Hydrogen peroxide concentration on-line analyzer with composite stirring extraction mechanism and use method of hydrogen peroxide concentration on-line analyzer

Abstract

The invention discloses a hydrogen peroxide concentration on-line analyzer with a composite stirring extraction mechanism and a use method.The on-line analyzer comprises a supporting frame, a main box body fixedly installed above the supporting frame, and an anti-explosion junction box fixedly installed above one side of the main box body; the analyzer host, the composite stirring extraction mechanism, the air inlet valve, the pressure reducing valve, the blowoff valve and the pneumatic pure water valve are fixedly mounted in the main box body, one end of the continuous sampling valve is communicated with the production pipeline, the other end of the continuous sampling valve is connected and communicated with the lower end of the composite stirring extraction mechanism, and the pure water module is connected and communicated with the analyzer host and the pneumatic pure water valve. The discharge valve is connected and communicated with the lower end of the composite stirring extraction mechanism; the waste liquid pipe is connected and communicated with the analyzer host and the discharge valve; through sufficient mixing and stirring and high-quality extraction of the composite stirring and extracting mechanism, efficient and accurate online analysis is achieved, the concentration of hydrogen peroxide is monitored in real time, automatic control and cleaning functions are achieved, and continuous and stable operation and data accuracy of equipment are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of hydrogen peroxide concentration detection technology, specifically to an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism and its usage method. Background Technology

[0002] Hydrogen peroxide, as an important chemical raw material, has a wide range of applications, including medical, hygiene, cleaning, and cosmetic fields, and its market size is showing a steady growth trend. The global hydrogen peroxide market has already reached a considerable size and is expected to continue to grow in the coming years. In the medical industry, hydrogen peroxide is used as a disinfectant for wounds and injuries, effectively killing bacteria and preventing infection. Simultaneously, in the disinfection industry, hydrogen peroxide is widely used in food processing plants, catering industries, and medical facilities to ensure the hygiene and safety of production and living environments. Furthermore, hydrogen peroxide is also used in electronic-grade products, especially in the electronics industry, where its oxidizing properties reduce pollution and lower costs, indicating a huge market potential.

[0003] The anthraquinone process for producing hydrogen peroxide is one of the most mature production methods in the world. It utilizes the property that quinones can be hydrogenated and reduced back to quinones. Using alkyl anthraquinone derivatives as a carrier, the hydrogen is hydrogenated under catalysis, and then oxidized to synthesize hydrogen peroxide (commonly known as hydrogen peroxide). Large international manufacturers use the anthraquinone process, and it is also almost universally used in China for hydrogen peroxide production. The process flow for producing hydrogen peroxide using the anthraquinone process can be divided into several steps: working solution preparation, hydrogenation, oxidation, extraction, purification, post-treatment of the raffinate working solution (working solution recycling), and preparation of potassium carbonate solution.

[0004] During the extraction process, hydrogen peroxide is extracted and recovered from the oxidation solution using pure water to generate a hydrogen peroxide solution of a certain concentration. This solution is then purified to produce a 27.5% product. The working liquid after extraction is called the raffinate, which contains trace amounts of hydrogen peroxide. When the hydrogen peroxide content in the raffinate exceeds 0.5 g / L (generally not exceeding 0.3 g / L), the oxygen produced by its decomposition in the drying tower can alter the contact state between the working liquid and the alkali in the tower, increasing the alkalinity of the working liquid exiting the tower. This leads to catalyst poisoning in the hydrogenation process and a decrease in oxidation yield and an increase in side reactions in the oxidation process. When neutralized with a large amount of phosphoric acid, the generated phosphate is carried into the finished product, increasing the content of non-volatile substances and reducing quality. If the hydrogen peroxide in the oxidation tower decomposes rapidly, the extraction tower may explode if not handled properly. At best, this disrupts normal extraction operations and further increases the hydrogen peroxide content in the raffinate, creating a vicious cycle. Therefore, the hydrogen peroxide content in both the raffinate and the hydrogen peroxide solution generated from the extraction and recovery of hydrogen peroxide must be tested.

[0005] However, most existing analyses of hydrogen peroxide in raffinate rely on manual sampling. The laboratory uses titration to manually test the hydrogen peroxide concentration, records the data, and then feeds it back to the production workshop. The production workshop then proceeds with the next step based on the test results. The entire testing process takes a certain amount of time. Furthermore, since manual sampling is used, factors such as testing methods can affect the test results. Deviations in the results can easily mislead production and even affect normal production.

[0006] Of course, besides manual testing, analytical instruments are also used for detection and analysis. For example, Chinese Patent Publication No. CN114441517B discloses an analytical device for hydrogen peroxide in hydrogen peroxide raffinate, which integrates the addition of water and mixing, the addition of colorimetric reagent and detection reagent, and can quickly complete the concentration detection and analysis of hydrogen peroxide. The addition of water, colorimetric reagent and detection reagent is more precise and quantitative, and can be mixed evenly in a timely manner to ensure the accuracy of the detection and analysis results. It has an innovative mixing mechanism that can confine the raffinate in the test tube to a specified space for vibration mixing, which improves the mixing efficiency and ensures the detection and analysis results. It can simultaneously perform multiple concentration detection and analysis on the same batch of hydrogen peroxide raffinate, improving the accuracy of the analysis results. However, this method still has the following problems: the first sampling process still requires manual sampling, and it is not possible to monitor the production process in real time. While online products undergo automated continuous sampling, the high intensity of manual operation and low testing frequency remain issues. Secondly, the document does not describe a cleaning system, leading those skilled in the art to assume manual cleaning, which carries the risk of incomplete cleaning and cross-contamination of samples. Thirdly, the document describes a principle of mixing and extracting the raffinate containing water by rapidly vibrating the raffinate container, but it does not directly stir the raffinate. This results in the mixing effect being affected by the amplitude of the test tube vibration, especially in the center of the raffinate container far from the support plate, where the vibration weakens. Furthermore, the vibration waves propagate laterally, leading to poorer vertical mixing of the raffinate containing water in the test tube. This affects the mixing effect and extraction quality, impacting the accuracy of the test results and resulting in large detection errors due to uneven mixing. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism and its usage method. By fully mixing and stirring the mixture, the extraction quality is improved, enabling efficient and accurate online analysis, real-time monitoring of hydrogen peroxide concentration during the production process, and providing automated control and cleaning functions to ensure stable equipment operation, high efficiency, and data accuracy.

