Acid etching line etching cylinder tail gas treatment system and treatment device

Abstract

The invention provides an acid etching line etching cylinder tail gas treatment system and a treatment device, and particularly relates to the technical field of etching line tail gas treatment.The acid etching line etching cylinder tail gas treatment system comprises an etching cylinder and an air draft assembly used for extracting tail gas in the etching cylinder; the absorption assembly is used for absorbing effective components in tail gas, the storage assembly is used for storing absorption liquid, the monitoring assembly is used for monitoring the state of the absorption liquid, the blending assembly is used for blending the absorption liquid, and the recycling assembly is used for returning the processed absorption liquid to the etching cylinder. A complete closed-loop system is formed by the monitoring assembly, the blending assembly and the recycling assembly, low-copper electrolyte of the etching liquid copper recovery system is used for replacing traditional alkali liquor to absorb tail gas, the defects that effective components are wasted, alkali liquor consumption is large and chlorine-containing waste water is additionally generated due to the fact that tail gas is directly discharged in a traditional process are overcome, and recycling of the effective components in the tail gas is achieved. Meanwhile, the consumption of alkali liquor and the discharge amount of chlorine-containing wastewater are reduced.

Description

Technical Field

[0001] This application provides an acid etching line etching cylinder exhaust gas treatment system and device, specifically relating to the field of etching line exhaust gas treatment technology. Background Technology

[0002] In the PCB industry, acid etching lines are the core equipment for copper-clad laminate (CCL) circuit forming. The etching section uses hydrochloric acid with chloride oxidant or a hydrochloric acid-copper chloride-ammonium chloride system as etching agents. When the CCL passes through the etching section, a solution at approximately 50 degrees Celsius is evenly sprayed onto the board surface through multiple rows of nozzles, etching the exposed copper layer to form the preset pattern. During the etching process, acidic mist containing hydrochloric acid and chlorine is continuously generated. This mist accumulates and overflows into the workshop, severely corroding production equipment and endangering the health of workers. Therefore, most PCB factories currently use exhaust ducts to collect the mist in a gasification tower for chemical neutralization, resulting in high alkali consumption and the generation of large amounts of saline wastewater.

[0003] Existing technologies have not yet solved the core problems mentioned above: Patent CN217988908U uses alkaline spraying to neutralize exhaust gas before emission, directly wasting effective components such as hydrochloric acid and chlorine, and increasing environmental protection pressure; Patent CN114032550B only achieves electrolytic reuse of etching waste liquid, without combining exhaust gas treatment with waste liquid reuse, requiring separate alkaline absorption of the exhaust gas. Neither of these technologies breaks through the separation of "exhaust gas treatment" and "waste liquid reuse," failing to simultaneously solve the problems of wasted effective components, high alkaline consumption, and wastewater discharge.

[0004] In order to reduce the loss of acidic mist and the amount of alkali solution used for neutralization, this application proposes a new method for treating the exhaust gas of the etching tank in acidic etching lines, which reduces the loss of acidic mist and can significantly save on the consumption of alkali solution. Summary of the Invention

[0005] In view of the deficiencies of the existing technology, this application provides an acid etching line etching cylinder exhaust gas treatment system and device, which can effectively solve the related technical problems mentioned in the background art.

[0006] To achieve the above objectives, this application provides the following technical solution: This application discloses an acid etching line etching tank exhaust gas treatment system, including an absorption component for absorbing effective components in the exhaust gas, a storage component for storing the absorption liquid, a monitoring component for monitoring the state of the absorption liquid, a mixing component for mixing the absorption liquid, and a recycling component for returning the treated absorption liquid to the etching tank. The exhaust assembly is connected to the absorption assembly to transport exhaust gas. The liquid outlet of the absorption assembly is connected to the storage assembly. The storage assembly is used to mix the absorbent liquid after absorbing the exhaust gas with fresh low-copper electrolyte from the etching solution copper recovery system to form a liquid to be prepared. The monitoring component is located between the storage component and the mixing component, and is used to monitor the state of the liquid to be mixed and control its delivery to the mixing component; The output of the mixing component is connected to the etching tank through the recycling component, which is used to replenish the etching components required for etching into the liquid to be mixed and form a regenerated liquid. The absorbent used in the absorption assembly is a low-copper electrolyte from the etching solution copper recovery system.

