Hydrogen chloride recovery device for loading hydrochloric acid

Abstract

This utility model discloses a hydrogen chloride recovery device for hydrochloric acid loading, comprising a two-stage falling film absorber, a first-stage falling film absorber, a water jet pump, an acid circulation tank, and a hydrochloric acid storage tank. The bottom of the second-stage falling film absorber is connected to the upper part of the first-stage falling film absorber via a lower acid pipe. The lower part of the first-stage falling film absorber is connected to the upper part of the second-stage falling film absorber via a tail gas pipe. The bottom of the first-stage falling film absorber is connected to the hydrochloric acid storage tank via a hydrochloric acid pipe. A loading pipe is located at the lower part of the hydrochloric acid storage tank. An automatically retractable loading arm is located at the end of the loading pipe, and a sealing cap is installed on the loading arm. An extraction pipe connected to the tail gas pipe is located at the top of the loading cap. An adjustable variable frequency centrifugal fan is installed on the extraction pipe, and a loading pump is installed on the loading pipe. This utility model recovers hydrogen chloride during loading, reducing corrosion of equipment and pipelines, improving the on-site working environment, and increasing on-site loading efficiency.

Description

Technical Field

[0001] This utility model relates to the field of chemical technology, and in particular to a hydrochloric acid loading and hydrogen chloride recovery device. Background Technology

[0002] In chemical production, hydrogen chloride synthesis furnaces continuously produce hydrogen chloride gas of stable purity. When abnormalities occur in downstream processes, the hydrogen chloride gas is absorbed by water to produce hydrochloric acid with a concentration greater than 30%. The by-product hydrochloric acid is sold using corrosive material tanker trucks. Due to the different sizes of the filling ports on these trucks, gaps may exist between the loading arm opening and the filling port during loading. Hydrogen chloride in the hydrochloric acid inside the tanker trucks evaporates through these gaps and forms small droplets of hydrochloric acid with moisture in the air. This can corrode surrounding equipment, damage the environment, and harm human health.

[0003] However, during actual hydrochloric acid loading and unloading, water jet pumps are used to absorb hydrogen chloride acid mist through water circulation. At this time, the extraction pipeline is also burdened with the task of venting the hydrochloric acid storage tank and recovering acid gas during loading, which increases the load on exhaust gas recovery and reduces the acid gas extraction capacity during loading. During loading and unloading, the flow rate needs to be reduced to reduce the large amount of hydrogen chloride gas volatilized when hydrochloric acid rises, reduce the load on the extraction pipeline, and reduce loading efficiency. Summary of the Invention

[0004] This utility model overcomes the shortcomings of the existing technology and provides a hydrogen chloride recovery device for hydrochloric acid loading. The purpose is to solve the problem of hydrogen chloride gas evaporating during hydrochloric acid loading polluting the environment and corroding equipment pipelines, to avoid personnel inhaling hydrogen chloride gas during on-site hydrochloric acid loading, thus protecting human health, and to improve loading efficiency.

[0005] The technical solution adopted by this utility model to solve its technical problem is as follows: it includes a secondary falling film absorber 2, a primary falling film absorber 1, a water jet pump 7, an acid circulation tank 8, and a hydrochloric acid storage tank 6. The bottom of the secondary falling film absorber 2 is provided with a lower acid pipe 3 connected to the upper part of the primary falling film absorber 1. The lower part of the primary falling film absorber 1 is connected to the upper part of the secondary falling film absorber 2 through a tail gas pipe 4. The bottom of the primary falling film absorber 1 is provided with a hydrochloric acid pipe 5 connected to the hydrochloric acid storage tank 6. The lower part of the hydrochloric acid storage tank 6 is provided with a loading pipe 20. The end of the loading pipe 20 is provided with an automatically retractable loading arm 12. The loading arm 12 is provided with a sealing cap 11. The top of the sealing cap 11 is provided with an exhaust pipe 19 connected to the tail gas pipe 4. The exhaust pipe 19 is provided with an adjustable variable frequency centrifugal fan 9. The loading pipe 20 is provided with a loading pump 10.

[0006] Furthermore, the lower part of the secondary falling film absorber 2 is provided with a tail gas absorption pipe 16 connected to the upper part of the water jet pump 7.

[0007] Furthermore, the lower part of the acid circulation tank 8 is provided with an acid circulation pipe 15 connected to the top of the water jet pump 7, and the acid circulation pipe 15 is provided with an acid circulation pump 7.

