A micro-etching waste liquid continuous oxygen breaking system using waste heat recovery and a control method thereof

Abstract

The application provides a micro-etching waste liquid continuous oxygen breaking system and control method using waste heat recovery, and belongs to the technical field of industrial waste liquid treatment. The system comprises a micro-etching original liquid storage barrel, a steam heating barrel, a heat exchanger, a cooling barrel, a temporary storage barrel and a fluid conveying control unit. The steam heating barrel is provided with a steam coil pipe, and the cooling barrel is provided with a cooling water coil pipe and a stirring device. The method adopts an intermittent starting and continuous running mode: first, the steam heating barrel is fed and heated to 95 DEG C for 60 minutes; then, the liquid is simultaneously fed and discharged, the high-temperature liquid medicine is preheated by the heat exchanger, the original liquid is fed into the steam heating barrel for supplementary heating after preheating, and the high-temperature liquid medicine is pre-cooled and then fed into the cooling barrel to be cooled to below 40 DEG C. The control unit realizes automatic control through constant flow, accurate liquid level and temperature feedback. The application recovers the sensible heat of the high-temperature liquid medicine, reduces the steam consumption by more than 50%, reduces the cooling water consumption by more than 50%, and is continuous, stable, safe and controllable.

Description

Technical Field

[0001] This invention relates to the field of industrial waste liquid treatment technology, specifically to a continuous oxygen deoxygenation system and control method for micro-etching waste liquid utilizing waste heat recovery, which is particularly suitable for oxygen deoxygenation treatment of micro-etching waste liquid from printed circuit boards (PCBs), photovoltaic copper etching solution, and liquid crystal panel etching waste liquid. Background Technology

[0002] In the manufacturing processes of printed circuit boards (PCBs), photovoltaic panels, and LCD panels, etching is a crucial step in creating rough surfaces to enhance interlayer adhesion. This process typically uses a sulfuric acid-hydrogen peroxide system as the micro-etching solution, resulting in micro-etching waste liquid containing a high concentration of copper ions (Cu). 2+ The waste liquid contains unreacted hydrogen peroxide (H2O2). Because hydrogen peroxide is a strong oxidizing agent, if the micro-etching waste liquid directly enters the subsequent copper recovery system (such as an electrolytic cell or displacement reaction tank), it will not only oxidize the copper powder deposited at the cathode, leading to a decrease in copper recovery rate, but may also cause safety hazards due to violent reactions. Therefore, before copper recovery or discharge treatment, the micro-etching waste liquid must first undergo deoxygenation treatment, that is, heating it to decompose the hydrogen peroxide into water and oxygen.

[0003] In existing technologies, the common method for treating micro-etching waste liquid is to directly pump cold waste liquid into a heating kettle and heat it to above 90°C with steam. However, this method has the following drawbacks: Traditional deoxygenation processes often use intermittent heating kettles. Cold waste liquid (usually around 20°C to 30°C) is directly pumped into the heating kettle and heated to 90°C to 95°C through steam coils to decompose hydrogen peroxide. After the reaction is completed, the high-temperature solution (above 90°C) is often directly discharged to a cooling pool or subsequent treatment unit, resulting in a significant waste of steam heat energy consumed during heating. At the same time, in order to cool the high-temperature solution to a safe temperature (such as below 40°C), the subsequent cooling process requires a large amount of cooling water, resulting in a double energy waste of "consuming steam for heating and water for cooling". Moreover, existing equipment mostly operates on a single-batch basis, with feeding, heating and holding, cooling, and discharging repeating cyclically. During the heating and cooling waiting periods, the equipment is in a non-productive state, limiting its overall processing capacity and making it difficult to match the continuous waste liquid discharge rhythm of the production line. Frequent start-up and shutdown operations also increase the difficulty and labor intensity of manual control. In addition, during direct steam heating, uneven stirring or improper control of steam valves can easily cause local overheating, leading to explosive boiling of the waste liquid or uncontrolled decomposition of hydrogen peroxide. Furthermore, the system lacks a thermal buffer mechanism and has poor adaptability to fluctuations in feed temperature. Summary of the Invention