[0008] The technical solution adopted by this invention to solve its technical problem is:

[0009] An online hydrogen peroxide concentration analyzer with a composite stirring and extraction mechanism includes a support frame, a main housing fixedly installed above the support frame, an explosion-proof junction box fixedly installed on one side of the main housing, an analyzer host fixedly installed inside the main housing, a composite stirring and extraction mechanism fixedly installed inside the main housing and located on one side of the analyzer host, an air inlet valve connected to the upper end of the composite stirring and extraction mechanism, a pressure reducing valve connected to the air inlet valve, an air vent valve connected to the upper end of the composite stirring and extraction mechanism, a pneumatic pure water valve connected to the lower end of the composite stirring and extraction mechanism, a pure water module connected at one end to the analyzer host and the pneumatic pure water valve and at the other end to a pure water tank, a discharge valve connected to the lower end of the composite stirring and extraction mechanism, a waste liquid pipe connected to the analyzer host and the discharge valve, and a continuous sampling valve located outside the main housing, connected at one end to a production pipeline and at the other end to the lower end of the composite stirring and extraction mechanism.

[0010] The composite stirring extraction mechanism includes a tempered glass tube, a lower end cap mounted at the bottom of the tempered glass tube, an upper end cap mounted at the top of the tempered glass tube, a tensioning screw distributed around the tempered glass tube and connecting the lower and upper end caps to fix the tempered glass tube between the lower and upper end caps, a lower liquid level switch and an upper liquid level switch fixedly mounted on the tensioning screw, a stirring motor fixedly mounted below the lower end cap, and a cylinder fixedly mounted above the upper end cap; the output shaft of the stirring motor extends to the lower end of the tempered glass tube, and a stirring head is fixedly mounted on its output end; the piston rod of the cylinder extends to the inside of the tempered glass tube, and a stirring piston is fixedly mounted on its piston rod end.

[0011] Furthermore, the analyzer main unit is equipped with a front door, a middle box, and a rear door. The front door is equipped with a touch screen, a power switch, and a USB interface; the rear door is equipped with a power board, a PLC controller, and a switching power supply; the middle box houses the analyzer panel, on which a photometric testing cup is fixedly mounted. A magnetic stirrer is installed below the photometric testing cup, a pure water pump is installed on one side of the photometric testing cup, and a pure water valve is installed below the pure water pump. The output end of the pure water pump is connected to the photometric testing cup, the input end is connected to the outlet of the pure water valve, and the inlet of the pure water valve is connected to the pure water module. Above the photometric testing cup... A plunger pump is installed on one side of the photometric test cup, with its output end connected to the photometric test cup. The feed end of the plunger pump is connected to a reagent storage tank. A sulfuric acid pump is installed above the photometric test cup, with its output end connected to the photometric test cup. The feed end of the sulfuric acid pump is connected to a sulfuric acid storage tank. A discharge pump is installed on the other side of the photometric test cup, with its input end connected to the photometric test cup and its output end connected to a waste liquid pipe. A feed pump is installed below the other side of the photometric test cup, with its output end connected to the photometric test cup and its input end connected to the lower end of the composite stirring extraction mechanism.

[0012] Furthermore, the outer side of the lower end cap is respectively provided with a sampling port, a pure water input port, a feed port, and a discharge port; the sampling port is connected to the input end of the feed pump; the pure water input port is connected to the outlet of the pneumatic pure water valve; the feed port is connected to the outlet of the continuous sampling valve; and the discharge port is connected to the waste liquid pipe via the discharge valve.

[0013] Furthermore, an air inlet port and an air outlet port are respectively provided on the outer side of the upper end cap. The air inlet port is connected to the outlet of the air inlet valve, and the air outlet port is connected to the inlet of the vent valve.

[0014] Furthermore, four tension screws are provided.

[0015] Furthermore, the stirring head is a PTFE stirring impeller.

[0016] Furthermore, the stirring piston is a PTFE piston, which includes a piston body, a fitting hole located in the center of the piston body, and several liquid passages distributed on the piston body with the fitting hole as the axis.

[0017] Furthermore, the liquid passage is inclined.

[0018] Furthermore, the liquid passage is provided with four channels.

[0019] Furthermore, the four liquid passages are evenly distributed around the perimeter of the fitting hole, and the angle formed by the four liquid passages and the central axis of the fitting hole is consistent.

[0020] To address the above problems, the present invention also provides a method for using an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism, comprising the following steps:

[0021] S1. System Start-up and Self-Test: Turn on the power switch on the front door of the analyzer host. After receiving the start signal, the PLC controller on the rear door first initializes the status of each component. The switching power supply in the analyzer host provides power to ensure that all electrical components in the analyzer host operate under safe voltage. The lower liquid level switch and the upper liquid level switch are initialized. The initial liquid level in the tempered glass tube of the composite stirring extraction mechanism is monitored to be empty.

[0022] S2. Material replacement: After completing the system startup and self-test in step S1, open the continuous sampling valve, the vent valve, and the discharge valve. Inject the hydrogen peroxide sample to be tested into the production pipeline through the feed port. Discharge the material into the waste liquid pipe through the discharge port and the discharge valve. Close the continuous sampling valve when the set time is reached. Close the discharge valve after the material in the tempered glass tube is completely discharged.

[0023] S3. After completing the material replacement in step S2, online sampling is performed. The specific steps are as follows:

[0024] S31. Add the hydrogen peroxide sample to be tested to the compound stirring extraction mechanism: Open the continuous sampling valve, and the hydrogen peroxide sample to be tested in the production pipeline is connected to the feed port through the continuous sampling valve and directly connected to the tempered glass tube of the compound stirring extraction mechanism. When the lower liquid level switch detects that the hydrogen peroxide sample to be tested in the tempered glass tube has reached the lower liquid level switch control line, stop feeding, and the volume quantification of the hydrogen peroxide sample to be tested added to the tempered glass tube is completed.

[0025] S32. Injecting pure water: After adding the hydrogen peroxide sample to be tested in step S31, the pneumatic pure water valve is opened, and the pure water module delivers pure water through the pneumatic pure water valve into the tempered glass tube of the composite stirring extraction mechanism through the pure water input port. The pure water is initially mixed with the hydrogen peroxide sample to be tested in the tempered glass tube to form a mixture. During this process, the drain valve remains open. When the upper liquid level switch detects that the liquid level in the tempered glass tube has reached the upper liquid level switch control line, the addition of pure water is stopped. At this time, the volume of pure water added to the tempered glass tube is quantified.

