Hydrogen chloride tail gas recovery device
By designing a multi-stage filtration, condensation, adsorption and absorption hydrogen chloride exhaust gas recovery device, the problem of low purity of hydrogen chloride exhaust gas recovery in the prior art is solved, and the recovery of high-purity hydrogen chloride is achieved, which improves the exhaust gas utilization rate, reduces resource waste and environmental protection management expenses.
Patent Information
- Application Number
- CN202423210207.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-03-14
- Estimated Expiration
- 2034-12-25
AI Technical Summary
In the prior art, it is difficult to achieve high purity recovery in the process of hydrogen chloride exhaust gas, resulting in the large amount of hydrochloric acid impurities recovered and low purity, which cannot be directly used for high-precision chemical production, and waste of resources and environmental protection management expenses.
A hydrogen chloride exhaust gas recovery device is designed, including a filter, a precooler, a cold trap, a purifier, a first-stage falling membrane absorber, a second-stage falling membrane absorber and a filler absorption tower. Through technical means such as multi-stage filtration, condensation, adsorption and absorption, high-purity recovery of hydrogen chloride is achieved.
The recycling of high-purity hydrogen chloride gas has been achieved, the utilization rate of exhaust gas is improved, the generation of waste acid is avoided, raw material waste and environmental protection management expenses are reduced, and significant economic benefits are brought.
Smart Images
Figure CN222605906U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of tail gas recovery, in particular to a hydrogen chloride tail gas recovery device. Background Art
[0002] In many production processes of the modern chemical industry, the generation of hydrogen chloride tail gas is extremely common. In many fields such as catalytic synthesis, metal surface treatment, electronic component etching, polyvinyl chloride (PVC) production, etc., hydrogen chloride is generated as a reaction by-product or process waste gas. As the scale of the chemical industry continues to expand, the total amount of hydrogen chloride tail gas emissions has also risen steadily, causing great pressure on environmental protection.
[0003] Hydrogen chloride tail gas needs to be treated for discharge. Traditional treatment processes mostly focus on the "end treatment" of hydrogen chloride tail gas to meet emission standards, but ignore the value of recycling and utilization, and fail to convert it into products with economic and practical value. This is a serious waste of resources. Chemical companies consume raw materials to generate hydrogen chloride to participate in the reaction, and on the other hand, they treat hydrogen chloride in the tail gas as a pollutant. At a time when raw material costs are high and market competition is fierce, this "high consumption and low use" model compresses corporate profit margins, is not conducive to the sustainable and high-quality development of the industry, and runs counter to the current concept of circular economy and green chemical industry.
[0004] At present, the focus of hydrogen chloride tail gas is to improve absorption efficiency and reduce emissions, but the purity of hydrogen chloride recovery is unsatisfactory. The recovered hydrochloric acid is difficult to be directly reused in high-precision chemical production due to its high impurities and low purity. It can only be downgraded and sold or treated with low added value, which cannot truly achieve the vision of "zero output" of waste acid and is difficult to meet the requirements of modern chemical industry for green, efficient and coordinated development of all economic factors. Designing a recovery device that integrates pretreatment, high-purity recovery and tail gas purification and reuse can reduce resource waste. Utility Model Content
[0005] The technical problem to be solved by the utility model is to provide a hydrogen chloride tail gas recovery device, which realizes the recovery of high-purity hydrogen chloride gas, improves the tail gas utilization rate, avoids the generation of waste acid, and reduces the waste of raw materials and environmental protection management expenses.
[0006] The utility model discloses a hydrogen chloride tail gas recovery device, comprising a filter, a precooler, a cold trap, a purifier, a primary falling film absorber, a secondary falling film absorber and a packed absorption tower, wherein the filter inlet is connected to a hydrogen chloride tail gas pipe, the filter outlet is connected to an air inlet below the precooler, an air outlet above the precooler is connected to an air inlet of the cold trap, an air outlet of the cold trap is connected to the purifier through a cold air pipe, the purifier is connected to an air inlet of the primary falling film absorber through an absorption gas main pipe, an air outlet of the primary falling film absorber is connected to an air inlet of the secondary falling film absorber through an absorption gas pipe 1, a bottom liquid outlet of the primary falling film absorber is connected to a hydrochloric acid storage tank, an inlet of the primary falling film absorber is connected to an bottom liquid outlet of the secondary falling film absorber through an inlet pipe 1, an air outlet of the secondary falling film absorber is connected to an air inlet at the bottom of the packed absorption tower through an absorption gas pipe 2, an inlet of the secondary falling film absorber is connected to an outlet at the bottom of the packed absorption tower through an inlet pipe 2, a top of the packed absorption tower is connected to a chilled water inlet pipe, and a regulating valve is arranged on the chilled water inlet pipe.
[0007] Preferably, the temperature of the chilled water in the chilled water inlet pipe is 0-5°C.
