Intelligent alkali liquor adding system based on real-time monitoring and feedback control of mercuric chloride production section

Abstract

The invention discloses an intelligent alkali liquor adding system based on real-time monitoring and feedback control of a mercuric chloride production section, which comprises a liquid chlorine supply system and raw material pretreatment systems in sequential pumping connection, and the system can dynamically and accurately match fluctuating chlorine load in tail gas; and the problem that the addition amount of the alkali liquor is not matched with the chlorine concentration is effectively solved. The chlorine gas absorption efficiency is remarkably improved, up-to-standard discharge is ensured, the consumption of the alkali liquor is greatly reduced, the operation cost and the wastewater treatment burden are reduced, and the double improvement of economic benefits and environmental benefits is realized.

Description

Technical Field

[0001] This invention relates to the field of mercuric chloride production technology, specifically to an intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production process. Background Technology

[0002] In the production of mercuric chloride, the chlorine concentration in the exhaust gas from the secondary separator is not constant due to the inability to maintain a 100% conversion rate or the presence of side reactions. Instead, it fluctuates significantly and unpredictably depending on factors such as production load, raw material batches, and operating conditions. Existing alkali supply systems (including alkali tanks and pumps) typically deliver alkali at preset fixed flow rates or concentrations. This static alkali addition method cannot respond in real-time to dynamic changes in chlorine concentration in the exhaust gas, leading to a specific technical problem: when the chlorine concentration in the exhaust gas is low, the system may over-add alkali, wasting alkali, increasing operating costs, and potentially causing excessively high pH values ​​in the treated wastewater, thus burdening subsequent wastewater treatment systems. Conversely, when the chlorine concentration in the exhaust gas suddenly increases, the fixed flow rate of alkali may not be sufficient to completely absorb all the chlorine, resulting in decreased treatment efficiency and excessive residual chlorine emissions in the exhaust gas. This not only violates environmental regulations but also poses a continuous threat to the environment and human safety. Therefore, how to achieve intelligent and dynamic adjustment of alkali dosage to accurately match the fluctuating chlorine load in the tail gas is a key technical problem that urgently needs to be solved in this application scenario.

[0003] To address the problem of low alkali dosing efficiency or substandard treatment caused by fluctuations in chlorine concentration in the exhaust gas, this optimization scheme proposes an intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section, so as to achieve dynamic optimization of the alkali dosing amount. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an intelligent alkali solution dosing system based on real-time monitoring and feedback control of the mercuric chloride production section, so as to realize the dynamic change of alkali solution dosing.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A smart alkali dosing system based on real-time monitoring and feedback control of a mercuric chloride production section includes: a liquid chlorine supply system and a raw material pretreatment system connected in sequence by pumps. The raw material pretreatment system is equipped with a liquid chlorine vaporizer, one end of which is connected to a primary water main, and the other end to a chlorine buffer tank. The upper end of the chlorine buffer tank is connected to the alkali supply system via a transmission pipeline, and the right end is connected to the liquid mercury pretreatment system via a transmission pipeline. The liquid mercury pretreatment system is equipped with an air-cooled tower, the upper end of which is connected to a primary separator and a secondary separator, and is connected to an injector via a transmission pipeline. The injector is connected to the alkali supply system via a transmission pipeline, and the other end is connected to a metering and packaging system. The metering and packaging system is connected to a mercuric chloride recovery system and a tail gas treatment system. The alkali supply system is equipped with an alkali tank, which is pumped to an alkali pump. The alkali pump pressurizes the alkali and transmits it to the injector via a transmission pipeline. The injector is connected to a wastewater treatment system.

[0006] Preferably, the liquid chlorine supply system includes a liquid chlorine cylinder, and a pressure valve is installed on the transmission pipeline connecting the liquid chlorine cylinder to the raw material pretreatment system to monitor and control the pressure within the system and ensure safety.

[0007] Preferably, the raw material pretreatment system further includes a level gauge and a pressure gauge installed on the liquid chlorine vaporizer for real-time monitoring of the liquid level and pressure parameters during the liquid chlorine vaporization process.

