Device and method for recovering and treating organic solvent and waste gas of yarns and textiles

Abstract

The invention provides a yarn and textile organic solvent and waste gas recovery treatment device and method. The device comprises a waste gas purification unit, a low-temperature condensation unit, a circulation pipeline and a filtering separation unit which are sequentially connected with the output end of a yarn / textile treatment unit. A primary pre-dedusting and secondary gradient absorption structure is adopted, DCS closed-loop control is matched, acid gases such as solid impurities, hydrogen chloride and the like and organic pollutants in waste gas are efficiently removed, and meanwhile, the treatment process is precisely regulated and controlled; the first absorption cavity is filled with lime milk containing a polycarboxylic acid dispersing agent, and the second absorption cavity is filled with sodium bicarbonate containing an organic amine buffering agent, so that acidic waste gas is effectively absorbed; through combination of gravity standing layering and multi-stage filtration, efficient separation of organic phase, water phase and solid impurities is realized by utilizing flow guide and membrane separation technologies. According to the invention, pre-dedusting, gradient absorption, low-temperature condensation, multi-stage filtration and intelligent control are integrated to form a closed circulation system adaptive to a multi-component silane system.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to an apparatus and method for the recovery and treatment of organic solvents and waste gases from yarns and textiles. Background Technology

[0002] Textile finishing processes often involve the use of large quantities of chemical reagents and organic solvents. Without effective control, the volatilization and emission of these chemicals can lead to environmental pollution and resource waste. For example, traditional superhydrophobic finishing often uses organic solvents as coating media. During the drying process, these solvents evaporate in large quantities, becoming volatile organic compounds (VOCs), which not only pose safety hazards to factory workshops and worker health but also pollute the atmosphere. Meanwhile, fluorinated compounds (PFAS) used to achieve durable hydrophobic effects are increasingly subject to regulatory restrictions due to their persistent environmental residues and potential toxicity. In the context of green manufacturing, the textile industry urgently needs to seek more environmentally friendly and sustainable finishing processes and supporting equipment.

[0003] While some green initiatives have been attempted, such as replacing organic solvents with aqueous systems or using biodegradable polymers to replace fluorinated reagents, shortcomings remain in meeting the requirements for superhydrophobic performance and efficient industrial production. Many production lines lack solvent recovery facilities, resulting in significant losses due to the evaporation of organic solvents. Furthermore, the use of different functional additives in the same treatment solution may lead to mutual interference or difficulties in disposing of byproduct waste.

[0004] Therefore, there is an urgent need for a system-integrated green treatment system that can fully recover and treat solvents and reaction byproducts in the process while achieving superhydrophobic modification, and is compatible with multi-component chemical systems to improve resource utilization. Summary of the Invention

[0005] This invention addresses the problems of non-recyclable treatment solutions, ineffective waste disposal leading to excessive solvent consumption and emissions, incompatible component recycling, and air pollution during the processing of superhydrophobic yarns / textiles. It provides a device and method for recovering and treating organic solvents and waste gases from yarns and textiles. The device employs a primary pre-dust removal + secondary gradient absorption structure, coupled with DCS closed-loop control, to efficiently remove solid impurities, acidic gases such as hydrogen chloride, and organic pollutants from waste gases, while precisely controlling the treatment process. The first absorption chamber is filled with lime slurry containing a polycarboxylic acid-based dispersant, and the second absorption chamber is filled with sodium bicarbonate containing an organic amine buffer, effectively absorbing acidic waste gases. This invention utilizes gravity-based static stratification and multi-stage filtration, along with flow guidance and membrane separation technology, to achieve efficient separation of the organic phase, aqueous phase, and solid impurities. This invention integrates "pre-dust removal - gradient absorption - low-temperature condensation - multi-stage filtration - intelligent control" into a single closed-loop circulation system adapted to multi-component silane systems.

[0006] This invention provides an organic solvent and waste gas recovery and treatment device for yarns and textiles, comprising a waste gas purification unit, a low-temperature condensation unit, a circulation pipeline and a filtration and separation unit connected in sequence to the output end of the yarn / textile processing unit; The exhaust gas purification unit includes a first absorption chamber and a second absorption chamber arranged sequentially on the output side of the yarn / textile processing unit, a first gas inlet pipe sealed between the output side of the yarn / textile processing unit and the first absorption chamber, a first gas guide pipe sealed between the first absorption chamber and the second absorption chamber, a second gas inlet pipe connected to the end of the first gas guide pipe and extending into the interior of the second absorption chamber, a second gas guide pipe sealed between the second absorption chamber and the low-temperature condensation unit, a pre-dust removal module connected to the input end of the first gas inlet pipe, a pH sensor located at the bottom of the second absorption chamber, and a suction pump connected to the second gas guide pipe. The pre-dust removal module removes solid impurities carried in the exhaust gas generated by the filtration system and the yarn / textile processing unit. The air pump located at the end of the second absorption chamber keeps the exhaust gas purification unit under negative pressure. The yarn / textile processing unit, the first absorption chamber, and the second absorption chamber are all closed cavities. The yarn / textile processing unit generates acidic waste gas including gaseous organic reagents. The first and second absorption chambers are connected in series to form a gradient absorption module. The first absorption chamber contains a lime milk suspension composed of lime milk, dispersant, and water to absorb the acidic waste gas generated by the yarn / textile processing unit. The second absorption chamber contains a composite liquid composed of sodium bicarbonate, organic buffer, and water to perform gradient absorption of the acidic waste gas. The low-temperature condensation unit condenses the gaseous organic reagents generated by the yarn / textile processing unit into liquid organic reagents and outputs them to the filtration and separation unit through a circulation pipeline. The filtration and separation unit recovers the organic reagents by gravity settling and multi-stage filtration.

[0007] The organic solvent and waste gas recovery and treatment device for yarn and textiles according to the present invention, in a preferred embodiment, the waste gas purification unit further includes a waste gas flow meter connected to the end of the first absorption chamber and a pump frequency converter connected to the pump. The circulation line is also connected between the top of the filtration and separation unit and the bottom of the yarn / textile processing unit, and a liquid transfer pump is connected to the circulation line. It also includes a distributed control system that is connected to the pH meter, the frequency converter of the air pump, and the exhaust gas flow meter. The distributed control system adjusts the air pumping rate based on the measurement results of the exhaust gas flow meter and the pH meter.

