Industrial waste gas acid mist absorption automatic control system and use method

Abstract

The invention provides an automatic control system for acid mist absorption of industrial waste gas and a use method. The control system comprises a waste gas tower, a fan, a circulating pump set, a liquid alkali pump, a pressure sensor, a pH meter, a liquid level meter, an electric valve, a regulating valve, an operation screen and a central processing unit. According to the acid mist absorption automatic control system for the industrial waste gas, the pressure of the waste gas is obtained through the central processing unit, the working frequency of the fan is adjusted through a preset pressure value, and the rate of the waste gas entering the waste gas tower is stabilized. According to the pH value in the waste gas tower, the addition amount of the liquid caustic soda is adjusted by adjusting the adjusting valve through the operation screen arranged on an operation site or the central processing unit, so that the pH value in the waste gas tower fluctuates smaller, the adjusting range is more accurate, and the comprehensive efficiency of waste gas treatment is improved. Besides, according to the using method of the automatic control system, the control system can be automatically controlled and run according to a preset method, unified management of the system is achieved, and the stability in the standard gas emission process is ensured.

Description

Technical Field

[0001] The present invention belongs to the field of waste gas treatment equipment generated in electrolytic manufacturing industry, and specifically relates to an automatic control system for acid mist absorption of industrial waste gas and a method for using the automatic control system. The automatic control system is simple to operate, can be operated by a touch screen and controlled by a central processing unit, and is specifically designed for acid mist absorption. Background Art

[0002] For the purpose of circular sustainable development, it is necessary to make full use of existing resources, and thus the electrolytic copper, nickel, cobalt and other metal industries have emerged. Specifically, various metals are extracted and separated from waste liquid and waste residue. Due to process reasons, the electrolytic industry inevitably produces industrial waste gas in the process of metal production, such as sulfuric acid dioxide mist. The acid mist will corrode the production workshop and mechanical equipment. At the same time, the acid mist is toxic to humans. Excessive inhalation will cause great harm to the human body, and direct release into the air will pollute the environment.

[0003] At present, in the process of producing copper, nickel, cobalt and other metals, the acid mist is generally treated by a vertical double-layer water curtain spray filtration acid mist treatment tower, in which alkaline water is added manually to neutralize the acid mist. The above method uses a large amount of water and alkali, and the manual addition of alkali cannot accurately control whether the air meets the standard, the treatment capacity is low and the treatment cost is high. Therefore, the traditional manual production method can no longer meet the production needs, which requires the design of a control system with automatic adjustment to replace the traditional manual operation mode. Summary of the invention

[0004] In view of the problems existing in the prior art, the purpose of the present invention is to provide an automatic control system for acid mist absorption of industrial waste gas and a method of use, which can quickly realize precise control of the pH meter in the waste gas tower, has a high degree of automation and standardized operation and control processes, and effectively improves the overall efficiency of waste gas treatment.

