Pre-treatment device and pre-treatment method for recovering monomers

Abstract

The application provides a pretreatment device and method for recycling monomers, which comprises a gas collecting tank, a water washer, a gas-water separator, a cyclone refrigerator, a first flow meter and an impurity and humidity detector; wherein the sample gas inlet of the gas collecting tank is used for introducing sample gas of monomers to be recycled, the circulating water inlet of the gas collecting tank is used for introducing circulating water, and the sample gas outlet of the gas collecting tank is communicated with the mixing inlet of the water washer; the waste water outlet of the water washer is used for discharging waste water, and the sample gas outlet on the top is communicated with the sample gas inlet of the gas-water separator; the sample gas outlet of the gas-water separator is communicated with the sample gas inlet of the cyclone refrigerator, and the drain port at the bottom of the cyclone refrigerator is communicated with the backflow port of the water washer; the sample gas outlet of the cyclone refrigerator is communicated with the sample gas inlet of the first flow meter; the sample gas outlet of the first flow meter is communicated with the sample gas inlet of the impurity and humidity detector, and the sample gas outlet of the impurity and humidity detector is used for outputting gas to be analyzed.

Description

Technical Field

[0001] This invention belongs to the field of chemical automation gas purification and treatment technology, specifically relating to a pretreatment device and pretreatment method for recovering monomers. Background Technology

[0002] In the polymerization process of monomers such as vinyl chloride, a large amount of unreacted monomers are usually left after the reaction, which need to be recycled. These recycled monomers often contain polymer microparticles, residual initiator fragments, undissipated foam, and other non-gaseous impurities, resulting in a high degree of instability in their composition and form.

[0003] To ensure the safety of recycled monomers when they re-enter the polymerization system and the quality of the final product, continuous and precise online monitoring of key parameters of the recycled monomers, especially oxygen content, is essential. Excessive trace oxygen concentrations can trigger serious safety accidents such as uncontrolled prepolymerization, explosive polymerization, or even combustion and explosion in subsequent processes, while directly affecting core quality indicators such as molecular weight and color of the product. However, existing pretreatment processes face significant technical bottlenecks:

[0004] Conventional pretreatment techniques are insufficient to effectively remove foam, fine solid particles, and droplets entrained in recovered monomers, easily causing blockages or signal anomalies in the sampling system of online oxygen analyzers, leading to sensor probe contamination, reading drift, or even malfunction. Due to impurities clogging pipelines, foam accumulation causing resistance changes, or sampling pressure fluctuations, the flow rate of the gas sample delivered to the analyzer often exhibits uncontrollable oscillations. This flow instability severely affects the accuracy of dynamic oxygen content measurements. Furthermore, traditional pretreatment equipment such as simple separation tanks and one-way filters have low removal efficiency for foam, submicron particles, and saturated water vapor. When the moisture content is too high or fine dust particles remain, they can corrode the instrument and accumulate dust in the optical chamber, compromising measurement baseline stability and failing to meet the sample introduction requirements of modern high-precision analytical equipment.

[0005] Therefore, there is an urgent need to develop a pretreatment technology for recycled monomers that can efficiently separate and remove foam, solid particles and aerosol-like moisture from the recycled monomers, and can achieve precise automatic adjustment of the gas flow rate. Summary of the Invention

[0006] This invention provides a pretreatment device and method for recovering monomers, which solves the problems in the prior art where the purity of the sample gas and the flow rate of the gas path cannot meet the requirements when detecting key parameters of recovered monomers.

[0007] In a first aspect, the present invention provides a pretreatment device for recovering monomers, comprising: a gas collecting tank, a water scrubber, a gas-liquid separator, a cyclone cooler, a first flow meter, and an impurity and humidity detector;

[0008] Among them, the sample gas inlet of the gas collecting tank is used to introduce the sample gas of the single unit to be recovered, the circulating water inlet of the gas collecting tank is used to introduce circulating water, and the sample gas outlet of the gas collecting tank is connected to the mixing inlet of the water scrubber.

[0009] The wastewater outlet of the water scrubber is used to discharge wastewater, and the sample gas outlet above it is connected to the sample gas inlet of the gas-liquid separator.

[0010] The sample gas outlet of the gas-water separator is connected to the sample gas inlet of the cyclone cooler, and the drain outlet at the bottom of the cyclone cooler is connected to the return outlet of the water washer.

