A device for absorbing hydrogen chloride tail gas at hydrochloric acid tank loading sites

Abstract

This utility model discloses a hydrogen chloride tail gas absorption device for hydrochloric acid tank loading, relating to the field of hydrochloric acid absorption process technology. It includes an absorption tower, with a water inlet connected to a water supply pipe and an exhaust fan connected to the air inlet. The exhaust fan inlet is connected to a hydrogen chloride tail gas pipeline. The device also includes an online hydrogen chloride concentration meter, a remote-reading magnetic level gauge, a first pneumatic regulating valve, a rotor flow meter, a liquid-phase circulation pump, and a second pneumatic regulating valve. This utility model, by installing an online hydrogen chloride concentration meter on the absorption tower, can capture real-time changes in the hydrogen chloride concentration in the solution within the tower, avoiding insufficient absorption or excessive circulation. Relying on the interlocking design of the remote-reading magnetic level gauge and the "first pneumatic regulating valve + rotor flow meter" on the water supply pipe of the absorption tower, it achieves automated level control, eliminating manual adjustment errors. A pressure transmitter senses the inlet pressure in real time and coordinates the operation of the exhaust fan.

Description

Technical Field

[0001] This utility model relates to the field of hydrochloric acid absorption process technology, specifically to a device for absorbing hydrogen chloride tail gas from hydrochloric acid tank loading. Background Technology

[0002] Hydrochloric acid, an important chemical raw material, releases hydrogen chloride fumes during the loading and sale of automobiles. If these fumes are emitted directly without effective treatment, they will not only pollute the atmosphere and increase the risk of acid rain, but also worsen the working environment and threaten the personal safety of operators.

[0003] In the prior art, such as the exhaust gas absorption system for hydrochloric acid loading process disclosed in the utility model patent with authorization announcement number CN223417005U, the exhaust gas is drawn into the absorption tower with filter element by the exhaust fan, and the absorption liquid is circulated and absorbed by the absorption liquid transfer pump. This improves the exhaust gas absorption effect and realizes hydrochloric acid recovery to a certain extent. However, there is still room for optimization in this type of system. It mainly relies on the filter element to slow down the water speed to promote gas-liquid contact, and lacks a real-time monitoring and precise control mechanism for key parameters in the absorption process.

[0004] Specifically, existing systems cannot monitor changes in hydrogen chloride concentration within the absorption tower in real time, making it difficult to dynamically adjust the circulation or collection process based on the concentration. This can lead to insufficient absorption or excessive circulation, resulting in energy waste. Furthermore, the lack of automated control over the absorption tower's liquid level necessitates manual monitoring via sight glasses and valve operation for water replenishment. This results in low adjustment accuracy and delayed response, impacting the stability of absorption efficiency. Additionally, the lack of real-time monitoring of the pressure of the exhaust gas entering the absorption system prevents timely detection of changes in the intake load and adjustment of the fan's operating status, further restricting the stability and reliability of exhaust gas treatment. Utility Model Content

[0005] The purpose of this invention is to provide a hydrogen chloride tail gas absorption device for loading hydrochloric acid tanks, which aims to solve the problems of energy waste and low adjustment accuracy caused by manual operation in the above-mentioned background technology.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a hydrogen chloride tail gas absorption device for loading hydrochloric acid tanks, comprising an absorption tower, an absorption tower water supply pipe connected to the inlet of the absorption tower, an exhaust fan connected to the inlet of the absorption tower, and a hydrogen chloride tail gas pipeline connected to the exhaust fan inlet. It also includes an online hydrogen chloride concentration meter, a remote-reading magnetic level gauge, a first pneumatic regulating valve, a rotor flow meter, a liquid-phase circulation pump, and a second pneumatic regulating valve. The online hydrogen chloride concentration meter and the remote-reading magnetic level gauge are installed on the absorption tower. The first pneumatic regulating valve and the rotor flow meter are installed on the absorption tower water supply pipe. The drain outlet at the bottom of the absorption tower is connected to the inlet of the liquid-phase circulation pump. The outlet of the liquid-phase circulation pump is connected to a hydrochloric acid pipeline. The other end of the hydrochloric acid pipeline is connected to a circulation pipeline. The other end of the circulation pipeline is connected to the circulating liquid inlet of the absorption tower. The second pneumatic regulating valve is installed on the circulation pipeline.

[0007] Furthermore, a pressure transmitter is installed on the hydrogen chloride tail gas pipeline and located on the air inlet side of the exhaust fan.

[0008] Furthermore, the top outlet of the absorption tower is connected to a tail gas vent pipe, and a fourth pneumatic regulating valve is provided on the tail gas vent pipe.

[0009] Furthermore, the other end of the hydrochloric acid pipeline is connected to a collection pipeline, the other end of the collection pipeline is connected to a hydrochloric acid storage tank, and a third pneumatic regulating valve is provided on the collection pipeline.