[0005] One aspect of the present invention provides an automatic control system for acid mist absorption of industrial waste gas, comprising: The exhaust tower includes a first-stage exhaust tower and a second-stage exhaust tower. The gas outlet pipe of the first-stage exhaust tower is connected with the gas inlet of the second-stage exhaust tower. The external exhaust gas enters the gas inlet of the first-stage exhaust tower through the external exhaust main pipe. A first-stage alkaline liquid tank is arranged at the bottom of the first-stage exhaust tower. A second-stage alkaline liquid tank is arranged at the bottom of the second-stage exhaust tower. Each alkaline liquid tank is connected with a water adding pipe and an alkali adding pipe. A spray device is arranged above the exhaust tower. The liquid alkali main tank is connected to the first-stage alkaline liquid tank and the second-stage alkaline liquid tank pipelines respectively, and is used to provide the liquid alkali required for neutralizing the acid mist; A fan is connected to the outlet of the second-stage exhaust gas pipeline, and the output end is connected to the emission tower; A circulation pump group, comprising a first-stage circulation pump connected to the first-stage alkaline liquid tank, and a second-stage circulation pump connected to the second-stage alkaline liquid tank, wherein the output ends of the first-stage circulation pump and the second-stage circulation pump are respectively connected to the pipe openings of the spray device above the exhaust tower; A liquid alkali pump, comprising a first-stage liquid alkali pump and a second-stage liquid alkali pump connected to the liquid alkali main tank, wherein the output end of the first-stage alkali liquid pump is connected to the first regulating valve, and the output end of the second-stage alkali liquid pump is connected to the second regulating valve; A pressure transmitter is installed above the external exhaust gas main pipeline to monitor the main pipeline pressure; The first-stage pH meter is installed at the exhaust gas flow pipe opening above the first-stage exhaust tower to monitor the pH value of the first-stage exhaust gas; The second stage pH meter is installed at the exhaust gas flow pipe opening above the second stage exhaust tower to monitor the pH value of the second stage exhaust gas; The first regulating valve is arranged in the alkali adding pipeline of the first-stage alkaline liquid tank; The second regulating valve is arranged on the alkali adding pipeline of the second-stage alkaline liquid tank; Further optimization solutions include: A liquid level meter is installed on each tank to monitor the liquid level value of each tank. A first liquid level meter is arranged on the first-stage alkaline liquid tank to monitor the liquid level height of the solution in the tank; A second liquid level meter is arranged on the second-stage alkaline liquid tank to monitor the liquid level height of the solution in the tank; The third liquid level meter is arranged on the liquid alkali main tank and is used to monitor the height of the remaining solution in the liquid alkali main tank; The electric valve is arranged in the water supply pipeline of the alkaline liquid tank; wherein, A first electric valve is arranged on a water supply pipeline of a first-stage alkaline liquid tank; A second electric valve is arranged on a water supply pipeline of the second-stage alkaline liquid tank; A further preferred solution is that the fan is a centrifugal fan; A further preferred solution is that the liquid level meter is a magnetic flap liquid level meter; A further preferred solution is that a parameter alarm program is provided in the central processing unit; A further preferred solution is that a group interlocking start and stop is provided in the central processing unit; Another aspect of the present invention provides a method for using an automatic control system for acid mist absorption of industrial waste gas, comprising: S1. When the waste gas enters the tower, the first-stage circulation pump and the second-stage circulation pump are started according to the preset program in the central processing unit, so that the alkaline liquid is sprayed through the spray device to neutralize the acid mist in the tower. The waste gas first passes through the first-stage waste gas tower and then the second-stage waste gas tower. The multi-stage waste gas treatment can better ensure the waste gas emission standards; S2. The specific monitoring data of the pH meter and the liquid level meter are uploaded to the central processing unit. The pH meter is used to monitor the pH value of the actual gas in the exhaust tower, and the liquid level meter is used to monitor the height of the residual solution in each tank; S3. The central processing unit sets the frequency of the relatively suitable pressure regulating fan according to the amount of waste gas generated by external production to adjust the amount of waste gas entering the waste gas tower. The central control unit adjusts the opening of the liquid alkali pipeline regulating valve according to the pH value of the pH meter to ensure that the waste gas can be neutralized to the greatest extent in the tower, and reasonably controls the amount of liquid alkali added to achieve dynamic balance; S4. The central processing unit controls the start and stop of the first-stage circulation pump and the switching action of the first electric valve according to the solution height of the first-stage alkaline liquid tank. The central processing unit controls the start and stop of the second-stage circulation pump and the switching action of the second electric valve according to the solution height of the second-stage alkaline liquid tank. The central processing unit can control the start and stop of the liquid alkali delivery pump according to the liquid level of the liquid alkali main tank. The circulation pump is interlocked with the liquid alkali pump and the fan. When the circulation pump stops due to a fault, the liquid alkali pump and the fan will automatically interlock and stop the pump.

[0006] S5. When the pH in the exhaust tower reaches the emission standard, the gas will be transported by the fan into the emission tower for emission; According to the above content, the automatic control system for acid mist absorption of industrial waste gas of the present invention can obtain the pressure of the waste gas through the central processing unit, and adjust the working frequency of the fan by presetting the pressure value, so as to stabilize the waste gas rate entering the waste gas tower. The pH value in the waste gas tower can be adjusted by adjusting the amount of liquid alkali added by adjusting the regulating valve through the operation screen set at the operation site or the central processing unit, so that the pH value in the waste gas tower fluctuates less and the range of regulation is more precise, thereby improving the overall efficiency of waste gas treatment. In addition, the method of using the automatic control system for acid mist absorption of industrial waste gas of the present invention can make the above-mentioned control system automatically controlled and operated according to the preset method, realize the unified management of the system, and ensure the stability of the standard exhaust gas during the process.