[0026] S4. After completing the online sampling in step S3, perform stirring, mixing, and extraction. The specific steps are as follows:

[0027] S41. Bottom Rotary Stirring: The stirring motor drives the stirring head to rotate at high speed, so that the hydrogen peroxide sample to be tested is initially dispersed with the aqueous phase;

[0028] S42. Reciprocating jet mixing: The cylinder pushes the stirring piston downward, causing it to tilt the liquid passage and cut the liquid surface, forcing the mixture to form a jet that is sprayed upward from the tilted liquid passage; when the piston retracts, the passage reverses the flow, forming an upward and downward circulating convection, so that the mixture forms a three-dimensional mixture in the tempered glass tube.

[0029] S43. Separation by standing: After stirring, let stand for more than 2 minutes to allow the mixture to separate into two layers. The extract of hydrogen peroxide and water is located in the lower layer, and other raw materials and impurities are located in the upper layer.

[0030] S5. After completing the stirring, mixing, and extraction in step S4, perform sample analysis and data acquisition of the extract. The specific steps are as follows:

[0031] S51. Extraction and quantification of extract sample: After extraction, the feed pump extracts the extract sample from the tempered glass tube through the sampling port and delivers it to the photometric test cup. The volume of the extracted sample is quantified by the working time of the feed pump or by the quantitative tube connected between the feed pump and the photometric test cup. Sampling stops when the set volume is reached and the feed pump is turned off.

[0032] S52. Drainage and Cleaning of the Composite Stirring Extraction Mechanism: After the extraction liquid sample is collected, the composite stirring extraction mechanism is cleaned: Open the vent valve and discharge valve, and discharge the remaining material in the tempered glass tube into the waste liquid pipe through the discharge valve from the discharge port. At this time, the air inlet valve can be opened and the vent valve closed to add compressed gas into the tempered glass tube, thereby accelerating the discharge speed of the remaining material in the tempered glass tube. After all the remaining material in the tempered glass tube has been discharged, close the discharge valve and air inlet valve, open the vent valve, open the pneumatic pure water valve, and discharge the pure water into the tempered glass tube through the pure water module. Pure water is injected into the glass tube. After the upper liquid level switch detects that the liquid level has reached the control line, the pneumatic pure water valve is closed, and the cylinder and stirring motor are started. The stirring piston and stirring head start to perform up-down and rotational cleaning. When the set time is reached, the cylinder and stirring motor are closed, the discharge valve and air inlet valve are opened, and the vent valve is closed to discharge the cleaning waste liquid. When the set time is reached, the discharge valve and air inlet valve are closed, and the vent valve is opened until all the liquid in the tempered glass tube is discharged. The cleaning is then complete. At this time, it can be cleaned again as needed or the extraction liquid sample to be tested next can be prepared.

[0033] S53. Add sulfuric acid: While draining and cleaning the tempered glass tube of the composite stirring extraction mechanism, start the pretreatment and detection: turn on the sulfuric acid pump, start the magnetic stirrer, and after the sulfuric acid pump injects a certain volume of sulfuric acid according to the preset ratio, stop the sulfuric acid pump so that the extract sample with added sulfuric acid is mixed evenly by high-speed rotation.

[0034] S54. Titration: After mixing for the set time in step S53, turn on the plunger pump to add potassium permanganate. Detect the change in photometric value using a photometric detector. When the set endpoint is detected, turn off the plunger pump. The PLC system automatically records the titration volume and calculates the hydrogen peroxide concentration.

[0035] S55. Data Upload and Storage: The detection results are uploaded to the central control system through the PLC controller, historical data is stored synchronously, and threshold alarms are triggered for abnormal data;

[0036] S6. After completing the sample analysis and data acquisition of the extract in step S5, proceed with the discharge and cleaning process. The specific steps are as follows:

[0037] S61. Waste liquid discharge: After the test is completed, the discharge pump will discharge the photometric test cup and residual liquid in the pipeline through the waste liquid pipe;

[0038] S62. Photometric test cup cleaning: Open the pure water valve and pure water pump, inject pure water into the photometric test cup, turn on the magnetic stirrer, rinse the photometric test cup independently, after the set time is reached, close the pure water valve and pure water pump, turn on the discharge pump, discharge the cleaning wastewater to the waste liquid pipe, after the set time is reached, turn off the discharge pump and magnetic stirrer, and the photometric test cup cleaning is completed.

[0039] S63. When further testing is required, the extract prepared in step S52 can be directly introduced into the photometric test cup for testing. When further testing is not required, the photometric test cup can be cleaned again following step S62.

[0040] Compared with existing related technologies, the beneficial effects of the present invention are as follows:

[0041] 1. The composite stirring extraction mechanism employs a combined action of rotary mechanical stirring and jet stirring: the bottom stirring head rotates at high speed to promote the initial dispersion of hydrogen peroxide and the aqueous phase; the top piston cuts the liquid surface through an inclined liquid passage to form an oblique jet, and the piston's reciprocating motion reverses the flow, achieving vertical circulation convection and forming three-dimensional mixing. This dual stirring mechanism significantly improves the mixing effect and the mass transfer efficiency of the extract, avoiding the problem of uneven local mixing that may be caused by single stirring, ensuring sufficient and stable extraction, providing reliable samples for subsequent testing, and improving the accuracy and efficiency of testing. The structural design of the upper and lower end caps not only makes the overall structure more compact but also ensures the safety of the extraction mechanism during operation. At the same time, the setting of the air inlet and outlet ports also improves the efficiency of the extraction process. Furthermore, the design of the circular groove and mounting slot of the lower end cap makes installation more convenient and operation safer and more reliable.

[0042] 2. Through integrated control with a PLC controller, a fully automated process is achieved for continuous online sampling, mixing and extraction, analysis and detection, and discharge and cleaning: Materials are directly sampled from the production pipeline via a continuous sampling valve, eliminating the need for manual intervention and meeting the real-time monitoring requirements of the production line; the cleaning process is automatically triggered by the PLC, avoiding the incompleteness of manual cleaning and the risk of cross-contamination. Furthermore, the lower and upper liquid level switches not only automatically control the added volume of hydrogen peroxide samples and pure water but also monitor the liquid level in real time, preventing dry running and overflow; the air inlet valve and vent valve work together to adjust the air pressure inside the tempered glass tube of the composite stirring extraction mechanism, making feeding and discharging easier and ensuring a stable extraction process. Therefore, the fully automated design significantly reduces the intensity of manual operation, increases the detection frequency, and is suitable for continuous production scenarios.

