Equipment for recovering chlorine in chlorination reaction tail gas

Abstract

The utility model discloses equipment for recovering chlorine in chlorination reaction tail gas, and relates to the technical field of fine chemical engineering. The device comprises a water absorption tower, a first-stage sulfuric acid drying tower and a second-stage sulfuric acid drying tower, the top end of the water absorption tower is fixedly communicated with a first communicating pipe, the first communicating pipe is fixedly communicated with the side end of the first-stage sulfuric acid drying tower, and the top end of the first-stage sulfuric acid drying tower is fixedly communicated with a second communicating pipe. The side end of the water absorption tower is fixedly communicated with a tail gas inlet pipe, the side end of the tail gas inlet pipe is fixedly communicated with a water inlet pipe, the water inlet pipe is fixedly provided with a tap water adjusting control valve, and the side end of the bottom of the first-stage sulfuric acid drying tower is fixedly provided and communicated with a second sulfuric acid overflow pipe; the second sulfuric acid overflow pipe is fixedly installed and communicated with the side end of the bottom of the second-stage sulfuric acid drying tower, chlorine consumption can be reduced, chlorine does not need to be discharged in the whole process, liquid caustic soda consumption is reduced, and meanwhile waste brine is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of fine chemical industry, and specifically relates to a chlorine recovery device in tail gas of chlorination reaction. Background Art

[0002] The chlorination reaction requires strict control of the moisture content of chlorine gas. Chlorine gas is often in excess of 2 times, and the tail gas produced contains a large amount of hydrogen chloride. The normal treatment process is to absorb the hydrogen chloride through water absorption first.

[0003] Since the chlorine gas has a high water content after being absorbed by water and cannot be reused, it can only be absorbed by sodium hydroxide. The excess chlorine in the tail gas is absorbed by sodium hydroxide to produce a large amount of sodium hypochlorite. If the absorption concentration is not well controlled, a large amount of waste salt will be produced, which not only increases the cost of liquid alkali consumption, but also the excess chlorine is not fully utilized and a large amount of waste brine is produced, resulting in higher production costs. Utility Model Content

[0004] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and provide a chlorine recovery device in chlorination reaction tail gas which can overcome the above problems or at least partially solve the above problems.

[0005] In order to solve the above technical problems, the basic concept of the technical solution adopted by the utility model is: a chlorine recovery device in the tail gas of a chlorination reaction, comprising a water absorption tower, a primary sulfuric acid drying tower and a secondary sulfuric acid drying tower, the top of the water absorption tower is fixedly installed and connected with a first connecting pipe, the first connecting pipe is fixedly connected and connected with the side end of the primary sulfuric acid drying tower, the top of the primary sulfuric acid drying tower is fixedly installed and connected with a second connecting pipe, the second connecting pipe is fixedly connected and connected with the side end of the secondary sulfuric acid drying tower, the side end of the water absorption tower is fixedly installed and connected with a tail gas inlet pipe, the side end of the tail gas inlet pipe is fixedly installed and connected with a water inlet pipe, a tap water regulating control valve is fixedly installed on the water inlet pipe, the bottom side end of the primary sulfuric acid drying tower is fixedly installed and connected with a second sulfuric acid overflow pipe, the second sulfuric acid overflow pipe is fixedly installed and connected with the bottom side end of the secondary sulfuric acid drying tower.

[0006] Preferably, a hydrochloric acid storage tank is fixedly installed on the bottom side of the water absorption tower and is connected to the water absorption tower, and a hydrochloric acid online concentration meter is fixedly installed on the output end of the hydrochloric acid storage tank.

[0007] Furthermore, a water absorption circulation pump is fixedly installed on the bottom side end of the water absorption tower and is connected to the water absorption circulation pump, and an output end of the water absorption circulation pump is fixedly installed on the bottom side end and is connected to the water absorption condenser, and an output end of the water absorption condenser is fixedly connected to the side end of the water absorption tower and is connected to the water absorption tower.

[0008] Furthermore, the connection point between the water inlet pipe and the water absorption tower and the connection point between the water absorption condenser and the water absorption tower are both higher than the connection point between the exhaust gas inlet pipe and the water absorption tower, the connection point between the exhaust gas inlet pipe and the water absorption tower is higher than the connection point between the hydrochloric acid storage tank and the water absorption tower, and the connection point between the hydrochloric acid storage tank and the water absorption tower is higher than the connection point between the water absorption circulation pump and the water absorption tower.