[0008] Preferably, the alkali supply system further includes a level gauge and a pressure gauge installed on the alkali tank for real-time monitoring of the alkali level and pressure in the alkali tank. The bottom of the alkali tank is provided with a drain port for thoroughly draining, cleaning and maintaining the alkali tank.

[0009] Preferably, the injector is equipped with a flow monitoring device and a concentration monitoring device for real-time monitoring of the flow rate and concentration of the alkali solution entering the injector.

[0010] Preferably, the system further includes a control unit, which is electrically connected to a temperature monitoring device, a pressure monitoring device, a liquid level monitoring device, a flow monitoring device, a concentration monitoring device, a pH sensor, and an alkali pump. The flow monitoring device is a flow control valve or a variable frequency speed-regulating alkali pump, which is installed on the alkali delivery pipeline between the alkali pump outlet and the ejector. The concentration monitoring device is an online chlorine concentration analyzer, which is installed on the tail gas pipeline connecting the secondary separator and the injector. It can measure the concentration of chlorine in the tail gas entering the treatment system in real time and accurately, and serve as the feedforward control signal for the system. The online pH sensor is installed on the liquid discharge pipe after the injector treatment; The control unit is used to receive data from the chlorine concentration analyzer and pH sensor, and send instructions to the flow controller according to the preset control logic; it corrects the accuracy of the feedforward control, compensates for uncertainties in the process, and ensures the thoroughness of chlorine absorption and the economy of alkali solution use. The system is also equipped with high chlorine concentration alarms and low pH alarms. When the chlorine concentration or pH value exceeds the safe range, the system will issue an alarm and start the backup alkali pump or adjust the production load to ensure that the exhaust gas emissions always meet environmental protection standards. This achieves intelligent alkali dosing.

[0011] Preferably, the tail gas treatment system includes a level gauge on the alkali tank, a pressure gauge on the alkali pump outlet pipeline, and a pressure gauge on the tail gas discharge pipeline from the secondary separator for monitoring key process parameters of chlorine.

[0012] Preferably, the metering and packaging system includes a metering scale and a packaging machine. The metering scale is used to accurately measure the mercuric chloride product, and the packaging machine is used to package the measured mercuric chloride product.

[0013] Preferably, the alkali solution in the alkali tank comes from a pre-prepared alkali solution in the alkali solution supply system, and the alkali solution is a sodium hydroxide solution.

[0014] Preferably, the alkali tank, alkali pump, and ejector are all configured with dual redundancy (A / B sets).

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The online chlorine concentration analyzer enables real-time detection of the chlorine concentration entering the injector from the exhaust gas, effectively solving the problem of mismatch between the alkali dosage and the chlorine concentration. The installation of the flow monitoring device enables the correction of the accuracy of the feedforward control system, improves the chlorine absorption efficiency, and significantly reduces the consumption of alkaline solution, thereby reducing operating costs and wastewater treatment burden, achieving a dual improvement in economic and environmental benefits. 3. The high chlorine concentration alarm and low pH alarm systems ensure that exhaust emissions always meet environmental protection standards. Attached Figure Description

[0016] Figure 1 This is a process flow diagram of the present invention; Figure 2 For the present invention Figure 1 Enlarged view at point A; Figure 3 For the present invention Figure 1 Enlarged view at point B; Figure 4 For the present invention Figure 1 Enlarged view at point C; Figure 5 For the present invention Figure 1 Enlarged view at point D. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] like Figure 1-5 As shown, an intelligent alkali dosing system based on real-time monitoring and feedback control of a mercuric chloride production section includes: a liquid chlorine supply system 1 and a raw material pretreatment system 2 connected sequentially by pumps. The raw material pretreatment system 2 is equipped with a liquid chlorine vaporizer 211. One end of the liquid chlorine vaporizer 211 is connected to a primary water main 3, and the other end is connected to a chlorine buffer tank 212. The upper end of the chlorine buffer tank 212 is connected to an alkali supply system 4 via a transmission pipeline, and the right end is connected to a liquid mercury pretreatment system 5 via a transmission pipeline. The liquid mercury pretreatment system 5 is equipped with an air-cooled tower 511. The air-cooled tower 511 is connected to a primary separator 6 and a secondary separator 7 at its upper end and is connected to an ejector 8 via a transmission pipeline. The ejector 8 is connected to an alkali supply system 4 via a transmission pipeline, and the other end is connected to a metering and packaging system 9. The metering and packaging system 9 is connected to a mercuric chloride recovery system 10 and a tail gas treatment system 11. The alkali supply system 4 is equipped with an alkali tank 411. The alkali tank 411 is pumped to an alkali pump 413. The alkali pump 413 pressurizes the alkali and transmits it to the ejector 8 via a transmission pipeline. The ejector 8 is connected to a wastewater decontamination treatment system 12.