[0043] 3. The online analyzer integrates a photometric testing cup, a magnetic stirrer, a pure water module, a sulfuric acid pump, and a plunger pump. It can automatically dilute samples, adjust acidity, perform colorimetric reactions, and detect absorbance. The sulfuric acid pump adds sulfuric acid at a preset ratio to eliminate interfering ions and promote colorimetric reactions, thus improving detection accuracy. The magnetic stirrer mixes the solution at high speed, avoiding localized concentration unevenness. The plunger pump quantitatively delivers potassium permanganate to ensure the repeatability of the titration reaction. The detection data is uploaded to the central control system in real time via a PLC controller, supporting storage and threshold alarms. The data has high reliability and meets the quality control requirements of industrial production.

[0044] 4. When cleaning the composite stirring extraction mechanism, pure water enters the tempered glass tube through the pure water inlet port. The stirring motor rotates at low speed, and the stirring piston reciprocates, using a jet to flush away residue from the inner wall. Switching the discharge valve to the drain mode allows the cleaning solution to be discharged through the discharge port, thoroughly removing impurities. When cleaning the photometric test cup, a pure water pump independently rinses the cup, and a magnetic stirrer assists in cleaning, avoiding cross-contamination between different batches of samples, improving the accuracy and efficiency of the test, ensuring long-term stable operation of the equipment, and reducing the frequency and cost of manual maintenance.

[0045] 5. Dynamic liquid level control to ensure process stability: The lower liquid level switch monitors and controls the liquid level of the hydrogen peroxide sample being drawn in, while the upper liquid level switch monitors and controls the volume of pure water being added, ensuring the accuracy of both volumes. At the same time, during cleaning, the upper liquid level switch can control the volume of pure water added, preventing the extract from overflowing and contaminating the equipment. This not only prevents external impurities from entering but also improves the mass transfer rate at the liquid interface, ensuring a stable and controllable extraction process.

[0046] 6. By setting the main housing on the support frame, the analyzer host, compound stirring extraction mechanism, pure water module and other components are placed inside the main housing, while the photometric test cup, magnetic stirrer, pure water pump, feed pump, discharge pump, sulfuric acid pump and plunger pump are integrated into the analyzer host. The overall structure is compact and can be adapted to various production environments, thus expanding the application range of the online analyzer. Attached Figure Description

[0047] Figure 1 This is a schematic diagram of the overall structure of an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to the present invention;

[0048] Figure 2 This is a structural diagram of an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to the present invention;

[0049] Figure 3 for Figure 2 Structural diagram of the main unit of the analyzer;

[0050] Figure 4 for Figure 3 Front door structure diagram of the main unit of the analyzer;

[0051] Figure 5 for Figure 3 Back view of the main unit of the analyzer;

[0052] Figure 6 for Figure 2 Structural diagram of the composite stirring extraction mechanism;

[0053] Figure 7 for Figure 6A partial sectional view of the lower end cap and stirring head of the composite stirring extraction mechanism (partial sectional view of the part below the lower liquid level switch);

[0054] Figure 8 for Figure 6 Schematic diagram of the structure of the lower and middle end caps;

[0055] Figure 9 for Figure 6 A three-dimensional structural diagram of the stirring piston;

[0056] Figure 10 for Figure 6 A three-dimensional perspective view of the stirring piston;

[0057] Figure 11 for Figure 6 Top view of the stirring piston;

[0058] Figure 12 This is a schematic diagram of the specific structure of an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to the present invention. Detailed Implementation

[0059] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0060] Example

[0061] like Figure 1-12 As shown, an online hydrogen peroxide concentration analyzer with a composite stirring and extraction mechanism includes a support frame 1, a main housing 2 fixedly installed above the support frame 1, an explosion-proof junction box 3 fixedly installed on one side of the main housing 2, an analyzer main unit 4 fixedly installed inside the main housing 2, a composite stirring and extraction mechanism 5 fixedly installed inside the main housing 2 and located on one side of the analyzer main unit 4, an air inlet valve 6 connected to the upper end of the composite stirring and extraction mechanism 5, a pressure reducing valve 7 connected to the air inlet valve 6, and a pressure reducing valve 7 connected to the upper end of the composite stirring and extraction mechanism 5. The system includes an air vent valve 8 connected to the end of the main body 2, a pneumatic pure water valve 9 connected to the lower end of the composite stirring extraction mechanism 5, a pure water module 11 connected at one end to the analyzer main unit 4 and the pneumatic pure water valve 9 and at the other end to a pure water tank, a discharge valve 12 connected to the lower end of the composite stirring extraction mechanism 5, a waste liquid pipe 13 connected to the analyzer main unit 4 and the discharge valve 12, and a continuous sampling valve 10 located outside the main body 2, connected at one end to the production pipeline and at the other end to the lower end of the composite stirring extraction mechanism 5.

[0062] The analyzer main unit 4 is equipped with a front door 410, a middle box 411, and a rear door 409. The analyzer panel 4111 is installed inside the middle box 411. A photometric test cup 402 is fixedly installed on the analyzer panel 4111. A magnetic stirrer 401 is installed below the photometric test cup 402. A pure water pump 403 is installed on one side of the photometric test cup 402. A pure water valve 404 is installed below the pure water pump 403. The output end of the pure water pump 403 is connected to the photometric test cup 402, and its input end is connected to the outlet of the pure water valve 404. The inlet of the pure water valve 404 is connected to the pure water module 11. A plunger pump 405 is installed on one side above the photometric test cup 402. The output end of the plunger pump 405 is connected to the photometric test cup 402. 02. A reagent storage tank is connected to the feed end of the plunger pump 405. A sulfuric acid pump 406 is installed above the photometric test cup 402. The output end of the sulfuric acid pump 406 is connected to the photometric test cup 402. The feed end of the sulfuric acid pump 406 is connected to the sulfuric acid storage tank. A discharge pump 408 is installed on the other side of the photometric test cup 402. The input end of the discharge pump 408 is connected to the photometric test cup 402. The output end of the discharge pump 408 is connected to the waste liquid pipe 13. A feed pump 407 is installed below the other side of the photometric test cup 402. The output end of the feed pump 407 is connected to the photometric test cup 402. The input end of the feed pump 407 is connected to the lower end of the composite stirring extraction mechanism 5.