[0007] The automatic control system of the present invention can realize automatic pH control of waste gas, thereby avoiding errors caused by multiple operations, and can monitor, debug and alarm the pH control process of waste gas in the waste gas tower. At the same time, the rate of alkali solution inlet and acid mist flow in the tower is stable, so that the pH value fluctuation range is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To achieve the above and related purposes, one or more aspects of the present invention include features that will be described in detail below and particularly pointed out in the claims. The following description and the accompanying drawings describe certain exemplary aspects of the present invention in detail. These aspects indicate only some ways in which the principles of the present invention can be used. In addition, the present invention is intended to include all these aspects and their equivalents.

[0009] A more complete understanding of the present invention may be obtained by referring to the following description and claims in conjunction with the accompanying drawings. In the accompanying drawings: Figure 1 It is a structural diagram of an automatic control system for acid mist absorption of industrial waste gas of the present invention; Figure 2 It is a control block diagram of an automatic control system for absorbing acid mist of industrial waste gas according to the present invention; Figure 3 The present invention is a flow chart of a method for using an automatic control system for acid mist absorption of industrial waste gas.

[0010] Description of reference numerals: 1. Pressure transmitter; 2. First-stage pH meter; 3. Second-stage pH meter; 4. First liquid level gauge; 5. Second liquid level gauge; 6. Third liquid level gauge; 7. First electric valve; 8. Second electric valve; 9. First regulating valve; 10. Second regulating valve; 11. Fan; 12. First-stage circulation pump; 13. Second-stage circulation pump; 14. First-stage liquid alkali pump; 15. Second-stage liquid alkali pump; 16. Operation panel; 17. Central processing unit. DETAILED DESCRIPTION

[0011] The specific embodiments of the present invention will be described in detail below in conjunction with the above drawings.

[0012] Figure 1 The structure of an automatic control system for acid mist absorption of industrial waste gas of the present invention is shown; in addition, Figure 2 The present invention is a flow chart showing a method for using an automatic control system for acid mist absorption of industrial waste gas.

[0013] like Figure 1 As shown, an automatic control system for acid mist absorption of industrial waste gas of the present invention includes a waste gas tower, a fan, a circulation pump group, a liquid alkali pump, a pressure sensor 1, a pH meter, a liquid level meter, an electric valve, a regulating valve, an operation screen 16, and a central processing unit 17. Among them, The waste gas tower includes a first-stage waste gas tower and a second-stage waste gas tower. The gas outlet pipe of the first-stage waste gas tower is connected with the gas inlet of the second-stage waste gas tower, and the external waste gas enters the gas inlet of the first-stage waste gas tower through the external waste gas main pipe; a first-stage alkaline liquid tank is arranged at the bottom of the first-stage waste gas tower; a second-stage alkaline liquid tank is arranged at the bottom of the second-stage waste gas tower; each alkaline liquid tank is connected with a water adding pipe and an alkali adding pipe, and a spray device is arranged above the waste gas tower; it should be noted that the specific internal structure of the waste gas tower is the existing conventional technology and will not be repeated here.

