Method for recovering and regenerating renewable ion-exchange resin filter

Abstract

A method for recovering and regenerating a renewable ion-exchange resin filter, comprising: S1, manufacturing a filter cloth; S2, assembling a filter; S3, a filter recovery step; and S4, a filter regeneration process. S4, the filter regeneration process comprises a regeneration step, a cleaning step, and a drying step. A filter cloth is manufactured using an adhesive-free process; during filter assembly, a filter element is first assembled to a corrosion-resistant plastic frame, with the filter then assembled to a metal outer frame, wherein the plastic frame and the metal outer frame are designed with matching grooves; and during filter recovery and regeneration, the plastic frame is removed from a non-corrosion-resistant aluminum profile frame.

Description

A method for recycling and regenerating regenerable ion exchange resin filters Technical Field

[0001] This invention relates to the field of air purification equipment recycling and reuse, specifically a method for recycling and regenerating a regenerable ion exchange resin filter. Background Technology

[0002] As the linewidth of large-scale integrated circuit chips continues to narrow, many stages of the chip manufacturing process need to be carried out in environments with extremely high cleanliness requirements. In electronic cleanrooms, the content of gaseous molecular contaminants (AMCs) affects industry development and yield rates. Installing chemical filters is one of the important technical measures for controlling AMCs in electronic cleanrooms. AMCs are mainly divided into four categories: 1. Acids; 2. Alkalis; 3. Gaseous organic contaminants; 4. Dopants.

[0003] Anion and cation exchange resins can effectively remove acidic and alkaline gases from AMCs. However, once these resins have deteriorated, they must undergo regeneration before reuse. On one hand, most current ion exchange resin regeneration is done using resin granules, rendering the filter frame unusable and resulting in waste. Choosing a suitable method to manufacture ion exchange resin filter cloth suitable for the regeneration environment requires the filter cloth to have a certain degree of hardness and acid / alkali resistance, and the filter frame to be acid / alkali resistant and not easily deformed. Simultaneously, selecting appropriate regeneration methods is an effective way to reduce resource waste. On the other hand, after recycling anion and cation exchange resins with regeneration solution, their lifespan decreases rapidly after three cycles. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a method for recycling and regenerating a regenerable ion exchange resin filter, comprising the following steps:

[0005] S1, making filter cloth; furthermore, using a glue-free process to make filter cloth;

[0006] Double-sided PP needle-punched cotton is mixed with ion exchange resin. The resin is fixed in the middle of the PP needle-punched cotton by the fiber filaments through the needle punching process. At the same time, the entire PP needle-punched cotton is sealed to form a filter cloth to prevent resin leakage.

[0007] S2, Assemble the filter

[0008] First, the filter element formed from the filter cloth is assembled into a corrosion-resistant frame to form a filter; then, the filter is assembled into a metal outer frame; the corrosion-resistant frame is detachably installed inside the metal outer frame; furthermore, the corrosion-resistant frame is a plastic frame, wherein the plastic frame and the metal outer frame are designed with matching grooves; during recycling, the plastic frame is removed from the non-corrosion-resistant metal outer frame.

[0009] S3, Filter Recycling Step

[0010] S31, After the filter is retrieved, remove it from the metal frame; if the frame is not deformed, place it directly on the regeneration equipment for regeneration.

[0011] S32, after the filter is retrieved, if the outer frame is deformed, tear open the filter element and put the recovered resin into the regeneration device for regeneration.

[0012] S4, Regeneration process of regenerable ion exchange resin filter

[0013] S41, after laying the filter flat, add acidic or alkaline regenerant at 3-25L / min. After the regenerant level covers the filter, continue adding regenerant while discharging regenerant at the same flow rate to ensure that the regenerant level always covers the filter. Stop regeneration after all the regenerant is consumed.

[0014] S42, Cleaning steps: Rinse the regenerated filter with pure water at a flow rate of 10-50L / min. After the liquid level exceeds the filter, discharge the wastewater at the same flow rate. Stop rinsing when the pH value of the rinsing wastewater reaches 6-8.