[0063] In the analyzer host 4, the front door 410 is equipped with a touch screen 4101, a power switch 4102 and a USB interface 4103, and the rear door 409 is equipped with a power board 4091, a PLC controller 4092 and a switching power supply 4093.

[0064] The composite stirring extraction mechanism 5 includes a tempered glass tube 501, a lower end cap 502 mounted at the bottom of the tempered glass tube 501, an upper end cap 503 mounted at the top of the tempered glass tube 501, a tension screw 504 distributed around the tempered glass tube 501 and connecting the lower end cap 502 and the upper end cap 503 and fixing the tempered glass tube 501 between the lower end cap 502 and the upper end cap 503, a lower liquid level switch 505 and an upper liquid level switch 506 fixedly mounted on the tension screw 504, a stirring motor 507 fixedly mounted below the lower end cap 502, and a cylinder 509 fixedly mounted above the upper end cap 503. The output shaft of the stirring motor 507 extends to the lower end of the interior of the tempered glass tube 501, and a stirring head 508 is fixedly mounted on the output end of its output shaft. The piston rod of the cylinder 509 extends to the interior of the tempered glass tube 501, and a stirring piston 510 is fixedly mounted on the end of its piston rod.

[0065] It should be noted that, in order to improve the safety of the tempered glass tube 501 when the stirring head 508 is stirring at high speed, the upper part of the lower end cap 502 is set into a circular groove, and the stirring head 508, which is installed on the output end of the output shaft of the stirring motor 507, is placed in the circular groove area. The bottom periphery of the circular groove is provided with an installation groove. The outer cylindrical surface of the wall of the tempered glass tube 501 is in close contact with the inner cylindrical surface of the circular groove of the lower end cap 502. The bottom end of the tempered glass tube 501 is installed in the installation groove, and a sealing ring is provided at the contact point. This not only ensures that the tempered glass tube 501 is installed more stably and reliably between the upper and lower end caps, but also provides a certain degree of protection for the wall of the tempered glass tube 501 with the inner cylindrical surface of the circular groove, avoiding damage caused by the force generated by the high-speed rotation of the stirring head 508.

[0066] There are four tension screws 504, which are evenly arranged around the outer circumference of the tempered glass tube 501 to improve the fixing effect of the tempered glass tube 501 and enhance the aesthetics of the mechanism.

[0067] The stirring head 508 is a PTFE stirring impeller.

[0068] The lower end cap 502 has a sampling port 5021, a pure water inlet port 5022, a feed port 5023, and a discharge port 5024 respectively provided on its outer side. The lower end cap 502 has internal channels that connect the sampling port 5021, the pure water inlet port 5022, the feed port 5023, and the discharge port 5024 to the tempered glass tube 501. These channels are independent of each other. Specifically, the sampling port 5021 is connected to the input end of the feed pump 407, allowing the feed pump 407 to extract the extract sample from the tempered glass tube 501 through the sampling port 5021. The sample is then transported to the photometric test cup 402 for stirring and testing. The pure water input port 5022 is connected to the outlet of the pneumatic pure water valve 9, which can supply pure water to the tempered glass tube 501 of the composite stirring extraction mechanism 5 for mixing and stirring or to rinse the inside of the tempered glass tube 501 of the composite stirring extraction mechanism 5. The feed port 5023 is connected to the outlet of the continuous sampling valve 10, which can continuously sample the raw materials transported from the production pipeline and transport them to the tempered glass tube 501 of the composite stirring extraction mechanism 5 for mixing and extraction with pure water. The discharge port 5024 is connected to the waste liquid pipe 13 via the discharge valve 12, which can discharge the residual extract liquid inside the composite stirring extraction mechanism 5 or discharge the wastewater generated from cleaning the composite stirring extraction mechanism 5.

[0069] The upper end cap 503 is provided with an air inlet port 5031 and an air outlet port 5032 on its outer side. The upper end cap 503 has channels that connect the air inlet port 5031 and the air outlet port 5032 to the tempered glass tube 501. The channels connecting the air inlet port 5031 and the air outlet port 5032 to the tempered glass tube 501 are independent of each other. Specifically, the air inlet port 5031 is connected to the outlet of the air inlet valve 6, and the air outlet port 5032 is connected to the inlet of the vent valve 8. This can adjust the air pressure inside the tempered glass tube 501 of the compound stirring extraction mechanism 5 and improve the working efficiency of the extraction mechanism.

[0070] The stirring piston 510 is a PTFE piston, comprising a piston body 5101, a centrally located fitting hole 5102, and several liquid passages 5103 distributed on the piston body 5101 around the fitting hole 5102. Specifically, the piston body 5101 is fixedly installed to the piston rod end of the cylinder 509 piston rod through the fitting hole 5102. PTFE material effectively prevents corrosion, improves equipment efficiency and service life, and reduces operating and maintenance costs.

[0071] It should be further noted that there are four liquid passages 5103, which can accelerate the flow of the mixture.

[0072] It should be further explained that the liquid passage 5103 is inclined. Specifically, during the process of the cylinder 509 squeezing or retrieving the piston body 5101, the mixture inside the tempered glass tube 501 can pass through the inclined liquid passage 5103 to form an oblique jet, thereby improving the mixing uniformity of the mixture and achieving a better extraction effect.

[0073] To facilitate processing and achieve better stirring and extraction effects, four liquid passages 5103 are evenly distributed around the perimeter of the fitting hole 5102. The angles formed by the four liquid passages 5103 and the central axis of the fitting hole 5102 are consistent. The specific angles can be set according to the process requirements of stirring, mixing and extraction.

[0074] Of course, the liquid passage can also be designed to be in the same direction as the central axis of the fitting hole 5102. The shape, relative position and number of the liquid passage cross-section can be flexibly set according to the actual process requirements.

[0075] In this invention, the method of using the online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism is as follows:

[0076] S1. System Start-up and Self-Test: Turn on the power switch 4102 on the front door 410 of the analyzer host 4. After receiving the start signal, the PLC controller 4092 on the rear door 409 first initializes the status of each component. The 24V switching power supply 4093 in the analyzer host 4 provides power to ensure that all electrical components in the analyzer host 4 operate under safe voltage. The lower liquid level switch 505 and the upper liquid level switch 506 are initialized, and the initial liquid level in the tempered glass tube 501 of the composite stirring extraction mechanism 5 is monitored to be empty.

