Device for treating hydrogen sulfide in thiourea production tail gas

Abstract

The invention relates to the technical field of tail gas treatment, and discloses a device for treating hydrogen sulfide in thiourea production tail gas, which comprises a spray tower main body, a homogenizing alkali preparation unit, a circulating spray unit and a control unit, the homogenizing alkali preparation unit comprises a preparation tank, a stirring part, a liquid level measuring part, a pH value measuring part and an alkali liquor supplementing part; the blending tank is positioned on one side of the spray tower main body, is communicated with the lower end of the spray tower through a communication valve and is used for collecting sprayed alkali liquor. According to the invention, by introducing the collaborative design of the homogeneous alkali preparation unit and the control unit, the homogeneous mixing is adopted to ensure the accurate measurement and the intelligent algorithm is adopted to realize the collaborative control of accurate alkali supplement, so that the problem of misalignment of pH measurement caused by non-uniform mixing of alkali liquor is obviously improved, the stable standard reaching of the tail gas treatment efficiency is realized, and the consumption of the alkali liquor is obviously reduced; the operation cost can be minimized, and the emission control efficiency can be improved.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas treatment technology, and more specifically, to a device for treating hydrogen sulfide in the exhaust gas from thiourea production. Background Technology

[0002] Thiourea, an important chemical raw material, is widely used in pharmaceuticals, pesticides, dyes, electroplating, and other fields. During industrial production, especially in processes involving the reaction of calcium cyanamide with hydrogen sulfide or sodium hydrosulfide, large quantities of tail gas containing hydrogen sulfide are generated. Hydrogen sulfide is highly toxic, corrosive, and has a foul odor, requiring effective treatment before discharge. Currently, the industry commonly uses alkaline spray absorption to treat this type of tail gas. This involves using a spray tower to bring alkaline solution into countercurrent contact with the tail gas, neutralizing the hydrogen sulfide and achieving purification.

[0003] In this absorption process, the pH value of the alkaline solution is a core parameter determining the treatment efficiency and economy, directly affecting the absorption rate and the degree of neutralization. Therefore, accurately stabilizing the pH value of the circulating alkaline solution within the optimal range is crucial to ensuring that the exhaust gas meets emission standards and reducing operating costs. However, existing devices typically fix the pH measurement probe at a single location within the circulating tank. Due to the slow flow of the alkaline solution within the tank and the existence of mixing dead zones, concentration gradients are easily formed, causing local pH measurements to fail to accurately reflect the overall average state of the system, resulting in inaccurate measurement results. Although this can be improved by increasing the number of probes for multi-point measurements, the large dynamic changes and uneven flow of the alkaline solution system often lead to high data dispersion at each point, resulting in some degree of deviation in the obtained measurement values.

[0004] Therefore, a processing device is needed that can achieve precise mixing of alkaline solutions and intelligent and precise control of pH value to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a device for treating hydrogen sulfide in the tail gas of thiourea production, so as to solve the above-mentioned technical problems.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0007] This invention provides a device for treating hydrogen sulfide in thiourea production tail gas, comprising:

[0008] The main body of the spray tower, the homogenization alkali preparation unit, the circulating spray unit, and the control unit;

[0009] The homogenization alkali preparation unit includes:

[0010] The mixing tank is connected to the lower end of the spray tower via a connecting valve and is used to collect the alkaline solution after spraying.

[0011] A stirring element, mounted on the mixing tank, is used to uniformly mix the alkaline solution inside the mixing tank;

[0012] A liquid level measuring device is installed inside the mixing tank to measure the liquid level of the alkaline solution inside the mixing tank;

[0013] A pH measuring device is installed inside the mixing tank to measure the pH value of the alkaline solution inside the tank.

[0014] The alkali replenishment unit, connected to the mixing tank, is used to replenish the alkali solution in the mixing tank to maintain the pH balance of the alkali solution.

[0015] The circulating spray unit is connected to the mixing tank, which is used to circulate the alkaline solution within the main body of the spray tower.