[0015] S43, Drying steps: Dry the cleaned filter until the filter element surface is dry and the moisture content is 15-25%;

[0016] Furthermore, in step S1, the PP needle-punched cotton is a 100-300gsm nonwoven fabric.

[0017] The ion-exchange resin is a gel-type ion exchange resin, a macroporous ion exchange resin, a strong acid cation exchange resin, a weak acid cation exchange resin, a strong base anion exchange resin, or a weak base anion exchange resin.

[0018] Furthermore, by employing a needle-punching process to fix resin within the PP needle-punched cotton using fiber filaments, the prepared filter cloth exhibits the following structural characteristics:

[0019] The filter cloth includes an upper layer of PP needle-punched cotton, a lower layer of PP needle-punched cotton, fiber filaments, and resin. The fiber filaments are needle-punched and connected to the upper and lower layers of PP needle-punched cotton, forming M (M≥2) longitudinal and N (N≥2) transverse fiber filament surfaces in the upper and lower layers of PP needle-punched cotton. M-1, N-1, or (M-1)*(N-1) cavities are formed between the fiber filament surfaces, the upper and lower layers of PP needle-punched cotton, and the resin is disposed in the cavities.

[0020] Furthermore, in step S2, the plastic frame is made of PP, PS, or ABS; the metal frame is made of aluminum profile, aluminum plate frame, galvanized steel plate, cold-rolled steel plate, or aluminum-zinc coated steel.

[0021] Furthermore, in step S2, the plastic frame and filter element are filled with glue to fill the groove inside the frame, so that no liquid remains in the frame after the regeneration liquid or pure water is removed.

[0022] Further, in step S41, the acidic regeneration solution is an aqueous solution of sulfuric acid, hydrochloric acid, phosphoric acid, or nitric acid; the alkaline regeneration solution is an aqueous solution of sodium hydroxide, ammonia, or potassium hydroxide.

[0023] Further, in step S41, the used and recovered failed ion exchange resin filter is regenerated with an alkaline or acidic solution at a volume ratio of 1:1 to 1:10, and the temperature of the regeneration solution is 25-98°C.

[0024] Furthermore, in steps S41 and S42, the temperature of the regenerated liquid and pure water is 25-98℃.

[0025] Further, in step S42, the filter from the cleaning step is rinsed with pure water at a volume ratio of 1:3 to 1:10.

[0026] Further, in step S43, the drying temperature is 40-70℃.

[0027] Beneficial effects: First, this invention uses a glue-free process to manufacture the filter cloth. Ion exchange resin is incorporated into the middle of double-sided PP needle-punched cotton. The resin is fixed to the PP needle-punched cotton using fiber filaments through the needle-punching process, while the entire filter cloth is sealed to prevent resin leakage. Second, during filter assembly, the filter element is first assembled onto a corrosion-resistant plastic frame, and then onto a metal outer frame. The plastic and metal frames are designed with matching grooves. During recycling, the plastic frame is removed from the non-corrosion-resistant aluminum profile frame. This allows for gradual disassembly and recycling from the filter element to the filter itself, and the filter frame can be reused, avoiding waste. Third, after the regeneration solution of this invention is recycled three times, its service life still exceeds 650 minutes, representing 80% of the original resin. Attached Figure Description

[0028] Figure 1 is a schematic diagram of the filter cloth needle punching process;

[0029] Figure 2 is a schematic diagram of the filter plastic frame structure; where 5 is the protective mesh; 6 is the card comb; 7 is the sealant; and 1 is the plastic frame.

[0030] Figure 3 is a schematic diagram of the metal outer frame structure of the filter; where 5 is the protective mesh; 6 is the card comb; 7 is the sealant; and 8 is the metal outer frame and the plastic inner frame, that is, the metal outer frame is fitted over the plastic frame shown in Figure 2.