[0077] S2. Material Replacement: After completing the system startup and self-test in step S1, material replacement is performed. The continuous sampling valve 10, the vent valve 8, and the discharge valve 12 are opened. The hydrogen peroxide sample to be tested is injected into the production pipeline through the feed port 5023. The material is discharged into the waste liquid pipe 13 through the discharge port 5024 and the discharge valve 12. The continuous sampling valve 10 is closed when the set time is reached. After the material in the tempered glass tube 501 is completely discharged, the discharge valve 12 is closed.

[0078] S3. After completing the material replacement in step S2, online sampling is performed. The specific steps are as follows:

[0079] S31. Add the hydrogen peroxide sample to be tested to the composite stirring extraction mechanism: Open the continuous sampling valve 10, and the hydrogen peroxide sample to be tested in the production pipeline is connected to the feed port 5023 through the continuous sampling valve 10, so as to be directly connected to the tempered glass tube 501 of the composite stirring extraction mechanism 5. When the lower liquid level switch 505 detects that the hydrogen peroxide sample to be tested in the tempered glass tube 501 has reached the control line of the lower liquid level switch 505, the feeding is stopped. At this time, the volume of the hydrogen peroxide sample to be tested added to the tempered glass tube 501 is quantified.

[0080] S32. Injecting pure water: After adding the hydrogen peroxide sample to be tested in step S31, the pneumatic pure water valve 9 is opened. The pure water module 11 delivers pure water through the pneumatic pure water valve 9 and enters the tempered glass tube 501 of the composite stirring extraction mechanism 5 through the pure water input port 5022. The pure water is initially mixed with the hydrogen peroxide sample to be tested in the tempered glass tube 501 to form a mixture. During this process, the drain valve 8 remains open. When the upper liquid level switch 506 detects that the liquid level in the tempered glass tube 501 has reached the control line of the upper liquid level switch 506, the addition of pure water is stopped. At this time, the volume of pure water added to the tempered glass tube 501 is quantitatively measured. By setting the upper and lower liquid level switches, the volume of the added hydrogen peroxide sample and pure water is precisely controlled.

[0081] S4. After completing the online sampling in step S3, perform stirring, mixing, and extraction. The specific steps are as follows:

[0082] S41. Bottom Rotary Stirring: Stirring motor 507 drives stirring head 508 to rotate at high speed, promoting the initial dispersion of the hydrogen peroxide sample to be tested with the aqueous phase;

[0083] S42. Reciprocating jet mixing: The cylinder 509 pushes the stirring piston 510 downward, and its inclined liquid passage 5103 cuts the liquid surface, forcing the mixture to form a jet that is sprayed upward from the inclined liquid passage 5103; when the piston retracts, the channel reverses the flow, forming an upward and downward circulating convection, so that the mixture forms a three-dimensional mixing in the tempered glass tube 501, which significantly improves the mixing quality and efficiency.

[0084] S43. Separation by standing: After stirring, let stand for more than 2 minutes to allow the mixture to separate into two layers. The extract of hydrogen peroxide and water is located in the lower layer, and the upper layer contains other raw materials and impurities.

[0085] S5. After completing the stirring, mixing, and extraction in step S4, perform sample analysis and data acquisition of the extract. The specific steps are as follows:

[0086] S51. Extraction and Quantification of Extract Sample: After extraction, the feed pump 407 extracts the extract sample from the tempered glass tube 501 through the sampling port 5021 and delivers it to the photometric test cup 402. The volume of the extracted sample is quantified by the working time of the feed pump 407 or by the quantitative tube connected between the feed pump 407 and the photometric test cup 402. Sampling stops when the set volume is reached, and the feed pump 407 is turned off. This step is also the process of transferring the extract sample to the analysis module.

[0087] S52. Drainage and Cleaning of the Composite Stirring Extraction Mechanism: After the extraction liquid sample is collected, the composite stirring extraction mechanism can be cleaned: Open the vent valve 8 and the discharge valve 12, and discharge the remaining material in the tempered glass tube 501 into the waste liquid pipe 13 through the discharge port 5024 and the discharge valve 12. At this time, the air inlet valve 6 can be opened to add compressed gas into the tempered glass tube 501 to speed up the discharge of the remaining material in the tempered glass tube 501 and improve the overall working efficiency. When opening the air inlet valve 6, the vent valve 8 should be closed at the same time. After all the remaining material in the tempered glass tube 501 has been discharged, close the discharge valve 12 and the air inlet valve 6, open the vent valve 8, and open the pneumatic pure water valve 9. Pure water module 11 injects pure water into tempered glass tube 501. After the upper liquid level switch 506 detects that the liquid level has reached the control line, it closes the pneumatic pure water valve 9, starts the cylinder 509 and the stirring motor 507, and starts the stirring piston 510 and the stirring head 508 to perform up-down and rotational cleaning. When the set time is reached, the cylinder 509 and the stirring motor 507 are closed, the discharge valve 12 and the air inlet valve 6 are opened, and the vent valve 8 is closed to discharge the cleaning waste liquid. When the set time is reached, the discharge valve 12 and the air inlet valve 6 are closed, and the vent valve 8 is opened until all the liquid in the tempered glass tube 501 is discharged, and the cleaning is completed. At this time, it can be cleaned again as needed or the extraction liquid sample to be tested next time can be prepared.

[0088] S53. Add sulfuric acid: While draining and cleaning the tempered glass tube 501 of the composite stirring extraction mechanism 5, start the pretreatment and detection: turn on the sulfuric acid pump 406, start the magnetic stirrer 401, and after the sulfuric acid pump 406 injects a certain volume of sulfuric acid according to the preset ratio, stop the sulfuric acid pump 406 so that the extract sample with added sulfuric acid is mixed evenly by high-speed rotation.

[0089] S54. Titration: After mixing for the set time in step S53, turn on the plunger pump 405 to add potassium permanganate. Detect the change in photometric value using a photometric detector. When the set endpoint is detected, turn off the plunger pump 405. The PLC system automatically records the titration volume and calculates the hydrogen peroxide concentration.