[0016] The control unit is signal-connected to the homogenization alkali preparation unit and the circulating spray unit, and is configured as follows:

[0017] The stirring element is controlled to ensure that the alkaline solution is mixed evenly, and an effective pH measurement value is obtained after confirming that the alkaline solution is mixed evenly.

[0018] The alkali replenishment device is controlled to quantitatively replenish alkali based on effective pH measurement values, so as to maintain the pH value of the alkali within a preset range.

[0019] Preferably, the stirring component includes a stirring motor located at the top of the mixing tank and stirring blades located inside the mixing tank, wherein the stirring blades are connected to the output end of the stirring motor.

[0020] Preferably, the liquid level measuring element is a liquid level sensor, and the pH value measuring element is a pH meter.

[0021] Preferably, the alkali replenishment component includes an alkali storage tank, a delivery pump connected to the alkali storage tank, and an inlet valve connecting the delivery pump and the mixing tank.

[0022] Preferably, the circulating spray unit includes a circulating pump connected to the mixing tank and a spray pipe located in the spray tower, wherein the spray pipe is connected to the output end of the circulating pump.

[0023] Preferably, the control unit is configured to: start the stirring element when a predetermined condition is met, and determine that the alkaline solution has been mixed evenly after the reading of the pH measuring element has stabilized.

[0024] Preferably, the predetermined conditions include at least one of the following:

[0025] Reaching the preset periodic time interval;

[0026] After the alkali replenishment device completes one alkali replenishment operation;

[0027] The rate of change in pH value was detected to exceed the preset fluctuation threshold.

[0028] Preferably, the criterion for determining stable readings is that the fluctuation range of the pH value measuring device reading over a continuous period of time is less than a preset stability threshold.

[0029] Preferably, the control unit is configured to: initiate an alkali replenishment program when the effective pH measurement value is lower than the alkali replenishment trigger threshold, calculate the amount of alkali solution to be replenished based on the deviation between the effective pH measurement value and the target value, and control the alkali replenishment device to perform quantitative replenishment.

[0030] Preferably, the control unit is further configured to: pause the judgment based on the pH measurement value during the alkali replenishment operation of the alkali replenishment component; after the alkali replenishment operation is completed, immediately start the stirring component, and after the alkali solution is mixed evenly again, perform the next pH measurement value acquisition and judgment.

[0031] The beneficial effects of this invention are as follows:

[0032] This invention introduces a homogenized alkali preparation unit and a control unit in a collaborative design. It uses homogenized mixing to ensure accurate measurement and intelligent algorithms to achieve precise alkali replenishment control, which significantly improves the pH measurement inaccuracy problem caused by uneven alkali mixing. This results in stable compliance of exhaust gas treatment efficiency and a significant reduction in alkali consumption, minimizing operating costs and improving emission control efficiency. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention.

[0034] Figure 2 This is a front view of a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention;

[0035] Figure 3 This is a cross-sectional view of a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention.

[0036] Figure 4 This is a schematic diagram of the internal structure of the mixing tank in a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention.

[0037] Figure 5 This is a block diagram showing the relationship between the functional units in a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention.

[0038] Figure 6 This is a flowchart of the working process of a hydrogen sulfide treatment device for thiourea production tail gas according to the present invention.

[0039] In the diagram: 10. Main body of the spray tower; 20. Homogenization alkali preparation unit; 201. Mixing tank; 202. Connecting valve; 203. Stirring motor; 204. Stirring blade; 205. Liquid level sensor; 206. pH meter; 207. Alkali storage tank; 208. Transfer pump; 209. Inlet valve; 210. Water inlet valve; 30. Circulating spray unit; 301. Circulating pump; 302. Spray pipe. Detailed Implementation

[0040] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, features described in some examples may be combined in other examples.

[0041] Please refer to the following: Figures 1 to 6 A hydrogen sulfide treatment device for thiourea production tail gas includes: a spray tower body 10, a homogenization alkali preparation unit 20, a circulating spray unit 30, and a control unit; the spray tower body 10 is provided with a tail gas inlet at the bottom and a purified gas outlet at the top; and the spray tower body 10 is also provided with a concentration sensor for detecting the tail gas concentration and a pressure sensor for detecting the internal pressure difference.