[0007] Preferably, the absorption assembly includes at least one set of L-shaped absorption towers connected in series by a series connecting pipe. The L-shaped absorption towers are equipped with spray units. The spray units are connected to the low-copper electrolyte supply end through a circulating pump. The circulating pump drives the low-copper electrolyte to circulate and spray into the tower to absorb the exhaust gas.

[0008] Preferably, the monitoring component is a specific gravity OPP controller, used to monitor the specific gravity and concentration characteristics of the liquid to be prepared, and to control the delivery of the liquid to be prepared to the preparation component when the characteristic value exceeds a preset threshold.

[0009] Preferably, the mixing component includes a mixing tank, which is used to replenish the effective components in the liquid to be mixed according to the production speed and line changes of the production line. The effective components include at least one or more of the following: inorganic salts containing chloride ions, corrosion aids, complexing agents, and corrosion inhibitors. The effective components are dissolved and mixed evenly in the mixing tank by a room temperature stirring mechanism.

[0010] Preferably, the recycling component includes a delivery pump and a delivery pipeline. The delivery pump is used to pump the prepared regenerated liquid to the etching tank through the delivery pipeline. The regenerated liquid participates in the etching reaction as a specific gravity adjuster for the etching liquid.

[0011] Preferably, the system also includes a multi-stage post-treatment component, which is connected to the outlet of the absorption component and is used to treat the residual exhaust gas that has not been completely absorbed. The subsequent treatment components include at least one absorption tower, the number of which can be increased or decreased according to the amount of exhaust gas to be treated.

[0012] Preferably, the subsequent treatment components include an acid removal absorption tower and a chlorine treatment absorption tower connected in series via a series connecting pipe. The acid removal absorption tower is used to remove hydrochloric acid from the residual tail gas and produce bleach, and the chlorine treatment absorption tower is used to remove chlorine from the residual tail gas.

[0013] Furthermore, an acid etching line etching cylinder exhaust gas treatment device, employing the aforementioned acid etching line etching cylinder exhaust gas treatment system, includes an L-shaped absorption tower body. The air inlet of the L-shaped absorption tower body is connected to the air outlet of the exhaust assembly. A spray unit is installed inside the L-shaped absorption tower body. The spray unit is connected to the low copper electrolyte supply end of the etching solution copper recovery system. The liquid outlet of the L-shaped absorption tower body is connected to a storage assembly.

[0014] Preferably, the spraying unit includes multiple conical nozzles, which are evenly distributed inside the L-shaped absorption tower body. The conical nozzles spray to form conical mist droplets to create a full-coverage spraying area.

[0015] Preferably, multiple L-shaped absorption tower bodies are provided, and the multiple L-shaped absorption tower bodies are connected in series by a series connecting pipe. The exhaust gas is transferred step by step and the absorption liquid is collected between two adjacent L-shaped absorption tower bodies through a series connecting pipe.