[0019] Specifically, the liquid chlorine supply system 1 includes a liquid chlorine cylinder 101. A pressure valve is installed on the transmission pipeline connecting the liquid chlorine cylinder 101 to the raw material pretreatment system 2 to monitor and control the pressure within the system, ensuring safety. By real-time monitoring of key parameters such as the alkali liquid level, alkali liquid delivery pressure, and tail gas inlet pressure, operators can promptly understand the system's operating status, detect abnormalities, and intervene. This helps optimize the alkali liquid flow rate and injection effect, ensuring the chlorine absorption reaction proceeds under optimal conditions, improving processing efficiency. It also allows for the timely detection of potential equipment failures or process deviations, thereby ensuring the safe and stable operation of the system and preventing excessive emissions of harmful gases.

[0020] Specifically, the raw material pretreatment system 2 also includes a level gauge and a pressure gauge installed on the liquid chlorine vaporizer 211, which are used to monitor the liquid level and pressure parameters in real time during the liquid chlorine vaporization process.

[0021] Specifically, the alkali supply system 4 also includes a level gauge and a pressure gauge installed on the alkali tank 411 for real-time monitoring of the alkali level and pressure in the alkali tank 411. The bottom of the alkali tank 411 is provided with a drain port 412 for thoroughly draining, cleaning and maintaining the alkali tank.

[0022] Specifically, the injector 8 is equipped with a flow monitoring device and a concentration monitoring device to monitor the flow rate and concentration of the alkali solution entering the injector 8 in real time.

[0023] Specifically, the system also includes a control unit, which is electrically connected to a temperature monitoring device, a pressure monitoring device, a liquid level monitoring device, a flow monitoring device, a concentration monitoring device, a pH sensor, and an alkali pump 413. The flow monitoring device is a flow control valve or a variable frequency speed-regulating alkali pump, which is installed on the alkali delivery pipeline between the outlet of the alkali pump 413 and the ejector 8. Furthermore, the concentration monitoring device is an online chlorine concentration analyzer, which is installed on the tail gas pipeline connecting the secondary separator and the injector 8. It can measure the concentration of chlorine in the tail gas entering the treatment system in real time and accurately, and serve as the feedforward control signal for the system. Furthermore, the online pH sensor is installed on the liquid discharge pipe after the injector treatment; Furthermore, the control unit is used to receive data from the chlorine concentration analyzer and pH sensor, and send instructions to the flow controller according to the preset control logic; it corrects the accuracy of the feedforward control, compensates for uncertainties in the process, and ensures the thoroughness of chlorine absorption and the economy of alkali solution use. Furthermore, the system is equipped with high chlorine concentration alarms and low pH alarms. When the chlorine concentration or pH value exceeds the safe range, the system will issue an alarm and activate the backup alkali pump or adjust the production load to ensure that exhaust emissions always meet environmental standards. This achieves intelligent alkali dosing.

[0024] Specifically, the tail gas treatment system 11 includes a level gauge on the alkali tank 411, a pressure gauge on the outlet pipeline of the alkali pump 413, and a pressure gauge on the tail gas discharge pipeline from the secondary separator for monitoring key process parameters of chlorine.

[0025] Specifically, the metering and packaging system 9 includes a metering scale and a packaging machine. The metering scale is used to accurately measure the mercuric chloride product, and the packaging machine is used to package the measured mercuric chloride product.

[0026] Specifically, the alkali solution in the alkali tank 411 is all from the pre-prepared alkali solution in the alkali solution supply system 4, and the alkali solution is a sodium hydroxide solution. Pre-preparing the alkali solution ensures that the absorbent with the required concentration can be provided immediately when needed, avoiding delays or inaccurate concentrations that may be caused by temporary preparation.