[0008] Preferably, the precooler is a shell-and-tube heat exchanger, a drain valve is provided at the bottom of the precooler, a condensing medium is provided in the precooler, and the condensing medium is dimethyl silicone oil. The drain valve is provided at the bottom of the precooler to facilitate the cleaning of impurities, and the shell-and-tube heat exchanger is used to improve the heat exchange efficiency.
[0009] Preferably, a plurality of filters are provided, and the plurality of filters are connected in series.
[0010] Preferably, an adsorbent is provided in the purifier, and the adsorbent is a molecular sieve or activated carbon.
[0011] Preferably, a packing is provided in the packed absorption tower, and the packing is one or more of ball rings, step rings, Raschig rings, and rosettes; a porous grid is provided above the packing to prevent the packing from splashing and to replace the function of the distributor.
[0012] Preferably, the absorption air main pipe is connected to the absorption air pipe one via the absorption air pipe three, and the absorption air pipe three is connected to the absorption air pipe two via the absorption air branch pipe.
[0013] Preferably, a main reflux pipe is provided on the hydrochloric acid storage tank, and the main reflux pipe is connected to the liquid inlet pipe one and the liquid inlet pipe two through the reflux pipe one and the reflux pipe two respectively.
[0014] Preferably, the purifier includes purifier 1 and purifier 2 arranged in parallel, the air inlet of purifier 1 and the air inlet of purifier 2 are connected through parallel pipe 1, parallel pipe 1 is connected to the cold air pipe, the air outlet of purifier 1 and the air outlet of purifier 2 are connected through parallel pipe 2, and parallel pipe 2 is connected to the absorption gas main pipe.
[0015] Preferably, parallel pipeline one and parallel pipeline two are connected via a connecting pipe.
[0016] Preferably, the first falling film absorber liquid outlet, the second falling film absorber liquid outlet and the packed absorption tower liquid outlet are all provided with thermometers. The thermometer can be interlocked with the regulating valve, and the chilled water flow in the chilled water inlet pipe can be controlled by the regulating valve according to the temperature, thereby regulating the temperature of the first falling film absorber and the second falling film absorber to ensure stable and efficient operation of the equipment.
[0017] Preferably, the hydrochloric acid storage tank is provided with a pH meter to monitor the acid concentration in the hydrochloric acid storage tank.
[0018] Valves can be installed on the pipeline according to the control needs, and the opening and closing of the valve can be conveniently used to control the flow of materials in the corresponding pipeline and adjust the flow of materials.
[0019] Compared with the prior art, the beneficial effects of the utility model are:
[0020] 1. Remove tiny particles through filters, collect heavy components through precoolers and cold traps, remove light component impurities through purifiers, and enter the primary falling film absorber and the secondary falling film absorber to contact with water, so that hydrogen chloride in the tail gas can be absorbed. Since the initial source of the absorption liquid is the chilled water inlet pipe, the water temperature entering the primary falling film absorber and the secondary falling film absorber is relatively low, and the heat generated when hydrogen chloride is dissolved in water is also absorbed, realizing the recovery of high-purity hydrogen chloride gas; the primary falling film absorber and the secondary falling film absorber can be selected in series or used alone according to the actual hydrogen chloride flow rate and temperature;
[0021] 2. The primary falling film absorber produces high-purity hydrochloric acid solution, which can be transported to the hydrochloric acid storage tank as needed or recirculated from the hydrochloric acid storage tank into the primary falling film absorber or the secondary falling film absorber to continue to participate in the reaction, absorption and concentration;
[0022] 3. The utility model can control the concentration of hydrochloric acid, rationally allocate resources, and make full use of the recovered products; it improves the utilization rate of tail gas, avoids the generation of waste acid, reduces the waste of raw materials and environmental protection expenses, and brings significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 This is a schematic diagram of the structure of the hydrogen chloride tail gas recovery device of the utility model;
[0024] In the figure: 1. filter; 2. precooler; 3. cold trap; 4. purifier; 5. primary falling film absorber; 6. secondary falling film absorber; 7. packed absorption tower; 8. hydrogen chloride tail gas pipe; 9. cold air pipe; 10. absorption gas main pipe; 11. absorption gas pipe 1; 12. hydrochloric acid storage tank; 13. liquid inlet pipe 1; 14. absorption gas pipe 2; 15. liquid inlet pipe 2; 16. chilled water inlet pipe; 17. regulating valve; 18. absorption gas pipe 3; 19. absorption gas branch pipe; 20. reflux main pipe; 21. reflux pipe 1; 22. reflux pipe 2; 23. purifier 1; 24. purifier 2; 25. parallel pipe 1; 26. parallel pipe 2; 27. connecting pipe; 28. pH meter. DETAILED DESCRIPTION
[0025] The present invention will be described clearly and completely below with reference to the accompanying drawings.
