery solvent (5) from the top, so that the high-solid paint resin (6) is fully mixed with the recovery solvent (5) in the process of penetrating to the bottom, so as to form a low-solid paint resin that can be reused; The filtering device comprises: A coarse filtering device (1) is used to filter the enameled wire waste solvent (4), intercept large particles in the enameled wire waste solvent (4) whose particle size is greater than or equal to a first filtering aperture, and obtain the waste solvent after coarse filtration; The fine filtering device (2) is used to filter small particles and floccules whose particle size is greater than or equal to the second filtering aperture to obtain a processed recovery solvent (5) containing the paint resin (42).

6. The equipment for secondary environmentally friendly recycling of waste solvents according to claim 5, characterized in that: The coarse filtering device (1) comprises at least a circulation pump (11) and a filter core (12) connected to the circulation pump (11); the filter core (12) is provided with a first filtering hole, and the aperture of the first filtering hole is the first filtering aperture; the fine filtering device (2) comprises at least a circulation pump (11) and a filter bag (21) connected to the circulation pump (11); the filter bag (21) is provided with a second filtering hole, and the aperture of the second filtering hole is the second filtering aperture.

7. The equipment for secondary environmentally friendly recycling of waste solvents according to claim 6, characterized in that: The processing device (3) comprises at least a chamber (32), a circulation pump (11) arranged in the chamber (32), and a spray pipe group (31) connected to the circulation pump (11), wherein the feed port of the circulation pump (11) extends into the bottom of the chamber (32), and the spray port of the spray pipe group (31) is located at the upper part of the chamber (32).

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