[0031] Figure 4 shows the test results of the service life of the cation resin filter prepared by the regenerable ion resin filter manufacturing process of the present invention.

[0032] Figure 5 shows the test results of the service life of the anion exchange resin filter prepared by the regenerable ion exchange resin filter manufacturing process of the present invention.

[0033] Figure 6 shows the service life of the cation exchange resin filter after recycling the regenerated solution according to the present invention.

[0034] Figure 7 is a schematic diagram of the composite filter assembly, where: 1, plastic frame; 2, filter element; 3, sealing gasket; 4, metal outer frame. Detailed Implementation

[0035] A method for recycling and regenerating a regenerable ion exchange resin filter includes the following steps:

[0036] S1 uses a glue-free process to manufacture the filter cloth;

[0037] Double-sided PP needle-punched cotton is mixed with ion exchange resin. The resin is fixed in the middle of the PP needle-punched cotton by the fiber filaments through the needle punching process. At the same time, the entire filter cloth is sealed to prevent resin leakage.

[0038] The needle-punching process uses fibers to fix resin in the middle of PP needle-punched cotton, resulting in filter cloths that are resistant to acids and alkalis, high temperature, have good water permeability, are easy to recycle, have high strength, and low resistance.

[0039] Furthermore, by fixing ion-exchange resin within the PP needle-punched cotton, the adsorption and processing capacity of the filter material is increased. The resin is fixed within the PP needle-punched cotton using fiber filaments, ensuring uniform and stable resin distribution. Edge sealing further enhances the structural strength of the filter cloth, preventing resin leakage or loss. Because the resin is fixed within the needle-punched cotton, it is less prone to loss during regeneration, ensuring the filter's durability and regeneration efficiency. This structure helps the resin maintain good filtration performance even after multiple regenerations. By fixing the resin and sealing the edges, the filter's durability is improved, extending its service life.

[0040] Furthermore, the PP needle-punched cotton is a 100-300gsm non-woven fabric with a white or gray side, a thickness, and a fluffiness of 1-5mm. When using it, the white and gray sides can be arbitrarily interchanged according to actual needs, with one white side and one gray side, or two white sides or two gray sides.

[0041] PP needle-punched cotton, a porous, lightweight, and relatively thick nonwoven material, provides an excellent support and dispersion substrate for ion-exchange resins. Its fabric weight range of 100-300 gsm allows the nonwoven fabric to maintain both sufficient strength and good air permeability and filtration efficiency. As a core component of the filter, the stable fiber structure of PP needle-punched cotton helps to immobilize the ion-exchange resin, preventing resin displacement or loss during use. This stability is crucial for maintaining the long-term performance and regeneration capacity of the filter. The porous structure of PP needle-punched cotton helps increase the contact area between the filter and the fluid, thereby improving filtration efficiency. Simultaneously, its thicker fabric can accommodate more ion-exchange resin, increasing the filter's processing capacity.

[0042] During filter regeneration, PP needle-punched cotton helps the resin to uniformly accept the regenerant, ensuring complete regeneration. Its excellent air permeability and liquid absorption contribute to the uniform distribution and rapid penetration of the regenerant into the resin. Due to its good durability and stability, PP needle-punched cotton can withstand multiple regeneration processes without easily being damaged.

[0043] Furthermore, the ion exchange resin can be classified according to its morphology into gel-type ion exchange resin or macroporous ion exchange resin, and according to its acidity or base into anion and cation resin: strong base anion exchange resin or weak base anion exchange resin, strong acid cation exchange resin or weak acid cation exchange resin.

[0044] Furthermore, regenerable ion exchange resin filters include cation exchange resin filters and anion exchange resin filters;

[0045] Preferably, cation exchange resin filters are regenerated using an acidic solution, while anion exchange resin filters are regenerated using an alkaline solution.