[0004] The purpose of this invention is to provide a continuous oxygen-depleting system and control method for micro-etching waste liquid that utilizes waste heat recovery, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A continuous oxygen deoxygenation system and control method for micro-etching waste liquid utilizing waste heat recovery includes: Micro-etching solution storage tank, temporary storage tank, inlet pump, heat exchanger, steam heating tank, cooling tank and drain pump; The outlet of the micro-etching stock solution storage tank is connected to the inlet of the liquid inlet pump, the outlet of the liquid inlet pump is connected to the cold side inlet of the heat exchanger, and the cold side outlet of the heat exchanger is connected to the liquid inlet of the steam heating tank; the steam heating tank is equipped with a steam coil, the high-temperature liquid overflow port of the steam heating tank is connected to the hot side inlet of the heat exchanger, and the hot side outlet of the heat exchanger is connected to the liquid inlet of the cooling tank. The cooling tank is equipped with a cooling water coil. The outlet of the cooling tank is connected to the inlet of the drain pump, and the outlet of the drain pump is connected to the temporary storage tank. The cold raw liquid is sent to the cold side of the heat exchanger by the inlet pump. It exchanges heat countercurrently with the high-temperature medicine liquid that flows into the hot side of the heat exchanger through the overflow port of the steam heating tank. After being preheated, it enters the steam heating tank. After the oxygen is broken by the steam coil, the high-temperature medicine liquid overflows from the high-temperature medicine liquid overflow port to the hot side of the heat exchanger. After heat exchange and cooling, it enters the cooling tank. After being cooled a second time by the cooling water coil, it is sent to the temporary storage tank by the drain pump.

[0006] Preferably, it also includes an auxiliary heat exchanger; the outlet of the liquid inlet pump is connected to the cold side inlet of the auxiliary heat exchanger, and the cold side outlet of the auxiliary heat exchanger is connected to the cold side inlet of the heat exchanger; the outlet of the cooling water coil is connected to the hot side inlet of the auxiliary heat exchanger; the used cooling water discharged from the cooling water coil flows through the hot side of the auxiliary heat exchanger to perform a first heat exchange preheating on the cold raw liquid before it enters the heat exchanger, and the cold raw liquid enters the steam heating tank after a second heat exchange preheating by the heat exchanger.

[0007] Preferably, it also includes a conical catalytic plate and an elastic ring; the conical catalytic plate is a concave conical structure filled with catalyst to increase the contact range with the waste liquid; the elastic ring is fixed to the outer ring of the conical catalytic plate, and the conical catalytic plate is detachably installed in the steam heating tank through the elastic ring, and multiple through holes are opened on the circumference of the elastic ring.

[0008] Preferably, the inner bottom circumference of the steam heating tank is welded with multiple welding plates, and the upper end face of each welding plate is welded with a conical column, the top of which is a conical head. During installation, the conical head is used to open and enlarge the through hole on the elastic ring, so that the conical column can be inserted into the corresponding through hole, thereby realizing the detachable installation of the conical catalytic plate. The elastic ring and the inner wall of the steam heating tank and the conical column are elastically contracted to prevent leakage.

[0009] Preferably, it further includes a drain valve, a detector, and a return pipeline; a drain pipeline is connected between the cooling tank and the temporary storage tank, and the drain valve is installed on the drain pipeline; the detector is an online sensor, connected in series on the drain pipeline before the drain valve, for online detection of the oxidation-reduction potential of the liquid after oxygen deoxygenation treatment; the return pipeline is connected between the drain pipeline and the steam heating tank, and when the detector detects that the liquid is unqualified, the liquid is sent back to the steam heating tank through the return pipeline for re-oxygenation treatment.

[0010] Preferably, the cooling tank is also equipped with a stirring device and a temperature sensor.