[0008] The organic solvent and waste gas recovery and treatment device for yarns and textiles according to the present invention, in a preferred embodiment, includes the following steps in its distributed control system control method: After the SA1, yarn and textile organic solvent and waste gas recovery and treatment device starts operation, the distributed control system enters the signal acquisition stage. The waste gas flow meter continuously monitors the instantaneous flow of waste gas in the pipeline and converts the physical flow signal into an electrical signal, which is then transmitted to the main controller of the distributed control system. The pH detector detects the pH value in the second absorption chamber in real time, converts it into an electrical signal, and transmits it to the main controller. SA2. After receiving the instantaneous flow rate and pH value of the exhaust gas, the main controller enters the signal feedback and analysis stage. The built-in signal processing module filters, amplifies, and calibrates the instantaneous flow rate and pH value electrical signals of the exhaust gas. Then, it compares the processed exhaust gas flow rate value with the preset flow rate threshold and the pH value with the preset pH threshold. When the exhaust gas flow rate value is less than or equal to the preset flow rate threshold or the pH value is greater than or equal to the preset pH threshold, the pipeline is in the normal range and is continuously monitored. When the exhaust gas flow rate value is greater than the preset flow rate threshold and the pH value is less than the preset pH threshold, it is determined that the amount of exhaust gas in the pipeline has increased, causing the accumulation of acidic substances. This triggers the control command generation logic and proceeds to step SA3. SA3. The main controller enters the instruction output and execution stage, outputs a speed control signal to the air pump frequency converter, starts the air pump frequency converter to adjust the output voltage and frequency, drives the air pump motor speed to increase and the output frequency to increase the air pump pump speed proportionally, thereby accelerating the discharge of waste gas in the pipeline. SA4. As the extraction rate increases, the amount of waste gas in the pipeline gradually decreases. The instantaneous flow rate electrical signal of the waste gas collected in real time by the waste gas flow meter decreases synchronously. At the same time, the pH value detected by the pH detector gradually rises and tends to the pH preset threshold. When the main control enters the closed-loop feedback regulation stage, when the waste gas flow rate is less than or equal to the preset flow threshold and the pH value is greater than or equal to the preset pH threshold, the main controller outputs the regulation command and controls the frequency converter of the extraction pump to reduce the output frequency, so that the extraction rate is restored to the reference value, forming a closed-loop stable control, and returns to step SA2.

[0009] In the preferred embodiment of the organic solvent and waste gas recovery and treatment device for yarn and textiles described in this invention, in step SA3, the speed control signal is a pulse width modulation (PWM) signal.

[0010] The organic solvent and waste gas recovery and treatment device for yarn and textiles according to the present invention, in a preferred embodiment, the waste gas purification unit further includes a lime milk storage tank sealed to the top of the first absorption chamber, a composite absorption storage tank sealed to the top of the second absorption chamber, liquid control valves respectively connected to the outlets of the lime milk storage tank and the composite absorption storage tank, a porous aeration pipe respectively connected to the end of the first gas inlet pipe and the end of the second gas inlet pipe, and a stirrer connected to the conical settling tank at the bottom of the first absorption chamber; The lime slurry storage tank and the composite absorption storage tank replenish the first absorption chamber and the second absorption chamber, respectively; The end of the first gas inlet tube is inserted below the surface of the lime slurry suspension. The beginning of the first gas inlet tube is above the surface of the lime slurry suspension and the end is connected to the second gas inlet tube. The end of the second gas inlet tube is inserted below the surface of the composite liquid, and the beginning of the second gas inlet tube is above the surface of the composite liquid. The side of the porous aeration pipe is connected to at least two aeration holes, which are located on the gas passage and below the liquid surface; The pre-dust removal module is a sintered metal mesh filter connected to the starting end of the first gas inlet pipe. The sintered metal mesh filter has a built-in removable filter element with a pore size of 5 to 10 μm. The first absorption chamber, the second absorption chamber, the first gas inlet pipe, the first gas guide pipe, the second gas inlet pipe, and the second gas guide pipe are all made of Hastelloy C-276 material, and the first gas inlet pipe, the first gas guide pipe, the second gas inlet pipe, and the second gas guide pipe are all L-shaped pipes.

[0011] The organic solvent and waste gas recovery and treatment device for yarn and textiles of the present invention, as a preferred embodiment, comprises a lime milk suspension consisting of 12-15% by mass of lime milk, 0.5-1% by mass of polycarboxylate dispersant and 84-87.5% by mass of water, and the pH value of the lime milk suspension is 12-13. The composite solution consists of 5-7% sodium bicarbonate, 3-5% organic amine buffer, and 88-92% water by mass. The pH value of the composite solution is 10-11.5. The organic amine buffer reacts with the acidic waste gas to generate water-soluble salts, thereby prolonging the pH stability period of the composite solution.

[0012] The organic solvent and waste gas recovery and treatment device for yarn and textiles of the present invention, as a preferred embodiment, is that the acidic waste gas generated by the yarn / textile treatment unit is hydrochloric acid waste gas, hydrogen bromide waste gas, or hydrogen fluoride waste gas, and the organic solvent is any one or more of the following: petroleum ether, dodecyltrichlorosilane, and trichlorosilane. The polycarboxylic acid dispersant is polymaleic anhydride, and the organic amine buffer is triethanolamine.

[0013] In a preferred embodiment of the organic solvent and waste gas recovery and treatment device for yarns and textiles described in this invention, the low-temperature condensation unit is a condenser, and a gradient cooling liquid is introduced into the jacket structure of the low-temperature condensation unit. The inlet temperature of the cooling liquid is -5 to 0°C and the outlet temperature is 15 to 20°C. The condensation temperature is controlled by a temperature controller. The gradient cooling liquid is a refrigerant, which is water or ethylene glycol. The inner layer of the circulation pipeline is made of PVDF, the middle layer is made of stainless steel, and the outer layer is an insulation layer. Fluororubber seals are used to prevent organic solvent leakage and condensation in the pipeline. The circulation pipeline is set with a slope of 1 to 2% and the connection port with the filter separation unit is set at the lowest point.

[0014] The organic solvent and waste gas recovery and treatment device for yarn and textiles according to the present invention, in a preferred embodiment, includes a filtration and separation unit comprising a tank, at least two inclined guide plates connected to the top of the tank, a ceramic membrane filter connected to the middle of the tank, a hydrophilic and oleophobic membrane connected to the bottom of the tank, and a solid particulate matter outlet, an organic solvent outlet, and an outlet respectively connected from top to bottom to the side of the tank. The solid particulate matter outlet is located at the top of the ceramic membrane filter, the organic solvent outlet is located at the top of the hydrophilic and oleophobic membrane, and the outlet is located at the bottom of the tank.