[0042] The homogenization alkali preparation unit 20 includes: a mixing tank 201, a stirring element, a liquid level measuring element, a pH measuring element, and an alkali replenishment element; the mixing tank 201 is located on one side of the spray tower body 10, and is connected to the lower end of the spray tower through a connecting valve 202 to collect the alkali solution after spraying, and is equipped with a process water inlet valve 210 at its top; the stirring element is installed on the mixing tank 201 to uniformly mix the alkali solution in the mixing tank 201; the stirring element includes a stirring motor 203 installed at the top of the mixing tank 201 and stirring blades 204 installed inside the mixing tank 201, and the stirring blades 204 are connected to the output end of the stirring motor 203;

[0043] Both the liquid level measuring device and the pH measuring device are located inside the mixing tank 201, and are used to measure the liquid level and pH value of the alkali solution inside the mixing tank 201, respectively. The liquid level measuring device is a liquid level sensor 205, and the pH measuring device is a pH meter 206. The alkali solution replenishment device is used to replenish the alkali solution into the mixing tank 201 to maintain the pH balance of the alkali solution. The alkali solution replenishment device includes an alkali solution storage tank 207, a transfer pump 208 connected to the alkali solution storage tank 207, and an inlet valve 209 connecting the transfer pump 208 and the mixing tank 201.

[0044] The circulating spray unit 30 is connected to the mixing tank 201 and is mainly used to circulate the alkali solution within the spray tower body 10. The circulating spray unit 30 includes a circulating pump 301 connected to the mixing tank 201 and a spray pipe 302 located in the spray tower. The spray pipe 302 is connected to the output end of the circulating pump 301. The circulating pump 301 transports the alkali solution to the spray pipe 302, and then the spray pipe 302 sprays it down from the top of the spray tower body 10.

[0045] The control unit is connected to the homogenization alkali preparation unit 20 and the circulating spray unit 30 via signals, and is configured as follows:

[0046] Data acquisition and monitoring:

[0047] Real-time reception of liquid level signals (L) from the liquid level measurement unit current ) and pH signal from pH measurement unit (pH current ).

[0048] Intelligent stirring control logic:

[0049] Set a stirring preparation time (T) before pH measurement. blend ) and a pH stability judgment threshold (ΔpH) threshold );

[0050] The stirring unit will start automatically when one of the following conditions is met:

[0051] a. Periodic start: to reach the preset periodic stirring time points;

[0052] b. Start-up after alkali replenishment: Start-up immediately after the alkali replenishment unit completes one alkali replenishment operation;

[0053] c. Abnormal pH fluctuation trigger: If the rate of change of the continuously monitored pH value exceeds the preset threshold, it is judged as uneven mixing;

[0054] The stirring unit runs continuously for a period of time up to T. blend Then, the control unit detects the pH. current The fluctuation value. When the fluctuation value is less than ΔpH threshold Maintain this state for a period of time (e.g., 10 seconds) to determine that the alkali solution has been thoroughly mixed, and then read the pH value. current Only then are they recognized as valid measurements for subsequent decision-making.

[0055] The logic of precise alkali replenishment based on uniform mixing:

[0056] Set the target pH range (pH) target-min pH target-max ) and alkali supplementation trigger threshold (pH) low );

[0057] When determining pH based on valid measurements current Below pH low At this time, the control unit starts the alkali replenishment program;

[0058] The control unit is based on pH current With pH target-min The deviation value is used to calculate the required amount of alkali to be added (V) using a fuzzy PID control algorithm. base Alternatively, control the alkali replenishment rate and duration using the alkali replenishment device;

[0059] During the alkali replenishment process, pH measurement can be selectively paused, or the stirring unit can be started immediately after alkali replenishment is completed, and the pH measurement can be performed again after the mixture is evenly mixed to prevent misjudgment.