[0090] S55. Data Upload and Storage: The detection results are uploaded to the central control system through the PLC controller 4092, historical data is stored synchronously, and threshold alarms are triggered for abnormal data, such as audible and visual warnings when the concentration is abnormal;

[0091] S6. After completing the sample analysis and data acquisition of the extract in step S5, proceed with the discharge and cleaning process. The specific steps are as follows:

[0092] S61. Waste liquid discharge: After the test is completed, the discharge pump 408 discharges the photometric test cup 402 and the residual liquid in the pipeline through the waste liquid pipe 13;

[0093] S62. Cleaning of photometric test cup 402: Open the pure water valve 404 and pure water pump 403, inject pure water into photometric test cup 402, turn on magnetic stirrer 401, rinse photometric test cup 402 independently to avoid cross-contamination. After the set time is reached, close the pure water valve 404 and pure water pump 403, turn on the discharge pump 408, and discharge the cleaning wastewater to waste liquid pipe 13 through discharge pump 408. After the set time is reached, turn off discharge pump 408 and magnetic stirrer 401. The cleaning of photometric test cup 402 is complete.

[0094] S63. When it is necessary to continue testing, the extraction solution prepared in step S52 can be directly introduced into the photometric test cup 402 for testing, which can greatly reduce the time waiting for the tempered glass tube 501 of the composite stirring extraction mechanism 5 to be cleaned; if it is not necessary to continue testing, the photometric test cup 402 can be cleaned again according to step S62 to reduce the impact on the next test and the corrosion of the photometric test cup 402 and other equipment.

[0095] It should be further explained that during stirring and mixing, the cylinder 509 and the stirring motor 507 can be set to start in a certain sequence or in a certain cycle according to the process requirements, or they can be started simultaneously to achieve the best mixing effect and extraction quality.

[0096] It should be further explained that in steps S4 and S5, if the current of the stirring motor 507 rises abnormally, the PLC controller 4092 will immediately stop the machine and sound an alarm, and it is necessary to manually check whether there are foreign objects wrapped around the stirring head 508 inside the tempered glass tube 501.

[0097] The above embodiments of the present invention are not intended to limit the scope of protection of the present invention. The implementation of the present invention is not limited thereto. All other modifications, substitutions or alterations made to the above structure of the present invention based on the above content of the present invention, in accordance with ordinary technical knowledge and common practice in the field, without departing from the basic technical idea of ​​the present invention, shall fall within the scope of protection of the present invention.

Claims

1. An online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism, characterized in that, The system includes a support frame, a main housing fixedly installed above the support frame, an explosion-proof junction box fixedly installed on one side of the main housing, an analyzer main unit fixedly installed inside the main housing, a composite stirring and extraction mechanism fixedly installed inside the main housing and located on one side of the analyzer main unit, an air inlet valve connected to the upper end of the composite stirring and extraction mechanism, a pressure reducing valve connected to the air inlet valve, an air vent valve connected to the upper end of the composite stirring and extraction mechanism, a pneumatic pure water valve connected to the lower end of the composite stirring and extraction mechanism, a pure water module connected at one end to the analyzer main unit and the pneumatic pure water valve and at the other end to a pure water tank, a discharge valve connected to the lower end of the composite stirring and extraction mechanism, a waste liquid pipe connected to the analyzer main unit and the discharge valve, and a continuous sampling valve located outside the main housing, connected at one end to the production pipeline and at the other end to the lower end of the composite stirring and extraction mechanism. The composite stirring extraction mechanism includes a tempered glass tube, a lower end cap mounted at the bottom of the tempered glass tube, an upper end cap mounted at the top of the tempered glass tube, a tensioning screw distributed around the tempered glass tube and connecting the lower and upper end caps to fix the tempered glass tube between the lower and upper end caps, a lower liquid level switch and an upper liquid level switch fixedly mounted on the tensioning screw, a stirring motor fixedly mounted below the lower end cap, and a cylinder fixedly mounted above the upper end cap; the output shaft of the stirring motor extends to the lower end of the tempered glass tube, and a stirring head is fixedly mounted on its output end; the piston rod of the cylinder extends to the inside of the tempered glass tube, and a stirring piston is fixedly mounted on its piston rod end.

2. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The analyzer main unit has a front door, a middle box, and a rear door. The front door is equipped with a touchscreen, a power switch, and a USB interface. The rear door houses a power board, a PLC controller, and a switching power supply. The middle box contains the analyzer panel, on which a photometric testing cup is fixedly mounted. A magnetic stirrer is installed below the photometric testing cup. A pure water pump is installed to one side of the photometric testing cup, and a pure water valve is installed below the pump. The pump's output is connected to the photometric testing cup, its input is connected to the outlet of the pure water valve, and the valve's inlet is connected to the pure water module. The top of the photometric testing cup... A plunger pump is installed, with its output end connected to the photometric test cup. The inlet end of the plunger pump is connected to a reagent storage tank. A sulfuric acid pump is installed above the photometric test cup, with its output end connected to the photometric test cup. The inlet end of the sulfuric acid pump is connected to a sulfuric acid storage tank. A discharge pump is installed on the other side of the photometric test cup, with its input end connected to the photometric test cup and its output end connected to a waste liquid pipe. A feed pump is installed below the other side of the photometric test cup, with its output end connected to the photometric test cup and its input end connected to the lower end of the composite stirring extraction mechanism.

3. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The outer side of the lower end cap is respectively provided with a sampling port, a pure water input port, a feed port, and a discharge port; the sampling port is connected to the input end of the feed pump; the pure water input port is connected to the outlet of the pneumatic pure water valve; the feed port is connected to the outlet of the continuous sampling valve; and the discharge port is connected to the waste liquid pipe via the discharge valve.

4. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The outer side of the upper end cap is provided with an air inlet and an air outlet. The air inlet is connected to the outlet of the air inlet valve, and the air outlet is connected to the inlet of the vent valve.

5. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The tensioning screws are provided in four parts.

6. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The stirring head is a PTFE stirring impeller.

7. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 1, characterized in that, The stirring piston is a PTFE piston, which includes a piston body, a fitting hole located in the center of the piston body, and several liquid passages distributed on the piston body with the fitting hole as the axis.

8. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 7, characterized in that, The liquid passage is inclined.

9. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 7, characterized in that, The liquid passage is provided with four channels.

10. The online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to claim 9, characterized in that, The four liquid passages are evenly distributed around the perimeter of the housing hole, and the angle formed by the four liquid passages and the central axis of the housing hole is consistent.

