Corrosive medium quantitative conveying pipe

Abstract

The utility model discloses a corrosive medium quantitative conveying pipe, belongs to the technical field of corrosive medium conveying, and solves the problems that a corrosive medium is directly sucked through a water pump during conveying, and the flow of the corrosive medium cannot be controlled when the corrosive medium is sucked through the water pump. Comprising a liquid storage tank, a breathing connector communicated with the liquid storage tank and used for being communicated with a breathing valve, and a nitrogen discharge valve communicated with the liquid storage tank. When the device works, the air pump enables nitrogen in the nitrogen cylinder to enter the liquid storage tank through the first nitrogen supply pipeline and then push a corrosive medium to flow and prevent retention through the second nitrogen supply pipeline and the liquid outlet pipeline. When the air pressure of the liquid storage tank is too large, the nitrogen release valve releases pressure, and the breathing connector is connected with the breathing valve to adjust air pressure. After entering the liquid outlet pipe, the corrosive medium is driven by the water pump to flow, and nitrogen in the second nitrogen supply pipeline is pressurized to make the medium flow smoothly. In the process, the first pressure sensor and the second pressure sensor measure the liquid pressure, the adjusting circuit transmits signals to the three pneumatic adjusting valves to control the opening degree, and it is ensured that the corrosive medium leaves quantitatively through triple control.

Description

Technical Field

[0001] This utility model relates to the field of corrosive medium transportation technology, and in particular to a quantitative transportation pipe for corrosive media. Background Technology

[0002] Corrosive media transportation refers to the process of transporting corrosive substances from one place to another. Common corrosive media include acids, alkalis, and salt solutions. Specialized corrosion-resistant containers, such as stainless steel tanks and glass-lined containers, must be used during transportation to ensure that the medium will not damage the container and to prevent leaks. At the same time, relevant safety regulations must be strictly followed, such as controlling transportation temperature and pressure, and preventing reactions with other substances. Transportation personnel must also possess professional knowledge and emergency response capabilities to deal with possible emergencies, ensure the safety and reliability of the transportation process, and minimize damage to the environment and equipment.

[0003] When transporting corrosive media, it is often necessary to control the flow rate. However, during transportation, the corrosive media is directly drawn in by a water pump, and the flow rate cannot be controlled by the water pump.

[0004] Therefore, a quantitative transport pipe for corrosive media is proposed to solve or alleviate the above problems. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a quantitative transport pipe for corrosive media.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A quantitative transport pipe for corrosive media includes a storage tank, a breather port connected to the storage tank for connecting to a breather valve, a nitrogen release valve connected to the storage tank, a first nitrogen supply line connected to the storage tank and capable of being switched on and off, a liquid outlet line connected to the bottom of the storage tank, a second nitrogen supply line connected to the liquid outlet line and capable of being switched on and off, and a gas pump connected to an external nitrogen cylinder.

[0008] The air outlet of the air pump is connected to the first nitrogen supply pipeline and the second nitrogen supply pipeline respectively. The liquid outlet pipeline includes a liquid outlet pipe connected to the bottom of the liquid storage tank, a water pump connected to the liquid outlet pipe, a first pneumatic regulating valve, a second pneumatic regulating valve, and a third pneumatic regulating valve. A first pressure sensor and a second pressure sensor are installed on the liquid outlet pipe to collect the pressure therein. A regulating circuit is coupled between the first pressure sensor and the first pneumatic regulating valve, the second pneumatic regulating valve, and between the second pressure sensor and the third pneumatic regulating valve.

[0009] Preferably, the first nitrogen supply pipeline includes a first gas supply pipe connecting the gas pump and the gas storage tank, a nitrogen supply valve connected to the first gas supply pipe, and a first gas source ball valve connected to the first gas supply pipe.

[0010] Preferably, the second nitrogen supply pipeline includes a second gas supply pipe connecting the gas pump and the liquid outlet pipe, a second gas source ball valve connected to the second gas supply pipe, and a gas check valve.

[0011] Preferably, the outlet pipe is connected to a manual ball valve, a liquid check valve, a self-regulating valve, and a flow sensor.

[0012] Preferably, the adjustment circuit includes a 5V reference voltage generation circuit, a 2.5V bias voltage generation circuit, a setpoint adjustment circuit, a proportional operational amplifier circuit, and a voltage-to-current conversion circuit.