[0060] Liquid level linkage and safety protection logic:

[0061] Set the safe liquid level range (L) low , L high );

[0062] When L current Below L low When this happens, the control unit will issue an alarm and may interlock to stop the circulation pump 301 to prevent the pump from running dry and being damaged; at the same time, it can trigger the automatic inlet valve 209 to add process water to the mixing tank 201.

[0063] When L current Higher than L high When this occurs, an alarm is triggered and the inlet valve 209 or the alkali replenishment unit is shut off.

[0064] Alkali replenishment can only be performed when the liquid level is within a safe range.

[0065] Additionally, it may include coordinated control of the circulating pump 301:

[0066] The start and stop of the circulating pump 301 are linked to the overall system status; for example, when the liquid level in the mixing tank 201 is normal and the spray tower is in operation, the circulating pump 301 will start automatically.

[0067] The control unit can adjust the frequency of the inverter of the circulating pump 301 according to the exhaust gas concentration or system pressure difference, thereby changing the spray volume and achieving energy-saving operation.

[0068] It should be noted that the fuzzy PID control algorithm used in this invention is because traditional PID controllers perform poorly in the following situations during the pH control process of alkali solution: the relationship between pH value and alkali addition is not linear, and it has extremely high gain near the neutralization point; there is a lag time between alkali addition and pH meter detection of the change, including mixing, reaction, and detection; the concentration and volume of hydrogen sulfide in the exhaust gas may fluctuate frequently, which is equivalent to the continuous change of the process "disturbance".

[0069] The fuzzy PID control algorithm combines the intelligent reasoning capability of fuzzy logic with the precision of PID control. It does not rely on a precise mathematical model and can automatically adjust the PID parameters according to the real-time state of the system (deviation and its changing trend), making it very suitable for the pH control requirements in this project.

[0070] The specifications of the fuzzy PID control algorithm in this invention are as follows:

[0071] (1) Definition of algorithm input and output

[0072] Input variables:

[0073] Deviation (e): Current valid pH measurement (pH) current ) and preset target value (pH) target The difference between ) and pH; that is, e(k) = pH target -pH current ;

[0074] Deviation change rate (ec): The rate of change of the deviation at the current moment compared with the deviation at the previous moment, reflecting the trend of pH value change; that is, ec(k) = [e(k) - e(k-1)] / ΔT (where ΔT is the sampling period);

[0075] (2) Output variables:

[0076] Alkali replenishment adjustment amount (ΔU): The amount that needs to be increased or decreased above the basic alkali replenishment amount, which is ultimately used to control the speed or running time of the metering pump;

[0077] (3) Blurring:

[0078] We convert precise input values ​​(e and ec) into fuzzy linguistic values; we define several fuzzy sets for each variable, for example:

[0079] Fuzzy sets of deviation (e): negative large (NB), negative small (NS), zero (ZE), positive small (PS), positive large (PB).

[0080] Fuzzy sets of deviation change rate (ec): negative fast (NF), zero (ZE), positive fast (PF);

[0081] Each fuzzy set corresponds to a membership function (such as a triangular or trapezoidal function) to determine the degree to which a precise input value belongs to a certain fuzzy set (membership, between 0 and 1).

[0082] (4) Fuzzy reasoning:

[0083] This is the core of the algorithm, namely the "IF-THEN" rule base based on past experience or system knowledge. These rules determine how to adjust the PID parameters (ΔKp, ΔKi, ΔKd) or directly output the alkali supplementation adjustment amount (ΔU) according to the current e and ec states.

[0084] Example rule base (partial):

[0085]

[0086] (Note: A complete rule base usually contains all possible combinations, such as 3x3 or 5x5, for a total of 9 or 25 rules).

[0087] (5) Defuzzification:

[0088] The result of fuzzy inference is a set of fuzzy quantities output by multiple rules. The defuzzification process is to convert this fuzzy output set back into a precise, executable value (ΔU). The most commonly used method is the centroid method, which calculates the centroid position of the fuzzy set as the final precise output value.