[0011] The sample gas outlet of the cyclone cooler is connected to the sample gas inlet of the first flow meter;

[0012] The sample gas outlet of the first flow meter is connected to the sample gas inlet of the impurity and humidity detector, and the sample gas outlet of the impurity and humidity detector is used to output the gas to be analyzed.

[0013] Compared with existing technologies, the advantages of this invention are: through the multi-stage series design of a gas collecting tank, a water scrubber, a gas-liquid separator, and a cyclone cooler, impurities such as foam, solid particles, and moisture in the sample gas from the recovered monomer are effectively removed. The combination of the gas collecting tank and the water scrubber achieves preliminary purification of the sample gas, while the gas-liquid separator and cyclone cooler further remove moisture, ensuring that the purity of the sample gas entering the analytical instrument meets the standards. The inclusion of a first flow meter and impurity and humidity detectors allows the system to monitor the flow rate and composition of the sample gas in real time, thereby ensuring the accuracy of subsequent analyses. This device has a compact structure, stable operation, and is particularly suitable for the pretreatment of recovered monomers in chemical production.

[0014] Furthermore, a first shut-off valve, a first regulating valve, and a second flow meter are sequentially installed on the circulating water pipeline connected to the circulating water inlet of the gas collecting tank; wherein, the first shut-off valve is used to control the opening and closing of the circulating water pipeline, and the first regulating valve is used to adjust the circulating water flow rate according to the feedback signal of the second flow meter.

[0015] A sample gas regulating valve is installed on the sample gas pipeline connected to the sample gas inlet. The sample gas regulating valve is used to adjust the sample gas flow rate according to the feedback signal of the first flow meter.

[0016] Furthermore, the washing machine has a wastewater outlet at the bottom and an overflow port on the side, and the wastewater outlet and overflow port are connected to the wastewater recovery system via a two-way ball valve; and / or,

[0017] The drain outlet at the bottom of the cyclone cooler is connected to the return outlet of the water washer via an automatic drain valve.

[0018] Furthermore, the cyclone cooler is also equipped with an instrument gas inlet, and a second shut-off valve and a second regulating valve are sequentially installed on the instrument gas pipeline connected to the instrument gas inlet; the second shut-off valve is used to control the opening and closing of the cyclone cooler, and the second regulating valve is used to adjust the centrifugal force of the cyclone cooler according to the humidity measurement value of the impurity and humidity detector.

[0019] Furthermore, the bottom of the gas-water separator is also equipped with a drain outlet, which is connected to the return port of the water scrubber through a third shut-off valve; the gas-water separator is equipped with dual liquid level sensors to monitor the liquid level and control the opening and closing of the third shut-off valve.

[0020] Secondly, the present invention provides a pretreatment method for recycled monomers, using the pretreatment apparatus for recycled monomers described in the first aspect, comprising the following steps:

[0021] The sample gas to be recovered is introduced into the gas collection tank, mixed with circulating water, and then enters the water scrubber for water washing treatment to obtain wastewater and impurity-removed sample gas.

[0022] The impurity sample gas is introduced into the gas-liquid separator, and gas-liquid separation is performed by gravity sedimentation to obtain a primary dehydrated sample gas and a primary condensate. When the liquid level of the gas-liquid separator reaches the highest set value, the third shut-off valve is opened, and when the liquid level drops to the lowest set value, the third shut-off valve is closed.

[0023] The primary dehydrated sample gas is introduced into the cyclone cooler. The instrument gas flow rate is adjusted by the second regulating valve to control the centrifugal force of the cyclone cooler for deep dehydration treatment, resulting in secondary dehydrated sample gas and secondary condensate.

[0024] After the secondary dehydrated sample gas passes the tests of the first flow meter and the impurity and humidity detector, the gas to be analyzed is output.

[0025] The opening of the sample gas regulating valve is dynamically adjusted based on the deviation between the real-time measured value and the set value of the first flow meter.

[0026] The opening of the first regulating valve is dynamically adjusted based on the deviation between the real-time measured value and the set value of the second flow meter.

[0027] The opening of the second regulating valve is dynamically adjusted based on the humidity measurement value from the impurity and humidity detectors.

[0028] Furthermore, based on the deviation between the real-time measured value and the set value of the second flow meter, the opening of the first regulating valve is dynamically adjusted according to equation (1):

[0029]

[0030] In the formula, θ v This indicates the opening degree of the first regulating valve, in %; t k t represents the current time in seconds;k-1 Indicates the previous moment, in seconds; ΔQ(t) k ) represents t k The flow deviation at time ΔQ(t) k )=Q1-F m (t k ), where F m (t k Q1 and Q2 represent the actual measured value and set value of the second flow meter, respectively, in cubic meters per second (m³). 3 / s;K p ,K i ,K d These represent the proportional, integral, and differential coefficients, respectively, with values ​​ranging from 0.5 to 1.2, 0.05 to 0.2, and 0.1 to 0.5.