[0015] This invention provides a method for treating organic solvents and waste gas from yarns and textiles using a recycling and treatment device, comprising the following steps: S1. When continuous modification is carried out inside the yarn / textile processing unit, the yarn / textile leaves after being immersed in a processing tank containing organic reagents. The acidic gas generated during the hydrolysis and crosslinking reaction of silane and the volatilization of organic solvents carried on the surface of the yarn / textile cause acidic waste gas including gaseous organic reagents to be generated in the yarn / textile processing unit. S2. Acidic waste gas passes through a pre-dust removal module to remove solid fiber particles, then enters the first absorption chamber through the first gas inlet pipe and is partially absorbed by the lime milk suspension. Untreated waste gas passes through the first gas guide pipe and the second gas inlet pipe into the second absorption chamber and is absorbed by the composite liquid. At the same time, the waste gas flow meter monitors the waste gas flow in real time. The negative pressure value of the acidic gas concentration in the waste gas inlet is -0.02 to -0.05 MPa. The pH detector monitors the pH value in the solution in the second absorption chamber in real time. The distributed control system controls the waste gas flow in the pipeline through the frequency converter of the air pump. When the concentration of the waste gas flow meter is higher than 50 ppm and the pH value of the pH detector is less than 9, the pumping speed of the air pump is automatically increased proportionally. S3. After passing through the exhaust gas purification unit, the acidic gas is absorbed and the organic reagent residue is removed to obtain the pre-treated exhaust gas. The pre-treated exhaust gas enters the low-temperature condensation unit through the circulation pipeline for condensation and is then transported to the filtration and separation unit by the liquid transfer pump. S4. The inclined guide plate of the filtration and separation unit gathers the dripping water and then intercepts the suspended solid particles by the ceramic membrane filter. Then, the hydrophilic and oleophobic membrane filters the aqueous phase to the bottom of the tank, while the organic solvent of the oil phase remains in the middle layer of the tank, realizing the recovery of organic reagents. The recovered organic reagents can be added to the yarn / textile processing unit for reuse after flowing out through the organic solvent outlet. The waste liquid remaining from the reaction in the yarn / textile processing unit can also be transported to the filtration and separation unit for filtration and organic reagent recovery via a liquid transfer pump.

[0016] The technical problem this invention aims to solve is how to achieve the recycling of treatment solutions and the environmentally friendly treatment of waste during the processing of superhydrophobic yarns / textiles, thereby overcoming the difficulties of large-scale solvent consumption and emissions, incompatible component recycling, and exhaust gas pollution in existing technologies. Specifically, the primary challenge is how to construct a closed-loop circulation system to efficiently recover the organic solvents volatilized after yarn impregnation and maintain effective concentrations of various functional chemical auxiliaries during the circulation process. Simultaneously, acidic gases such as hydrogen chloride generated during the hydrolysis and crosslinking reaction of silanes need to be purified to prevent corrosion of equipment or emission into the environment. These problems have not yet been comprehensively solved in traditional textile finishing equipment.

[0017] To address the three major pain points in superhydrophobic finishing of the textile industry—solvent waste, exhaust pollution, and multi-component incompatibility—an integrated solution of "closed-loop circulation + multi-stage treatment + intelligent control" is proposed. This solution responds to green manufacturing policies and addresses the industry's urgent needs for environmental compliance and cost control.

[0018] The present invention has the following advantages: (1) The green solvent recycling system of the present invention significantly improves the environmental protection level and resource utilization rate of superhydrophobic textile finishing.

[0019] (2) Environmental protection, emission reduction and safety assurance: avoid the use of persistent harmful chemicals such as PFAS, reduce potential environmental pollutants from the source; reduce VOC emissions to extremely low levels, far superior to traditional open processes, and meet strict environmental regulations; efficiently remove corrosive gases such as hydrogen chloride produced by silane reaction, prevent equipment corrosion, ensure the safety of workshop operating environment, and prevent secondary pollution.

[0020] (3) Resource recovery and cost saving: Constructing a closed-loop solvent circulation system, the volatile organic solvent recovery rate can be reused multiple times, greatly reducing the cost of raw material consumption; the calcium chloride solid generated by the absorption of hydrogen chloride in the exhaust gas purification unit 200 by lime water suspension can be dehydrated at 200-300℃ to obtain food-grade anhydrous calcium chloride, realizing the secondary resource utilization of waste and reducing the cost of reagent procurement and waste treatment.

[0021] (4) Process stability and efficiency improvement: The multi-component compatible circulation mechanism combined with online monitoring and automatic replenishment function maintains the long-term stability of the treatment liquid formula, eliminating the need for frequent replacement of the treatment liquid, reducing the amount of waste liquid generated and the burden of subsequent treatment, and ensuring the consistency of the processing technology; the whole set of equipment adopts the distributed control system 600 (DCS) to realize real-time monitoring, automatic control and fault warning of the entire process parameters, with a high degree of automation, reducing operating costs and improving the safety and reliability of system operation.

[0022] (5) The system of this invention fully embodies the concept of green manufacturing. Through resource recycling and process emission reduction, it achieves clean production of superhydrophobic fiber modification processing. This system not only ensures the high performance and durability of the final product, but also makes the production process meet the requirements of sustainable development, providing an environmentally friendly manufacturing guarantee for the next generation of waterproof fabrics in outdoor, protective, and medical fields. Attached Figure Description

[0023] Figure 1 A schematic diagram of a device for recovering and treating organic solvents and waste gas from yarns and textiles. Figure 2 This is a schematic diagram of a method for recovering and treating organic solvents and waste gas from yarns and textiles. Figure 3a A top view of the pre-dust removal module of a device and method for recovering and treating organic solvents and waste gas from yarns and textiles; Figure 3b A side view of the pre-dust removal module of an apparatus and method for the recovery and treatment of organic solvents and waste gas from yarns and textiles; Figure 4 This is a schematic diagram of the low-temperature condensation unit structure of an organic solvent and waste gas recovery and treatment device and method for yarn and textiles. Figure 5a A front view of a porous aeration pipe for the treatment of organic solvents and waste gas in yarns and textiles. Figure 5b A partial side view of a porous aeration pipe for the treatment of organic solvents and waste gas in yarns and textiles. Figure 5c A top view of a porous aeration pipe for the treatment of organic solvents and waste gas from yarns and textiles. Figure 6 A schematic diagram of the control system information flow for a distributed control system of a device and method for recovering and treating organic solvents and waste gases from yarns and textiles. Figure 7 A schematic diagram of a low-temperature condensation unit structure for a device and method for recovering and treating organic solvents and waste gases from yarns and textiles. Figure 8 A schematic diagram of a liquid transfer pump structure for an organic solvent and waste gas recovery and treatment device and method for yarns and textiles; Figure 9 This is a schematic diagram of the filtration and separation unit structure of an organic solvent and waste gas recovery and treatment device and method for yarn and textiles.