[0046] Furthermore, the acidic regeneration solution is an aqueous solution of sulfuric acid, hydrochloric acid, phosphoric acid, or nitric acid, which makes the regeneration more complete;

[0047] Regenerating cation exchange resins using acidic regenerants such as sulfuric acid, hydrochloric acid, phosphoric acid, or nitric acid solutions can efficiently remove impurities. These acidic regenerants effectively remove impurities adsorbed on the cation exchange resin, restoring its exchange capacity. Sulfuric acid and hydrochloric acid, in particular, due to their strong acidity, can rapidly replace the adsorbed cations on the resin, restoring it to a near-original state. This increases exchange capacity. Using acidic regenerants can significantly improve the exchange capacity of cation exchange resins. Through regeneration, the active groups of the resin are re-exposed, increasing the availability of its exchange sites. It extends resin lifespan. Regular regeneration of cation exchange resins with acidic regenerants can significantly extend the resin's lifespan. By removing adsorbed impurities and restoring exchange capacity, the resin can maintain high performance for a longer period. It improves ammonia removal efficiency. Cation exchange resins treated with acidic regenerants can more effectively remove ammonia from the air, thereby improving the treatment of alkaline pollutants in the air. This is particularly important for applications requiring high levels of clean air.

[0048] Furthermore, the alkaline regeneration solution is an aqueous solution of sodium hydroxide, ammonia, or potassium hydroxide, which makes the regeneration more complete.

[0049] This invention relates to an alkaline regeneration solution, using an aqueous solution of sodium hydroxide or potassium hydroxide, which provides highly efficient regeneration during the regeneration of anion exchange resins. Sodium hydroxide and potassium hydroxide are strongly alkaline, effectively replacing the anions adsorbed on the anion exchange resin, thus achieving efficient resin regeneration. This efficient regeneration can quickly restore the resin's exchange capacity and improve its working efficiency. It can remove SO2 from the air as well as organic matter and pigments. When using an alkaline regeneration solution containing sodium hydroxide, its strongly alkaline environment helps dissolve and clean acidic ions, organic matter, and pigments adsorbed on the resin surface, further improving the regeneration effect and purity of the resin. This is particularly important for applications requiring high-purity products. It can extend the resin's service life. Regularly using the alkaline regeneration solution to regenerate anion exchange resin can effectively remove contaminants from the resin, preventing them from clogging resin pores or damaging the resin structure. This not only maintains the resin's high performance but also significantly extends its service life, reduces replacement frequency and maintenance costs, and improves air treatment efficiency. After treatment with alkaline regenerant, anion exchange resins can more effectively remove acidic pollutants from the air, such as sulfur dioxide, thereby improving air treatment efficiency. This is of great significance in the field of air purification. Compared with replacing the resin with new ones, the environmentally friendly and sustainable use of alkaline regenerants for resin regeneration reduces waste generation and minimizes environmental impact. This sustainable practice not only aligns with environmental protection principles but also helps companies achieve green production and sustainable development goals.

[0050] Furthermore, by employing a needle-punching process to fix resin within the PP needle-punched cotton using fiber filaments, the prepared filter cloth exhibits the following structural characteristics:

[0051] As shown in Figure 1 (filter cloth needle punching process), the filter cloth consists of an upper layer of PP needle punched cotton, a lower layer of PP needle punched cotton, fiber filaments, and resin.

[0052] The fibers are needle-punched and connected to the upper and lower layers of PP needle-punched cotton, forming M (M≥2) longitudinal and N (N≥2) transverse fiber surfaces in the upper and lower layers of PP needle-punched cotton.

[0053] M-1, N-1, or (M-1)*(N-1) cavities are formed between the fiber filament surface, the upper PP needle-punched cotton, and the lower PP needle-punched cotton, and the resin is disposed in the cavity.

[0054] The resin is placed in the cavity formed by the fiber filaments between the upper and lower PP needle-punched cotton layers, thus firmly fixing the resin in the cavity and preventing resin from scattering during the regeneration and cleaning processes of the regenerable ion exchange resin filter.