[0016] In summary, the technical solution provided in this application has at least one of the following advantages compared with the prior art: This acid etching line etching tank exhaust gas treatment system and device uses a ventilation component to absorb low-copper electrolyte, a storage component to mix, a monitoring component to adjust, and a reuse component to form a complete closed-loop system. The low-copper electrolyte of the etching solution copper recovery system replaces the traditional alkaline solution to absorb the exhaust gas, solving the defects of the traditional process of directly discharging exhaust gas and wasting effective components, consuming a large amount of alkaline solution and generating additional chlorine-containing wastewater. This achieves the recovery and reuse of effective components in the exhaust gas, while reducing the consumption of alkaline solution and the discharge of chlorine-containing wastewater. By using L-shaped absorption towers connected in series with conical nozzles, the problems of insufficient contact between tail gas and absorbent liquid and low absorption rate of effective components in traditional single-stage absorption towers are solved. The multi-stage series connection extends the flow path of tail gas, and the mist spray from the conical nozzles covers the tower without dead corners, allowing for full mass transfer between tail gas and absorbent liquid, which greatly improves the absorption efficiency of effective components in tail gas and reduces the operating load of subsequent treatment components. By coordinating the monitoring and mixing components, the problems of large fluctuations in the composition of the recycled liquid and poor adaptability to production line conditions are solved. The monitoring component compares the state parameters of the liquid to be mixed in real time, and the mixing component replenishes raw materials as needed and mixes them with the ambient temperature stirring mechanism. This allows the composition of the recycled liquid to accurately match the production speed and line changes of the etching line, stabilizes the etching reaction effect, and avoids product defects caused by unstable liquid. By flexibly configuring the number of subsequent treatment components, the problem of poor performance of fixed-stage treatment components in adapting to different production capacities of exhaust gas can be solved. When the production capacity is increased, the number of acid removal absorption towers or chlorine treatment absorption towers can be increased. At the same time, the acid removal absorption tower can produce bleach for reuse, which not only ensures that the exhaust gas can meet the emission standards under different loads, but also converts the by-products of the treatment process into production auxiliary agents, further reducing the overall material cost of production. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the process of collecting and treating exhaust gas from the etching tank in the acid etching line of this application. Figure 2 This is a flowchart of the acid etching tail gas treatment system - material recycling and regeneration process in this application; Figure 3 This is a structural diagram of the exhaust gas treatment device chain and spray unit in this application.

[0018] The labels in the diagram represent: 1. Etching tank; 2. Exhaust system; 3. Absorption system; 4. Storage system; 5. Monitoring system; 6. Mixing system; 7. Recycling system; 8. Copper recovery system for etching solution; 9. Post-processing system; 10. L-shaped absorption tower; 11. Spray unit; 12. Circulation pump; 13. Low copper electrolyte supply unit; 14. L-shaped absorption tower body; 15. Conical nozzle; 16. Series connection pipeline; 17. Specific gravity OPP controller; 18. Mixing tank; 19. Ambient temperature stirring mechanism; 20. Conveying pump body; 21. Conveying pipeline; 22. Acid removal absorption tower; 23. Chlorine treatment absorption tower. Detailed Implementation

[0019] The present application will be further described below with reference to embodiments.

[0020] As a first embodiment of this application: Reference Appendix Figures 1 to 3 As shown, an acid etching line etching cylinder exhaust gas treatment system and device specifically includes an etching cylinder 1, an exhaust assembly 2, an absorption assembly 3, a storage assembly 4, a monitoring assembly 5, a mixing assembly 6, a recycling assembly 7, an etching solution copper recovery system 8, a post-treatment assembly 9, and supporting connecting pipes, etc.

[0021] Etching tank 1 is a conventional reaction vessel in an acid etching production line. It uses a sodium chlorate-hydrochloric acid etching solution. During the etching process, copper etching and regeneration reactions occur, specifically Cu + CuCl2 → Cu2Cl2 and 3Cu2Cl2 + NaClO3 + 6HCl → 6CuCl2 + NaCl + 3H2O. During the reaction, highly corrosive, toxic and harmful exhaust gases containing hydrochloric acid and chlorine are continuously generated. If these exhaust gases are directly emitted, they will irritate the respiratory mucosa of the human body. Long-term exposure may also cause chronic respiratory diseases, and at the same time, they will corrode the surrounding equipment.

[0022] This embodiment has been practically applied on the inner and outer etching lines of a factory in northern China: by adding a pipe to connect to the exhaust pipe on the etching line, i.e. the pipe of the exhaust component 2, the tail gas of the etching line is connected to the L-shaped absorption tower body 14. The overflowing acidic gases such as hydrochloric acid and chlorine are absorbed by the absorption liquid. After mixing, monitoring and adjusting, the absorption liquid is reused as a regenerated liquid in the etching line to participate in etching production.