[0031] Furthermore, based on the humidity measurement value from the impurity and humidity detector, the opening of the second regulating valve is dynamically adjusted according to equation (2):

[0032]

[0033] In the formula, θ w This indicates the opening degree of the second regulating valve, in %; t k t represents the current time in seconds; k-1 H represents the previous moment in seconds; target Indicates target humidity, in %; H f (t k ) represents t k The humidity measurement value at any given time is expressed in %; α represents the humidity deviation response gain, ranging from 0.8 to 1.5; β represents the historical humidity deviation compensation gain, ranging from 0.1 to 0.3; n represents the number of backtracking control cycles, ranging from 5 to 10.

[0034] Furthermore, it also includes increasing the water washing intensity by raising the setpoint of the second flow meter when the humidity measurement value of the impurity and humidity detector is higher than the target impurity value. The setpoint of the second flow meter is calculated according to equations (3) and (4):

[0035] Q2=Q1+ΔQ boost Equation (3)

[0036]

[0037] In the formula, Q2 represents the set value of the second flow meter after increasing the intensity of the water washing treatment, and the unit is m. 3 / s; Q1 represents the set flow rate value of the original second flow meter, in units of m³ / s. 3 / s;ΔQ boostThis represents the flow rate difference used to increase the intensity of the water washing treatment, in meters per second (m³). 3 / s, where H c This represents the real-time impurity measurement value, in g / m³. 3 H0 represents the target impurity value, in g / m³. 3 η represents the water washing strength coefficient, which ranges from 0.3 to 0.6.

[0038] Furthermore, the second regulating valve adjusts the instrument air flow to control the centrifugal force of the cyclone cooler, satisfying equation (5):

[0039] F C =mω 2 r (5)

[0040] In the formula, F C ω represents centrifugal force, in N; m represents the mass of secondary condensate removed, in kg; ω represents the angular velocity of the cyclone cooler's rotating shaft, in rad / s; and r represents the cyclone cooler's rotation radius, in m. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of a preprocessing device in one embodiment of the present invention;

[0042] Figure 2 This is a flowchart of a preprocessing method according to an embodiment of the present invention.

[0043] Explanation of reference numerals in the attached figures:

[0044] 1. First shut-off valve; 2. First regulating valve; 3. Second flow meter; 4. Gas collection tank; 5. Water washer; 6. Overflow port; 7. Second shut-off valve; 8. Second regulating valve; 9. Cyclone cooler; 10. Gas-water separator; 11. Third shut-off valve; 12. Automatic drain valve; 13. First flow meter; 14. Impurity and humidity detector; 15. Sample gas regulating valve; 16. Two-way ball valve. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0046] Please see Figure 1In a first aspect, the present invention provides a pretreatment device for recycling monomers, comprising: a gas collecting tank 4, a water washing device 5, a gas-water separator 10, a cyclone cooler 9, a first flow meter 13, and an impurity and humidity detector 14.

[0047] Among them, the sample gas inlet of the gas collecting tank 4 is used to introduce the sample gas of the unit to be recovered, the circulating water inlet of the gas collecting tank 4 is used to introduce the circulating water, and the sample gas outlet of the gas collecting tank 4 is connected to the mixing inlet of the water washer 5.

[0048] The wastewater outlet of the water washer 5 is used to discharge wastewater, and the sample gas outlet above it is connected to the sample gas inlet of the gas-water separator 10.

[0049] The sample gas outlet of the gas-water separator 10 is connected to the sample gas inlet of the cyclone cooler 9, and the drain outlet at the bottom of the cyclone cooler 9 is connected to the return outlet of the water washer 5.

[0050] The sample gas outlet of the cyclone cooler 9 is connected to the sample gas inlet of the first flow meter 13;

[0051] The sample gas outlet of the first flow meter 13 is connected to the sample gas inlet of the impurity and humidity detector 14, and the sample gas outlet of the impurity and humidity detector 14 is used to output the gas to be analyzed.