[0055] This invention utilizes fiber filaments to form a fiber surface between the upper and lower layers of PP needle-punched cotton. The gaps between the fiber filaments create good air and water permeability between adjacent cavities. This ensures that each surface of the regenerable ion exchange resin is fully impregnated during the regeneration process, resulting in more complete regeneration. Furthermore, the cleaning step allows for more thorough cleaning of each surface of the regenerable ion exchange resin, reducing or eliminating the residue of regeneration solution on its surface.

[0056] S2, Assemble the filter

[0057] As shown in Figure 7, first, the filter element is assembled onto the corrosion-resistant plastic frame; then, it is assembled onto the metal outer frame. The plastic frame and the metal outer frame are designed with matching grooves; during recycling, the plastic frame is removed from the non-corrosion-resistant metal outer frame.

[0058] Furthermore, the plastic frame is made of PP, PS, or ABS.

[0059] The metal frame material is: aluminum profile, or aluminum sheet metal frame, or galvanized steel sheet, or cold-rolled steel sheet, or aluminum-zinc coated.

[0060] While a plastic frame alone is corrosion-resistant, it has a poor structure. This invention adds a metal outer frame to the outside of the plastic frame, which improves the overall strength of the filter.

[0061] The design of the plastic frame and metal outer frame of this invention has matching grooves, which eliminates the need for glue and connectors, and allows the plastic frame to be easily removed from the metal outer frame.

[0062] Furthermore, as shown in Figure 2 (filter plastic frame) and Figure 3 (metal outer frame), the plastic frame and filter element are filled with glue to fill the groove inside the frame, so that no liquid remains in the frame after the regeneration liquid or pure water is removed.

[0063] S3, Recycling Steps:

[0064] S31. After the filter is retrieved, if the outer frame is not deformed, it can be placed directly into the regeneration equipment for regeneration.

[0065] S32, after the filter is retrieved, if the outer frame is deformed, remove the plastic frame, tear open the needle-punched cotton, and put the recovered resin into the regeneration device for regeneration.

[0066] S4, Regeneration process of regenerable ion exchange resin filter

[0067] S41, after laying the filter flat, add acidic or alkaline regenerant at 3-25L / min. After the regenerant level covers the filter, continue to add regenerant at the same flow rate to discharge the regenerant, ensuring that the regenerant level always covers the filter, until all the regenerant is consumed, then stop regeneration.

[0068] Continuously adding regenerant at a rate of 3-25 L / min ensures that the regenerant flows evenly through every part of the filter, resulting in uniform and efficient regeneration. This continuous flow prevents localized accumulation of regenerant within the filter, ensuring uniform treatment of the entire filter and achieving a consistent and efficient regeneration effect.

[0069] Continuously dripping and draining the regenerant at a rate of 3-25 L / min can accelerate the chemical reaction rate during regeneration, thereby shortening the total regeneration time. This dynamic regeneration method is more efficient than static soaking, quickly restoring filter performance and achieving the effects of reducing regeneration time and improving regeneration efficiency.

[0070] Regeneration via continuous flow effectively prevents the ion exchange resin channels from becoming clogged again by other impurities during the regeneration process. The continuous flow of the regenerant helps remove impurities from the ion exchange resin in the filter, maintaining its permeability.

[0071] Uniform regeneration maximizes filter performance and extends its lifespan. By ensuring the regeneration liquid level consistently covers the filter, every part of the filter is fully regenerated, effectively improving the regeneration rate.

[0072] Continuously dripping and discharging the regenerated solution at a controlled flow rate ensures its full utilization. This method avoids waste, improves its utilization efficiency, and reduces wastewater treatment costs and environmental burden.

[0073] Through uniform regeneration, the structure and performance of the filter can be made more stable. This stability not only improves the filter's performance but also reduces the frequency and cost of maintenance.

[0074] Furthermore, the regenerated liquid is recycled more than twice, saving regenerated liquid.