[0023] Specifically, the top of the etching cylinder 1 has a pre-reserved exhaust port, which is sealed to the air inlet of the exhaust assembly 2 via a flange. The exhaust assembly 2 uses a corrosion-resistant centrifugal fan, and the fan's start and stop are synchronized with the etching operation of the etching cylinder 1. Automatic control is achieved through a PLC controller, ensuring that the fan starts immediately when the etching reaction begins and shuts off after a preset delay after the reaction stops, preventing residual exhaust gas. A filter screen is installed at the fan inlet to initially filter out small amounts of etching solution droplets and solid particles entrained in the exhaust gas, reducing contamination of subsequent components. The exhaust outlet of the exhaust assembly 2 is connected to the air inlet of the absorption assembly 3, ensuring a stable supply of etching exhaust gas.

[0024] The absorption assembly 3 includes two sets of L-shaped absorption towers 10 connected in series by a series connecting pipe 16, namely L-shaped absorption tower bodies 14. The two sets of L-shaped absorption tower bodies 14 are arranged sequentially along the exhaust gas conveying direction. The gas outlet of the first-stage L-shaped absorption tower body 14 is connected to the gas inlet of the next stage through the series connecting pipe 16, and the liquid outlet is also connected to the storage assembly 4 through a pipe. This series design can extend the contact path and time between the exhaust gas and the absorption liquid, improve the absorption efficiency, and increase the absorption rate of effective components by more than 30% compared with single-stage absorption. Each L-shaped absorption tower body 14 is equipped with a spray unit 11 at the top. The spray unit 11 consists of an annular spray pipe and multiple evenly distributed conical nozzles 15. The spray angle of the conical nozzles 15 is optimized, and the spray areas of adjacent nozzles overlap to ensure that a full-coverage spray area without dead angles is formed in the tower. The conical mist droplets formed by the spray can increase the contact area with the exhaust gas, improve the mass transfer efficiency, and allow components such as hydrochloric acid and chlorine to fully dissolve in the absorption liquid.

[0025] The spray unit 11 is connected to the low-copper electrolyte supply end 13 via the circulation pump 12. The low-copper electrolyte supply end 13 is the electrolyte output port of the etching solution copper recovery system 8. Specifically, the circulation pump 12 is an acid and alkali resistant magnetic pump to avoid electrolyte corrosion of the pump body and leakage. Its output flow rate can be adjusted by a frequency converter to dynamically adjust the spray intensity according to the exhaust gas treatment volume. At the same time, flow sensors and pressure sensors are installed on the circulation pipeline to provide real-time feedback on the spray status, which is convenient for operators to monitor and adjust.

[0026] The outlet of the absorption component 3 is welded to the inlet of the storage component 4. Specifically, the storage component 4 is a corrosion-resistant storage tank with an insulation layer. The inner wall of the storage tank is coated with a polytetrafluoroethylene anti-corrosion coating to prevent acidic components and copper ions in the absorption liquid from corroding the tank and extending the service life of the equipment. A breather valve is installed on the top of the storage tank to balance the pressure inside the tank and avoid abnormal pressure inside the tank due to temperature changes or feeding. The absorption liquid after absorbing the tail gas—containing absorbed hydrochloric acid, chlorine, and the original copper ions—flows into the storage component 4 and mixes with the fresh low-copper electrolyte 9 continuously replenished by the etching solution copper recovery system 8 to form the preparation solution 10. The replenishment amount of the fresh low-copper electrolyte 9 is controlled by a flow control valve and automatically adjusted according to the liquid level sensor signal in the storage component 4 to maintain the liquid level in the storage tank within a preset range and ensure a stable mixing ratio.

[0027] A monitoring component 5 is installed between the storage component 4 and the mixing component 6. The monitoring component 5 uses a specific gravity OPP controller 17, whose detection probe extends into the liquid to be mixed 10 in the storage component 4 to monitor characteristic values ​​such as specific gravity and copper ion concentration of the liquid to be mixed 10 in real time, and transmits the monitoring data to the control system for comparison with preset thresholds. The controller has data recording and export functions and can store monitoring data for nearly 3 months, which is convenient for production traceability and process optimization. When the monitored characteristic value is within the preset threshold range, the specific gravity OPP controller 17 controls the solenoid valve on the connecting pipeline to open, and the liquid to be mixed 10 flows into the mixing component 6; when the characteristic value exceeds the threshold, the solenoid valve closes and at the same time, an audible and visual alarm signal is issued to prompt the operator to check and adjust.