[0013] The input terminal of the 5V reference voltage generation circuit is powered on. The output terminal of the 5V reference voltage generation circuit is connected to the input terminals of the 2.5V bias voltage generation circuit and the setpoint adjustment circuit. The output terminal of the 2.5V bias voltage generation circuit is connected to the bias input terminal of the proportional operational amplifier circuit and the voltage-to-current conversion circuit. The signal output terminal of the setpoint adjustment circuit is connected to the setpoint input terminal of the proportional operational amplifier circuit. The detection signal input terminal of the proportional operational amplifier circuit receives the pressure signal. The control signal output terminal of the proportional operational amplifier circuit is connected to the voltage signal input terminal of the voltage-to-current conversion circuit. The current output terminal of the voltage-to-current conversion circuit is used to output the control signal of the pneumatic regulating valve.

[0014] Preferably, the 5V reference voltage generation circuit includes a first resistor and a first Zener diode. One end of the first resistor is connected to a 24V power supply, and the other end of the first resistor is connected to the cathode of the first Zener diode. The anode of the first Zener diode is grounded.

[0015] Preferably, the 2.5V bias voltage generation circuit includes a second resistor and a third resistor. One end of the second resistor is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit, and the other end of the second resistor is connected to one end of the third resistor. The other end of the third resistor is grounded, and the connection point between the second resistor and the third resistor is set as the bias output point.

[0016] Preferably, the setpoint adjustment circuit includes a potentiometer, the first fixed terminal of which is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit, the second fixed terminal of which is grounded, and the sliding terminal of which is connected to the setpoint input terminal of the proportional operational amplifier circuit.

[0017] Preferably, the proportional operational amplifier circuit includes an LM358 operational amplifier and a gain adjustment potentiometer. The first inverting input terminal of the LM358 operational amplifier is used to receive a pressure signal. The first non-inverting input terminal of the LM358 operational amplifier is connected to the sliding terminal of the potentiometer in the setpoint adjustment circuit through a fourth resistor. The first non-inverting input terminal of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit through a fifth resistor. The first output terminal of the LM358 operational amplifier is connected to the first inverting input terminal of the LM358 operational amplifier through the first fixed terminal of the gain adjustment potentiometer. The second fixed terminal of the gain adjustment potentiometer is connected to the first output terminal of the LM358 operational amplifier through a sixth resistor. The sliding terminal of the gain adjustment potentiometer is connected to the first output terminal of the LM358 operational amplifier. The first output terminal of the LM358 operational amplifier is connected to the voltage-to-current conversion circuit through a seventh resistor. The power supply terminal of the LM358 operational amplifier is connected to a 24V power supply.

[0018] Preferably, the voltage-to-current conversion circuit includes a transistor, the first output terminal of the LM358 operational amplifier is connected to the second inverting input terminal of the LM358 operational amplifier through a seventh resistor, the second non-inverting input terminal of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit through an eighth resistor, and also includes a ninth resistor, the second non-inverting input terminal of the LM358 operational amplifier is coupled to one end of the ninth resistor, and this end of the ninth resistor is connected to the emitter of the transistor, the other end of the ninth resistor is grounded, the second output terminal of the LM358 operational amplifier is connected to the base of the transistor, and the collector of the transistor is connected to the positive terminal of the first pneumatic regulating valve or the second pneumatic regulating valve.

[0019] This utility model has the following beneficial effects:

[0020] In operation, this invention uses an air pump to supply nitrogen from the nitrogen cylinder into the storage tank via the first nitrogen supply line, and then into the outlet pipe via the second nitrogen supply line, promoting the smooth flow of the corrosive medium and preventing its stagnation. When the pressure in the storage tank is too high, the nitrogen release valve releases pressure, and the breather valve connected to the breather interface adjusts the pressure. After the corrosive medium enters the outlet pipe, the water pump drives its flow, and the nitrogen in the second nitrogen supply line is pressurized again, making the medium flow even smoother. During this process, the first and second pressure sensors measure the liquid pressure, and the regulating circuit transmits the signal to three pneumatic regulating valves to control their opening. Through this triple control, the corrosive medium is ensured to be released in a measured quantity. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of this utility model;

[0023] Figure 2 This is a structural block diagram of the adjustment circuit in this utility model.