[0014] The liquid alkali main tank is connected to the first-stage alkaline liquid tank and the second-stage alkaline liquid tank pipelines respectively, and is used to provide the liquid alkali required for neutralizing the acid mist; The fan 11 is a centrifugal fan, connected to the outlet of the second-stage exhaust gas pipeline, and the output end is connected to the discharge tower; the circulation pump group includes a first-stage circulation pump 12 connected to the first-stage alkaline liquid tank, and a second-stage circulation pump 13 connected to the second-stage alkaline liquid tank, and the output ends of the first-stage circulation pump 12 and the second-stage circulation pump 13 are connected to the pipeline outlet of the spray device above the exhaust tower; the liquid alkali pump includes a first-stage liquid alkali pump 14 and a second-stage liquid alkali pump 15 connected to the liquid alkali main tank, the output end of the first-stage alkali liquid pump 14 is connected to the first regulating valve 9, and the output end of the second-stage alkali liquid pump 15 is connected to the second regulating valve 10; the pH meter includes a first-stage pH meter 2, which is arranged at the exhaust gas circulation pipeline outlet above the first-stage exhaust tower, and is used to monitor the pH value of the first-stage exhaust gas; the second-stage pH meter 3 is arranged at the exhaust gas circulation pipeline outlet above the second-stage exhaust tower, and is used to monitor the pH value of the second-stage exhaust gas; the liquid level meter includes a first-stage pH meter 2, which is arranged at the exhaust gas circulation pipeline outlet above the first-stage exhaust tower, and is used to monitor the pH value of the second-stage exhaust gas. The first liquid level meter 4 is arranged on the first-stage alkaline liquid tank to monitor the liquid level of the solution in the tank; the second liquid level meter 5 is arranged on the second-stage alkaline liquid tank to monitor the liquid level of the solution in the tank; the third liquid level meter 6 is arranged on the liquid alkali tank to monitor the height of the remaining solution in the liquid alkali tank; the electric valve includes a first electric valve 7, which is arranged on the first-stage alkaline liquid tank water supply pipeline; the second electric valve 8 is arranged on the second-stage alkaline liquid tank water supply pipeline; the regulating valve includes a first regulating valve 9, which is arranged on the first-stage alkaline liquid tank alkali supply pipeline; the second regulating valve 10 is arranged on the second-stage alkaline liquid tank alkali supply pipeline; the central processing unit 17 is connected with the instrument and the valve, and controls the frequency of the fan through a preset program, thereby controlling the cumulative average amount of waste gas in the waste gas tower to reach a balance, and then controls the regulating valve through the feedback value of the pH meter to balance the amount of liquid alkali entering the alkaline liquid tank. Under the action of the balance of the waste gas amount and the relative balance of the alkaline liquid concentration, the stability of the pH in the waste gas tower is controlled.

[0015] Figure 2The present invention is a control block diagram of an automatic control system for acid mist absorption of industrial waste gas; wherein, the central processing unit 17 uses a single-loop PID control method to adjust the working frequency of the fan 11 to adjust the air intake in the waste gas tower according to the feedback value of the waste gas pipeline pressure transmitter 1, the central processing unit 17 uses a single-loop PID control method to control the opening of the first regulating valve 9 according to the feedback value of the first-stage pH meter 3, and then controls the amount of liquid alkali added, and the central processing unit 17 uses a single-loop PID control method to control the opening of the second regulating valve 10 according to the feedback value of the second-stage pH meter 4, and then controls the amount of liquid alkali added. The central processing unit 17 is a device with logical operation capabilities, program code that can run, and real-time data processing. Devices with the above functions, such as smart phones, portable computers, desktop computers, servers, etc. In the present invention, a desktop computer is used, which has a display for viewing and operation. The central processing unit 17 controls the start and stop of the fan, the circulation pump, and the liquid alkali pump, and at the same time, by setting the pressure and pH value parameters, the amount of waste gas treatment and the amount of liquid alkali added form a dynamic balance. The real-time parameters and changes of the pressure and pH meters during the exhaust gas treatment can be displayed in real time on the central processing unit 17 .

[0016] In the example of the present invention, the pressure transmitter 1 is arranged above the external exhaust gas main pipeline, monitors the pressure of the exhaust gas main pipeline, and is connected to the central processing unit 17. Specific control method: when the fan 11 is started, the pressure data of the pressure transmitter 1 is collected to the central processing unit 17, and the collected pressure data is compared with the preset pressure range of the central processing unit 17. When the pressure data is lower than or exceeds the preset pressure range, the central processing unit 17 sends a control instruction to the frequency converter where the fan 11 is located, and adjusts the pressure of the exhaust gas pipeline by adjusting the operating frequency of the fan 11, so that the real-time pressure data measured by the pressure transmitter 1 meets the preset pressure range, thereby achieving the exhaust gas intake volume we want according to actual production.

[0017] The pH value control method is similar to the pressure control method. When the liquid alkali pump is started, the liquid alkali is added to the alkaline liquid tank of the exhaust tower through the pipeline, but a regulating valve is set on the pipeline path, and the addition of alkali liquid needs to be controlled by the opening of the regulating valve. The opening of the regulating valve is adjusted by the data of the pH meter. The pH meter is connected to the central processing unit 17, and the collected real-time data of the pH value is compared with the pH value preset by the central processing unit 17. When there is a range difference, the central processing unit 17 sends a control instruction to the regulating valve, and controls the amount of liquid alkali added per unit time through the opening of the regulating valve so that the real-time data measured by the pH meter meets the preset pH value range. The pH value control includes a one-stage pH meter and a two-stage pH meter.