[0009] Preferably, a dilute sulfuric acid storage tank is fixedly installed on the bottom side of the primary sulfuric acid drying tower and is connected to the dilute sulfuric acid storage tank, and a sulfuric acid online concentration meter is fixedly installed on the output end of the dilute sulfuric acid storage tank.

[0010] Furthermore, a primary sulfuric acid circulation pump is fixedly installed on the bottom side end of the primary sulfuric acid drying tower and is connected to the primary sulfuric acid circulation pump, an output end of the primary sulfuric acid circulation pump is fixedly installed on the bottom side end and is connected to the primary sulfuric acid condenser, and an output end of the primary sulfuric acid condenser is fixedly connected to the side end of the primary sulfuric acid drying tower and is connected to the primary sulfuric acid drying tower.

[0011] Furthermore, the connection point between the primary sulfuric acid condenser and the primary sulfuric acid drying tower is higher than the connection point between the first connecting pipe and the primary sulfuric acid drying tower, the connection point between the first connecting pipe and the primary sulfuric acid drying tower is higher than the connection point between the dilute sulfuric acid storage tank and the primary sulfuric acid drying tower, the connection point between the dilute sulfuric acid storage tank and the primary sulfuric acid drying tower is higher than the connection point between the primary sulfuric acid circulation pump and the primary sulfuric acid drying tower, and the connection point between the second sulfuric acid overflow pipe and the primary sulfuric acid drying tower is higher than the connection point between the primary sulfuric acid circulation pump and the primary sulfuric acid drying tower.

[0012] Preferably, the top of the secondary sulfuric acid drying tower is fixedly installed and connected to a chlorine circulation compressor, the side end of the secondary sulfuric acid drying tower is fixedly installed and connected to a concentrated sulfuric acid high-position storage tank, and the output end of the concentrated sulfuric acid high-position storage tank is fixedly installed with a sulfuric acid control regulating valve.

[0013] Furthermore, a secondary sulfuric acid circulation pump is fixedly installed on the bottom side end of the secondary sulfuric acid drying tower and is connected to the secondary sulfuric acid circulation pump, an output end of the secondary sulfuric acid circulation pump is fixedly installed on the bottom side end and is connected to the secondary sulfuric acid condenser, and an output end of the secondary sulfuric acid condenser is fixedly connected to the side end of the secondary sulfuric acid drying tower and is connected to the secondary sulfuric acid drying tower.

[0014] Furthermore, the connection point between the concentrated sulfuric acid high-position storage tank and the secondary sulfuric acid drying tower and the connection point between the secondary sulfuric acid condenser and the secondary sulfuric acid drying tower are both higher than the connection point between the second connecting pipe and the secondary sulfuric acid drying tower, the connection point between the second connecting pipe and the secondary sulfuric acid drying tower is higher than the connection point between the second sulfuric acid overflow pipe and the secondary sulfuric acid drying tower, and the connection point between the second sulfuric acid overflow pipe and the secondary sulfuric acid drying tower is higher than the connection point between the secondary sulfuric acid circulation pump and the secondary sulfuric acid drying tower.

[0015] After adopting the above technical scheme, the utility model has the following beneficial effects compared with the prior art: the utility model is a chlorine recovery device in chlorination reaction tail gas. By installing a water absorption circulation pump on a water absorption tower, a primary sulfuric acid circulation pump on a primary sulfuric acid drying tower, and a secondary sulfuric acid circulation pump on a secondary sulfuric acid drying tower, the whole process can be operated without the need for personnel, and automatic control can be realized. The concentration of hydrochloric acid and the concentration of dilute sulfuric acid are controlled by an online hydrochloric acid concentration meter and an online sulfuric acid concentration meter, and the settings are adjusted according to needs. The chlorine in the tail gas is dried by the water absorption tower, the primary sulfuric acid drying tower, and the secondary sulfuric acid drying tower to remove hydrogen chloride and moisture, and is returned to the reaction system through a chlorine circulation compressor for full utilization, thereby saving chlorine consumption. The whole process does not require external chlorine discharge, reduces liquid alkali consumption, and reduces the generation of waste brine. The hydrogen chloride in the chlorinated tail gas is removed and dried, and the dried chlorine is returned to the chlorination reactor for utilization, thereby reducing the unit consumption of chlorine, reducing liquid alkali consumption, reducing the generation of waste brine, and saving production costs.

[0016] The specific implementation of the utility model is further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In the attached picture:

[0018] Figure 1 It is a front structural schematic diagram of the utility model;

[0019] Figure 2 It is a rear view structural schematic diagram of the utility model.