[0028] The mixing component 6 includes a mixing tank 18 and a room temperature stirring mechanism 19 disposed inside the tank. Specifically, the room temperature stirring mechanism 19 adopts a paddle-type stirrer, which is driven by a motor to rotate at low speed. The stirring rate is controlled at 60-80 r / min to avoid high-speed stirring from generating bubbles that affect the uniformity of component mixing, while also reducing energy consumption.

[0029] The mixing tank 18 is equipped with multiple raw material addition ports to replenish the effective components according to the production line speed and line changes. The effective components include chloride-containing inorganic salts, etching aids, complexing agents, and corrosion inhibitors. In actual use, replenishment can be selectively performed based on the consumption of the etching solution. For example, when the chloride ion concentration is insufficient, chloride-containing inorganic salts are added; when the etching rate decreases, etching aids and complexing agents are added. Each component is added precisely via a metering pump, with the addition error controlled within ±1%, ensuring the stable performance of the regenerated solution after mixing. The effective components are dissolved and mixed uniformly within the mixing tank 18 by a room-temperature stirring mechanism 19, eliminating the need for additional heating or cooling equipment and reducing energy consumption.

[0030] The reuse component 7 includes a delivery pump body 20 and a delivery pipe 21. The inlet end of the delivery pump body 20 is connected to the outlet of the mixing cylinder 18, and the output end is connected to the replenishment port of the etching cylinder 1 through the delivery pipe 21. Specifically, the delivery pipe 21 is made of PVDF material, which is resistant to acid and alkali corrosion and does not easily form scale. A check valve is installed on the pipe to prevent the etching solution from flowing back. At the same time, an inspection port is set every 3 meters to facilitate later maintenance and cleaning.

[0031] The delivery pump 20 pumps the prepared regenerated liquid to the etching tank 1. The regenerated liquid acts as a specific gravity adjuster for the etching liquid and participates in the etching reaction. The delivery volume of the regenerated liquid is automatically adjusted according to the specific gravity change of the etching liquid in the etching tank 1, forming a closed-loop control with the monitoring component 5 to maintain the stability of the etching liquid concentration and realize resource recycling.

[0032] Actual application data shows that after the scheme was changed, the consumption of hydrochloric acid decreased to 30%-60% of that before the change [typical data is about 50%], and the unit consumption of oxidant decreased to 15%-60% [typical data is about 35%]; the liquid alkali consumption of the gasification tower in the etching workshop was reduced by 80%, which greatly saved the cost of tail gas treatment, and the amount of chloride ion-containing wastewater discharged to the wastewater station was also greatly reduced.

[0033] The following table compares the consumption of relevant materials before and after the equipment modification [Reference Table]: Note: The data in the above table are all derived from actual data readings and calculations based on verified data.

[0034] Specifically, the data is calculated as follows: the consumption data for this month is the reading of this month minus the reading of last month. The monthly consumption data is divided by the copper output of this month to obtain the unit consumption data. The unit consumption data for the months before and after the equipment installation is compared.

[0035] Furthermore, the outlet of the absorption component 3 is connected to the subsequent treatment component 9. The subsequent treatment component 9 includes an acid removal absorption tower 22 and a chlorine treatment absorption tower 23 connected in series via a series connection pipe 16. The acid removal absorption tower 22 is filled with corrosion-resistant packing material. It uses alkaline absorbent liquid spray to absorb hydrochloric acid in the residual tail gas, reacts to generate salt substances and produces bleach. The bleach can be collected and reused as an auxiliary agent in production, realizing the resource utilization of waste. The tower is equipped with a level gauge and an online pH monitor to monitor the absorbent liquid status in real time. When the pH value is lower than the preset value, alkaline raw materials are automatically added. The chlorine treatment absorption tower 23 uses an enhanced absorbent liquid to remove residual chlorine through chemical reaction. The two-stage absorption tower design ensures that harmful substances in the exhaust gas are fully removed, and the final exhaust gas meets the emission standards. The number of series stages of the subsequent treatment components 9 can be flexibly configured according to the exhaust gas treatment volume. When the production line capacity increases and the exhaust gas emission volume increases, the number of acid removal absorption towers 22 or chlorine treatment absorption towers 23 can be increased to ensure that the treatment effect is not affected.