[0052] The pretreatment device for recovered monomers provided by this invention, through a multi-stage series design of a gas collecting tank 4, a water scrubber 5, a gas-liquid separator 10, and a cyclone cooler 9, can effectively remove impurities such as foam, solid particles, and moisture from the sample gas of the recovered monomers. The combination of the gas collecting tank 4 and the water scrubber 5 achieves preliminary purification of the sample gas, while the gas-liquid separator 10 and the cyclone cooler 9 further remove moisture, ensuring that the purity of the sample gas entering the analytical instrument meets the standards. The setting of the first flow meter 13 and the impurity and humidity detector 14 enables the system to monitor the flow rate and composition of the sample gas in real time, thereby ensuring the accuracy of subsequent analysis. The device has a compact structure, stable operation, and is particularly suitable for the pretreatment of recovered monomers in chemical production.

[0053] Specifically, one end of the first shut-off valve 1 is connected to the circulating water pipeline, and the other end is connected to the first regulating valve 2. The first regulating valve 2 is connected to the second flow meter 3, and the second flow meter 3 is connected to the top of the gas collecting tank 4. The lower half of the gas collecting tank 4 is provided with a sample gas inlet. The lower opening of the gas collecting tank 4 is connected to the water scrubber 5. The water scrubber 5 is provided with an overflow port 6, which is connected to a two-way ball valve 16. The wastewater outlet below the water scrubber 5 is connected to the two-way ball valve 16, which is connected to the wastewater recovery system. The water scrubber 5 is provided with a sample gas outlet at the top, which is connected to the gas-water separator 10. The lower part of the gas-water separator 10 is connected to the inlet of the third shut-off valve 11, and the outlet of the third shut-off valve 11 is connected to the water scrubber 5. One end of the second shut-off valve 7 is connected to the instrument gas inlet pipe, and the other end is connected to the second regulating valve 8. The second regulating valve 8 is connected to the instrument gas inlet of the cyclone cooler 9. The lower drain pipe of the cyclone cooler 9 is connected to the automatic drain 12. The automatic drain 12 is connected to the water washer 5. The cyclone cooler 9 is connected to the first flow meter 13. The first flow meter 13 is connected to the impurity and humidity detector 14. The impurity and humidity detector 14 is connected to the oxygen analyzer sensor.

[0054] Furthermore, a first shut-off valve 1, a first regulating valve 2, and a second flow meter 3 are sequentially installed on the circulating water pipeline connected to the circulating water inlet of the gas collecting tank 4; wherein, the first shut-off valve 1 is used to control the opening and closing of the circulating water pipeline, and the first regulating valve 2 is used to adjust the circulating water flow rate according to the feedback signal of the second flow meter 3; a sample gas regulating valve 15 is installed on the sample gas pipeline connected to the sample gas inlet, and the sample gas regulating valve 15 is used to adjust the sample gas flow rate according to the feedback signal of the first flow meter 13.

[0055] By installing a first regulating valve 2 and a sample gas regulating valve 15 on the circulating water pipeline and the sample gas pipeline respectively, and combining the feedback signals from the second flow meter 3 and the first flow meter 13, precise control of the circulating water flow rate and sample gas flow rate is achieved. This closed-loop regulation method can effectively avoid measurement errors caused by flow fluctuations and ensure the stability of the pretreatment process. At the same time, the setting of the first shut-off valve 1 enhances the safety of the system, allowing for rapid shut-off of the circulating water supply in emergencies.

[0056] Optionally, the scrubber 5 has a wastewater outlet at its bottom and an overflow port 6 on its side. The wastewater outlet and overflow port 6 are connected to the wastewater recycling system via a two-way ball valve 16. This achieves more efficient wastewater discharge and prevents overflow caused by excessively high water levels in the scrubber 5. The drain outlet at the bottom of the cyclone cooler 9 is connected to the return port of the scrubber 5 via an automatic drain valve 12. This enables the recycling of condensate and reduces water waste. This design optimizes system operating efficiency and reduces energy consumption and operating costs.

[0057] In one specific embodiment, the cyclone cooler 9 is further provided with an instrument air inlet, and a second shut-off valve 7 and a second regulating valve 8 are sequentially provided on the instrument air pipeline connected to the instrument air inlet; the second shut-off valve 7 is used to control the opening and closing of the cyclone cooler 9, and the second regulating valve 8 is used to adjust the centrifugal force of the cyclone cooler 9 according to the humidity measurement value of the impurity and humidity detector 14.

[0058] The centrifugal force is dynamically adjusted based on the humidity measurement value of the impurity and humidity detector 14, which further improves the dehydration effect and facilitates equipment maintenance and debugging.