[0024] In the diagram: 1. Liquid storage tank; 2. Breathing interface; 3. Nitrogen release valve; 4. Nitrogen supply valve; 5. First air supply pipe; 6. First air source ball valve; 7. Air pump; 8. Liquid outlet pipe; 9. Manual ball valve; 10. Water pump; 11. Liquid check valve; 12. First pneumatic regulating valve; 13. Self-regulating regulating valve; 14. Second air supply pipe; 15. Second air source ball valve; 16. Gas check valve; 17. First pressure sensor; 18. Flow sensor; 19. Second pneumatic regulating valve; 20. Second pressure sensor; 21. Third pneumatic regulating valve; 22. 5V reference voltage generation circuit; 23. 2.5V bias voltage generation circuit; 24. Setpoint adjustment circuit; 25. Proportional operational amplifier circuit; 26. Voltage-to-current conversion circuit. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0028] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0029] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0030] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] A quantitative transport pipe for corrosive media, such as Figure 1 As shown, it includes a storage tank 1, a breathing interface 2 connected to the storage tank 1 for connecting to a breathing valve, a nitrogen release valve 3 connected to the storage tank 1, a first nitrogen supply pipeline connected to the storage tank 1 and capable of being switched on and off, an outlet pipe 8 connected to the bottom of the storage tank 1, a second nitrogen supply pipeline connected to the outlet pipe 8 and capable of being switched on and off, and a gas pump 7 connected to an external nitrogen cylinder.

[0032] The air outlet of the air pump 7 is connected to the first nitrogen supply line and the second nitrogen supply line respectively. The liquid outlet pipe 8 includes a liquid outlet pipe 8 connected to the bottom of the liquid storage tank 1, a water pump 10 connected to the liquid outlet pipe 8, a first pneumatic regulating valve 12, a second pneumatic regulating valve 19, and a third pneumatic regulating valve 21. A first pressure sensor 17 and a second pressure sensor 20 are installed on the liquid outlet pipe 8 to collect the pressure therein. The first pressure sensor 17 is connected to the first pneumatic regulating valve 12 and the second pneumatic regulating valve 19, and the second pressure sensor 20 is connected to the third pneumatic regulating valve 21. A regulating circuit is coupled between the pneumatic regulating valves 21. The first nitrogen supply pipeline includes a first gas supply pipe 5 connecting the gas pump 7 and the gas storage tank, a nitrogen supply valve 4 connected to the first gas supply pipe 5, and a first gas source ball valve 6 connected to the first gas supply pipe 5. The second nitrogen supply pipeline includes a second gas supply pipe 14 connecting the gas pump 7 and the liquid outlet pipe 8, a second gas source ball valve 15 connected to the second gas supply pipe 14, and a gas check valve 16. The liquid outlet pipe 8 is connected to a manual ball valve 9, a liquid check valve 11, a self-regulating regulating valve 13, and a flow sensor 18.

[0033] like Figure 2 As shown, the adjustment circuit includes a 5V reference voltage generation circuit 22, a 2.5V bias voltage generation circuit 23, a setpoint adjustment circuit 24, a proportional operational amplifier circuit 25, and a voltage-to-current conversion circuit 26.

[0034] The input terminal of the 5V reference voltage generation circuit 22 is powered on. The output terminal of the 5V reference voltage generation circuit 22 is connected to the input terminals of the 2.5V bias voltage generation circuit 23 and the setpoint adjustment circuit 24. The output terminal of the 2.5V bias voltage generation circuit 23 is connected to the bias input terminals of the proportional operational amplifier circuit 25 and the voltage-to-current conversion circuit 26. The signal output terminal of the setpoint adjustment circuit 24 is connected to the setpoint input terminal of the proportional operational amplifier circuit 25. The detection signal input terminal of the proportional operational amplifier circuit 25 receives the pressure signal. The control signal output terminal of the proportional operational amplifier circuit 25 is connected to the voltage signal input terminal of the voltage-to-current conversion circuit 26. The current output terminal of the voltage-to-current conversion circuit 26 is used to output the control signal of the pneumatic regulating valve.