[0089] (6) Calculation and execution of the final alkali replenishment:

[0090] The final control signal sent to the alkali replenishment unit consists of the following parts:

[0091] U(k) = U base + ΔU(k);

[0092] Among them, U base : A baseline alkali replenishment amount set based on experience to maintain steady state; ΔU(k): The adjustment amount at the current moment calculated by the fuzzy PID controller;

[0093] The control unit converts the calculated U(k) into a speed command or activation pulse width for the metering pump, thereby achieving precise control of the alkali replenishment amount.

[0094] Based on the above scheme, the specific working process of the hydrogen sulfide treatment device provided by the present invention is as follows:

[0095] Step S100. Initial alkali preparation:

[0096] The control unit first instructs the process water inlet valve 210 to open, injecting a fixed amount of process water into the mixing tank 201;

[0097] Subsequently, the control unit opens the inlet valve 209 and starts the delivery pump 208 to deliver the concentrated alkali solution in the alkali storage tank 207 to the mixing tank 201 according to the preset initial amount;

[0098] The control unit starts the stirring motor 203, which drives the stirring blades 204 to powerfully mix the water and concentrated alkali solution in the tank.

[0099] Step S200. Precise pH calibration:

[0100] The control unit reads the pH value from pH meter 206 in real time;

[0101] Based on the deviation between the reading and the preset target pH value, the control unit uses a fuzzy PID control algorithm (see the relevant section of the instruction manual for algorithm details) to dynamically adjust the alkali addition rate or amount of alkali added by the delivery pump 208.

[0102] When the pH value reaches and stabilizes within the target range, alkali addition is stopped; at this time, a batch of initial alkali solution with uniform concentration and accurately known pH value has been prepared in the mixing tank 201; the control unit closes the inlet valve 210 and the inlet valve 209, while the connecting valve 202 is closed by default, ready to enter the tail gas treatment stage.

[0103] Step S300. Start exhaust gas treatment:

[0104] Hydrogen sulfide-containing tail gas generated during the thiourea production process is introduced into the tail gas inlet at the bottom of the spray tower;

[0105] After the control unit confirms that the liquid level in the mixing tank 201 is normal, it starts the circulation pump 301. The circulation pump 301 transports the alkaline solution in the mixing tank 201 to the spray pipe 302 at the top of the tower for atomized spraying.

[0106] Step S400. Absorption and reflux:

[0107] The sprayed alkaline solution comes into full contact with the counter-current hydrogen sulfide tail gas in the packing layer or the space inside the tower, and a neutralization reaction occurs, effectively removing hydrogen sulfide from the tail gas.

[0108] After the reaction, the waste alkali liquid falls back to the bottom of the spray tower under the action of gravity; at this time, the connecting valve 202 is closed; when the control unit detects through the liquid level sensor 205 that the liquid level of the mixing tank 201 has dropped to the point where it needs to be replenished, it commands the connecting valve 202 to open, so that the waste alkali liquid at the bottom of the tower flows back to the mixing tank 201, realizing circulation.

[0109] Step S500. Real-time data acquisition:

[0110] Throughout the process, the control unit continuously monitors in real time: pH value of mixing tank 201 (pH meter 206), liquid level of mixing tank 201 (liquid level sensor 205), tail gas concentration (concentration sensor, optional), and system differential pressure (pressure sensor, used to determine the condition inside the tower).

[0111] Step S600. Trigger uniform mixing and effective measurement:

[0112] The control unit automatically starts a measurement cycle when any of the following conditions are met:

[0113] Timed trigger: Reaching preset periodic stirring and detection time points;

[0114] Event triggered: After the last alkali replenishment operation is completed;

[0115] Abnormal trigger: An abnormal rate of pH change is detected, indicating uneven mixing or sudden load changes;

[0116] The control unit activates the agitator to forcibly mix the alkali solution returning to the mixing tank 201 in order to eliminate the concentration gradient.