[0020] In the figure: 1. tail gas inlet pipe; 2. water absorption tower; 3. primary sulfuric acid drying tower; 4. secondary sulfuric acid drying tower; 5. water inlet pipe; 501. tap water regulating control valve; 6. water absorption condenser; 7. water absorption circulation pump; 8. hydrochloric acid online concentration meter; 9. hydrochloric acid storage tank; 10. primary sulfuric acid condenser; 11. primary sulfuric acid circulation pump; 12. sulfuric acid online concentration meter; 13. dilute sulfuric acid storage tank; 14. secondary sulfuric acid condenser; 15. secondary sulfuric acid circulation pump; 16. concentrated sulfuric acid high-level storage tank; 17. sulfuric acid control regulating valve; 18. chlorine circulation compressor; 19. first connecting pipe; 20. second connecting pipe; 21. second sulfuric acid overflow pipe. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the embodiments of the utility model clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. The following embodiments are used to illustrate the utility model but are not used to limit the scope of the utility model.

[0022] Example:

[0023] Reference Figure 1-2 As shown, a chlorine recovery device in chlorination reaction tail gas includes a water absorption tower 2, a primary sulfuric acid drying tower 3 and a secondary sulfuric acid drying tower 4, the top of the water absorption tower 2 is fixedly installed and connected with a first connecting pipe 19, the first connecting pipe 19 is fixedly connected and connected with the side end of the primary sulfuric acid drying tower 3, the top of the primary sulfuric acid drying tower 3 is fixedly installed and connected with a second connecting pipe 20, the second connecting pipe 20 is fixedly connected and connected with the side end of the secondary sulfuric acid drying tower 4, the side end of the water absorption tower 2 is fixedly installed and connected with a tail gas inlet pipe 1, the side end of the tail gas inlet pipe 1 is fixedly installed and connected with a water inlet pipe 5, a tap water regulating control valve 501 is fixedly installed on the water inlet pipe 5, the bottom side end of the primary sulfuric acid drying tower 3 is fixedly installed and connected with a second sulfuric acid overflow pipe 21, the second sulfuric acid overflow pipe 21 is fixedly installed and connected with the bottom side end of the secondary sulfuric acid drying tower 4.

[0024] The bottom side end of the water absorption tower 2 is fixedly installed and connected with a hydrochloric acid storage tank 9, the output end of the hydrochloric acid storage tank 9 is fixedly installed with a hydrochloric acid online concentration meter 8, the bottom side end of the water absorption tower 2 is fixedly installed and connected with a water absorption circulation pump 7, the output end of the water absorption circulation pump 7 is fixedly installed and connected with a water absorption condenser 6, the output end of the water absorption condenser 6 is fixedly connected and connected with the side end of the water absorption tower 2, the connection point between the water inlet pipe 5 and the water absorption tower 2 and the connection point between the water absorption condenser 6 and the water absorption tower 2 are both higher than the connection point between the tail gas inlet pipe 1 and the water absorption tower 2, the connection point between the tail gas inlet pipe 1 and the water absorption tower 2 is higher than the connection point between the hydrochloric acid storage tank 9 and the water absorption tower 2, and the connection point between the hydrochloric acid storage tank 9 and the water absorption tower 2 is higher than the connection point between the water absorption circulation pump 7 and the water absorption tower 2.

[0025] The bottom side end of the primary sulfuric acid drying tower 3 is fixedly installed and connected with a dilute sulfuric acid storage tank 13, the output end of the dilute sulfuric acid storage tank 13 is fixedly installed with a sulfuric acid online concentration meter 12, the bottom side end of the primary sulfuric acid drying tower 3 is fixedly installed and connected with a primary sulfuric acid circulating pump 11, the output end of the primary sulfuric acid circulating pump 11 is fixedly installed and connected with a primary sulfuric acid condenser 10, the output end of the primary sulfuric acid condenser 10 is fixedly connected and connected with the side end of the primary sulfuric acid drying tower 3, the high pressure at the connection between the primary sulfuric acid condenser 10 and the primary sulfuric acid drying tower 3 is connected with the first connecting pipe 19 and the primary sulfuric acid drying tower 3, the connection between the first connecting pipe 19 and the primary sulfuric acid drying tower 3 is higher than the connection between the dilute sulfuric acid storage tank 13 and the primary sulfuric acid drying tower 3, the connection between the dilute sulfuric acid storage tank 13 and the primary sulfuric acid drying tower 3 is higher than the connection between the primary sulfuric acid circulating pump 11 and the primary sulfuric acid drying tower 3, and the connection between the second sulfuric acid overflow pipe 21 and the primary sulfuric acid drying tower 3 is higher than the connection between the primary sulfuric acid circulating pump 11 and the primary sulfuric acid drying tower 3.