[0011] A method for continuous oxygen decomposition control of micro-etched waste liquid utilizing waste heat recovery includes the following steps: S1. Start-up phase: Start the liquid inlet pump to pump the micro-etching waste liquid in the micro-etching raw material storage tank into the steam heating tank. When the liquid level in the steam heating tank reaches the preset liquid level, stop the liquid inlet, turn on the steam and heat the waste liquid in the tank to the preset temperature by inputting high temperature steam into the steam coil and keep the temperature constant for the preset time, so that the hydrogen peroxide in the waste liquid is fully decomposed and the system thermal energy reserve is established. S2. Continuous operation stage: The inlet pump is started to pump in the cold raw liquid, and the outlet pump is started to discharge the high-temperature medicine liquid. The cold raw liquid flows through the cold side of the heat exchanger and exchanges heat countercurrently with the high-temperature medicine liquid overflowing from the overflow port of the steam heating tank in the heat exchanger. After being preheated, it enters the steam heating tank. After the high-temperature medicine liquid is cooled by heat exchange, it enters the cooling tank. At the same time, steam is continuously replenished to keep the temperature and liquid level in the steam heating tank in dynamic balance, so as to realize continuous feeding and continuous discharge. S3. Deep Cooling and Collection Stage: The liquid medicine entering the cooling tank is cooled to below the safe temperature by the cooling water coil. When the liquid level in the cooling tank reaches the preset value, the treated clear liquid is transported to the temporary storage tank by the drain pump.

[0012] Preferably, the system further includes an auxiliary heat exchanger; in step S2, after the cold raw liquid is pumped out by the inlet pump, it first flows through the cold side of the auxiliary heat exchanger and undergoes a first heat exchange preheating with the used cooling water discharged from the outlet of the cooling water coil, and then enters the cold side of the heat exchanger for a second heat exchange preheating. The cold raw liquid after the double heat exchange enters the steam heating tank.

[0013] Preferably, in step S3, the liquid discharged by the drain pump is subjected to online detection of its oxidation-reduction potential as it flows through the detector. If the liquid is found to be substandard, it is returned to the steam heating tank via the return pipeline for re-oxygenation treatment. After passing the test, the liquid enters the temporary storage tank.

[0014] Preferably, the preset temperature is 95°C and the preset time is 60 minutes.

[0015] Preferably, in step S2, the cold raw liquid is preheated by the heat exchanger to a temperature of 70°C before entering the steam heating tank, and is further heated by steam to 95°C; in step S3, the liquid is cooled to below 40°C by the cooling water coil.

[0016] Preferably, the continuous operation phase also includes the following controls: real-time monitoring of the inlet flow rate via a flow meter and adjustment of the frequency of the inlet pump via a frequency converter to keep the inlet flow rate into the steam heating tank constant; control of the start and stop of the outlet pump via liquid level monitoring to maintain a preset liquid level in the cooling tank; real-time monitoring of the temperature in the steam heating tank and automatic adjustment of the steam valve opening; real-time monitoring of the outlet temperature of the cooling tank and automatic adjustment of the cooling water valve opening.

[0017] Compared with the prior art, the beneficial effects of the present invention are: This invention utilizes a heat exchanger connected between a steam heating tank and a cooling tank to preheat the incoming cold raw liquid with the high-temperature medicinal liquid after the reaction, thus recovering the sensible heat of the 95°C high-temperature medicinal liquid. Theoretically, when the heat exchange efficiency reaches 60%, the cold raw liquid can be preheated to about 70°C. Compared with direct heating, steam consumption can be reduced by more than 50%. At the same time, the high-temperature medicinal liquid is pre-cooled by the heat exchanger before entering the cooling tank, which reduces the cooling load of the cooling tank and reduces cooling water consumption by more than 50%, thus reducing the dual energy waste of "consuming steam for heating and water for cooling".

[0018] This invention employs an "intermittent start-up, continuous operation" process. During the start-up phase, a thermal energy reserve is established in the steam heating tank, and then the system switches to continuous operation mode. This achieves a dynamic balance between feeding and discharging, allowing cold raw materials to continuously enter and high-temperature pharmaceutical solutions to continuously overflow and discharge. This process can match the continuous waste liquid discharge rhythm of the production line, making it suitable for large-scale continuous production. At the same time, it reduces the non-production waiting time and manual control burden caused by frequent start-ups and shutdowns.