[0018] The system also includes a level gauge on each tank, a first level gauge 4 is set at the top of the first-stage alkaline tank, a second level gauge 5 is set at the top of the second-stage alkaline tank, and a third level gauge 6 is set at the top of the total liquid alkali tank. The above-mentioned level gauges are connected to the central processing unit 17, and transmit the real-time data of the height of the solution in each tank to the central processing unit 17, and complete the control of the pump and the electric valve through the internal program. When the real-time liquid level data of the first level gauge 4 is higher than the preset valve closing liquid level of the first electric valve 7, the first electric valve will be closed, otherwise the valve will be opened to add water, when the liquid level data is higher than the preset first-stage circulating pump 12 start liquid level, the first-stage circulating pump 12 will work, otherwise the circulating pump cannot start automatically. When the real-time liquid level data of the second level gauge 5 is higher than the preset valve closing liquid level of the second electric valve 8, the second electric valve 8 will be closed, otherwise the valve will be opened to add water, when the liquid level data is higher than the preset second-stage circulating pump 13 start liquid level, the first-stage circulating pump 13 will work, otherwise the circulating pump cannot start automatically. When the real-time liquid level data of the third liquid level meter 6 is higher than the preset liquid caustic soda pump start-up liquid level, the liquid caustic soda pump 14 and the liquid caustic soda pump 15 will work, otherwise they cannot start automatically. To a certain extent, human operation is avoided, and the system can be operated only by presetting the liquid level parameters of the central processing unit 17.

[0019] According to a further improvement of the present invention, the liquid level gauge is a magnetic flap liquid level gauge, the fan 11 is a centrifugal fan, and an operation screen 16 is also provided at the operation site. The operation screen 16 is connected to the central processing unit 17. The operation screen 16 receives data information on the central processing unit 17, interacts with the central processing unit 17 and displays it on the operation screen 16. According to the above-mentioned present invention, the displayed data includes control signals of the circulation pump, liquid alkali pump, fan, liquid level gauge, pressure transmitter, pH meter and other operation options.

[0020] The automatic control system also has an alarm function. The specific alarm program of the system is set in the central processing unit 17. By displaying a real-time alarm screen on the interface of the operation screen 16, the alarm content mainly includes alarms such as excessive pH value deviation, low liquid level, high liquid level, equipment failure and shutdown, and disconnection of the connecting line. The function is to remind the operator to adjust the process parameters in time to ensure the smooth operation of the production equipment and avoid accidents.

[0021] Specifically, the operation screen 16 is arranged on the site of the automatic control system, and the operator can directly read the required data information through the operation screen 16 and adjust the acid mist absorption automatic control system according to the information.

[0022] Specifically, a parameter alarm program is set on the central processing unit 17, and the central processing unit 17 is set in the central control room. The central control unit 17 detects the acid mist absorption automatic control system. When there is data abnormality, it can be displayed on the display screen of the central processing unit 17 through the parameter alarm program to remind production personnel to deal with the problem in time, thereby improving the efficiency of acid mist treatment and the control accuracy of pH value in the exhaust gas tower.

[0023] Furthermore, the central processing unit 17 is also provided with an interlocking start-stop function of the equipment. The specific measures of the interlocking start-stop function include: the circulating pump is interlocked with the liquid alkali pump and the fan. When the circulating pump fails and stops, the liquid alkali pump and the fan will automatically interlock and stop the pump. In the state of equipment failure, the process parameters of the acid mist absorption automatic control system are guaranteed to remain unchanged to avoid losses. In addition, the first-stage circulating pump 12 is interlocked with the first liquid level gauge 4. When the preset interlocking start liquid level is reached, the first-stage circulating pump 12 will start automatically. When the preset interlocking stop liquid level is reached, the first-stage circulating pump will stop. The second-stage circulating pump 13 is interlocked with the second liquid level gauge 5. When the preset interlocking start liquid level is reached, the second-stage circulating pump 13 will start automatically. When the preset interlocking stop liquid level is reached, the second-stage circulating pump will stop. The first-stage liquid alkali pump 14 and the second-stage alkali liquid pump 15 are interlocked with the third liquid level gauge. When the liquid level is low, an alarm is issued. If there is no increase in the liquid level, the pump will stop automatically after ten minutes.

[0024] The PID control is a logic control program in the central processing unit 17 .

[0025] Next, the automatic control system for absorbing acid mist of industrial waste gas involved in the present invention is further described through specific embodiments.