[0024] Figure label: 100. Yarn / Textile Processing Unit; 200. Exhaust Gas Purification Unit; 201. First Absorption Chamber; 202. Second Absorption Chamber; 203. First Gas Inlet Pipe; 204. First Gas Guide Pipe; 205. Second Gas Inlet Pipe; 206. Second Gas Guide Pipe; 207. Pre-dust Removal Module; 208. pH Meter; 209. Air Pump; 210. Exhaust Gas Flow Meter; 211. Air Pump Frequency Converter; 212. Lime Slurry Storage Tank; 213. Composite Absorption Storage Tank; 214. Liquid Control Valve; 215. Porous Aeration Pipeline; 216. Agitator; 300. Low-Temperature Condensation Unit; 400. Circulation Pipeline; 401. Liquid Transfer Pump; 500. Filtration and Separation Unit; 501. Tank Body; 502. Inclined Baffle Plate; 503. Ceramic Membrane Filter; 504. Hydrophilic and Oleophobic Membrane; 505. Solid Particulate Matter Outlet; 506. Organic solvent export; 507. Export; 600. Distributed control system. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0026] An apparatus and method for recovering and treating organic solvents and waste gases from yarns and textiles are disclosed, used for the recovery and treatment of process waste liquids and gases during the continuous yarn superhydrophobic modification process. The apparatus mainly comprises: a yarn / textile processing unit 100, a waste gas purification unit 200, a low-temperature condensation unit 300, a multi-component compatible circulation pipeline 400, a filtration and separation unit 500, and a distributed control system 600 (DCS). This invention is an integrated solution of closed-loop circulation + multi-stage treatment + intelligent control.

[0027] The yarn / textile processing unit 100 is used to hold a processing liquid containing organic solvents and at least two silane reagents for hydrophobic treatment of yarn / textiles; the exhaust gas purification unit 200, in the area after the yarn leaves the processing unit, adopts a multi-stage structure of "first-stage pre-dust removal + second-stage gradient absorption" and a distributed control system 600 (DCS); the low-temperature condensation unit 300 adopts an integrated design of "serpentine condenser tube"; the filtration and separation unit 500 adopts a "gravity static stratification + multi-stage filtration" mode.

[0028] Multi-stage exhaust gas purification design: It adopts a "first-stage pre-dust removal + second-stage gradient absorption" structure, combined with DCS closed-loop control, to efficiently remove solid impurities, acidic gases such as hydrogen chloride and organic pollutants from exhaust gas, while precisely controlling the treatment process.

[0029] High-efficiency condensation recovery technology: The integrated design of the "serpentine condenser tube" combines cooling and material optimization to achieve high-purity organic solvent recovery (purity ≥99.5%).

[0030] Precise filtration and separation mechanism: Through the combination of "gravity settling and stratification + multi-stage filtration", the organic phase, aqueous phase and solid impurities are efficiently separated by the flow guiding and membrane separation technologies.

[0031] The innovation of this invention lies not in separate condensation recovery or waste gas absorption, but in integrating "pre-dust removal - gradient absorption - low temperature condensation - multi-stage filtration - intelligent control" into one system to form a closed-loop circulation system adapted to multi-component silane systems.

[0032] The organic solvent and waste gas recovery and treatment device for yarn textiles includes: Yarn / textile processing unit 100 (e.g.) Figure 1 and Figure 2 As shown in the diagram, this unit contains a yarn / textile modified superhydrophobic treatment solution. The generated waste gases include, but are not limited to, hydrogen chloride gas, low-boiling-point organic reagent azeotropes, aerosol reagent droplets, and trace amounts of siloxane oligomers and other byproducts produced during the reaction. The entire treatment unit is placed at ambient temperature and pressure. Exhaust gas purification unit 200 (e.g.) Figure 2 , Figure 3a , Figure 3b , Figure 4 As shown), the exhaust gas purification unit 200 adopts a multi-stage structure of "first-stage pre-dust removal + second-stage gradient absorption" and a distributed control system 600 (DCS).

[0033] Pre-dust removal module 207 (e.g.) Figure 3a , Figure 3b As shown): A sintered metal mesh filter (pore size 5-10μm) is added to the end of the gas inlet pipe, with a built-in removable filter element to intercept solid impurities such as yarn fiber debris and treatment liquid droplets carried in the exhaust gas, so as to avoid subsequent absorption liquid clumping and blockage. Gradient absorption module (e.g.) Figure 4 As shown): Two absorption chambers are set up in series. The first absorption chamber 201 is filled with a concentration of 12-15% lime milk + 0.5-1% polycarboxylic acid dispersant (such as polymaleic anhydride). The dispersant can reduce the probability of lime particle agglomeration, reduce the dependence on stirrer 216, and at the same time increase the capacity of the absorption liquid to HCl, pH=12-13). The second absorption chamber 202 is filled with a 5-7% sodium bicarbonate + 3-5% triethanolamine composite solution (pH=10-11.5). Triethanolamine, as an organic amine buffer, can extend the pH stability period of the absorbent solution (from the current 24 hours to 48 hours), and the triethanolamine hydrochloride formed by the reaction with HCl is easily soluble in water, preventing crystallization and pipe blockage. Corresponding liquid storage tanks (lime slurry storage tank 212, composite absorption storage tank 213) are installed at the top of the two absorption chambers to ensure timely supply of absorbent solution. The bottom of the first absorption chamber 201 is equipped with a conical settling tank and a built-in stirrer 216 (speed 30-60 r / min) to prevent lime slurry from clumping. The bottom of the second absorption chamber 202 has a pH meter 208 to monitor the pH value in real time. The first gas inlet pipe 203 and the second gas inlet pipe 205 that introduce gas to the liquid surface adopt a porous aeration design (e.g., Figure 5a , Figure 5b , Figure 5c As shown, the aeration holes are 0.5–1 mm in diameter and 30–50 holes / cm² in density. The aeration hole is inserted 8–10 cm below the surface of the absorbent liquid to increase the gas-liquid contact area through aeration. A waste gas flow meter 210 is installed on the gas pipeline between the first absorption chamber 201 and the second absorption chamber 202 to continuously monitor the instantaneous flow rate of the waste gas in the pipeline. A vacuum pump 209 containing a vacuum pump frequency converter 211 is installed at the end of the second absorption chamber 202. The waste gas flow meter 210, pH meter 208, and vacuum pump 209 are controlled by a distributed control system 600 (DCS) to jointly control the waste gas treatment of the entire system. Distributed Control System 600 (DCS, such as...) Figure 6 As shown): The DSC control system takes the main controller as its core, realizes the acquisition, analysis, decision-making and closed-loop control of the gas flow rate of the exhaust gas flow meter 210 and pH value signal, and the variable frequency regulation of the gas flow of the suction pump 209. The entire information flow adopts a modular transmission design.