11. A method of using an online hydrogen peroxide concentration analyzer with a composite stirring extraction mechanism according to any one of claims 1-10, characterized in that, Includes the following steps: S1. System Start-up and Self-Test: Turn on the power switch on the front door of the analyzer host. After receiving the start signal, the PLC controller on the rear door first initializes the status of each component. The switching power supply in the analyzer host provides power to ensure that all electrical components in the analyzer host operate under safe voltage. The lower liquid level switch and the upper liquid level switch are initialized. The initial liquid level in the tempered glass tube of the composite stirring extraction mechanism is monitored to be empty. S2. Material replacement: After completing the system startup and self-test in step S1, open the continuous sampling valve, the vent valve, and the discharge valve. Inject the hydrogen peroxide sample to be tested into the production pipeline through the feed port. Discharge the material into the waste liquid pipe through the discharge port and the discharge valve. Close the continuous sampling valve when the set time is reached. Close the discharge valve after the material in the tempered glass tube is completely discharged. S3. After completing the material replacement in step S2, online sampling is performed. The specific steps are as follows: S31. Add the hydrogen peroxide sample to be tested to the compound stirring extraction mechanism: Open the continuous sampling valve, and the hydrogen peroxide sample to be tested in the production pipeline is connected to the feed port through the continuous sampling valve and directly connected to the tempered glass tube of the compound stirring extraction mechanism. When the lower liquid level switch detects that the hydrogen peroxide sample to be tested in the tempered glass tube has reached the lower liquid level switch control line, stop feeding, and the volume quantification of the hydrogen peroxide sample to be tested added to the tempered glass tube is completed. S32. Injecting pure water: After adding the hydrogen peroxide sample to be tested in step S31, the pneumatic pure water valve is opened, and the pure water module delivers pure water through the pneumatic pure water valve into the tempered glass tube of the composite stirring extraction mechanism through the pure water input port. The pure water is initially mixed with the hydrogen peroxide sample to be tested in the tempered glass tube to form a mixture. During this process, the drain valve remains open. When the upper liquid level switch detects that the liquid level in the tempered glass tube has reached the upper liquid level switch control line, the addition of pure water is stopped. At this time, the volume of pure water added to the tempered glass tube is quantified. S4. After completing the online sampling in step S3, perform stirring, mixing, and extraction. The specific steps are as follows: S41. Bottom Rotary Stirring: The stirring motor drives the stirring head to rotate at high speed, so that the hydrogen peroxide sample to be tested is initially dispersed with the aqueous phase; S42. Reciprocating jet mixing: The cylinder pushes the stirring piston downward, causing it to tilt the liquid passage and cut the liquid surface, forcing the mixture to form a jet that is sprayed upward from the tilted liquid passage; when the piston retracts, the passage reverses the flow, forming an upward and downward circulating convection, so that the mixture forms a three-dimensional mixture in the tempered glass tube. S43. Separation by standing: After stirring, let stand for more than 2 minutes to allow the mixture to separate into two layers. The extract of hydrogen peroxide and water is located in the lower layer, and other raw materials and impurities are located in the upper layer. S5. After completing the stirring, mixing, and extraction in step S4, perform sample analysis and data acquisition of the extract. The specific steps are as follows: S51. Extraction and quantification of extract sample: After extraction, the feed pump extracts the extract sample from the tempered glass tube through the sampling port and delivers it to the photometric test cup. The volume of the extracted sample is quantified by the working time of the feed pump or by the quantitative tube connected between the feed pump and the photometric test cup. Sampling stops when the set volume is reached and the feed pump is turned off. S52. Drainage and Cleaning of the Composite Stirring Extraction Mechanism: After the extract sample is collected, the composite stirring extraction mechanism is cleaned: Open the vent valve and discharge valve, and discharge the remaining material in the tempered glass tube into the waste liquid pipe through the discharge valve from the discharge port. At this time, the air inlet valve can be opened and the vent valve closed to add compressed gas into the tempered glass tube, thereby accelerating the discharge speed of the remaining material in the tempered glass tube. After all the remaining material in the tempered glass tube has been discharged, close the discharge valve and air inlet valve, open the vent valve, open the pneumatic pure water valve, and discharge the pure water into the tempered glass tube through the pure water module. Pure water is injected into the glass tube. After the upper liquid level switch detects that the liquid level has reached the control line, the pneumatic pure water valve is closed, and the cylinder and stirring motor are started. The stirring piston and stirring head start to perform up-down and rotational cleaning. When the set time is reached, the cylinder and stirring motor are closed, the discharge valve and air inlet valve are opened, and the vent valve is closed to discharge the cleaning waste liquid. When the set time is reached, the discharge valve and air inlet valve are closed, and the vent valve is opened until all the liquid in the tempered glass tube is discharged. The cleaning is then complete. At this time, it can be cleaned again as needed or the extraction liquid sample to be tested next can be prepared. S53. Add sulfuric acid: While draining and cleaning the tempered glass tube of the composite stirring extraction mechanism, start the pretreatment and detection: turn on the sulfuric acid pump, start the magnetic stirrer, and after the sulfuric acid pump injects a certain volume of sulfuric acid according to the preset ratio, stop the sulfuric acid pump so that the extract sample with added sulfuric acid is mixed evenly by high-speed rotation. S54. Titration: After mixing for the set time in step S53, turn on the plunger pump to add potassium permanganate. Detect the change in photometric value using a photometric detector. When the set endpoint is detected, turn off the plunger pump. The PLC system automatically records the titration volume and calculates the hydrogen peroxide concentration. S55. Data Upload and Storage: The detection results are uploaded to the central control system through the PLC controller, historical data is stored synchronously, and threshold alarms are triggered for abnormal data; S6. After completing the sample analysis and data acquisition of the extract in step S5, proceed with the discharge and cleaning process. The specific steps are as follows: S61. Waste liquid discharge: After the test is completed, the discharge pump will discharge the photometric test cup and residual liquid in the pipeline through the waste liquid pipe; S62. Photometric test cup cleaning: Open the pure water valve and pure water pump, inject pure water into the photometric test cup, turn on the magnetic stirrer, rinse the photometric test cup independently, after the set time is reached, close the pure water valve and pure water pump, turn on the discharge pump, discharge the cleaning wastewater to the waste liquid pipe, after the set time is reached, turn off the discharge pump and magnetic stirrer, and the photometric test cup cleaning is completed. S63. When further testing is required, the extract prepared in step S52 can be directly introduced into the photometric test cup for testing. When further testing is not required, the photometric test cup can be cleaned again following step S62.

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