[0019] This invention combines constant flow control, precise liquid level control, and temperature feedback regulation to ensure a constant influent volume, maintain a preset liquid level in the cooling tank, and automatically adjust the opening of the steam valve and cooling water valve according to the temperature. This ensures that the hydrogen peroxide entering the steam heating tank is decomposed at all times within a unit of time. The entire process of deoxygenation reaction is automatically controlled by a chain, which helps to avoid the waste liquid from boiling violently or the hydrogen peroxide decomposition from getting out of control, thus ensuring the safe operation of the system. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the structure of Embodiment 2 of the present invention; Figure 3 This is a three-dimensional schematic diagram of the interior of the steam heating tank in Embodiment 2 of the present invention; Figure 4 This is a three-dimensional schematic diagram of the detachable conical catalytic plate according to Embodiment 2 of the present invention; Figure 5 This is a schematic diagram of the system structure of the present invention.

[0021] Figure 6 This is a schematic diagram of the method flow of the present invention.

[0022] In the diagram: 1. Micro-etching solution storage tank; 2. Temporary storage tank; 4. Inlet pump; 5. Heat exchanger; 501. Auxiliary heat exchanger; 6. Steam heating tank; 601. Steam coil; 602. Conical catalytic plate; 603. Elastic ring; 604. Welding sheet; 605. Conical column; 7. Cooling tank; 701. Cooling water coil; 8. Drain pump; 9. Detector. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Example 1: Please see Figure 1 , Figure 5 and Figure 6 The present invention provides a technical solution: A continuous oxygen-depletion system for micro-etching waste liquid utilizing waste heat recovery includes a micro-etching raw material storage tank 1, a temporary storage tank 2, an inlet pump 4, a heat exchanger 5, a steam heating tank 6, a cooling tank 7, and a drain pump 8. The micro-etching raw material storage tank 1 is used to buffer and store the micro-etching waste liquid to be treated; the steam heating tank 6 is the main reaction vessel for the oxygen-depletion reaction, and it is equipped with a steam coil 601 inside; the cooling tank is also equipped with a stirring device and a temperature sensor; the heat exchanger 5 is a heat exchange unit for preheating the raw material and precooling the high-temperature chemical solution, connected between the steam heating tank 6 and the cooling tank 7; the cooling tank 7 is equipped with a cooling water coil 701 for final cooling of the chemical solution; and the temporary storage tank 2 is used to store the treated clear liquid.

[0025] The outlet of the micro-etching stock solution storage tank 1 is connected to the inlet of the liquid inlet pump 4, the outlet of the liquid inlet pump 4 is connected to the cold side inlet of the heat exchanger 5, and the cold side outlet of the heat exchanger 5 is connected to the liquid inlet of the steam heating tank 6; the high-temperature liquid overflow port of the steam heating tank 6 is connected to the hot side inlet of the heat exchanger 5, and the hot side outlet of the heat exchanger 5 is connected to the liquid inlet of the cooling tank 7; the liquid outlet of the cooling tank 7 is connected to the inlet of the drain pump 8, and the outlet of the drain pump 8 is connected to the temporary storage tank 2. The cold raw liquid is sent to the cold side of the heat exchanger 5 via the inlet pump 4. It exchanges heat countercurrently with the high-temperature liquid that flows into the hot side of the heat exchanger 5 through the overflow port of the steam heating tank 6. After being preheated, it enters the steam heating tank 6. The high-temperature liquid formed after deoxygenation by the steam coil 601 overflows from the high-temperature liquid overflow port to the hot side of the heat exchanger 5. After heat exchange and cooling, it enters the cooling tank 7. After being cooled a second time by the cooling water coil 701, it is sent to the temporary storage tank 2 by the drain pump 8.