[0026] like Figure 1 As shown, the hydrogen chloride tail gas recovery device comprises a filter 1, a precooler 2, a cold trap 3, a purifier 4, a primary falling film absorber 5, a secondary falling film absorber 6 and a packed absorption tower 7, the inlet of the filter 1 is connected to a hydrogen chloride tail gas pipe 8, the outlet of the filter 1 is connected to an air inlet below the precooler 2, the air outlet above the precooler 2 is connected to an air inlet of the cold trap 3, the air outlet of the cold trap 3 is connected to the purifier 4 through a cold air pipe 9, the purifier 4 is connected to an air inlet of the primary falling film absorber 5 through an absorption gas main pipe 10, and the air outlet of the primary falling film absorber 5 is connected to an absorption gas main pipe 11. 11 is connected to the air inlet of the secondary falling film absorber 6, the bottom liquid outlet of the primary falling film absorber 5 is connected to the hydrochloric acid storage tank 12, the liquid inlet of the primary falling film absorber 5 is connected to the bottom liquid outlet of the secondary falling film absorber 6 through the liquid inlet pipe 13, the bottom gas outlet of the secondary falling film absorber 6 is connected to the bottom air inlet of the packed absorption tower 7 through the absorption gas pipe 2 14, the liquid inlet of the secondary falling film absorber 6 is connected to the bottom liquid outlet of the packed absorption tower 7 through the liquid inlet pipe 2 15, the top of the packed absorption tower 7 is connected to the chilled water inlet pipe 16, and the chilled water inlet pipe 16 is provided with a regulating valve 17.
[0027] The chilled water temperature in the chilled water inlet pipe is 0-5℃.
[0028] The precooler 2 is a shell-and-tube heat exchanger. A drain valve is provided at the bottom of the precooler 2. A condensing medium is provided in the precooler 2, and the condensing medium is dimethyl silicone oil.
[0029] Two filters 1 are provided, and the two filters 1 are connected in series.
[0030] The purifier 4 is provided with an adsorbent, which is a molecular sieve.
[0031] The packed absorption tower 7 is provided with packing, and the packing is ball ring.
[0032] The absorption gas main pipe 10 is connected to the absorption gas pipe 1 11 via the absorption gas pipe 3 18 , and the absorption gas pipe 3 18 is connected to the absorption gas pipe 2 14 via the absorption gas branch pipe 19 .
[0033] A reflux main pipe 20 is provided on the hydrochloric acid storage tank 12, and the reflux main pipe 20 is connected to the liquid inlet pipe 1 13 and the liquid inlet pipe 2 15 through the reflux pipe 1 21 and the reflux pipe 2 22 respectively.
[0034] The purifier 4 includes a purifier 1 23 and a purifier 2 24 arranged in parallel, the air inlet of the purifier 1 23 and the air inlet of the purifier 2 24 are connected through a parallel pipe 1 25, the parallel pipe 1 25 is connected to the cold air pipe 9, the air outlet of the purifier 1 23 and the air outlet of the purifier 2 24 are connected through a parallel pipe 2 26, and the parallel pipe 2 26 is connected to the absorption gas main pipe 10. The parallel pipe 1 25 and the parallel pipe 2 26 are connected through a connecting pipe 27.
[0035] The liquid outlet of the first falling film absorber 5, the liquid outlet of the second falling film absorber 6 and the liquid outlet of the packed absorption tower 7 are all provided with thermometers.
[0036] The hydrochloric acid storage tank 12 is provided with a pH meter 28 .
[0037] The working process is as follows:
[0038] The tail gas in the hydrogen chloride tail gas pipe 8 enters the filter 1 to remove tiny particles, and then enters the precooler 2 and the cold trap 3 in turn for two-stage condensation, wherein the heavy components are condensed and removed, and the remaining light components enter the purifier 4 through the cold gas pipe 9. It can be selected to enter the purifier 1 23 and the purifier 2 24 at the same time through the parallel pipe 1 25 according to needs, or only through the purifier 1 23 or the purifier 2 24, or the gas can enter the purifier 1 23 and then enter the purifier 2 24 through the connecting pipe 27 to complete two purifications; after the gas is purified, the light component impurities therein are adsorbed by the adsorbent, and then enter the primary falling film absorber 5 through the absorption gas main pipe 10, the hydrogen chloride is absorbed by the absorption liquid in the primary falling film absorber 5 to obtain high-purity hydrochloric acid, and then enters the hydrochloric acid storage tank 12, and the gas not absorbed by the primary falling film absorber 5 enters the second falling film absorber 12 through the absorption gas pipe 11 The gas not absorbed by the secondary falling film absorber 6 enters the packed absorption tower 7 through the absorption gas pipe 14, contacts with the chilled water flowing out through the chilled water inlet pipe 16, and is absorbed to obtain low-concentration hydrochloric acid, and then enters the secondary falling film absorber 6 through the liquid inlet pipe 15 as the absorption liquid to absorb hydrogen chloride, thereby improving the concentration of the low-concentration hydrochloric acid. The liquid outlet temperatures of the primary falling film absorber 5 and the secondary falling film absorber 6 are detected by a thermometer. The temperature range of the primary falling film absorber 5 and the secondary falling film absorber 6 is 5-35°C. When the temperature is lower or higher than this range, the regulating valve 17 automatically reduces or increases the opening to adjust the chilled water flow rate.