[0117] Step S700. Determine the mixing uniformity:

[0118] Preset stirring operation time (T) blend After that, the control unit begins monitoring the stability of the pH meter readings;

[0119] When the fluctuation range of the reading over a continuous period of time (e.g., 10 seconds) is less than the preset stability threshold (ΔpH) threshold When the pH value reaches 0, the system determines that the alkali solution has been mixed evenly, and the pH reading at this point is confirmed as a valid measurement.

[0120] Step S800. Decision-making and Execution of Precise Alkali Supplementation:

[0121] Demand Judgment: The control unit compares the effective measured value with the preset alkali replenishment trigger threshold (pH). low Compare the pH values; if the pH value is below the threshold, initiate the alkali replenishment procedure.

[0122] Intelligent Calculation: Based on the deviation (e) between the current pH value and the target value and its rate of change (ec), the control unit runs a fuzzy PID control algorithm to accurately calculate the amount of alkali solution (V) that needs to be added. base );

[0123] Quantitative alkali replenishment: The control unit instructs the delivery pump 208 and inlet valve 209 to operate precisely, adding a volume of V into the mixing tank 201. base Concentrated alkaline solution; during this process, decisions based on pH measurements can be paused to prevent misjudgment;

[0124] Post-addition mixing: Once the alkali addition operation is completed, the control unit immediately restarts the agitator to run one cycle, ensuring that the newly added concentrated alkali solution is fully and evenly mixed with the original liquid in the tank.

[0125] Step S900. Safety Interlock and Closed-Loop Cycle

[0126] Low level interlock: If the liquid level is below the safety lower limit (L) lowThe control unit will interlock and stop the circulation pump 301 to prevent it from running dry and causing damage, and will issue an audible and visual alarm.

[0127] High liquid level alarm: If the liquid level is too high (L) high If the alarm sounds, the inlet valve 210 or the alkali solution replenishment unit will be shut off.

[0128] All alkali replenishment operations must be performed only when the liquid level is within a safe range;

[0129] Closed-loop circulation and optimization: After the post-mixing is completed, the system automatically returns to step S600 and continues to perform a cycle of monitoring, mixing, measuring and decision-making; the control unit can also adjust the frequency of the circulating pump 301 according to the data of the concentration sensor or pressure sensor to dynamically optimize the spray volume and achieve efficient and energy-saving operation.

[0130] As can be seen from the above, the hydrogen sulfide treatment device in the tail gas of thiourea production provided by the present invention, through the synergistic design of the homogenization alkali preparation unit 20 and the intelligent control strategy, solves the problems of inaccurate pH measurement, control lag and low precision caused by uneven alkali mixing in the prior art. Compared with traditional devices, it has the following technical effects:

[0131] The authenticity and reliability of pH measurement are fundamentally ensured: through the control logic of "forced mixing, stability determination and acquisition of effective value", the measurement deviation caused by flow dead zone and concentration gradient in mixing tank 201 is greatly reduced, so that the control decision is based on the effective pH measurement value that reflects the overall state of the system, laying a solid foundation for precise control.

[0132] It achieves precision and optimization of alkali replenishment operation: Based on the real pH measurement value, the fuzzy PID intelligent control algorithm is used to make alkali replenishment decisions. This algorithm can dynamically adapt to the nonlinearity and hysteresis characteristics of the system, and accurately calculate the amount of alkali to be replenished according to the pH deviation and its changing trend. It realizes quantitative and on-demand replenishment, fundamentally avoiding the over- or under-replenishment of alkali under the traditional method, improving the utilization rate of alkali solution, and reducing the cost of chemical consumption in operation.

[0133] The system improves the stability and efficiency of the entire treatment system: precise pH control ensures that the alkaline solution is always kept in the optimal reactivity range, thereby ensuring the continuous stability of hydrogen sulfide absorption efficiency and effectively eliminating the risk of excessive exhaust emissions due to inaccurate pH control, resulting in significant environmental benefits; at the same time, the automated and intelligent operation of the system reduces the reliance on manual operation and enhances the reliability of operation.