[0075] On the one hand, recycling the regenerated solution reduces the consumption of fresh regenerated solution, thereby improving resource utilization efficiency. This not only lowers production costs but also helps reduce environmental impact, achieving a more environmentally friendly production method. On the other hand, recycling the regenerated solution allows for more sufficient contact and reaction time between the resin and the ions in the regenerated solution, thus enhancing the regeneration effect. Multiple recycling of the regenerated solution helps to more thoroughly wash away adsorbed ions and impurities from the resin, restoring the resin to a state closer to its original properties. Thirdly, recycling the regenerated solution helps stabilize the chemical environment during the regeneration process because the chemical components in the regenerated solution may reach a dynamic equilibrium through multiple cycles. This stability improves the controllability and consistency of the regeneration process, ensuring that each regeneration achieves the expected results.

[0076] Furthermore, the used and discarded ion exchange resin filter is regenerated with an alkaline or acidic solution at a volume ratio of 1:1 to 1:5.

[0077] S42, Cleaning steps: Rinse the regenerated filter with pure water at a flow rate of 10-50L / min. After the liquid level exceeds the filter, discharge the wastewater at the same flow rate. Stop rinsing when the pH value of the rinse wastewater reaches 6-8.

[0078] The regenerated ion exchange resin filter is rinsed using the specific cleaning steps and parameters of this invention to thoroughly remove residual regenerant. Rinsing with pure water at a flow rate of 10-50 L / min ensures that any alkaline or acidic regenerant used during regeneration is completely removed. This helps prevent regenerant residue from dripping acid / alkali solutions in high humidity environments, optimizing the operating environment. The final pH value of the rinse is set to 6-8 to ensure the resin is neutral and non-corrosive. Thorough rinsing ensures that the internal pores and surfaces of the resin are thoroughly cleaned, allowing for faster ion adsorption and release during the next regeneration, improving regeneration efficiency. This also extends the resin's lifespan. Regular and proper rinsing reduces damage to the resin caused by residues or improper handling, thus extending its service life.

[0079] Ideally, the temperature of the regenerated solution should be 25-98℃ to ensure more complete regeneration.

[0080] Regenerating ion exchange resin at a higher temperature can effectively accelerate the reaction rate and shorten the regeneration time.

[0081] Ideally, the pure water temperature should be 25-98℃ for a more thorough cleaning.

[0082] This invention utilizes pure water at 25-98°C for rinsing during the cleaning and regeneration of ion exchange resin filters, achieving a series of unexpected technical benefits. First, it enhances the cleaning effect. Within this temperature range, the solubility and flowability of pure water are optimized, enabling more effective removal of contaminants from the resin surface and interior. High-temperature water helps soften and dissolve stubborn dirt, thus improving the thoroughness of the cleaning. Second, it promotes resin regeneration. Appropriate temperature accelerates the ion exchange process within the resin, allowing it to recover to its optimal working state more quickly. This helps improve regeneration efficiency and shorten the regeneration cycle. Third, it extends resin lifespan. Regular rinsing with pure water at suitable temperatures reduces performance degradation caused by dirt accumulation, thereby extending its lifespan. This reduces the cost of frequent resin replacements and the risk of operational interruptions. Fourth, it improves the stability of the filter system. The contaminants and impurities removed during cleaning reduce clogging and wear within the filter system, helping to maintain stable operation of the ion exchange system. This reduces the probability of filter system failure and improves overall reliability.

[0083] Preferably, the filter and rinsing pure water are rinsed at a volume ratio of 1:3 to 1:10 during the cleaning process to ensure that the pH of the water reaches neutral after rinsing.

[0084] S43, Drying steps: Dry the cleaned regenerated ion exchange resin filter. Stop drying when the filter element surface is dry and the moisture content is 15-25%.

[0085] This invention controls the resin's moisture content within the range of 15-25%. On one hand, this prevents the resin from becoming brittle due to excessive drying, or from experiencing performance degradation due to excessive moisture. This helps maintain the resin's activity, extend its service life, and reduce replacement frequency.