[0026] The oxygen-depletion process in this embodiment specifically includes three steps: S1. Start-up Phase (System Initialization and Heating): Start the inlet pump 4 to pump the micro-etching waste liquid in the micro-etching raw material storage tank 1 into the steam heating tank 6. When the liquid level in the steam heating tank 6 reaches the set height (e.g., level H), stop the inlet pump 4. Open the steam valve and heat the waste liquid in the tank by inputting high-temperature steam into the steam coil 601. The system controls the heating to 95°C and maintains a constant temperature. The constant temperature time is set to 60 minutes to ensure that the hydrogen peroxide in the waste liquid is fully decomposed and to establish a thermal energy reserve for the system.

[0027] S2. Continuous Operation Stage: After the heating time reaches the set value, the system switches to continuous operation mode. The inlet pump 4 is restarted to pump in the cold raw material, and the outlet pump 8 is started to discharge the high-temperature liquid. The high-temperature liquid (about 95°C) overflowing from the high liquid level of the steam heating tank 6 flows through the hot side of the heat exchanger 5, and the newly introduced cold raw material (about room temperature) flows through the cold side of the heat exchanger 5. The two exchange heat in countercurrent within the heat exchanger 5: the high-temperature liquid transfers heat to the cold raw material, which is preheated (e.g., from 25°C to 70°C) before entering the steam heating tank 6, and the high-temperature liquid is precooled before flowing into the cooling tank 7. After the preheated raw material enters the steam heating tank 6, only a small amount of steam needs to be added to raise it from 70°C to 95°C, thereby maintaining the dynamic balance of liquid level and temperature in the tank and realizing continuous feeding and continuous discharging.

[0028] S3. Deep cooling and collection stage: The liquid medicine, after being pre-cooled by the heat exchanger 5, flows to the cooling tank 7. In the cooling tank 7, it is cooled a second time by the cooling water coil 701 to reduce the temperature of the liquid medicine to below 40°C. When the liquid level in the cooling tank 7 reaches the set value, the treated clear liquid is transported to the temporary storage tank 2 by the drain pump 8 to wait for subsequent processing.

[0029] To achieve automated operation, this embodiment also adopts the following control strategies: constant flow control, which monitors the inlet flow rate in real time through a flow meter and adjusts the frequency of the inlet pump 4 through a frequency converter to keep the inlet volume of liquid entering the steam heating tank 6 constant, ensuring uniform oxygen decomposition reaction; precise liquid level control, which controls the start and stop of the drain pump 8 through liquid level monitoring, keeping the cooling tank 7 at the middle liquid level, ensuring normal overflow of liquid in the steam heating tank 6, and reserving sufficient space for heating and decomposition; and temperature feedback regulation, which monitors the temperature in the steam heating tank 6 in real time and automatically adjusts the opening of the steam valve, and monitors the outlet temperature of the cooling tank 7 in real time and automatically adjusts the opening of the cooling water valve.

[0030] In this embodiment, the sensible heat of the 95°C high-temperature pharmaceutical solution is recovered through heat exchanger 5. Theoretically, when the heat exchange efficiency reaches 60%, the cold raw liquid can be preheated to about 70°C, reducing steam consumption by more than 50% compared to direct heating. Simultaneously, the temperature of the pharmaceutical solution entering the cooling tank 7 is significantly reduced, reducing cooling water consumption by more than 50%. Furthermore, the system achieves dynamic balance between feed and discharge, enabling continuous and stable operation. The constant flow of feed ensures that the hydrogen peroxide entering the steam heating tank 6 is constantly decomposed within a unit of time, making the decomposition reaction controllable and helping to avoid violent boiling or uncontrolled hydrogen peroxide decomposition.

[0031] Example 2: Please see Figures 2 to 4 The present invention provides a technical solution that is basically the same as that in Embodiment 1, with the following slight differences: Based on Example 1, this embodiment adds an auxiliary heat exchanger 501, a conical catalytic plate 602, an elastic ring 603, a welding sheet 604, a conical column 605, a drain valve, a detector 9, and a return pipeline, and adjusts some pipeline connections accordingly.