[0026] In this embodiment, the start and stop control signals of the circulation pump, the liquid alkali pump and the fan, the detection signal of the liquid level meter, the detection signal of the pressure transmitter, the detection signal of the pH meter, the control signal of the electric valve, the control signal of the regulating valve and the feedback signal are connected to the DCS control system (central processing unit 17).

[0027] Among them, a single-loop PID control method is used according to the feedback value of the exhaust gas pipeline pressure transmitter; the exhaust gas pressure can be set as a given value on the touch screen (operation screen 16) on site or the DCS control system in the main control room, and the pressure transmitter is used as the actual measurement. The single-loop PID control is used to adjust the working frequency of the fan through the frequency converter to achieve a relatively stable intake volume of exhaust gas entering the exhaust tower. The PID control parameters can be set on the DCS control system in the main control room.

[0028] Among them, a single-loop PID control method is adopted according to the feedback value of the first-stage pH meter; the given value of the first-stage pH meter can be set on the touch screen (operation screen 16) on site or the DCS control system in the main control room, and the detection value of the pH meter is used as the actual measurement, and the single-loop PID control is used to adjust the opening of the first-stage waste gas tower liquid alkali regulating valve. A single-loop PID control method is adopted according to the feedback value of the second-stage pH meter; the given value of the second-stage pH meter can be set on the touch screen (operation screen 16) on site or the DCS control system in the main control room, and the detection value of the pH meter is used as the actual measurement, and the single-loop PID control is used to adjust the opening of the second-stage waste gas tower liquid alkali regulating valve.

[0029] In addition, the level meter interlock controls the start and stop of the pump. When the liquid level reaches the preset level, the circulation pump, alkali pump and fan start in sequence. The interlock function can be turned on on the touch screen on site or the DCS control system in the main control room.

[0030] The control screen of the touch screen on site can display the value of the pH meter, the real-time liquid level of each tank, the real-time pressure value of the pressure transmitter, the switch status of the electric valve, the opening of the regulating valve and the real-time operating frequency of the frequency converter in real time. It also has important alarm functions, such as alarms for excessive pH value deviation, low liquid level, high liquid level, equipment failure and shutdown, and disconnection of connecting lines.

[0031] The control screen of the DCS control system in the main control room includes all the functions of the above touch screen, as well as PID parameter settings, historical data and trend curves. The interlocking procedures of each pump and fan, and the alarm procedures of system parameters are all in the DCS control system, effectively ensuring the centralized and stable operation of the system.

[0032] The automatic control system for acid mist absorption of industrial waste gas was finally realized, and the amount of liquid alkali added was accurately controlled to stabilize the pH value in the waste gas tower, and the stability of the waste gas intake volume made the system reach dynamic balance. Through the control, alarm and detection of both the site and the main control room, the automatic control system for acid mist absorption of industrial waste gas was stably controlled.

[0033] Figure 3 The invention discloses a process for using an automatic control system for absorbing acid mist of industrial waste gas.

[0034] like Figure 3 As shown, a method for using an automatic control system for acid mist absorption of industrial waste gas is provided, which is implemented using the automatic control system as described above, and includes the following steps: S1. When the waste gas enters the tower, the first-stage circulation pump and the second-stage circulation pump are started according to the preset program in the central processing unit, so that the alkaline liquid is sprayed through the spray device to neutralize the acid mist in the tower. The waste gas first passes through the first-stage waste gas tower and then the second-stage waste gas tower. Through multi-stage waste gas treatment, the waste gas emission standards can be better guaranteed; S2. The pH meter is used to monitor the pH value of the actual gas in the exhaust tower, and the liquid level meter is used to monitor the height of the residual solution in each tank. The specific monitoring data of the pH meter and the liquid level meter are uploaded to the central processing unit; S3. The central processing unit sets the frequency of the relatively suitable pressure regulating fan according to the amount of waste gas generated by external production to adjust the amount of waste gas entering the waste gas tower. The central control unit adjusts the opening of the liquid alkali pipeline regulating valve according to the pH value of the pH meter to ensure that the waste gas can be neutralized to the greatest extent in the tower, and reasonably controls the amount of liquid alkali added to achieve dynamic balance; S4. The central processing unit controls the start and stop of the first-stage circulation pump and the switching action of the first electric valve according to the solution height of the first-stage alkaline liquid tank. The central processing unit controls the start and stop of the second-stage circulation pump and the switching action of the second electric valve according to the solution height of the second-stage alkaline liquid tank. The central processing unit controls the start and stop of the liquid alkali delivery pump according to the liquid level of the liquid alkali main tank. The circulation pump is interlocked with the liquid alkali pump and the fan. When the circulation pump stops due to a fault, the liquid alkali pump and the fan will automatically interlock and stop the pump.