[0010] This utility model has the following beneficial effects: This utility model provides a hydrogen chloride tail gas absorption device for hydrochloric acid tank loading. By installing an online hydrogen chloride concentration meter on the absorption tower, the changes in hydrogen chloride concentration in the solution inside the tower can be captured in real time, avoiding insufficient absorption or excessive circulation. Relying on the interlocking design of the "first pneumatic regulating valve + rotor flow meter" on the water supply pipe of the absorption tower with a remote magnetic float level gauge, the liquid level is automatically controlled, eliminating the error of manual adjustment. The pressure transmitter senses the inlet pressure in real time and controls the operation of the exhaust fan in conjunction with it. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall structure of this utility model; In the diagram: 1. Absorption tower; 2. Absorption tower water supply pipe; 3. Exhaust fan; 4. Hydrogen chloride tail gas pipeline; 5. Online hydrogen chloride concentration meter; 6. Magnetic level gauge with remote transmission; 7. First pneumatic control valve; 8. Rotor flow meter; 9. Liquid phase circulation pump; 10. Hydrochloric acid pipeline; 11. Circulation pipeline; 12. Second pneumatic control valve; 13. Tail gas vent pipe; 14. Collection pipeline; 15. Hydrochloric acid storage tank; 16. Third pneumatic control valve; 17. Pressure transmitter; 18. Fourth pneumatic control valve. Detailed Implementation

[0012] like Figure 1 As shown, a hydrogen chloride tail gas absorption device for loading hydrochloric acid tanks includes an absorption tower 1, which serves as the core equipment for tail gas treatment. Its inlet is connected to a pure water tank via a water supply pipe 2. An exhaust fan 3, a corrosion-resistant centrifugal fan, is horizontally mounted on a bracket on one side of the inlet of the absorption tower 1. Its inlet end is sealed to a hydrogen chloride tail gas pipeline 4 via a flange, and its outlet end is welded and fixed to the inlet of the absorption tower 1 to ensure leak-free gas transmission. An online hydrogen chloride concentration meter 5 is installed on the middle side wall of the absorption tower 1, with its probe extending into the gas phase region inside the tower for real-time monitoring of the tail gas concentration. A remote-reading magnetic level gauge 6 is vertically installed on one side of the absorption tower 1, with a level detection range covering the effective liquid volume range of the absorption tower, providing real-time feedback on the absorbent liquid level inside the tower.

[0013] One end of the water supply pipe 2 of the absorption tower is connected to the clean water network of the plant area, and the other end is connected to the water inlet at the top of the absorption tower 1. The first pneumatic regulating valve 7 and the rotor flow meter 8 are connected in series on the pipeline. The first pneumatic regulating valve 7 is close to the clean water network end, and the rotor flow meter 8 is close to the water inlet end of the absorption tower, so as to facilitate precise control of the water inlet flow.

[0014] The bottom drain of the absorption tower 1 is connected to the inlet flange of the liquid circulation pump 9 via a pipeline. The liquid circulation pump 9 is a fluoroplastic alloy centrifugal pump. The outlet of the liquid circulation pump 9 is connected to the hydrochloric acid pipeline 10. The hydrochloric acid pipeline 10 branches to form a circulation pipeline 11 and a collection pipeline 14. The other end of the circulation pipeline 11 is connected to the circulation liquid inlet in the lower part of the absorption tower 1. A second pneumatic regulating valve 12 is installed on the pipeline to regulate the flow rate of the circulation liquid. The other end of the collection pipeline 14 is connected to the top feed port of the hydrochloric acid storage tank 15. The hydrochloric acid storage tank 15 is a PP material storage tank used to store the qualified hydrochloric acid generated by absorption. A third pneumatic regulating valve 16 is installed on the pipeline to control the discharge and collection of qualified hydrochloric acid.

[0015] A pressure transmitter 17 is installed on the hydrogen chloride tail gas pipeline 4 at the air inlet side of the exhaust fan 3. It can monitor the tail gas inlet pressure in real time and adjust the operation of the exhaust fan 3 in conjunction with the pressure. When the inlet pressure is too high (such as when multiple vehicles are loading at the same time, causing a surge in tail gas volume), the fan frequency is automatically increased to enhance the extraction capacity. When the pressure is too low (such as when loading is about to end and tail gas volume decreases), the fan frequency is automatically reduced to save energy. This avoids the problem of "tail gas escape when the load is too high and energy is wasted when the load is too low" caused by the existing system's "constant fan speed operation, unable to adapt to changes in inlet load". The tail gas collection rate is increased to over 99.5%. The top outlet of the absorption tower 1 is connected to the tail gas vent pipe 13. A fourth pneumatic regulating valve 18 is installed on the pipe to control the emission of purified tail gas.

[0016] The specific operation process of this utility model is as follows: Open the first pneumatic regulating valve 7 and inject clean water into the absorption tower 1 through the water supply pipe 2. The rotor flow meter 8 displays the inlet water flow in real time. The operator can control the liquid level in the absorption tower within a preset range (such as 60%-80% of the effective volume of the tower body) based on the feedback from the remote magnetic level gauge 6. After the preset liquid level is reached, close the first pneumatic regulating valve 7.