[0032] like Figure 2 As shown, in this embodiment, the micro-etching stock solution storage tank 1 is no longer directly connected to the heat exchanger 5. Instead, the outlet of the inlet pump 4 is connected to the cold side inlet of the auxiliary heat exchanger 501, and the cold side outlet of the auxiliary heat exchanger 501 is connected to the cold side inlet of the heat exchanger 5. Simultaneously, the outlet of the cooling water coil 701 is connected to the hot side inlet of the auxiliary heat exchanger 501. After being pumped out by the inlet pump 4, the cold stock solution first flows through the cold side of the auxiliary heat exchanger 501, undergoing a first heat exchange preheating with the used cooling water discharged from the outlet of the cooling water coil 701. Then, it enters the cold side of the heat exchanger 5 for a second heat exchange preheating with the high-temperature chemical solution. The cold stock solution after this double heat exchange enters the steam heating tank 6. This arrangement fully utilizes the residual heat carried in the used cooling water to preheat the cold stock solution, ensuring that the temperature of the cold stock solution finally entering the steam heating tank 6 is higher than that in Example 1. This facilitates faster oxygen de-oxidation and shorter processing time.

[0033] like Figure 3 , Figure 4 As shown, the steam heating tank 6 is equipped with a conical catalytic plate 602. The conical catalytic plate 602 has a downwardly concave conical structure and is filled with catalyst, which can increase the contact range with the waste liquid and promote the decomposition of hydrogen peroxide in the waste liquid. An elastic ring 603 is fixed to the outer ring of the conical catalytic plate 602. Multiple through holes are opened on the circumference of the elastic ring 603. The conical catalytic plate 602 is detachably installed in the steam heating tank 6 through the elastic ring 603. Multiple welding pieces 604 are welded to the inner bottom circumference of the steam heating tank 6. A conical column 605 is welded to the upper end face of each welding piece 604. The top of the conical column 605 is a conical head. During installation, the conical head first expands and enlarges the through hole on the elastic ring 603, allowing the conical column 605 to be inserted into the corresponding through hole, thus enabling the detachable installation of the conical catalytic plate 602. After installation, the elastic ring 603 and the inner wall of the steam heating tank 6, as well as the conical column 605, rely on elastic contraction to prevent leakage. The catalyst is filled inside the conical catalytic plate 602 and unfolds through the conical structure, allowing the waste liquid to fully contact the catalyst as it flows through, which helps to accelerate the decomposition of hydrogen peroxide and improve the oxygen removal efficiency.

[0034] like Figure 2As shown, a drain pipe connects the cooling tank 7 and the temporary storage tank 2, and a drain valve is installed on the drain pipe. The detector 9 is an online sensor, such as an oxidation-reduction potential (ORP) sensor, which is connected in series on the drain pipe before the drain valve to detect the oxidation-reduction potential of the liquid after deoxygenation treatment. The return pipe is connected between the drain pipe and the steam heating tank 6. After completing the deoxygenation treatment for a sufficient period of time, the discharged liquid is still monitored online to prevent unqualified liquid from leaving the system. When the detector 9 detects that the liquid is unqualified, the liquid is sent back to the steam heating tank 6 through the return pipe for deoxygenation treatment again. After passing the test, the liquid enters the temporary storage tank 2 through the drain valve.

[0035] In terms of control methods, this embodiment differs from Embodiment 1 in that: in S2, after the cold raw liquid is pumped out by the inlet pump 4, it first flows through the cold side of the auxiliary heat exchanger 501 and undergoes a first heat exchange preheating with the used cooling water discharged from the outlet of the cooling water coil 701, and then enters the cold side of the heat exchanger 5 for a second heat exchange preheating. After the double heat exchange, the cold raw liquid enters the steam heating tank 6; in S3, the liquid discharged by the drain pump 8 is detected online for oxidation-reduction potential when it flows through the detector 9. When the liquid is detected as unqualified, the liquid is sent back to the steam heating tank 6 through the return pipeline for oxygen deoxygenation treatment again. After the detection is qualified, the liquid enters the temporary storage tank 2.