[0086] On the other hand, controlling the resin's moisture content within the range of 15-25% helps maintain the stability of the resin structure and prevents its performance from changing due to environmental variations (such as temperature and humidity fluctuations). This ensures that the resin maintains consistent performance under various environmental conditions.

[0087] Ideally, the drying temperature should be 40-70℃ to ensure that ions do not precipitate out of the resin.

[0088] On the one hand, the present invention dries the resin within a temperature range of 40-70℃, which helps to fine-tune and optimize the internal structure of the resin. This temperature range is relatively mild and can avoid the damage to the resin structure that may be caused by high temperatures, thereby maintaining the integrity and performance of the resin.

[0089] On the other hand, a lower drying temperature can prevent the resin from undergoing thermal degradation. High temperatures can cause the resin to decompose, producing harmful substances that affect its quality and performance. A temperature range of 40-70℃ can effectively avoid this.

[0090] Third, a suitable drying temperature can maintain the activity of the resin and avoid resin deactivation caused by excessively high temperatures. Drying at a temperature of 40-70℃ can ensure that the resin retains its ion exchange capacity during the regeneration process.

[0091] As shown in Figure 4, the service life of the cation exchange resin filter prepared by the regenerable ion exchange resin filter recycling method of the present invention was tested. For the cation exchange resin filter, the service life was tested when the filter efficiency decreased from 100% to 70%, and the test results are as follows:

[0092] When the efficiency of the original resin filter decreases from 100% to 70%, the filter life is 1000-1100 minutes.

[0093] When the filter efficiency drops from 95-100% to 70% after one regeneration, the filter life is 900-1000 minutes.

[0094] When the filter efficiency drops from 95-100% to 70% after 5 regenerations, the filter life is 800-900 minutes.

[0095] Therefore, it can be seen that the cation resin filter prepared by the regenerable ion resin filter recycling and regeneration method of the present invention has an initial efficiency of >97% within five regenerations and can maintain 85% of the original resin life.

[0096] As shown in Figure 5, the service life of the anion exchange resin filter prepared by the regenerable ion exchange resin filter recycling method of the present invention was tested. For the anion exchange resin filter, the service life was tested when the filter efficiency decreased from 100% to 70%, and the test results are as follows:

[0097] When the efficiency of the original resin filter decreases from 100% to 70%, the filter life is 600-700 minutes.

[0098] When the filter efficiency drops from 95-100% to 70% after one regeneration, the filter life is 500-600 minutes.

[0099] When the filter efficiency drops from 95-100% to 70% after 5 regenerations, the filter life is 400-500 minutes.

[0100] When the filter efficiency drops from 95-100% to 70% after 7 regenerations, the filter life is 300-400 minutes.

[0101] Therefore, it can be seen that the anion exchange resin filter prepared by the regenerable ion exchange resin filter recycling and regeneration method of the present invention has an initial efficiency of >97% within five regenerations and can maintain 85% of the original resin life.

[0102] As shown in Figure 6, the number of cycles of the cation resin filter regeneration liquid prepared by the regeneration method of the present invention was tested. After the regeneration liquid was used 3 times, its service life was still more than 650 minutes, which is more than 80% of the original resin, and it can maintain a good performance.

[0103] Furthermore, as shown in Figure 7, the filter includes a metal outer frame 4, a plastic frame 1, a sealing gasket 3, and a filter element 2. Both ends of the filter element 2 are installed inside the plastic frame 1, and the plastic frame 1 is disposed inside the metal outer frame 4, connected by the sealing gasket 3. The plastic frame 1 and the metal outer frame 4 are designed with matching grooves, and the plastic frame 1 and the metal outer frame 4 are connected by inserting into these grooves.

[0104] Furthermore, as shown in Figures 2 and 3, the filter also includes a protective mesh 5, a card comb 6, and a sealant 7. The card comb 6 is used to fix the filter cloth, the protective mesh 5 is used to prevent the filter cloth from deforming, and the sealant 7 is used to fix the filter cloth and the plastic frame.