[0034] Signal acquisition phase: The exhaust gas flow meter 210 and pH sensor 208 acquire the exhaust gas flow parameters and liquid pH value parameters in the exhaust gas treatment pipeline in real time, respectively. Among them, the exhaust gas flow meter 210 continuously monitors the instantaneous flow rate of the exhaust gas in the pipeline and converts the physical flow signal into a standard electrical signal; the pH sensor 208 is inserted into the pipeline into the wastewater to be treated or into the liquid medium carried by the tail gas after the reaction, detects the pH value in real time and converts it into a corresponding electrical signal. Both transmit the acquired signals to the main controller simultaneously. Signal feedback and analysis phase: After receiving dual signals from the exhaust gas flow meter 210 and pH sensor 208, the main controller filters, amplifies, and calibrates the signals through its built-in signal processing module to eliminate interference. Subsequently, the main controller compares the processed exhaust gas flow rate with a preset flow threshold and the pH value with a preset pH threshold. When both conditions are met ("exhaust gas flow rate > preset flow threshold" and "pH value < preset pH threshold"), it determines that the increased exhaust gas volume in the pipeline has caused the accumulation of acidic substances, triggering the control command generation logic. Command output and execution phase: Based on the above judgment results, the main controller outputs a speed control signal (such as a pulse width modulation signal PWM) to the vacuum pump inverter 211, instructing the vacuum pump inverter 211 to start and increase its output frequency. After receiving the control signal, the vacuum pump inverter 211 adjusts its own output voltage and frequency, driving the motor speed of the vacuum pump 209 to increase, thereby increasing the vacuuming rate of the vacuum pump 209 proportionally and accelerating the discharge of waste gas from the pipeline; Closed-loop feedback regulation stage: As the extraction rate increases, the amount of waste gas in the pipeline gradually decreases, and the flow signal collected in real time by the waste gas flow meter 210 decreases synchronously. At the same time, the pH value detected by the pH sensor 208 gradually rises and tends to the preset threshold. The main controller continuously receives two feedback signals. When the waste gas flow rate drops below the preset threshold and the pH value recovers to the preset range, the main controller outputs an adjustment command to control the pump inverter 211 to reduce the output frequency, so that the extraction rate recovers to the reference value, forming a closed-loop stable control.

[0035] Low-temperature condensing unit 300 (e.g.) Figure 7 As shown, the low-temperature condensing unit 300 adopts a serpentine condenser tube design. The inner tube of the serpentine condenser tube is made of a composite material of borosilicate glass and polytetrafluoroethylene (inner layer of polytetrafluoroethylene, outer layer of borosilicate glass), which is resistant to high-temperature corrosion and improves thermal conductivity by 30%. The outer tube of the serpentine condenser tube adopts a jacketed structure, through which a gradient cooling coolant is introduced (inlet temperature -5~0℃, outlet temperature 15~20℃). The condensing temperature is precisely controlled by a temperature controller (error ≤ ±0.5℃). Utilizing the boiling point difference between petroleum ether and trace amounts of water and impurities (petroleum ether boiling point 60~90℃, water 100℃), secondary separation is achieved, ensuring the purity of the recovered solvent is ≥99.5%. The temperature of the condensing pipe is maintained below 20℃, and the solution in the condenser tube can be widely used refrigerants such as water and ethylene glycol. The multi-component compatible circulation pipeline 400 features a three-layer structure (inner PVDF, middle stainless steel, and outer insulation layer) and is equipped with fluororubber seals to prevent solvent leakage and condensation. The pipeline has a slope (1-2%) and a drain outlet at the lowest point for easy maintenance. Quick-release couplings improve equipment maintenance efficiency. Waste gas contact components (inlet pipe, absorption chamber, etc.) are made of Hastelloy C-276, improving hydrogen chloride corrosion resistance by 50%. A liquid transfer pump (e.g., [missing information]) is installed in the pipeline between the yarn / textile treatment unit 100, the low-temperature condensation unit 300, and the filtration and separation unit 500. Figure 8 As shown in the figure, the liquid is accelerated into the separation unit by a pumping device.

[0036] Filter separation unit 500 (e.g.) Figure 9 As shown, the filtration and separation unit 500 employs a "gravity-driven static stratification + multi-stage filtration" approach. The upper layer features an inclined guide plate 502 (inclination angle 15–20°) to guide the rapid collection of organic solvents. The middle layer contains a ceramic membrane filter 503 (pore size 0.1–0.2 μm) to intercept suspended solid particles (particle size ≥ 0.1 μm). The lower layer is configured with a membrane separation structure based on actual conditions, ensuring that the organic reagent remains in the middle layer under gravity, while the water layer is separated to the bottom. The entire device operates at ambient temperature and pressure. During continuous modification processing, yarns / textiles are immersed in a treatment tank containing organic reagents before leaving the tank. At this point, the organic solvents carried on the yarn surface will rapidly evaporate. To prevent solvent loss and environmental pollution, this system incorporates a sealed collection chamber or hood at the tank outlet to immediately capture the evaporated liquid vapors and liquefy and recover them via a condenser. This invention provides a green solvent recycling and environmentally friendly treatment system suitable for textiles, used for the recovery and treatment of process waste liquids and gases during continuous yarn superhydrophobic modification.

[0037] To make the present invention more apparent and understandable, a preferred embodiment is described below, wherein the waste gas generated in the yarn / textile processing unit 100 is preferably hydrogen chloride gas and volatile silane treatment liquid, and the solid matter includes fiber particles.