[0017] When loading, the exhaust fan 3 is started. The hydrogen chloride tail gas enters the absorption tower 1 through the hydrogen chloride tail gas pipeline 4 and the pressure transmitter 17. The pressure transmitter 17 monitors the intake pressure in real time. If the pressure exceeds the normal range, the control system automatically adjusts the frequency of the exhaust fan 3 to maintain stable intake.

[0018] Start the liquid phase circulation pump 9. The absorbent liquid (initially pure water) at the bottom of the absorption tower 1 enters the circulation pipe 11 through the hydrochloric acid pipe 10 and is sprayed into the absorption tower 1 at a stable flow rate. The tail gas comes into countercurrent contact with the pure water in the absorption tower 1 to carry out the hydrogen chloride absorption reaction. The online hydrogen chloride concentration meter 5 detects the concentration of the solution in the tower in real time. When the concentration detected by the online hydrogen chloride concentration meter 5 is low, the absorbent liquid continues to circulate in the tower through the liquid phase circulation pump 9 and the second pneumatic regulating valve 12.

[0019] When the concentration detected by the online hydrogen chloride concentration meter 5 reaches the collection threshold of 10-15%, the control system issues a command: close the second pneumatic regulating valve 12 and open the third pneumatic regulating valve 16. The liquid phase circulation pump 9 then transports the qualified dilute hydrochloric acid through the collection pipeline 14 to the hydrochloric acid storage tank 15 for storage.

[0020] During this process, the remote magnetic level gauge 6 continuously monitors the liquid level. When the liquid level in the absorption tower 1 is lower than 50%, the remote magnetic level gauge 6 sends a signal to the control system, the first pneumatic regulating valve 7 automatically opens, the rotor flow meter 8 measures the water replenishment flow, and when the liquid level rises to 80%, the first pneumatic regulating valve 7 automatically closes to maintain a stable liquid level.

[0021] After absorption, the exhaust gas enters the exhaust pipe 13 through the top outlet of the absorption tower 1. If the exhaust gas meets the environmental emission standards through online monitoring (linked with the online hydrogen chloride concentration meter 5), the fourth pneumatic regulating valve 18 will automatically open, and the exhaust gas will be safely discharged into the atmosphere. If the standards are not met, the fourth pneumatic regulating valve 18 will remain closed, and the exhaust gas will continue to be absorbed with the circulating liquid until the standards are met.

[0022] After the loading operation is completed, the device is run continuously for 30 minutes to ensure that the residual exhaust gas in the pipeline is completely absorbed.

[0023] After the exhaust fan 3 is turned off and the concentration of the solution in the absorption tower 1 is stable, if the concentration is ≥10%, the third pneumatic regulating valve 16 is opened to transport the remaining dilute hydrochloric acid to the hydrochloric acid storage tank 15; if the concentration is <10%, it can be retained in the tower for the next use, or discharged to the designated corrosion-resistant waste liquid collection device.

[0024] Turn off the liquid phase circulation pump 9 and all pneumatic regulating valves, disconnect the power supply to the control system, and complete the shutdown.

Claims

1. A device for absorbing hydrogen chloride tail gas from a hydrochloric acid tanker loading area, comprising an absorption tower (1), wherein the inlet of the absorption tower (1) is connected to a water supply pipe (2), the inlet of the absorption tower (1) is connected to an exhaust fan (3), and the inlet of the exhaust fan (3) is connected to a hydrogen chloride tail gas pipeline (4), characterized in that: It also includes an online hydrogen chloride concentration meter (5), a remote magnetic level gauge (6), a first pneumatic regulating valve (7), a rotor flow meter (8), a liquid phase circulation pump (9), and a second pneumatic regulating valve (12). The online hydrogen chloride concentration meter (5) and the remote magnetic level gauge (6) are installed on the absorption tower (1). The first pneumatic regulating valve (7) and the rotor flow meter (8) are installed on the water supply pipe (2) of the absorption tower. The drain port at the bottom of the absorption tower (1) is connected to the inlet of the liquid phase circulation pump (9). The outlet of the liquid phase circulation pump (9) is connected to a hydrochloric acid pipe (10). The other end of the hydrochloric acid pipe (10) is connected to a circulation pipe (11). The other end of the circulation pipe (11) is connected to the circulation liquid inlet of the absorption tower (1). The second pneumatic regulating valve (12) is installed on the circulation pipe (11).

2. The hydrogen chloride tail gas absorption device according to claim 1, characterized in that: A pressure transmitter (17) is installed on the hydrogen chloride tail gas pipeline (4) and on the air inlet side of the exhaust fan (3).

3. The hydrogen chloride tail gas absorption device according to claim 1, characterized in that: The top outlet of the absorption tower (1) is connected to a tail gas exhaust pipe (13), and a fourth pneumatic regulating valve (18) is provided on the tail gas exhaust pipe (13).

4. The hydrogen chloride tail gas absorption device according to claim 1, characterized in that: The other end of the hydrochloric acid pipeline (10) is connected to a collection pipeline (14), and the other end of the collection pipeline (14) is connected to a hydrochloric acid storage tank (15). A third pneumatic regulating valve (16) is provided on the collection pipeline (14).

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