[0027] Specifically, the alkali tank 411, alkali pump 413, and ejector 8 all adopt an A / B dual-redundant configuration. This redundancy significantly improves the operational stability of the exhaust gas treatment system. When one set of equipment fails or requires maintenance, the other backup equipment can be immediately put into operation, ensuring uninterrupted exhaust gas treatment and continuous, effective removal of harmful gases. This avoids the emission of untreated chlorine or other harmful gases due to equipment downtime, ensuring environmental safety and production continuity.

[0028] Working principle of the invention: The chlorine gas in the exhaust gas is chemically absorbed and neutralized using an alkaline solution. The specific process is as follows: The tail gas containing unreacted chlorine and other gases produced during the production of mercuric chloride is discharged from the secondary separator 7 and then introduced into the injector 8 through a closed pipeline.

[0029] Meanwhile, the pre-prepared alkali solution (sodium hydroxide solution) in the alkali tank 411 is pressurized by the alkali pump 413 and sent into the ejector 8 in the form of a high-speed jet.

[0030] Inside the injector 8, a high-speed jet of alkaline solution draws in the exhaust gas and mixes it thoroughly. Chlorine (Cl2) reacts chemically with the alkaline solution (NaOH), for example: Cl2 + 2NaOH → NaCl + NaClO + H2O, converting the toxic chlorine into non-toxic or low-toxic salts such as sodium chloride (table salt) and sodium hypochlorite, thereby achieving effective removal and neutralization of chlorine.

[0031] After being processed by injector 8, the liquid's main harmful component, chlorine, has been absorbed and converted. It is then sent through pipelines to wastewater treatment system 12 for further centralized treatment, ensuring that the final exhaust gas and wastewater emissions meet environmental protection standards.

[0032] By setting a control unit in the system, the control unit is electrically connected to a temperature monitoring device, a pressure monitoring device, a liquid level monitoring device, a flow monitoring device, a concentration monitoring device, a pH sensor, and an alkali pump 413. The flow monitoring device is installed on the alkali delivery pipeline between the outlet of the alkali pump 413 and the ejector 8. The online chlorine concentration analyzer is installed on the tail gas pipeline connecting the secondary separator and the ejector 8, which can measure the concentration of chlorine in the tail gas entering the treatment system in real time and accurately, serving as the system's feedforward control signal. The online pH sensor is installed on the liquid discharge pipeline after the ejector treatment. The control unit is used to receive data from the chlorine concentration analyzer and the pH sensor, and send instructions to the flow controller according to the preset control logic. This corrects the accuracy of the feedforward control, compensates for uncertainties in the process, and ensures the thorough absorption of chlorine and the economical use of alkali. The system is also equipped with high chlorine concentration alarms and low pH alarms. When the chlorine concentration or pH value exceeds the safe range, the system will issue an alarm and start the backup alkali pump or adjust the production load to ensure that the exhaust gas emissions always meet environmental protection standards. This achieves intelligent alkali dosing.

[0033] In practice, the tail gas containing a small amount of chlorine, discharged from the secondary separator 7 after the mercuric chloride production reaction, is piped to the inlet of the ejector 8. Simultaneously, the sodium hydroxide solution (alkali solution) stored in the alkali tank 411 is pressurized by the alkali pump 413 and sent to the ejector 8 through another pipeline. Inside the ejector 8, the high-speed ejected alkali solution comes into full contact with the tail gas, and the chlorine gas rapidly reacts chemically with the sodium hydroxide solution, being absorbed and neutralized. The liquid treated by the ejector 8, i.e., wastewater containing neutralization products, is piped to the plant's wastewater treatment system 12 for further treatment. This method ensures that the tail gas generated during the mercuric chloride production process is effectively purified before emission, avoiding environmental pollution from toxic chlorine gas.