[0035] The 5V reference voltage generation circuit 22 includes a first resistor and a first Zener diode. One end of the first resistor is connected to a 24V power supply, and the other end of the first resistor is connected to the cathode of the first Zener diode. The anode of the first Zener diode is grounded.

[0036] The 2.5V bias voltage generation circuit 23 includes a second resistor and a third resistor. One end of the second resistor is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit 22, and the other end of the second resistor is connected to one end of the third resistor. The other end of the third resistor is grounded, and the connection point between the second resistor and the third resistor is set as the bias output point.

[0037] The setpoint adjustment circuit 24 includes a potentiometer. The first fixed terminal of the potentiometer is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit 22. The second fixed terminal of the potentiometer is grounded. The sliding terminal of the potentiometer is connected to the setpoint input terminal of the proportional operational amplifier circuit 25.

[0038] The proportional operational amplifier circuit 25 includes an LM358 operational amplifier and a gain adjustment potentiometer. The first inverting input of the LM358 operational amplifier is used to receive the pressure signal. The first non-inverting input of the LM358 operational amplifier is connected to the sliding terminal of the potentiometer in the set point adjustment circuit 24 through a fourth resistor. The first non-inverting input of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit 23 through a fifth resistor. The first output of the LM358 operational amplifier is connected to the first inverting input of the LM358 operational amplifier through the first fixed terminal of the gain adjustment potentiometer. The second fixed terminal of the gain adjustment potentiometer is connected to the first output of the LM358 operational amplifier through a sixth resistor. The sliding terminal of the gain adjustment potentiometer is connected to the first output of the LM358 operational amplifier. The first output of the LM358 operational amplifier is connected to the voltage-to-current conversion circuit 26 through a seventh resistor. The power supply terminal of the LM358 operational amplifier is connected to a 24V power supply.

[0039] The voltage-to-current conversion circuit 26 includes a transistor. The first output terminal of the LM358 operational amplifier is connected to the second inverting input terminal of the LM358 operational amplifier through a seventh resistor. The second non-inverting input terminal of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit 23 through an eighth resistor. It also includes a ninth resistor. The second non-inverting input terminal of the LM358 operational amplifier is coupled to one end of the ninth resistor, and this end of the ninth resistor is connected to the emitter of the transistor. The other end of the ninth resistor is grounded. The second output terminal of the LM358 operational amplifier is connected to the base of the transistor. The collector of the transistor is connected to the positive terminal of the first pneumatic regulating valve 12 or the second pneumatic regulating valve 19.

[0040] In actual operation, this utility model can operate through the air pump 7, allowing nitrogen from the nitrogen cylinder to enter the first nitrogen supply line and then the liquid storage tank 1, and through the second nitrogen supply line and then the liquid outlet pipe 8, thereby guiding the corrosive medium to flow smoothly and avoiding the stagnation of the corrosive medium. When the gas pressure in the liquid storage tank 1 is too high, the pressure can be released through the nitrogen release valve 3, and the breathing port 2 is connected to the breathing valve to regulate the gas pressure in the liquid storage tank 1.

[0041] When the corrosive medium enters the outlet pipe 8, the water pump 10 drives the medium to flow. Nitrogen gas entering the outlet pipe 8 through the second nitrogen supply line further pressurizes the corrosive medium, making its flow in the outlet pipe 8 smoother and less prone to stagnation. In order to control the flow rate of the corrosive medium relatively accurately, the first pressure sensor 17 and the second pressure sensor 20 detect the liquid pressure. The signal is transmitted to the first pneumatic regulating valve 12, the second pneumatic regulating valve 19, and the third pneumatic regulating valve 21 through the regulating circuit, so that the three valves can control the opening of the channel. Through the setting of three checkpoints, the corrosive medium can be controlled multiple times to ensure that the final departing corrosive medium is quantitatively released.

[0042] When the regulating circuit is actually working...

[0043] The first pressure sensor 17 and the second pressure sensor 20 detect the fluid pressure in the liquid pipe 8 in real time and convert it into a linear voltage signal of 0-5V.

[0044] The sensor signal is input to the first inverting input of the operational amplifier. At the same time, the 5V stable reference voltage generated by the first Zener diode and the first resistor is divided by the potentiometer to generate the target pressure value voltage set by the user. This set voltage is input to the first non-inverting input of the LM358 operational amplifier through the fourth resistor.