[0035] S5. When the pH in the exhaust tower reaches the emission standard, the gas will be transported by the fan into the emission tower for emission; Furthermore, the central processing unit uses a single-loop PID control method to adjust the operating frequency of the fan according to the feedback value of the exhaust gas pipeline pressure transmitter to adjust the air intake volume in the exhaust gas tower.

[0036] Furthermore, the central processing unit adopts a single-loop PID control method to control the opening of the regulating valve according to the feedback value of the pH meter in the first stage, thereby controlling the amount of liquid alkali added.

[0037] The system is implemented and controlled according to the above scheme, wherein the pH value reaches a dynamic balance in the above control and is always kept within the preset pH range of the central processing unit, thereby achieving stable absorption of waste gas. According to the above implementation case, the automatic control system for absorbing acid mist of industrial waste gas and the method for using the same have the following advantages: (1) Easy to operate, with the central processing unit as the control basis, and an operation screen is set up on site, which can observe dynamic changes and control remotely or locally; (2) Precise control: the feedback value of the pressure transmitter adopts a single-loop PID control method, and the feedback value of the pH meter adopts a single-loop PID control method, so that the amount of waste gas absorbed and the amount of alkali solution added reach a dynamic balance; (3) Real-time alarm at two locations: a centralized alarm is set up in the central processing unit of the main control room, and a local alarm function is set up on the control screen on site to ensure production safety; In the description of this specification, reference may be made to other descriptions such as "one embodiment", "example" or "some examples", which means that the specific structure, materials, control process and other features of the embodiment or example are included in the embodiment or example of the present invention. Figure 1 and Figure 2 An automatic control system for absorbing acid mist of industrial waste gas according to the present invention is described in a graphical example.

[0038] The above is a specific description and specific implementation method of the present invention, but it should be understood by those skilled in the art that the above-described automatic control system for acid mist absorption of industrial waste gas and its use method of the present invention can be changed within the scope of the claims and combined with the prior art, or more improvements can be made without departing from the content of the present invention. The embodiments disclosed in the specification are only characteristic embodiments and not all methods. In summary, the scope of protection of the present invention should be determined by the specific content of the attached claims.

Claims

1. An automatic control system for acid mist absorption of industrial waste gas, comprising: The exhaust tower includes a first-stage exhaust tower and a second-stage exhaust tower. The gas outlet pipe of the first-stage exhaust tower is connected with the gas inlet of the second-stage exhaust tower. A first-stage alkaline liquid tank is arranged at the bottom of the first-stage exhaust tower; a second-stage alkaline liquid tank is arranged at the bottom of the second-stage exhaust tower; and a spray device is arranged above the exhaust tower; A fan (11) is connected to the outlet of the second-stage exhaust tower pipeline, and the output end is connected to the exhaust tower; A circulation pump group comprises a first-stage circulation pump (12) connected to the first-stage alkaline liquid tank and a second-stage circulation pump (13) connected to the second-stage alkaline liquid tank, wherein the output ends of the first-stage circulation pump (12) and the second-stage circulation pump (13) are respectively connected to the pipe openings of the spray device above the exhaust tower; A liquid alkali pump, comprising a first-stage liquid alkali pump (14) and a second-stage liquid alkali pump (15) connected to the liquid alkali main tank, wherein the output end of the first-stage alkali liquid pump (14) is connected to a first regulating valve (9), and the output end of the second-stage alkali liquid pump (15) is connected to a second regulating valve (10); A pressure transmitter (1) is arranged above the external exhaust gas main pipeline to monitor the pressure of the exhaust gas main pipeline; The pH meter comprises a first-stage pH meter (2) and a second-stage pH meter (3), wherein the first-stage pH meter (2) is arranged at the outlet of the exhaust gas flow pipe above the first-stage exhaust gas tower, and is used to monitor the pH value of the first-stage exhaust gas; the second-stage pH meter (3) is arranged at the outlet of the exhaust gas flow pipe above the second-stage exhaust gas tower, and is used to monitor the pH value of the second-stage exhaust gas; A first regulating valve (9) is arranged in the alkali adding pipeline of the first-stage alkaline liquid tank; A second regulating valve (10) is arranged in the alkali adding pipeline of the second-stage alkaline liquid tank; The central processing unit (17) is electrically connected to the fan (11), the circulation pump, the caustic soda pump, the pressure transmitter (1), the pH meter, the liquid level meter, the electric valve, and the regulating valve.