[0059] Optionally, the bottom of the gas-water separator 10 is also provided with a drain outlet, which is connected to the return port of the water washer 5 through the third shut-off valve 11; the gas-water separator 10 is provided with dual liquid level sensors to monitor the liquid level and control the opening and closing of the third shut-off valve 11.

[0060] The interlocking design of the dual liquid level sensors and the third shut-off valve 11 in the gas-liquid separator 10 enables precise monitoring and automatic control of the liquid level. When the liquid level exceeds the high set value, the third shut-off valve 11 automatically opens to drain; when the liquid level falls below the low set value, it automatically closes, ensuring that the gas-liquid separator 10 always maintains a dynamic balance. This design not only prevents gas escape but also improves separation efficiency, making the system operation safer and more reliable.

[0061] Secondly, please refer to Figure 2 The present invention provides a pretreatment method for recycled monomers, which uses a pretreatment device for recycled monomers according to the first aspect, and includes the following steps:

[0062] The sample gas to be recovered is introduced into the gas collection tank 4, mixed with circulating water, and then enters the water scrubber 5 for water washing treatment to obtain wastewater and impurity-removed sample gas.

[0063] The impurity sample gas is introduced into the gas-liquid separator 10, and gas-liquid separation is performed by gravity sedimentation to obtain a first dehydrated sample gas and a first condensate. When the liquid level of the gas-liquid separator 10 reaches the highest set value, the third shut-off valve 11 is opened, and when the liquid level drops to the lowest set value, the third shut-off valve 11 is closed.

[0064] The first dehydrated sample gas is introduced into the cyclone cooler 9. The instrument gas flow rate is adjusted by the second regulating valve 8 to control the centrifugal force of the cyclone cooler 9 for deep dehydration treatment, resulting in a second dehydrated sample gas and a second condensate.

[0065] After the secondary dehydrated sample gas passes the tests of the first flow meter 13 and the impurity and humidity detector 14, the gas to be analyzed is output.

[0066] The opening degree of the sample gas regulating valve 15 is dynamically adjusted based on the deviation between the real-time measured value and the set value of the first flow meter 13.

[0067] The opening degree of the first regulating valve 2 is dynamically adjusted based on the deviation between the real-time measured value and the set value of the second flow meter 3.

[0068] The opening of the second regulating valve 8 is dynamically adjusted based on the humidity measurement value of the impurity and humidity detector 14.

[0069] The pretreatment method of this invention significantly improves the treatment effect of the recovered single sample gas through multi-stage purification and closed-loop control; water washing and gas-liquid separation effectively remove large particulate impurities and moisture, and the deep dehydration of the cyclone cooler 9 further improves the purity of the sample gas; by monitoring the flow rate and humidity in real time and dynamically adjusting the valve opening, the system can quickly respond to changes in operating conditions, ensuring the stability and consistency of the output sample gas, and providing a reliable guarantee for subsequent oxygen content analysis.

[0070] Specifically, circulating water enters the air collection tank 4 through the first shut-off valve 1, the first regulating valve 2, and the second flow meter 3. Based on the indication of the second flow meter 3, the first regulating valve 2 is automatically adjusted to stabilize the pipeline flow rate within the required set range. When the pipeline flow rate exceeds or falls below the required set value Q1 of the second flow meter 3, the opening of the pneumatic regulating valve is automatically adjusted to control the stability of the circulating water supply.

[0071] The gas collecting tank 4 mixes the sample gas from the sample gas inlet with water and enters the water washing device 5. The mixture of impurities and water after passing through the water washing device 5 is discharged into the wastewater recycling system through the two-way ball valve 16. The overflow port 6 of the water washing device 5 is also connected to the two-way ball valve 16 to ensure that the water level of the water washing device 5 is not higher than the overflow port 6.

[0072] The water-insoluble sample gas, after being washed with water, enters the gas-liquid separator 10 from the sample gas outlet above the water washer 5, where the moisture in the sample gas is initially removed. When the water level in the gas-liquid separator 10 is greater than or equal to the high setting value L1, the third shut-off valve 11 automatically opens, allowing water to flow into the water washer 5. When the water level in the gas-liquid separator 10 is less than or equal to the low setting value L2, the third shut-off valve 11 automatically closes, thereby ensuring that no gas is lost from the gas-liquid separator 10.

[0073] The sample gas discharged from the gas-water separator 10 enters the cyclone cooler 9. The centrifugal force of the cyclone cooler 9 dissipates the water, which is then discharged into the water washer 5 by the automatic drain condenser 12. The instrument gas inlet pipe of the cyclone cooler 9 is equipped with a second shut-off valve 7 and a second regulating valve 8. When the cyclone cooler 9 is running, the second shut-off valve 7 is open; when it is not in use, the second shut-off valve 7 is closed.