[0036] Based on the content of Embodiment 1 above, it is worth noting that: Existing acid etching tank exhaust gas treatment technologies mainly suffer from two core defects: First, the traditional absorption technology, as described in patent publication number CN217988908U, uses water or alkaline solution as the absorption medium. This only neutralizes and removes harmful substances in the exhaust gas, directly wasting effective components such as hydrochloric acid and chlorine. Furthermore, the chlorine-containing wastewater generated after neutralization requires additional treatment, increasing environmental costs and process complexity. Second, the etching waste liquid reuse technology, as described in patent publication number CN114032550B, while achieving the recovery of electrolytic waste liquid, does not combine exhaust gas treatment with waste liquid reuse. The exhaust gas still requires separate alkaline absorption, resulting in high alkaline consumption, inability to recover effective components, and a risk of leakage during chlorine transportation.

[0037] Compared with the prior art, this application has outstanding substantive features: First, it breaks through the traditional approach of separating "tail gas treatment" and "waste liquid reuse," creatively employing a low-copper electrolyte from an etching solution copper recovery system as the tail gas absorbent. This utilizes the electrolyte's properties to efficiently absorb the effective components in the tail gas while avoiding the additional investment of specialized absorbents, solving the dual problems of absorbent consumption and effective component waste in existing technologies. Second, through the combined design of a series L-shaped absorption tower and a conical nozzle, the contact path and time between the tail gas and the absorbent are extended, significantly improving absorption efficiency compared to existing single-stage absorption towers or stirred absorption devices, while avoiding the safety hazards of long-distance chlorine transportation. Third, it constructs a closed-loop system encompassing "extraction-absorption-monitoring-adjustment-reuse," combining dual monitoring and online adjustment functions to ensure stable performance of the regenerated liquid adapted to etching conditions, overcoming the shortcomings of large fluctuations in regenerated liquid composition and unstable etching effects in existing reuse technologies.

[0038] The technical solution of this application brings significant progress: on the one hand, by recovering and recycling effective components, the amount of raw material replenishment and wastewater discharge is reduced, thereby lowering production and environmental protection costs; on the other hand, the automated linkage design of the closed-loop system reduces the need for manual intervention, improves operational stability and safety, and is adaptable to etching production lines with different capacities, making it more industrially practical and valuable for promotion compared to existing technologies.

[0039] As a second embodiment of this application: The core difference between this embodiment and Embodiment 1 is that the number of L-shaped absorption tower bodies 14 of the absorption component 3 and the configuration of the subsequent processing components 9 remain the same, while the rest of the structure and connection relationships remain the same, making it suitable for etching production lines with high capacity and large exhaust emissions.

[0040] In this embodiment, the absorption component 3 includes three sets of L-shaped absorption tower bodies 14 connected in series. The series connection method of the three sets of L-shaped absorption tower bodies 14 is the same as that in Embodiment 1. By increasing the number of series stages, the exhaust gas purification effect is further improved. Even under high load conditions, the absorption rate of effective components in the exhaust gas can be maintained at more than 98%, while reducing the single tower processing pressure and extending the equipment operation cycle.

[0041] The number of conical nozzles 15 inside each L-shaped absorption tower body 14 is increased according to the tower volume to maintain uniform spray density. Each tower body is also equipped with an independent circulation pump 12, which facilitates individual adjustment of spray flow rate and ensures stable absorption effect at each stage.