[0045] In the proportional operational amplifier circuit 25, the LM358 operational amplifier differentially amplifies the sensor signal and the set value. Its first non-inverting input terminal also receives a 2.5V bias voltage generated by the voltage division of the second and third resistors, while the first inverting input terminal of the LM358 operational amplifier forms a negative feedback network through the sixth resistor and the gain adjustment potentiometer.

[0046] When the actual pressure increases, the voltage at the first output terminal of the LM358 operational amplifier will be lower than the 2.5V reference value, and the deviation will be amplified by the gain factor set by the gain adjustment potentiometer.

[0047] Conversely, when the pressure is insufficient, the voltage signal increases. This voltage signal is transmitted to the second inverting input of the LM358 operational amplifier through the seventh resistor. The second non-inverting input of the LM358 operational amplifier simultaneously receives a 2.5V bias voltage and a feedback signal from the ninth current sensing resistor. The LM358 operational amplifier drives its output by comparing the voltage difference between its second non-inverting input and its second inverting input.

[0048] When the voltage signal decreases, the output voltage at the second output terminal of the LM358 operational amplifier increases, causing the base current of the transistor to increase. The transistor then increases its conduction level, resulting in an increase in its collector output current. This current flows through the coils of the first pneumatic regulating valve 12, the second pneumatic regulating valve 19, and the third pneumatic regulating valve 21, forming a feedback voltage across the ninth sensing resistor. This feedback voltage acts in real-time on the second non-inverting input terminal of the LM358 operational amplifier, forming a closed-loop control.

[0049] Finally, when the pressure in the outlet pipe 8 equals the set value, the voltage signal stabilizes at 2.5V. At this time, the transistor outputs a 12mA current to keep the valve open at 50%. If the pressure rises abnormally, the output current drops to the range of 4-12mA to close the valve. If the pressure is insufficient, a 12-20mA current is output to open the valve, thereby realizing closed-loop pressure regulation of the fully analog hardware.

[0050] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A quantitative transport pipe for corrosive media, characterized in that, It includes a storage tank (1), a breathing port (2) connected to the storage tank (1) for connecting to the breathing valve, a nitrogen release valve (3) connected to the storage tank (1), a first nitrogen supply pipeline connected to the storage tank (1) and capable of being switched on and off, an outlet pipe (8) connected to the bottom of the storage tank (1), a second nitrogen supply pipeline connected to the outlet pipe (8) and capable of being switched on and off, and a gas pump (7) connected to an external nitrogen cylinder; The outlet of the air pump (7) is connected to the first nitrogen supply pipeline and the second nitrogen supply pipeline respectively. The liquid outlet pipeline (8) includes a liquid outlet pipeline (8) connected to the bottom of the liquid storage tank (1), a water pump (10) connected to the liquid outlet pipeline (8), a first pneumatic regulating valve (12), a second pneumatic regulating valve (19), and a third pneumatic regulating valve (21). The liquid outlet pipeline (8) is equipped with a first pressure sensor (17) and a second pressure sensor (20) for collecting the pressure therein. The first pressure sensor (17) is coupled to the first pneumatic regulating valve (12) and the second pneumatic regulating valve (19), and the second pressure sensor (20) is coupled to the third pneumatic regulating valve (21) with a regulating circuit.

2. The corrosive medium quantitative transport pipe according to claim 1, characterized in that, The first nitrogen supply pipeline includes a first gas supply pipe (5) connecting the gas pump (7) and the gas storage tank, a nitrogen supply valve (4) connected to the first gas supply pipe (5), and a first gas source ball valve (6) connected to the first gas supply pipe (5).

3. The corrosive medium quantitative transport pipe according to claim 2, characterized in that, The second nitrogen supply pipeline includes a second gas supply pipe (14) connecting the gas pump (7) and the liquid outlet pipe (8), a second gas source ball valve (15) connected to the second gas supply pipe (14), and a gas check valve (16).

4. The corrosive medium quantitative transport pipe according to claim 1, characterized in that, The outlet pipe (8) is connected to a manual ball valve (9), a liquid check valve (11), a self-regulating valve (13), and a flow sensor (18).