[0008] Furthermore, the upper part of the secondary falling film absorber 2 is provided with an acid inlet pipe 14 connected to an acid circulation pipe 15.

[0009] Furthermore, the loading pipe 20 and the extraction pipe 19 are respectively equipped with a loading valve 17 and an extraction valve 18, which are pneumatic shut-off valves.

[0010] Furthermore, the primary falling film absorber 1 and the secondary falling film absorber 2 are made of impermeable graphite material, which is resistant to acid and alkali and is not easily corroded.

[0011] Furthermore, the bottom of the sealing cap 11 is open, the inside of the sealing cap 11 is hollow, and the sealing cap 11 is made of PVC material.

[0012] Furthermore, the acid circulation tank 8 is equipped with a non-condensable gas vent pipe 21 at the top.

[0013] This invention connects a secondary falling film absorber and a primary falling film absorber in series via an acid drain pipe. During loading, a sealing cap seals the loading port. The generated hydrogen chloride is then sent to the secondary falling film absorber for absorption via an extraction pipe. The absorbed hydrochloric acid is then sent to a hydrochloric acid storage tank. This design reduces the corrosion of surrounding equipment and pipelines by hydrogen chloride overflowing during loading, improves the on-site environment, and reduces the exposure of on-site personnel to toxic and harmful gases. It also improves loading efficiency and reduces the extraction load on the extraction pipeline. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the system of this utility model.

[0015] Figure 1 In the diagram, 1 is the primary falling film absorber, 2 is the secondary falling film absorber, 3 is the acid inlet pipe, 4 is the tail gas pipe, 5 is the hydrochloric acid pipe, 6 is the hydrochloric acid storage tank, 7 is the water jet pump, 8 is the acid circulation tank, 9 is the adjustable frequency centrifugal fan, 10 is the loading pump, 11 is the sealing cap, 12 is the loading arm, 13 is the acid circulation pump, 14 is the acid inlet pipe, 15 is the acid circulation pipe, 16 is the tail gas absorption pipe, 17 is the loading valve, 18 is the extraction valve, 19 is the extraction pipe, 20 is the loading pipe, 21 is the non-condensable gas vent pipe, a is hydrogen chloride gas, and b is primary water. Detailed Implementation

[0016] Reference Figure 1 The preferred embodiments of this utility model will be described in detail below.

[0017] Example: A hydrochloric acid loading and hydrogen chloride recovery device includes a secondary falling film absorber 2, a primary falling film absorber 1, a water jet pump 7, an acid circulation tank 8, and a hydrochloric acid storage tank 6. The secondary falling film absorber 2 has a bottom acid pipe 3 connected in series with the upper part of the primary falling film absorber 1. The lower part of the primary falling film absorber 1 is connected to the upper part of the secondary falling film absorber 2 via a tail gas pipe 4. The bottom of the primary falling film absorber 1 has a hydrochloric acid pipe 5 connected to the hydrochloric acid storage tank 6. The lower part of the hydrochloric acid storage tank 6 has a loading pipe 20. The end of the loading pipe 20 has an automatically retractable loading arm 12. The loading arm 12 has a sealing cap 11. The top of the sealing cap 11 has a suction pipe 19 connected to the tail gas pipe 4. The bottom of the sealing cap 11... The sealing cap 11 is open and hollow inside. An adjustable variable frequency centrifugal fan 9 is installed on the exhaust pipe 19. A loading pump 10 is installed on the loading pipe 20. The lower part of the secondary falling film absorber 2 is provided with a tail gas absorption pipe 16 connected to the upper part of the water jet pump 7. The lower part of the acid circulation tank 8 is provided with a circulating acid pipe 14 connected to the top of the water jet pump 7. An acid circulation pump 13 is installed on the acid circulation pipe 15. The upper part of the secondary falling film absorber 2 is provided with an acid inlet pipe 14 connected to the acid circulation pipe 15. A loading valve 17 and an exhaust valve 18 are respectively installed on the loading pipe 20 and the exhaust pipe 19. The loading valve 17 and the exhaust valve 18 are pneumatic shut-off valves. The bottom of the sealing cap 12 is open and the interior of the sealing cap 12 is hollow. The sealing cap is made of PVC material.