[0042] The subsequent treatment component 9 adds a demister after the acid removal absorption tower 22 and the chlorine treatment absorption tower 23. The demister is equipped with a baffle-type demister to remove mist droplets entrained in the exhaust gas after the two-stage absorption treatment. This prevents corrosive components and copper ions carried by the droplets from corroding subsequent emission pipes, while also reducing the emission of liquid pollutants into the atmosphere, further improving the cleanliness of the exhaust gas. The liquid outlet of the demister is returned to the acid removal absorption tower 22 through a pipeline, realizing the recycling of the absorbent and reducing waste. The demister is cleaned regularly to prevent blockages that could affect the flow of exhaust gas.

[0043] In this embodiment, in addition to the specific gravity OPP controller 17, the monitoring component 5 is equipped with a pH sensor. The pH sensor works in conjunction with the specific gravity OPP controller 17 to simultaneously monitor the specific gravity and pH value of the solution to be prepared 10. This dual-parameter monitoring ensures the stability of the performance of the solution to be prepared 10 and avoids deviations that may occur when monitoring a single parameter. When either parameter exceeds a preset threshold, the control mechanism is triggered, closing the delivery valve and triggering an alarm. Simultaneously, pH and copper ion concentration monitoring probes are also installed in the etching tank 1 to provide real-time feedback on the etching solution status, providing a basis for adjusting the delivery volume of the reuse component 7, thus forming a closed-loop control throughout the entire process.

[0044] In this embodiment, the mixing component 6 is further equipped with an online component detection module, which can monitor key indicators such as chloride ion concentration and complexing agent content of the regenerated liquid in real time during the mixing process. Based on the detection results, the addition amount of each raw material is automatically adjusted, which is more precise and efficient than manual control, ensuring that the fluctuation range of various performance parameters of the regenerated liquid is controlled within ±2%. The ambient temperature stirring mechanism 19 adopts a double-layer blade design, resulting in more uniform stirring, shorter mixing time, and improved mixing efficiency.

[0045] The complete working principle of the above embodiments is as follows: When the copper etching reaction starts in etching tank 1 and exhaust gas containing hydrochloric acid and chlorine is emitted, the exhaust fan assembly 2 will start synchronously to draw the exhaust gas into the L-shaped absorption tower 10 connected in series. The low-copper electrolyte of the etching solution copper recovery system 8 is pumped into the spray unit 11 inside the tower by the circulation pump 12. The conical nozzle 15 sprays out atomized droplets to coat the exhaust gas and dissolve the effective components in it into the absorption liquid.

[0046] The absorbed liquid flows into storage component 4 and is mixed with fresh low-copper electrolyte to form a pre-mixed solution. Monitoring component 5 monitors the state of this liquid; if it meets the standards, it is sent to mixing tank 18, where raw materials are added according to the production line conditions and stirred thoroughly. Then, it is returned to etching tank 1 via recycling component 7 as a specific gravity adjuster for the etching solution. Any unabsorbed exhaust gas will enter subsequent acid removal absorption tower 22 and chlorine treatment absorption tower 23, where it will be treated to meet emission standards before being discharged.

[0047] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A tail gas treatment system for an acid etching line etching cylinder, comprising an etching cylinder (1) and a ventilation assembly (2) for extracting tail gas from the etching cylinder (1), characterized in that, Also includes: The absorption assembly (3) for absorbing the effective components in the exhaust gas, the storage assembly (4) for storing the absorption liquid, the monitoring assembly (5) for monitoring the state of the absorption liquid, the preparation assembly (6) for preparing the absorption liquid, and the recycling assembly (7) for returning the treated absorption liquid to the etching tank (1). The exhaust assembly (2) is connected to the absorption assembly (3) to transport exhaust gas. The liquid outlet of the absorption assembly (3) is connected to the storage assembly (4). The storage assembly (4) is used to mix the absorbent liquid after absorbing the exhaust gas with the fresh low-copper electrolyte from the etching solution copper recovery system (8) to form a liquid to be prepared. The monitoring component (5) is located between the storage component (4) and the mixing component (6) and is used to monitor the state of the liquid to be mixed and control its delivery to the mixing component (6); The output end of the mixing component (6) is connected to the etching tank (1) through the recycling component (7) to replenish the etching components required for etching into the liquid to be mixed and to form a regenerated liquid; The absorption component (3) uses a low-copper electrolyte from the etching solution copper recovery system (8).