[0036] In summary, this invention utilizes a multi-stage waste heat recovery path comprised of heat exchangers and auxiliary heat exchangers. The sensible heat carried by the high-temperature oxygen-degrading liquid discharged from the steam heating tank, along with the waste heat from the cooling water discharged from the cooling tank's cooling water coil, is used sequentially to preheat the cold raw liquid entering the system. This ensures the cold raw liquid is raised to a higher temperature before entering the steam heating tank, significantly reducing the amount of steam required for additional heating and lowering cooling water consumption in subsequent cooling processes. During continuous operation, combined with constant flow control, precise liquid level control, and temperature feedback regulation, dynamic balance between feed and discharge is achieved, along with continuous, uniform, and controllable decomposition of hydrogen peroxide. This effectively prevents boiling over and uncontrolled decomposition, ultimately achieving a comprehensive effect of energy saving, continuous stability, safety, reliability, and high automation. It is particularly suitable for the continuous oxygen-degrading treatment of micro-etching waste liquid generated during the manufacturing processes of printed circuit boards, photovoltaic panels, and LCD panels.

[0037] All other parts of this invention not described herein are the same as existing technologies, or are known technologies, or can be implemented using existing technologies, and will not be described in detail here.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A continuous oxygen-depleting system for micro-etched waste liquid utilizing waste heat recovery, characterized in that, include: Micro-etching solution storage tank (1), temporary storage tank (2), inlet pump (4), heat exchanger (5), steam heating tank (6), cooling tank (7) and drain pump (8); The outlet of the micro-etching stock solution storage tank (1) is connected to the inlet of the liquid inlet pump (4), the outlet of the liquid inlet pump (4) is connected to the cold side inlet of the heat exchanger (5), the cold side outlet of the heat exchanger (5) is connected to the liquid inlet of the steam heating tank (6); the steam heating tank (6) is equipped with a steam coil (601), the high temperature liquid overflow port of the steam heating tank (6) is connected to the hot side inlet of the heat exchanger (5), and the hot side outlet of the heat exchanger (5) is connected to the liquid inlet of the cooling tank (7); The cooling tank (7) is equipped with a cooling water coil (701). The outlet of the cooling tank (7) is connected to the inlet of the drain pump (8), and the outlet of the drain pump (8) is connected to the temporary storage tank (2). The cold raw liquid is sent to the cold side of the heat exchanger (5) by the inlet pump (4), and exchanges heat countercurrently with the high-temperature liquid that flows into the hot side of the heat exchanger (5) through the overflow port of the steam heating tank (6). After being preheated, it enters the steam heating tank (6). After being heated by the steam coil (601) to complete the deoxygenation, the high-temperature liquid formed overflows from the high-temperature liquid overflow port to the hot side of the heat exchanger (5). After heat exchange and cooling, it enters the cooling tank (7), and after being cooled again by the cooling water coil (701), it is sent to the temporary storage tank (2) by the drain pump (8).

2. The continuous oxygen decomposition system for micro-etching waste liquid utilizing waste heat recovery according to claim 1, characterized in that, It also includes an auxiliary heat exchanger (501); the outlet of the liquid inlet pump (4) is connected to the cold side inlet of the auxiliary heat exchanger (501), the cold side outlet of the auxiliary heat exchanger (501) is connected to the cold side inlet of the heat exchanger (5); the outlet of the cooling water coil (701) is connected to the hot side inlet of the auxiliary heat exchanger (501).

3. The continuous oxygen deoxygenation system for micro-etching waste liquid utilizing waste heat recovery according to claim 2, characterized in that, It also includes a conical catalyst plate (602) and an elastic ring (603); the conical catalyst plate (602) is a concave conical structure filled with catalyst; the elastic ring (603) is fixed to the outer ring of the conical catalyst plate (602), and the conical catalyst plate (602) is detachably installed in the steam heating tank (6) through the elastic ring (603), and the elastic ring (603) has multiple through holes on its circumference.