[0038] A method for recovering and treating organic solvents and waste gas from yarns and textiles includes the following steps: Yarn and textiles are processed in yarn / textile processing unit 100. The organic reagents in yarn / textile processing unit 100 include petroleum ether, dodecyltrichlorosilane, and trichlorosilane. Petroleum ether (boiling point 60–90°C) accounts for 90–95%, dodecyltrichlorosilane accounts for 3–5%, and trichlorosilane accounts for 1–2%, with the sum of the mass fractions of each component being 100%. The generated waste gas (containing hydrogen chloride and volatile silane treatment liquid) first passes through pre-dust removal module 207 (e.g., ...). Figure 3a , Figure 3b(As shown) Remove any solid fiber particles that may be present in the exhaust gas.

[0039] The gas enters the exhaust gas purification unit 200 through the L-shaped gas inlet pipe (e.g., ...). Figure 4 As shown in the figure, the first absorption chamber 201 contains 12-15% lime milk (12% by mass in this embodiment) + 0.5-1% polycarboxylic acid dispersant (0.5% by mass in this embodiment) with a pH of 12.2. The second absorption chamber 202 contains a composite aqueous solution of 5% sodium bicarbonate + 3% triethanolamine with a pH of 11.0. The first gas inlet pipe 203 extends into the lime milk suspension. The bottom of the first gas inlet pipe 203 is a porous aeration pipe 215 (Figure 5) to ensure that the hydrogen chloride gas and the lime milk suspension react completely. At this time, the untreated waste gas enters the second absorption chamber 202 of the composite absorption liquid through the pipeline. Simultaneously, the waste gas flow meter 210 monitors the waste gas flow rate in real time, and the negative pressure value within the HCl concentration range at the waste gas inlet (controlled range 0.02~0.05MPa) is monitored. The second absorption chamber 202 contains a pH meter 208 that monitors the pH value of the solution in real time. At the end of the second absorption chamber 202 is a vacuum pump 209 with a frequency converter 211. These machines are controlled by a distributed control system 600 (e.g., ...). Figure 6 As shown in the diagram, when the exhaust gas concentration in the flow meter 210 exceeds 50 ppm and the pH value is below 9, the pump speed automatically increases, and the suction rate of the extraction pump 209 increases proportionally, accelerating the discharge of exhaust gas from the pipeline. As the suction rate increases, the amount of exhaust gas in the pipeline gradually decreases, and the flow signal collected in real time by the exhaust gas flow meter 210 decreases synchronously. Simultaneously, the pH value detected by the pH sensor 208 gradually rises and approaches the preset threshold. The main controller continuously receives two feedback signals. When the exhaust gas flow rate drops below the preset threshold and the pH value recovers to the preset range, the main controller outputs an adjustment command to control the frequency converter 211 of the extraction pump to reduce its output frequency, restoring the suction rate to the reference value, thus forming a closed-loop stable control. The entire exhaust gas purification unit remains under negative pressure under the action of the extraction pump 209. The reference speed of the extraction pump 209 is 1500 r / min.

[0040] After passing through the exhaust gas purification unit 200, the HCl in the exhaust gas is absorbed. At this point, some volatile, usable organic reagents remain, which are then transported to the low-temperature condensation unit 300 (e.g., Figure 7 As shown), the boiling point of low-boiling-point petroleum ether is 30–60°C. The cryogenic liquid in the cryogenic condensation unit flows in from the condensate inlet and out from the condensate outlet to ensure that the temperature of the condensation unit is sufficient to convert the gaseous organic reagent into a liquid state, which is then transferred by the liquid transfer pump 401 (e.g., ...). Figure 8 (As shown) is conveyed to the filtration and separation unit 500 (e.g.) Figure 9(As shown). The coolant in the low-temperature condensation unit 300 is a 50% ethylene glycol aqueous solution, with an inlet temperature of -3℃ and an outlet temperature of 3℃.

[0041] Simultaneously, the waste liquid remaining from the reaction in the yarn / textile processing unit 100 is also transported to the filtration and separation unit 500 via the liquid transfer pump 401. The separation unit has an inclined guide plate 502 to collect the dripping liquid, a ceramic membrane filter 503 in the middle layer to intercept suspended solid particles, and a hydrophilic-oleophobic membrane in the lower layer to filter the aqueous phase to the bottom, while petroleum ether / n-hexane, etc., remain in the middle layer, achieving reagent recovery. The recovered reagents can be added back to the yarn / textile processing unit 100 to treat yarns and textiles, thus obtaining a recyclable reagent treatment system.

[0042] After absorption by the entire system, the HCl absorption rate is about 96.5%, and the VOC and HCl exhaust emission concentrations are both below 10 mg / m³, which is far superior to the national environmental protection standard (GB37822~2019 "Standard for the Control of Unorganized Emissions of Volatile Organic Compounds").

[0043] Equipment maintenance and support The removable filter element of the pre-dust removal module 207 should be cleaned or replaced regularly to avoid clogging.

[0044] The absorbent in the absorption chamber is replenished or replaced in a timely manner through a storage tank according to changes in pH value and liquid level. The agitator 216 of the first absorption chamber 201 is checked regularly to prevent malfunctions that could cause lime slurry to clump. When the pH meter 208 detects that the pH value of the second absorption chamber 202 is <10, the liquid control valve 214 is opened to replenish the composite absorbent until the pH is 10-11. When the exhaust gas flow meter 210 detects that the flow rate is <10ppm for 10 minutes, the speed of the vacuum pump 209 is reduced to 1000r / min for energy-saving operation.

[0045] The 400mm circulating pipeline has a drain outlet for regular drainage, and quick-release connectors facilitate equipment maintenance. Exhaust gas contact components and pipelines are regularly inspected for corrosion and maintained promptly.

[0046] The distributed control system 600 periodically calibrates the sensors (exhaust gas flow meter 210, pH sensor 208) to ensure accurate signal acquisition and guarantee the stability of closed-loop control. Example 2

[0047] An apparatus and method for recovering and treating organic solvents and waste gas from yarns and textiles are disclosed. The yarns and textiles are treated in a yarn / textile treatment unit 100. The organic reagents in the yarn / textile treatment unit 100 include petroleum ether, hexadecyltrichlorosilane, and trichlorosilane. Petroleum ether (boiling point 60–90°C) accounts for 90%, hexadecyltrichlorosilane accounts for 5%, and trichlorosilane accounts for 5%, with the sum of the mass fractions of all components being 100%. The generated waste gas (containing hydrogen chloride and volatile silane treatment liquid) is also disclosed. The organic solvent and waste gas recovery and treatment device and method in this example are exactly the same as those in Example 1, except that the concentrations in the first absorption chamber 201 and the second absorption chamber 202 are different. In this example, the first absorption chamber 201 contains 15% lime milk + 1% polycarboxylic acid dispersant with a pH of 12.6, and the second absorption chamber 202 contains a 7% sodium bicarbonate + 5% triethanolamine composite aqueous solution with a pH of 11.5.