[0074] The sample gas outlet pipeline of the cyclone cooler 9 is equipped with a first flow meter 13 and an impurity and humidity detector 14, which can monitor the flow rate and purity of the sample gas entering the oxygen analyzer sensor at any time. If the impurity and humidity detector 14 detects impurities, the washing intensity in the water washer 5 is increased. The second regulating valve 8 can automatically adjust the valve opening according to the moisture content returned by the impurity and humidity detector 14, thereby adjusting the instrument gas volume and regulating the centrifugal force of the cyclone cooler 9 to achieve a good gas-water separation effect. In addition, based on the monitoring of the first flow meter 13, the flow rate of the purified sample gas entering the oxygen analyzer is displayed in real time. If the flow rate is lower or higher than the set value, the sample gas intake volume is automatically adjusted.

[0075] Furthermore, based on the deviation between the real-time measured value and the set value of the second flow meter 3, the opening degree of the first regulating valve 2 is dynamically adjusted according to equation (1):

[0076]

[0077] In the formula, θ v This indicates the opening degree of the first regulating valve, in %; t k t represents the current time in seconds; k-1 t0 represents the previous moment in seconds; t0 represents the initial adjustment moment in seconds; ΔQ(t k ) represents t k The flow deviation at time ΔQ(t) k )=Q1-F m (t k ), where F m (t k Q1 and Q2 represent the actual measured value and set value of the second flow meter, respectively, in cubic meters per second (m³). 3 / s;K P ,K i ,K d These represent the proportional, integral, and differential coefficients, respectively, with values ​​ranging from 0.5 to 1.2, 0.05 to 0.2, and 0.1 to 0.5.

[0078] This invention employs dynamic flow response control, which dynamically adjusts the opening of the first regulating valve 2 (pneumatic regulating valve) based on the deviation between the real-time measured value and the set value of the second flow meter 3, thereby achieving dynamic control of the circulating water flow.

[0079] Similarly, based on the deviation between the real-time measured value and the set value of the first flow meter 13, the flow rate of the sample gas after purification in the oxygen analyzer is displayed in real time, and the opening of the sample gas regulating valve 15 is dynamically adjusted. If the flow rate is lower or higher than the set value, the sample gas intake is automatically adjusted. This algorithm is the same as the algorithm described above, and will not be described in detail here.

[0080] By introducing a time-series integral term to compensate for historical deviations and a derivative term to predict disturbance trends, it is more adaptable to traffic surge scenarios than conventional PID.

[0081] In one specific embodiment, the opening of the second regulating valve 8 is dynamically adjusted according to the humidity measurement value of the impurity and humidity detector 14, as per equation (2):

[0082]

[0083] In the formula, θ w This indicates the opening degree of the second regulating valve, in %; t k t represents the current time in seconds; k-1 H represents the previous moment in seconds; target Indicates target humidity, in %; H f (t k ) represents t k The humidity measurement value at any given time is expressed in %; α represents the humidity deviation response gain, ranging from 0.8 to 1.5; β represents the historical humidity deviation compensation gain, ranging from 0.1 to 0.3; n represents the number of backtracking control cycles, ranging from 5 to 10.

[0084] Through the above algorithm adjustment, adaptive control of steam-water separation efficiency is realized. Based on the real-time residual humidity feedback value of the impurity and humidity detector 14, the opening degree of the second regulating valve 8 (pneumatic regulating valve) of the cyclone cooler 9 is dynamically adjusted, thereby realizing dynamic control of centrifugal force.

[0085] Furthermore, it also includes increasing the water washing intensity by raising the setpoint of the second flow meter 3 when the humidity measurement value of the impurity and humidity detector 14 is higher than the target impurity value. The setpoint of the second flow meter 3 is calculated according to equations (3) and (4):

[0086] Q2=Q1+ΔQ boost Equation (3)

[0087]

[0088] In the formula, Q2 represents the set value of the second flow meter after increasing the intensity of the water washing treatment, and the unit is m. 3 / s; Q1 represents the set flow rate value of the original second flow meter, in units of m³ / s. 3 / s;ΔQ doost This represents the flow rate difference used to increase the intensity of the water washing treatment, in meters per second (m³). 3 / s, where H c This represents the real-time impurity measurement value, in g / m³. 3 H0 represents the target impurity value, in g / m³. 3η represents the water washing strength coefficient, which ranges from 0.3 to 0.6.