[0034] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A smart alkali solution dosing system based on real-time monitoring and feedback control in a mercuric chloride production line, comprising: The liquid chlorine supply system (1) and the raw material pretreatment system (2) connected in sequence by pumping are characterized in that: the raw material pretreatment system (2) is equipped with a liquid chlorine vaporizer (211), one end of the liquid chlorine vaporizer (211) is connected to the primary water main pipe (3), and the other end is connected to the chlorine buffer tank (212). The upper end of the chlorine buffer tank (212) is connected to the alkali supply system (4) through a transmission pipeline, and the right end is connected to the liquid mercury pretreatment system (5) through a transmission pipeline. The liquid mercury pretreatment system (5) is equipped with an air-cooled tower (511), and the upper end of the air-cooled tower (511) is connected to a primary separator. (6) and the secondary separator (7) are connected to the injector (8) through the transmission pipeline. The injector (8) is connected to the alkali supply system (4) through the transmission pipeline, and the other end is connected to the metering and packaging system (9). The metering and packaging system (9) is connected to the mercuric chloride recovery system (10) and the tail gas treatment system (11). The alkali supply system (4) is equipped with an alkali tank (411). The alkali tank (411) is pumped to the alkali pump (413). The alkali pump (413) pressurizes the alkali and transmits it to the injector (8) through the transmission pipeline. The injector (8) is connected to the wastewater decontamination treatment system (12).

2. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The liquid chlorine supply system (1) includes a liquid chlorine cylinder (101). A pressure valve is installed on the transmission pipeline connecting the liquid chlorine cylinder (101) to the raw material pretreatment system (2) to monitor and control the pressure in the system and ensure safety.

3. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The raw material pretreatment system (2) also includes a level gauge and a pressure gauge installed on the liquid chlorine vaporizer (211) for real-time monitoring of the liquid level and pressure parameters during the liquid chlorine vaporization process.

4. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The alkali supply system (4) also includes a level gauge and a pressure gauge installed on the alkali tank (411) for real-time monitoring of the alkali level and pressure in the alkali tank (411). The bottom of the alkali tank (411) is provided with a drain port (412) for thoroughly draining, cleaning and maintaining the alkali tank.

5. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The injector (8) is equipped with a flow monitoring device and a concentration monitoring device for real-time monitoring of the flow rate and concentration of the alkali solution entering the injector (8).

6. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that, The system also includes a control unit, which is electrically connected to a temperature monitoring device, a pressure monitoring device, a liquid level monitoring device, a flow monitoring device, a concentration monitoring device, a pH sensor and an alkali pump (413). The flow monitoring device is a flow control valve or a variable frequency speed regulated alkali pump, which is installed on the alkali delivery pipeline between the outlet of the alkali pump (413) and the ejector (8). The concentration monitoring device is an online chlorine concentration analyzer, which is installed on the tail gas pipeline connecting the secondary separator and the injector (8). It can measure the concentration of chlorine in the tail gas entering the treatment system in real time and accurately, and serve as the feedforward control signal of the system. The online pH sensor is installed on the liquid discharge pipe after the injector treatment; The control unit is used to receive data from the chlorine concentration analyzer and pH sensor, and send instructions to the flow controller according to the preset control logic; it corrects the accuracy of the feedforward control, compensates for uncertainties in the process, and ensures the thoroughness of chlorine absorption and the economy of alkali solution use. The system is also equipped with high chlorine concentration alarm and low pH alarm. When the chlorine concentration or pH value exceeds the safe range, the system will issue an alarm and start the backup alkali pump or adjust the production load to ensure that the exhaust gas emissions always meet environmental protection standards. To achieve intelligent dosing of alkali solution.

7. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The tail gas treatment system (11) includes a level gauge on the alkali tank (411), a pressure gauge on the outlet pipeline of the alkali pump (413), and a pressure gauge on the tail gas discharge pipeline from the secondary separator for monitoring key process parameters of chlorine.

8. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The metering and packaging system (9) includes a metering scale and a packaging machine. The metering scale is used to accurately measure the mercuric chloride product, and the packaging machine is used to package the measured mercuric chloride product.

9. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The alkali solution in the alkali tank (411) is all from the alkali solution pre-prepared in the alkali solution supply system (4), and the alkali solution is sodium hydroxide solution.

10. The intelligent alkali dosing system based on real-time monitoring and feedback control of the mercuric chloride production section according to claim 1, characterized in that: The alkali tank (411), alkali pump (413) and ejector (8) are all configured with dual redundancy (A / B).

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