5. A quantitative transport pipe for corrosive media according to claim 1, characterized in that, The adjustment circuit includes a 5V reference voltage generation circuit (22), a 2.5V bias voltage generation circuit (23), a setpoint adjustment circuit (24), a proportional operational amplifier circuit (25), and a voltage-to-current conversion circuit (26). The input terminal of the 5V reference voltage generation circuit (22) is powered on. The output terminal of the 5V reference voltage generation circuit (22) is connected to the input terminals of the 2.5V bias voltage generation circuit (23) and the setpoint adjustment circuit (24). The output terminal of the 2.5V bias voltage generation circuit (23) is connected to the bias input terminals of the proportional operational amplifier circuit (25) and the voltage-to-current conversion circuit (26). The signal output terminal of the setpoint adjustment circuit (24) is connected to the set value input terminal of the proportional operational amplifier circuit (25). The detection signal input terminal of the proportional operational amplifier circuit (25) receives the pressure signal. The control signal output terminal of the proportional operational amplifier circuit (25) is connected to the voltage signal input terminal of the voltage-to-current conversion circuit (26). The current output terminal of the voltage-to-current conversion circuit (26) is used to output the control signal of the pneumatic regulating valve.

6. A quantitative transport pipe for corrosive media according to claim 5, characterized in that, The 5V reference voltage generation circuit (22) includes a first resistor and a first Zener diode. One end of the first resistor is connected to a 24V power supply, and the other end of the first resistor is connected to the cathode of the first Zener diode. The anode of the first Zener diode is grounded.

7. A quantitative transport pipe for corrosive media according to claim 5, characterized in that, The 2.5V bias voltage generation circuit (23) includes a second resistor and a third resistor. One end of the second resistor is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit (22). The other end of the second resistor is connected to one end of the third resistor. The other end of the third resistor is grounded. The connection point between the second resistor and the third resistor is set as the bias output point.

8. A quantitative transport pipe for corrosive media according to claim 5, characterized in that, The setpoint adjustment circuit (24) includes a potentiometer. The first fixed terminal of the potentiometer is connected to the cathode of the first Zener diode in the 5V reference voltage generation circuit (22). The second fixed terminal of the potentiometer is grounded. The sliding terminal of the potentiometer is connected to the setpoint input terminal of the proportional operational amplifier circuit (25).

9. A quantitative transport pipe for corrosive media according to claim 5, characterized in that, The proportional operational amplifier circuit (25) includes an LM358 operational amplifier and a gain adjustment potentiometer. The first inverting input terminal of the LM358 operational amplifier is used to receive the pressure signal. The first non-inverting input terminal of the LM358 operational amplifier is connected to the sliding terminal of the potentiometer in the set point adjustment circuit (24) through a fourth resistor. The first non-inverting input terminal of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit (23) through a fifth resistor. The first output terminal of the LM358 operational amplifier is connected to the first inverting input terminal of the LM358 operational amplifier through the first fixed terminal of the gain adjustment potentiometer. The second fixed terminal of the gain adjustment potentiometer is connected to the first output terminal of the LM358 operational amplifier through a sixth resistor. The sliding terminal of the gain adjustment potentiometer is connected to the first output terminal of the LM358 operational amplifier. The first output terminal of the LM358 operational amplifier is connected to the voltage-to-current conversion circuit (26) through a seventh resistor. The power terminal of the LM358 operational amplifier is connected to a 24V power supply.

10. A quantitative transport pipe for corrosive media according to claim 9, characterized in that, The voltage-to-current conversion circuit (26) includes a transistor. The first output terminal of the LM358 operational amplifier is connected to the second inverting input terminal of the LM358 operational amplifier through a seventh resistor. The second non-inverting input terminal of the LM358 operational amplifier is connected to the bias output point in the 2.5V bias voltage generation circuit (23) through an eighth resistor. The circuit also includes a ninth resistor. The second non-inverting input terminal of the LM358 operational amplifier is coupled to one end of the ninth resistor, and this end of the ninth resistor is connected to the emitter of the transistor. The other end of the ninth resistor is grounded. The second output terminal of the LM358 operational amplifier is connected to the base of the transistor. The collector of the transistor is connected to the positive terminal of the first pneumatic regulating valve (12) or the second pneumatic regulating valve (19).

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