2. The automatic control system for acid mist absorption of industrial waste gas according to claim 1, characterized in that: Also includes: A liquid level meter, provided on each of the tanks to monitor the liquid level value of each of the tanks, comprises: A first liquid level meter (4) is arranged on the first-stage alkaline liquid tank to monitor the liquid level of the solution in the tank; A second liquid level meter (5) is arranged on the second-stage alkaline liquid tank to monitor the liquid level of the solution in the tank; The third liquid level meter (6) is arranged on the liquid caustic soda main tank and is used to monitor the height of the remaining solution in the liquid caustic soda main tank.

3. The automatic control system for acid mist absorption of industrial waste gas according to claim 1, characterized in that: Also includes: The electric valve is arranged in the water supply pipeline of the alkaline liquid tank; wherein, A first electric valve (7) is arranged in a water supply pipeline of a first-stage alkaline liquid tank; The second electric valve (8) is arranged on the water supply pipeline of the second-stage alkaline liquid tank.

4. The automatic control system for acid mist absorption of industrial waste gas according to claim 1, characterized in that: The fan is a centrifugal fan; the liquid level gauge is a magnetic flap liquid level gauge.

5. The automatic control system for acid mist absorption of industrial waste gas as claimed in claim 1, characterized in that: A parameter alarm program is arranged in the central processing unit.

6. The automatic control system for acid mist absorption of industrial waste gas according to claim 1, characterized in that: A group interlocking start and stop is arranged in the central processing unit.

7. A method for using an automatic control system for absorbing acid mist of industrial waste gas, which is implemented by using an automatic control system for absorbing acid mist of industrial waste gas as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. When the waste gas enters the waste gas tower, the first-stage circulation pump (12) and the second-stage circulation pump (13) are started according to the preset program in the central processing unit (17), so that the alkaline liquid is sprayed through the spray device, thereby neutralizing the acid mist in the tower; the waste gas first passes through the first-stage waste gas tower and then passes through the second-stage waste gas tower. The waste gas emission standard can be better guaranteed through multi-stage waste gas treatment; S2, the specific monitoring data of the pH meter and the liquid level meter are uploaded to the central processing unit (17), the pH meter is used to monitor the pH value of the actual gas in the exhaust tower, and the liquid level meter is used to monitor the height of the residual solution in each tank; S3, the central processing unit (17) sets a relatively suitable frequency of the pressure regulating fan (11) according to the amount of waste gas generated by external production to adjust the amount of waste gas entering the waste gas tower, and the central control unit (17) can also adjust the opening of the liquid alkali pipeline regulating valve according to the pH value of the pH meter to ensure that the waste gas can be neutralized to the greatest extent in the waste gas tower, and reasonably control the amount of liquid alkali added; S4, the central processing unit (17) controls the start and stop of the first-stage circulation pump (12) and the switch action of the first electric valve (7) according to the solution height of the first-stage alkaline liquid tank, the central processing unit (17) controls the start and stop of the second-stage circulation pump (13) and the switch action of the second electric valve (8) according to the solution height of the second-stage alkaline liquid tank, and the central processing unit (17) controls the start and stop of the liquid alkali delivery pump according to the liquid level of the liquid alkali main tank; S5. When the pH in the exhaust tower reaches the emission standard, the gas will be transported by the fan (11) into the emission tower for emission.

8. The method for using the automatic control system for acid mist absorption of industrial waste gas as claimed in claim 7, characterized in that: The central processing unit (17) uses a single-loop PID control to adjust the operating frequency of the fan (11) according to the feedback value of the pressure transmitter (1), thereby adjusting the average air intake rate of the acid mist; The central processing unit (17) uses a single-loop PID control to adjust the opening of the regulating valve according to the feedback value of the pH meter, thereby adjusting the amount of liquid alkali added; wherein the first-stage pH meter (2) is used to adjust the opening of the first regulating valve (9); and the second-stage pH meter (3) is used to adjust the opening of the second regulating valve (10).

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