[0089] It is understandable that if the impurity and humidity detector 14 still detects impurities, meaning the measured purity is lower than the target purity, then the washing intensity in the water washer is increased, and the flow rate of the circulating water is increased, which means increasing the opening of the first regulating valve 2. The end impurity signal is converted into a front-end water washing intensity adjustment command, realizing cross-unit collaborative optimization and solving the passive control problem of the traditional system of "treating the symptoms rather than the root cause".

[0090] Among them, the second regulating valve 8 regulates the instrument air flow to control the centrifugal force of the cyclone cooler 9, satisfying equation (5):

[0091] F C =mω 2 r (5)

[0092] In the formula, F c Centrifugal force is expressed in N; m represents the mass of secondary condensate removed in kg; ω represents the angular velocity of the cyclone cooler's shaft in rad / s; r is the radius of rotation of the cyclone cooler in m. Gas flow rate f w It is directly proportional to the angular velocity ω, that is, increasing the opening of the regulating valve increases the gas flow rate f. w As the angular velocity ω increases, F can be obtained. C ∝f w 2 Increase centrifugal force to further enhance the intensity of air-water separation.

[0093] In one specific embodiment, the actual monitored liquid level L0(t) is obtained based on the dual liquid level sensor of the gas-liquid separator 10, thereby obtaining the on / off control V of the third shut-off valve 11. 11 The control logic of (t) is shown in equation (6):

[0094]

[0095] In the formula, L1 is the high liquid level safety threshold, i.e., the highest set value; L2 is the low liquid level safety threshold, i.e., the lowest set value. A dynamic liquid seal zone is formed within the interval (L1, L2), ensuring gas-liquid isolation without continuous adjustment.

[0096] Compared with the prior art, the outstanding features of this invention are:

[0097] 1. Water-Air Co-purification System. The circulating water supply pipeline is sequentially equipped with a shut-off valve, a pneumatic regulating valve, and a flow meter to form a constant flow control module, dynamically maintaining a stable water washing environment within the air collection tank. When the flow sensor reading deviates from the preset threshold Q1, the pneumatic regulating valve adjusts its opening in real time to ensure continuous water phase renewal.

[0098] 2. Cascaded Impurity Removal Channel. The sample gas enters the gas collection tank through the inlet, forming a turbulent mixture with the aqueous phase before entering the water scrubber. Foam and solid impurities are discharged with the aqueous phase through the drain valve to the wastewater system. An overflow prevention outlet is connected in parallel with the drain valve to establish a water level safety redundancy mechanism. The dehydrated sample gas rises to the top of the water scrubber and enters the gas-liquid separator, where primary water removal is achieved through gravity settling.

[0099] 3. Dynamic Sealing Separation System. The gas-liquid separator is equipped with dual liquid level sensing nodes (high level L1 / low level L2). When the liquid level ≥ L1, the quick-closing valve opens to drain water to the water washer; when the liquid level ≤ L2, it immediately closes, forming a dynamic balance of gas-liquid seal. The separated sample gas enters the cyclone cooler. The instrument gas pipeline is equipped with on / off valves and regulating valves. During operation, secondary separation of particles and droplets is achieved through a centrifugal field.

[0100] 4. Closed-loop quality feedback mechanism. A flow meter and a precision filter are sequentially installed at the outlet of the cyclone chiller, forming a flow monitoring channel and an impurity detection channel. When the filter detects excessive residue, the working intensity of the water washer is automatically increased; at the same time, based on the moisture content feedback signal, the opening of the instrument air regulating valve is automatically adjusted to dynamically optimize the centrifugal dehydration efficiency.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, they should all be considered to be within the protection scope of the present invention.