[0039] The pH meter 28 can reflect the concentration of hydrochloric acid in the hydrochloric acid storage tank 12. When the concentration of hydrochloric acid is insufficient, the hydrochloric acid in the hydrochloric acid storage tank 12 is pumped into the reflux pipe 1 21 through the reflux main pipe 20 to enter the primary falling film absorber 5 or into the reflux pipe 2 22 to enter the secondary falling film absorber 6 to continue to absorb hydrogen chloride for concentration. In addition, the purified gas can also enter the secondary falling film absorber 6 through the absorption gas pipe 3 18 or enter the packed absorption tower 7 through the absorption gas branch pipe 19 to facilitate the regulation of the hydrochloric acid concentration.
Claims
1. A hydrogen chloride tail gas recovery device, characterized in that: The invention comprises a filter (1), a precooler (2), a cold trap (3), a purifier (4), a first-stage falling film absorber (5), a second-stage falling film absorber (6) and a packed absorption tower (7), wherein the inlet of the filter (1) is connected to a hydrogen chloride tail gas pipe (8), the outlet of the filter (1) is connected to an air inlet below the precooler (2), the air outlet above the precooler (2) is connected to an air inlet of the cold trap (3), the air outlet of the cold trap (3) is connected to the purifier (4) via a cold air pipe (9), the purifier (4) is connected to an air inlet of the first-stage falling film absorber (5) via an absorption gas main pipe (10), and the air outlet of the first-stage falling film absorber (5) is connected to an absorption gas main pipe (11). The air inlet of the secondary falling film absorber (6) is connected, the bottom liquid outlet of the primary falling film absorber (5) is connected to the hydrochloric acid storage tank (12), the liquid inlet of the primary falling film absorber (5) is connected to the bottom liquid outlet of the secondary falling film absorber (6) through a liquid inlet pipe 1 (13), the bottom gas outlet of the secondary falling film absorber (6) is connected to the bottom air inlet of the packed absorption tower (7) through an absorption gas pipe 2 (14), the liquid inlet of the secondary falling film absorber (6) is connected to the bottom liquid outlet of the packed absorption tower (7) through a liquid inlet pipe 2 (15), the top of the packed absorption tower (7) is connected to a chilled water inlet pipe (16), and a regulating valve (17) is provided on the chilled water inlet pipe (16).
2. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: A plurality of filters (1) are provided, and the plurality of filters (1) are connected in series.
3. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The purifier (4) is provided with an adsorbent, which is a molecular sieve or activated carbon.
4. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The packed absorption tower (7) is provided with a packing, and the packing is one or more of a ball ring, a step ring, a Raschig ring, and a rosette.
5. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The absorption gas main pipe (10) is connected to the absorption gas pipe one (11) via the absorption gas pipe three (18), and the absorption gas pipe three (18) is connected to the absorption gas pipe two (14) via the absorption gas branch pipe (19).
6. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The hydrochloric acid storage tank (12) is provided with a reflux main pipe (20), which is connected to the liquid inlet pipe 1 (13) and the liquid inlet pipe 2 (15) via a reflux pipe 1 (21) and a reflux pipe 2 (22), respectively.
7. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The purifier (4) comprises a purifier 1 (23) and a purifier 2 (24) which are arranged in parallel. The air inlet of the purifier 1 (23) and the air inlet of the purifier 2 (24) are connected via a parallel pipe 1 (25). The parallel pipe 1 (25) is connected to a cold air pipe (9). The air outlet of the purifier 1 (23) and the air outlet of the purifier 2 (24) are connected via a parallel pipe 2 (26). The parallel pipe 2 (26) is connected to an absorption gas main pipe (10).
8. The hydrogen chloride tail gas recovery device according to claim 7, characterized in that: The parallel pipeline 1 (25) and the parallel pipeline 2 (26) are connected via a connecting pipe (27).
9. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The liquid outlet of the first falling film absorber (5), the liquid outlet of the second falling film absorber (6) and the liquid outlet of the packed absorption tower (7) are all provided with thermometers.
10. The hydrogen chloride tail gas recovery device according to claim 1, characterized in that: The hydrochloric acid storage tank (12) is provided with a pH meter (28).