2. The acid etching line etching cylinder exhaust gas treatment system according to claim 1, characterized in that, The absorption assembly (3) includes at least one set of L-shaped absorption towers (10) connected in series by a series connection pipe (16). The L-shaped absorption tower (10) is equipped with a spray unit (11). The spray unit (11) is connected to the low copper electrolyte supply end (13) through a circulation pump (12). The circulation pump (12) drives the low copper electrolyte to circulate and spray into the tower to absorb the tail gas.

3. The acid etching line etching cylinder exhaust gas treatment system according to claim 1, characterized in that, The monitoring component (5) is a specific gravity OPP controller (17), which is used to monitor the specific gravity and concentration characteristics of the liquid to be prepared, and control the delivery of the liquid to be prepared to the preparation component (6) when the characteristic value exceeds the preset threshold.

4. The acid etching line etching cylinder exhaust gas treatment system according to claim 1, characterized in that, The mixing component (6) includes a mixing cylinder (18), which is used to replenish the effective components in the liquid to be mixed according to the production speed and line changes of the production line. The effective components include at least one or more of the following: inorganic salts containing chloride ions, corrosion aids, complexing agents, and corrosion inhibitors. The effective components are dissolved and mixed evenly in the mixing cylinder (18) by a room temperature stirring mechanism (19).

5. The acid etching line etching cylinder exhaust gas treatment system according to claim 1, characterized in that, The recycling component (7) includes a delivery pump body (20) and a delivery pipe (21). The delivery pump body (20) is used to pump the prepared regenerated liquid to the etching tank (1) through the delivery pipe (21). The regenerated liquid participates in the etching reaction as a specific gravity adjuster of the etching liquid.

6. The acid etching line etching cylinder exhaust gas treatment system according to claim 1, characterized in that, It also includes a multi-stage post-treatment component (9), which is connected to the outlet of the absorption component (3) and is used to treat the residual exhaust gas that has not been completely absorbed. The subsequent processing component (9) includes at least one absorption tower, the number of which can be increased or decreased according to the amount of exhaust gas to be treated.

7. The acid etching line etching cylinder exhaust gas treatment system according to claim 6, characterized in that, The subsequent processing component (9) includes an acid removal absorption tower (22) and a chlorine treatment absorption tower (23) connected in series via a series connection pipe (16). The acid removal absorption tower (22) is used to remove hydrochloric acid from the residual tail gas and produce bleach, and the chlorine treatment absorption tower (23) is used to remove chlorine from the residual tail gas.

8. An acid etching line etching cylinder exhaust gas treatment device, employing the acid etching line etching cylinder exhaust gas treatment system according to any one of claims 1 to 7, characterized in that, The L-shaped absorption tower body (14) is connected to the air outlet of the exhaust assembly (2) at the air inlet end of the L-shaped absorption tower body (14). The L-shaped absorption tower body (14) is equipped with a spray unit (11) inside. The spray unit (11) is connected to the low copper electrolyte supply end (13) of the etching solution copper recovery system (8). The liquid outlet end of the L-shaped absorption tower body (14) is connected to the storage assembly (4).

9. The acid etching line etching cylinder exhaust gas treatment device according to claim 8, characterized in that, The spray unit (11) includes multiple conical nozzles (15), which are evenly distributed inside the L-shaped absorption tower body (14). The conical nozzles (15) spray to form conical mist droplets to form a full-coverage spray area.

10. The acid etching line etching cylinder exhaust gas treatment device according to claim 8, characterized in that, Multiple L-shaped absorption tower bodies (14) are provided. Multiple L-shaped absorption tower bodies (14) are connected in series by a series connection pipe (16). The exhaust gas is transferred step by step and the absorption liquid is collected between two adjacent L-shaped absorption tower bodies (14) through the series connection pipe (16).

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