Claims

1. A pretreatment method for recycled monomers, comprising using a pretreatment device for recycled monomers, characterized in that, The pretreatment device for the recovered monomers includes: a gas collecting tank, a water scrubber, a gas-water separator, a cyclone cooler, a first flow meter, and an impurity and humidity detector. Among them, the sample gas inlet of the gas collecting tank is used to introduce the sample gas of the single unit to be recovered, the circulating water inlet of the gas collecting tank is used to introduce circulating water, and the sample gas outlet of the gas collecting tank is connected to the mixing inlet of the water scrubber. The wastewater outlet of the water scrubber is used to discharge wastewater, and the sample gas outlet above it is connected to the sample gas inlet of the gas-liquid separator. The sample gas outlet of the gas-water separator is connected to the sample gas inlet of the cyclone cooler, and the drain outlet at the bottom of the cyclone cooler is connected to the return outlet of the water washer. The sample gas outlet of the cyclone cooler is connected to the sample gas inlet of the first flow meter; The sample gas outlet of the first flow meter is connected to the sample gas inlet of the impurity and humidity detector, and the sample gas outlet of the impurity and humidity detector is used to output the gas to be analyzed. A first shut-off valve, a first regulating valve, and a second flow meter are sequentially installed on the circulating water pipeline connected to the circulating water inlet of the gas collecting tank; wherein, the first shut-off valve is used to control the opening and closing of the circulating water pipeline, and the first regulating valve is used to adjust the circulating water flow rate according to the feedback signal of the second flow meter. A sample gas regulating valve is installed on the sample gas pipeline connected to the sample gas inlet. The sample gas regulating valve is used to adjust the sample gas flow rate according to the feedback signal of the first flow meter. The cyclone cooler is also equipped with an instrument air inlet, and a second shut-off valve and a second regulating valve are sequentially installed on the instrument air pipeline connected to the instrument air inlet; the second shut-off valve is used to control the opening and closing of the cyclone cooler, and the second regulating valve is used to adjust the centrifugal force of the cyclone cooler according to the humidity measurement value of the impurity and humidity detector. The bottom of the gas-water separator is also equipped with a drain outlet, which is connected to the return port of the water scrubber through a third shut-off valve; the gas-water separator is equipped with dual liquid level sensors to monitor the liquid level and control the opening and closing of the third shut-off valve. The preprocessing method includes the following steps: The sample gas to be recovered is introduced into the gas collection tank, mixed with circulating water, and then enters the water scrubber for water washing treatment to obtain wastewater and impurity-removed sample gas. The impurity sample gas is introduced into the gas-liquid separator, and gas-liquid separation is performed by gravity sedimentation to obtain a primary dehydrated sample gas and a primary condensate. When the liquid level of the gas-liquid separator reaches the highest set value, the third shut-off valve is opened, and when the liquid level drops to the lowest set value, the third shut-off valve is closed. The primary dehydrated sample gas is introduced into the cyclone cooler. The instrument gas flow rate is adjusted by the second regulating valve to control the centrifugal force of the cyclone cooler for deep dehydration treatment, resulting in secondary dehydrated sample gas and secondary condensate. After the secondary dehydrated sample gas passes the tests of the first flow meter and the impurity and humidity detector, the gas to be analyzed is output. The opening of the sample gas regulating valve is dynamically adjusted based on the deviation between the real-time measured value and the set value of the first flow meter. The opening of the second regulating valve is dynamically adjusted based on the humidity measurement value from the impurity and humidity detectors. Based on the deviation between the real-time measured value and the set value of the second flow meter, the opening of the first regulating valve is dynamically adjusted according to formula (1): Equation (1) In the formula, This indicates the opening degree of the first regulating valve, expressed in % . This indicates the current time, expressed in seconds. This indicates the previous moment, expressed in seconds. express Flow deviation at any moment ,in and The actual measured value and the set value of the second flow meter are respectively, in units of ; These represent the proportional, integral, and differential coefficients, respectively, with values ​​ranging from 0.5 to 1.2, 0.05 to 0.2, and 0.1 to 0.

5.

2. The pretreatment method for recycled monomers according to claim 1, characterized in that, The scrubber has a wastewater outlet at the bottom and an overflow port on the side. The wastewater outlet and overflow port are connected to a wastewater recovery system via a two-way ball valve; and / or, The drain outlet at the bottom of the cyclone cooler is connected to the return outlet of the water washer via an automatic drain valve.

3. The pretreatment method for recycled monomers according to claim 1, characterized in that, Based on the humidity measurement value from the impurity and humidity detector, the opening of the second regulating valve is dynamically adjusted according to formula (2): Equation (2) In the formula, This indicates the opening degree of the second regulating valve, expressed in % . This indicates the current time, expressed in seconds. This indicates the previous moment, expressed in seconds. The target humidity is expressed in % (%). express Humidity measurement at any given time, in %; This represents the humidity deviation response gain, with a value ranging from 0.8 to 1.

5. represents the historical humidity deviation compensation gain, with a value range of 0.1-0.3; n represents the number of backtracking control cycles, with a value range of 5-10.

4. The pretreatment method for recycled monomers according to claim 3, characterized in that, It also includes increasing the intensity of water washing by raising the set value of the second flow meter when the humidity measurement value of the impurity and humidity detector is higher than the target impurity value.

Images