[0048] After absorption by the entire system, the HCl absorption rate is about 96.8%, and the VOC and HCl exhaust emission concentrations are both below 10 mg / m³, which is far superior to the national environmental protection standard (GB37822~2019 "Standard for the Control of Unorganized Emissions of Volatile Organic Compounds").

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for recovering and treating organic solvents and waste gas from yarns and textiles, characterized in that: It includes an exhaust gas purification unit (200), a low-temperature condensation unit (300), a circulation pipeline (400), and a filtration and separation unit (500) that are sequentially connected to the output end of the yarn / textile processing unit (100). The exhaust gas purification unit (200) includes a first absorption chamber (201) and a second absorption chamber (202) sequentially arranged on the output side of the yarn / textile processing unit (100), a first gas inlet pipe (203) sealed between the output side of the yarn / textile processing unit (100) and the first absorption chamber (201), a first gas guide pipe (204) sealed between the first absorption chamber (201) and the second absorption chamber (202), a second gas inlet pipe (205) connected to the end of the first gas guide pipe (204) and extending into the second absorption chamber (202), a second gas guide pipe (206) sealed between the second absorption chamber (202) and the low-temperature condensation unit (300), a pre-dust removal module (207) connected to the input end of the first gas inlet pipe (203), a pH meter (208) located at the bottom of the second absorption chamber (202), and a vacuum pump (209) connected to the second gas guide pipe (206). The pre-dust removal module (207) is a filtration system that processes solid impurities carried in the exhaust gas generated by the yarn / textile processing unit (100). The air pump (209) is located at the end of the second absorption chamber (202) to keep the exhaust gas purification unit (200) under negative pressure. The yarn / textile processing unit (100), the first absorption chamber (201), and the second absorption chamber (202) are all closed cavities. The yarn / textile processing unit (100) generates acidic waste gas including gaseous organic reagents. The first absorption chamber (201) and the second absorption chamber (202) are connected in series to form a gradient absorption module. The first absorption chamber (201) contains a lime milk suspension composed of lime milk, dispersant, and water to absorb the acidic waste gas generated by the yarn / textile processing unit (100). The second absorption chamber (202) contains a composite liquid composed of sodium bicarbonate, organic buffer, and water to perform gradient absorption of acidic waste gas. The low-temperature condensation unit (300) condenses the gaseous organic reagent generated by the yarn / textile processing unit (100) into a liquid organic reagent and outputs it to the filtration and separation unit (500) through the circulation pipeline (400). The filtration and separation unit (500) recovers the organic reagent by gravity settling and multi-stage filtration.

2. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 1, characterized in that: The exhaust gas purification unit (200) also includes an exhaust gas flow meter (210) connected to the end of the first absorption chamber (201) and an air pump frequency converter (211) connected to the air pump (209). The circulation pipeline (400) is also connected between the top of the filter separation unit (500) and the bottom of the yarn / textile processing unit (100), and a liquid transfer pump (401) is connected to the circulation pipeline (400). It also includes a distributed control system (600) connected to the pH sensor (208), the pump frequency converter (211) and the exhaust gas flow meter (210), the distributed control system (600) adjusting the pumping rate of the pump (209) according to the measurement results of the exhaust gas flow meter (210) and the pH sensor (208).

3. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 2, characterized in that: The control method of the distributed control system (600) includes the following steps: After the SA1, yarn and textile organic solvent and waste gas recovery and treatment device starts operation, the distributed control system (600) enters the signal acquisition stage. The waste gas flow meter (210) continuously monitors the instantaneous flow rate of the waste gas in the pipeline and converts the physical flow signal into an electrical signal and transmits it to the main controller of the distributed control system (600). The pH detector (208) detects the pH value in the second absorption chamber (202) in real time and converts it into an electrical signal and transmits it to the main controller. SA2. After receiving the instantaneous flow rate and pH value of the exhaust gas, the main controller enters the signal feedback and analysis stage. The built-in signal processing module filters, amplifies, and calibrates the instantaneous flow rate and pH value electrical signals of the exhaust gas. Then, it compares the processed exhaust gas flow rate value with a preset flow rate threshold and the pH value with a preset pH threshold. When the exhaust gas flow rate value is less than or equal to the preset flow rate threshold or the pH value is greater than or equal to the preset pH threshold, the pipeline is in the normal range and is continuously monitored. When the exhaust gas flow rate value is greater than the preset flow rate threshold and the pH value is less than the preset pH threshold, it is determined that the amount of exhaust gas in the pipeline has increased, causing the accumulation of acidic substances. This triggers the control command generation logic and proceeds to step SA3. SA3. The main controller enters the instruction output and execution stage, outputs a speed control signal to the vacuum pump frequency converter (211), starts the vacuum pump frequency converter (211) to adjust the output voltage and frequency, drives the motor speed of the vacuum pump (209) to increase and the output frequency to increase, thereby increasing the vacuum pump (209) pumping speed proportionally and accelerating the discharge of waste gas in the pipeline. SA4. As the pumping speed increases, the amount of waste gas in the pipeline gradually decreases. The instantaneous flow signal of the waste gas collected in real time by the waste gas flow meter (210) decreases synchronously. At the same time, the pH value detected by the pH detector (208) gradually rises and tends to the pH preset threshold. When the main controller enters the closed-loop feedback adjustment stage, when the waste gas flow value is less than or equal to the preset flow threshold and the pH value is greater than or equal to the preset pH threshold, the main controller outputs an adjustment command and controls the pump frequency converter (211) to reduce the output frequency, so that the pumping speed is restored to the reference value, forming a closed-loop stable control, and returns to step SA2.

4. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 3, characterized in that: In step SA3, the speed control signal is a pulse width modulation (PWM) signal.

5. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 2, characterized in that: The exhaust gas purification unit (200) further includes a lime slurry storage tank (212) sealed to the top of the first absorption chamber (201), a composite absorption storage tank (213) sealed to the top of the second absorption chamber (202), liquid control valves (214) respectively connected to the outlets of the lime slurry storage tank (212) and the composite absorption storage tank (213), a porous aeration pipe (215) respectively connected to the end of the first gas inlet pipe (203) and the end of the second gas inlet pipe (205), and a stirrer (216) connected to the conical settling tank at the bottom of the first absorption chamber (201). The lime slurry storage tank (212) and the composite absorption storage tank (213) respectively replenish the first absorption chamber (201) and the second absorption chamber (202); The end of the first gas inlet tube (203) is inserted below the surface of the lime slurry suspension. The starting end of the first gas guide tube (204) is above the surface of the lime slurry suspension and the end is connected to the second gas inlet tube (205). The end of the second gas inlet tube (205) is inserted below the surface of the composite liquid. The starting end of the second gas guide tube (206) is above the surface of the composite liquid. The porous aeration pipe (215) has at least two aeration holes connected to its side, and the aeration holes are located on the gas passage and below the liquid surface; The pre-dust removal module (207) is a metal sintered mesh filter connected to the starting end of the first gas inlet pipe (203). The metal sintered mesh filter has a built-in detachable filter element with a pore size of 5 to 10 μm. The first absorption chamber (201), the second absorption chamber (202), the first gas inlet pipe (203), the first gas guide pipe (204), the second gas inlet pipe (205), and the second gas guide pipe (206) are all made of Hastelloy C-276 material. The first gas inlet pipe (203), the first gas guide pipe (204), the second gas inlet pipe (205), and the second gas guide pipe (206) are all L-shaped pipes.

6. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 2, characterized in that: The lime milk suspension is composed of 12-15% lime milk by mass, 0.5-1% polycarboxylate dispersant by mass, and 84-87.5% water by mass, and the pH value of the lime milk suspension is 12-13. The composite solution consists of 5-7% sodium bicarbonate, 3-5% organic amine buffer, and 88-92% water by mass. The pH value of the composite solution is 10-11.

5. The organic amine buffer reacts with acidic waste gas to generate water-soluble salts, thereby prolonging the pH stability period of the composite solution.

7. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 6, characterized in that: The acidic waste gas generated by the yarn / textile processing unit (100) is hydrochloric acid waste gas, hydrogen bromide waste gas, or hydrogen fluoride waste gas, and the organic solvent is any one or more of the following: petroleum ether, dodecyltrichlorosilane, and trichlorosilane. The polycarboxylic acid dispersant is polymaleic anhydride, and the organic amine buffer is triethanolamine.

8. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 2, characterized in that: The low-temperature condensing unit (300) is a condenser. A gradient cooling liquid is introduced into the jacket structure of the low-temperature condensing unit (300). The temperature of the cooling liquid inlet is -5 to 0°C and the temperature of the outlet is 15 to 20°C. The condensation temperature is controlled by a temperature controller. The gradient cooling liquid is a refrigerant, which is water or ethylene glycol. The inner layer of the circulation pipeline (400) is made of PVDF, the middle layer is made of stainless steel, and the outer layer is an insulation layer. The organic solvent leakage and pipeline condensation are prevented by fluororubber seals. The circulation pipeline (400) is set with a slope of 1 to 2% and the connection port with the filter separation unit (500) is set at the lowest point.

9. The organic solvent and waste gas recovery and treatment device for yarns and textiles according to claim 2, characterized in that: The filtration and separation unit (500) includes a tank (501), at least two inclined baffles (502) connected to the top of the tank (501), a ceramic membrane filter (503) connected to the middle of the tank (501), a hydrophilic and oleophobic membrane (504) connected to the lower part of the tank (501), and a solid particulate outlet (505), an organic solvent outlet (506), and an outlet (507) respectively connected from top to bottom to the side of the tank (501). The solid particulate matter outlet (505) is located above the ceramic membrane filter (503), the organic solvent outlet (506) is located above the hydrophilic and oleophobic membrane (504), and the outlet (507) is located at the bottom of the tank (501).

10. The treatment method of the organic solvent and waste gas recovery and treatment device for yarn and textiles according to any one of claims 2 to 9, characterized in that: Includes the following steps: S1. When the yarn / textile processing unit (100) is continuously modified, the yarn / textile leaves after being immersed in a processing tank containing organic reagents. The acidic gas generated when the silane undergoes hydrolysis and crosslinking reaction and the organic solvent carried on the surface of the yarn / textile evaporates, causing the yarn / textile processing unit (100) to generate acidic waste gas including gaseous organic reagents. S2. The acidic waste gas passes through the pre-dust removal module (207) to remove solid fiber microparticles, and then enters the first absorption chamber (201) through the first gas inlet pipe (203) and is partially absorbed by the lime milk suspension. The untreated waste gas passes through the first gas guide pipe (204) and the second gas inlet pipe (205) into the second absorption chamber (202) and is absorbed by the composite liquid. At the same time, the waste gas flow meter (210) monitors the waste gas flow in real time. The negative pressure value of the acidic gas concentration in the waste gas inlet is -0.02 to -0.05 MPa. The pH detector (208) monitors the pH value in the solution in the second absorption chamber (202) in real time. The distributed control system (600) controls the waste gas flow in the pipeline through the pump frequency converter (211). When the concentration of the waste gas flow meter (210) is higher than 50 ppm and the pH value of the pH detector (208) is less than 9, the pumping speed of the pump (209) is automatically increased proportionally. S3. After the exhaust gas passes through the exhaust gas purification unit (200), the acidic gas is absorbed and the organic reagent residue is obtained as pre-treated exhaust gas. The pre-treated exhaust gas enters the low temperature condensation unit (300) through the circulation pipeline (400) for condensation and is then transported to the filtration and separation unit (500) by the liquid transfer pump (401). S4. The inclined guide plate (502) of the filtration and separation unit (500) gathers the dripping water and intercepts the suspended solid particles by the ceramic membrane filter (503). Then, the hydrophilic and oleophobic membrane (504) filters the aqueous phase to the bottom layer of the tank (501), while the organic solvent of the oil phase remains in the middle layer of the tank (501), thus realizing the recovery of organic reagents. The recovered organic reagents can be added back to the yarn / textile processing unit (100) for reuse after flowing out through the organic solvent outlet (506). The waste liquid remaining from the reaction in the yarn / textile processing unit (100) can also be transported to the filtration and separation unit (500) by the liquid transfer pump (401) for filtration and organic reagent recovery.

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