[0018] Working Principle: Hydrogen chloride gas generated by the hydrochloric acid synthesis furnace enters the primary falling film absorber 1. After absorption by the secondary falling film absorber 2, hydrochloric acid with a concentration of 15%-25% enters the primary falling film absorber 1 through the lower acid pipe 3 to absorb the hydrogen chloride. The incompletely absorbed hydrogen chloride gas after absorption by the primary falling film absorber 1 enters the upper part of the secondary falling film absorber 2 through the tail gas pipe 4. The secondary falling film absorber 2 uses hydrochloric acid with a concentration of 10%-20% in the acid circulation tank 8 for absorption through the acid inlet pipe 14. The hydrochloric acid in the circulation tank 8 enters the secondary absorption falling film absorber through the acid inlet pipe 14 of the acid circulation pump 13. Primary water is also provided on the acid inlet pipe 14. When the concentration of hydrochloric acid in the acid circulation tank 8 is greater than 20%, the secondary falling film absorber 2 uses primary water to absorb the hydrogen chloride gas. The non-condensable gas generated by the secondary falling film absorber 2 is drawn into the secondary absorption falling film absorber through the tail gas absorption pipe 16. The water jet pump 7 mixes with the hydrochloric acid sent to the acid circulation tank 8 by the acid circulation pipe 15. The hydrogen chloride gas in the non-condensable gases is absorbed by the hydrochloric acid, and other non-condensable gases that cannot be absorbed are discharged into the atmosphere through the non-condensable gas vent pipe 21. When loading hydrochloric acid, the loading valve 17 and the extraction valve 18 are opened, and the loading arm 12 is automatically lowered to the loading port of the loading tank. The loading port of the loading tank is sealed with the sealing cap 11. The hydrogen chloride gas in the hydrochloric acid will not have gaps due to the different sizes of the loading port of the loading tank. The hydrogen chloride gas volatilized during loading is sent to the tail gas pipe 4 through the adjustable variable frequency centrifugal fan 9 on the extraction pipe 19 and enters the secondary falling film absorber 2. The non-condensable gas after being treated by the secondary falling film absorber 2 is discharged into the atmosphere through the non-condensable gas vent pipe 21. The hydrochloric acid produced enters the primary falling film absorber 1 to absorb the hydrogen chloride gas and then enters the hydrochloric acid storage tank 6 for sale.

Claims

1. A hydrochloric acid loading and hydrogen chloride recovery device, characterized in that, The system includes a secondary falling film absorber (2), a primary falling film absorber (1), a water jet pump (7), an acid circulation tank (8), and a hydrochloric acid storage tank (6). The bottom of the secondary falling film absorber (2) is provided with an acid drain pipe (3) connected to the upper part of the primary falling film absorber (1). The lower part of the primary falling film absorber (1) is connected to the upper part of the secondary falling film absorber (2) through a tail gas pipe (4). The bottom of the primary falling film absorber (1) is provided with a hydrochloric acid pipe (5) connected to the salt... Acid storage tank (6) is connected. The lower part of the hydrochloric acid storage tank (6) is provided with a loading pipe (20). The end of the loading pipe (20) is provided with an automatically retractable loading arm (12). The loading arm (12) is provided with a sealing cap (11). The top of the sealing cap (11) is provided with an exhaust pipe (19) connected to the exhaust pipe (4). The exhaust pipe (19) is provided with an adjustable variable frequency centrifugal fan (9). The loading pipe (20) is provided with a loading pump (10).

2. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The lower part of the secondary falling film absorber (2) is provided with a tail gas absorption pipe (16) which is connected to the upper part of the water jet pump (7).

3. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The acid circulation tank (8) is provided with an acid circulation pipe (15) at the bottom, which is connected to the top of the water jet pump (7). An acid circulation pump (13) is provided on the acid circulation pipe (15).

4. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The upper part of the secondary falling film absorber (2) is provided with an acid inlet pipe (14) connected to an acid circulation pipe (15).

5. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The loading pipe (20) and the extraction pipe (19) are respectively equipped with a loading valve (17) and an extraction valve (18), and the loading valve (17) and the extraction valve (18) are pneumatic shut-off valves.

6. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The primary falling film absorber (1) and the secondary falling film absorber (2) are made of impermeable graphite material.

7. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The bottom of the sealing cap (11) is open, the inside of the sealing cap (11) is hollow, and the sealing cap (11) is made of PVC material.

8. The hydrochloric acid loading and hydrogen chloride recovery device according to claim 1, characterized in that, The acid circulation tank (8) is equipped with a non-condensable gas vent pipe (21) at the top.

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