[0134] It achieves safe and energy-saving intelligent operation: the integrated liquid level linkage and safety protection logic can effectively prevent safety accidents such as equipment idling and overflow; in addition, the control unit can also dynamically adjust the operating status of equipment such as the circulating pump 301 according to the exhaust gas load (such as concentration and gas volume), so as to achieve on-demand energy supply while ensuring the treatment effect, and achieve the purpose of energy saving and consumption reduction.

[0135] In summary, this invention transforms the traditional passive and extensive control mode into an active and refined intelligent closed-loop control mode, accurately and stably controlling the key parameter pH value within the optimal range, ultimately achieving a comprehensive technical effect of maximizing treatment efficiency, minimizing operating costs, and ensuring stable emission compliance, thus possessing outstanding industrial application value.

[0136] The embodiments of the present invention have been described above, but the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention, all of which are within the protection scope of the present invention.

Claims

1. A device for treating hydrogen sulfide in tail gas from thiourea production, characterized in that, include: The main body of the spray tower, the homogenization alkali preparation unit, the circulating spray unit, and the control unit; The homogenization alkali preparation unit includes: The mixing tank is connected to the lower end of the spray tower via a connecting valve and is used to collect the alkaline solution after spraying. A stirring element, mounted on the mixing tank, is used to uniformly mix the alkaline solution inside the mixing tank; A liquid level measuring device is installed inside the mixing tank to measure the liquid level of the alkaline solution inside the mixing tank; A pH measuring device is installed inside the mixing tank to measure the pH value of the alkaline solution inside the tank. The alkali replenishment unit connects to the mixing tank and is used to replenish the alkali solution in the mixing tank to maintain the pH balance of the alkali solution. The circulating spray unit is connected to the mixing tank to allow the alkaline solution to circulate within the main body of the spray tower. The control unit is signal-connected to the homogenization alkali preparation unit and the circulating spray unit, and is configured as follows: The stirring element is controlled to ensure that the alkaline solution is mixed evenly, and an effective pH measurement value is obtained after confirming that the alkaline solution is mixed evenly. The alkali replenishment device is controlled to quantitatively replenish alkali based on effective pH measurement values, so as to maintain the pH value of the alkali within a preset range.

2. The hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The stirring component includes a stirring motor located at the top of the mixing tank and stirring blades located inside the mixing tank, wherein the stirring blades are connected to the output end of the stirring motor.

3. The hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The liquid level measuring device is a liquid level sensor, and the pH value measuring device is a pH meter.

4. The hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The alkali replenishment component includes an alkali storage tank, a transfer pump connected to the alkali storage tank, and an inlet valve connecting the transfer pump and the mixing tank.

5. The hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The circulating spray unit includes a circulating pump connected to the mixing tank and a spray pipe located inside the spray tower. The spray pipe is connected to the output end of the circulating pump.

6. The hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The control unit is configured to: activate the stirring element when predetermined conditions are met, and determine that the alkaline solution has been mixed evenly after the pH value measurement reading stabilizes.

7. A hydrogen sulfide treatment device for thiourea production tail gas according to claim 6, characterized in that, The predetermined conditions include at least one of the following: Reaching the preset periodic time interval; After the alkali replenishment device completes one alkali replenishment operation; The rate of change in pH value was detected to exceed the preset fluctuation threshold.

8. A hydrogen sulfide treatment device for thiourea production tail gas according to claim 6, characterized in that, The criterion for determining stable readings is that the fluctuation range of the pH value measurement device over a continuous period of time is less than a preset stability threshold.

9. A hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The control unit is configured to: when the effective pH measurement value is lower than the alkali replenishment trigger threshold, start the alkali replenishment program, calculate the amount of alkali solution to be replenished based on the deviation between the effective pH measurement value and the target value, and control the alkali replenishment device to perform quantitative replenishment.

10. A hydrogen sulfide treatment device for thiourea production tail gas according to claim 1, characterized in that, The control unit is also configured to: pause the judgment based on the pH measurement value during the alkali replenishment operation of the alkali replenishment component; immediately start the stirring component after the alkali replenishment operation is completed, and perform the next pH measurement value acquisition and judgment after the alkali solution is mixed evenly again.

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