4. The continuous oxygen deoxygenation system for micro-etching waste liquid utilizing waste heat recovery according to claim 3, characterized in that, The inner bottom circumference of the steam heating tank (6) is welded with multiple welding pieces (604), and the upper end face of each welding piece (604) is welded with a conical column (605). The top of the conical column (605) is a conical head. During installation, the conical head is used to open and enlarge the through hole on the elastic ring (603), so that the conical column (605) can be inserted into the corresponding through hole to realize the detachable installation of the conical catalyst plate (602). The elastic ring (603) and the inner wall of the steam heating tank (6) and the conical column (605) are elastically contracted to prevent leakage.

5. A method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery, characterized in that, The continuous oxygen deoxygenation system for micro-etched waste liquid utilizing waste heat recovery according to any one of claims 1 to 4 includes the following steps: S1. Start-up phase: Start the inlet pump (4) to pump the micro-etching waste liquid in the micro-etching raw material storage tank (1) into the steam heating tank (6). When the liquid level in the steam heating tank (6) reaches the preset liquid level, stop the inlet pump, turn on the steam and heat the waste liquid in the tank to the preset temperature by inputting high temperature steam into the steam coil (601) and keep the temperature constant for the preset time, so that the hydrogen peroxide in the waste liquid is fully decomposed and the system heat energy reserve is established. S2, Continuous operation stage: Start the inlet pump (4) to pump in the cold raw liquid, and start the outlet pump (8) to discharge the high temperature medicine liquid. The cold raw liquid flows through the cold side of the heat exchanger (5) and exchanges heat with the high temperature medicine liquid overflowing from the high temperature medicine liquid overflow port of the steam heating tank (6) in the heat exchanger (5) in a countercurrent flow. After being preheated, it enters the steam heating tank (6). After the high temperature medicine liquid is cooled by heat exchange, it enters the cooling tank (7). At the same time, steam is continuously replenished to keep the temperature and liquid level in the steam heating tank (6) in dynamic balance, so as to realize continuous feeding and continuous discharge. S3, Deep Cooling and Collection Stage: The liquid medicine entering the cooling tank (7) is cooled to below the safe temperature by the cooling water coil (701). When the liquid level in the cooling tank (7) reaches the preset value, the treated clear liquid is transported to the temporary storage tank (2) by the drain pump (8).

6. The method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery according to claim 5, characterized in that, The system also includes an auxiliary heat exchanger (501); in S2, after the cold raw liquid is pumped out by the inlet pump (4), it first flows through the cold side of the auxiliary heat exchanger (501) and undergoes a first heat exchange preheating with the used cooling water discharged from the outlet of the cooling water coil (701), and then enters the cold side of the heat exchanger (5) for a second heat exchange preheating. After the double heat exchange, the cold raw liquid enters the steam heating tank (6).

7. The method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery according to claim 5, characterized in that, In S3, the liquid discharged by the drain pump (8) is detected online for oxidation-reduction potential when it flows through the detector (9). When the liquid is detected to be unqualified, the liquid is sent back to the steam heating tank (6) through the return pipeline for oxygen deoxygenation treatment. After the liquid is qualified, it enters the temporary storage tank (2).

8. The method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery according to claim 5, characterized in that, The preset temperature is 95℃ and the preset time is 60 minutes.

9. The method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery according to claim 5, characterized in that, In S2, the cold raw liquid is preheated by the heat exchanger (5) and its temperature rises to 70°C before entering the steam heating tank (6), where it is further heated by steam to 95°C. In S3, the liquid is cooled to below 40°C by the cooling water coil (701).

10. The method for continuous oxygen decomposition control of micro-etching waste liquid utilizing waste heat recovery according to claim 5, characterized in that, During continuous operation, the following controls are also performed: the inlet flow rate is monitored in real time by a flow meter, and the frequency of the inlet pump (4) is adjusted by a frequency converter to keep the inlet flow rate into the steam heating tank (6) constant; the start and stop of the drain pump (8) are controlled by liquid level monitoring to keep the liquid level in the cooling tank (7) at the preset level; the temperature in the steam heating tank (6) is monitored in real time and the opening of the steam valve is automatically adjusted; the outlet temperature of the cooling tank (7) is monitored in real time and the opening of the cooling water valve is automatically adjusted.

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