Claims

1. A method for recycling and regenerating a regenerable ion exchange resin filter, characterized in that... Includes the following steps: S1, Making filter cloth Double-sided PP needle-punched cotton is mixed with ion exchange resin. The resin is fixed in the middle of the PP needle-punched cotton by the fiber filaments through the needle-punching process. At the same time, the entire PP needle-punched cotton is sealed to form a filter cloth. S2, Assemble the filter First, the filter element formed from the filter cloth is assembled into a corrosion-resistant frame to form a filter; Then, the filter is assembled into the metal frame; the corrosion-resistant frame is detachably installed inside the metal frame. S3, Filter Recycling Step S31, Remove the filter from the metal frame; S32, If the filter is not deformed, it can be placed flat on the regeneration equipment for regeneration. S32, If the filter is deformed, tear open the filter element and put the recovered resin into the regeneration device for regeneration; S4, Filter regeneration process S41, Regeneration steps: The regeneration equipment drips acidic or alkaline regeneration solution at a rate of 3-25 L / min. After the regeneration solution level covers the filter, the regeneration solution continues to drip while being discharged at the same flow rate to ensure that the regeneration solution level always covers the filter. Regeneration is stopped after all the regeneration solution is consumed. S42, Cleaning steps: Rinse the regenerated filter with pure water at a flow rate of 10-50L / min. After the liquid level exceeds the filter, discharge the wastewater at the same flow rate. Stop rinsing when the pH value of the rinsing wastewater reaches 6-8. S43, Drying steps: Dry the cleaned filter until the filter element surface is dry and the moisture content is 15-25%.

2. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: In step S1, the PP needle-punched cotton is a 100-300gsm nonwoven fabric. The ion exchange resin is a gel-type ion exchange resin, or a macroporous ion exchange resin, or a strong acid cation exchange resin, or a weak acid cation exchange resin, or a strong base anion exchange resin, or a weak base anion exchange resin; the cation exchange resin filter is regenerated using an acidic solution, and the anion exchange resin filter is regenerated using an alkaline solution.

3. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: The prepared filter cloth has the following structural characteristics: The filter cloth includes an upper layer of PP needle-punched cotton, a lower layer of PP needle-punched cotton, fiber filaments, and resin. The fiber filaments are needle-punched and connected to the upper and lower layers of PP needle-punched cotton, forming M longitudinal and / or N transverse fiber filament surfaces, where N≥2 and M≥2. M-1, N-1, or (M-1)*(N-1) cavities are formed between the fiber filament surfaces, the upper and lower layers of PP needle-punched cotton, and the resin is disposed within the cavities.

4. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: In step S2, the corrosion-resistant frame is made of PP, PS, or ABS; the metal outer frame is made of aluminum profile, aluminum plate frame, galvanized steel plate, cold-rolled steel plate, or aluminum-zinc coated steel.

5. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: In step S2, the filter element and corrosion-resistant frame are filled with glue to fill the grooves inside the frame, so that no liquid residue remains in the frame after regeneration.

6. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: Step S41: The acidic regeneration solution is an aqueous solution of sulfuric acid, hydrochloric acid, phosphoric acid, or nitric acid; the alkaline regeneration solution is an aqueous solution of sodium hydroxide, ammonia, or potassium hydroxide.

7. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: Step S41: Regenerate the used and recycled filter with an alkaline or acidic solution at a volume ratio of 1:1 to 1:

10.

8. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: Step S42: The filter from the cleaning step is rinsed with pure water at a volume ratio of 1:3 to 1:

10.

9. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: In steps S41 and S42, the temperature of the regenerated solution and pure water is 25-98℃.

10. The method for recycling and regenerating a regenerable ion exchange resin filter according to claim 1, characterized in that: Step S43, drying temperature is 40-70℃; In steps S41 and S42, the regenerated liquid and pure water can be recycled more than twice.

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