[0026] The top of the secondary sulfuric acid drying tower 4 is fixedly installed and connected with a chlorine circulation compressor 18, the side end of the secondary sulfuric acid drying tower 4 is fixedly installed and connected with a concentrated sulfuric acid high-position storage tank 16, the output end of the concentrated sulfuric acid high-position storage tank 16 is fixedly installed with a sulfuric acid control regulating valve 17, the bottom side end of the secondary sulfuric acid drying tower 4 is fixedly installed and connected with a secondary sulfuric acid circulation pump 15, the output end of the secondary sulfuric acid circulation pump 15 is fixedly installed and connected with a secondary sulfuric acid condenser 14, the output end of the secondary sulfuric acid condenser 14 is fixedly connected and connected with the side end of the secondary sulfuric acid drying tower 4, the connection point between the concentrated sulfuric acid high-position storage tank 16 and the secondary sulfuric acid drying tower 4 and the connection point between the secondary sulfuric acid condenser 14 and the secondary sulfuric acid drying tower 4 are both higher than the connection point between the second connecting pipe 20 and the secondary sulfuric acid drying tower 4, the connection point between the second connecting pipe 20 and the secondary sulfuric acid drying tower 4 is higher than the connection point between the second sulfuric acid overflow pipe 21 and the secondary sulfuric acid drying tower 4, and the connection point between the second sulfuric acid overflow pipe 21 and the secondary sulfuric acid drying tower 4 is higher than the connection point between the secondary sulfuric acid circulation pump 15 and the secondary sulfuric acid drying tower 4.

[0027] The tail gas intake pipe 1 is connected to the air inlet of the water absorption tower 2. The upper part of the water absorption tower 2 is connected to tap water through the water inlet pipe 5 to supplement the water required for absorption. The water inlet pipe 5 is provided with a tap water regulating control valve 501 to adjust the water volume. The bottom outlet of the water absorption tower 2 is connected to the water absorption circulation pump 7, which is connected in series with the water absorption condenser 6. The outlet of the water absorption condenser 6 is connected to the spray inlet of the water absorption tower 2. A hydrochloric acid overflow pipe is arranged at the upper position of the bottom of the water absorption tower 2. The hydrochloric acid overflow pipe is connected to the hydrochloric acid storage tank 9. The hydrochloric acid overflow pipe is provided with a hydrochloric acid online concentration meter 8. The hydrochloric acid concentration is adjusted by controlling the size of the tap water regulating control valve 501. The larger the tap water, the smaller the hydrochloric acid concentration, and the smaller the tap water, the greater the hydrochloric acid concentration.

[0028] The tail gas outlet at the top of the water absorption tower 2 is connected to the air inlet of the primary sulfuric acid drying tower 3 through the first connecting pipe 19, and the water-containing chlorine is preliminarily dried and dehydrated through the primary sulfuric acid drying tower 3. The bottom outlet of the primary sulfuric acid drying tower 3 is connected to a primary sulfuric acid circulation pump 11, which is connected in series with a primary sulfuric acid condenser 10. The outlet of the primary sulfuric acid condenser 10 is connected to the spray inlet of the primary sulfuric acid drying tower 3. A first sulfuric acid overflow pipe is arranged at the upper position of the bottom of the primary sulfuric acid drying tower 3, and the first sulfuric acid overflow pipe is connected to a dilute sulfuric acid storage tank 13. A sulfuric acid online concentration meter 12 is arranged on the first sulfuric acid overflow pipe to monitor the sulfuric acid concentration.

[0029] The tail gas outlet at the top of the primary sulfuric acid drying tower 3 is connected to the air inlet of the secondary sulfuric acid drying tower 4 through the second connecting pipe 20, and the water-containing chlorine is further dried and dehydrated through the secondary sulfuric acid drying tower 4. The bottom outlet of the secondary sulfuric acid drying tower 4 is connected to the secondary sulfuric acid circulation pump 15, which is connected in series with the secondary sulfuric acid condenser 14. The outlet of the secondary sulfuric acid condenser 14 is connected to the spray inlet of the secondary sulfuric acid drying tower 4. A second sulfuric acid overflow pipe 21 is arranged at the upper position of the bottom of the secondary sulfuric acid drying tower 4. The second sulfuric acid overflow pipe 21 is connected to the upper position of the bottom of the primary sulfuric acid drying tower 3. During operation, the sulfuric acid in the secondary sulfuric acid drying tower 4 overflows into the primary sulfuric acid drying tower 3.

[0030] The upper feed port of the secondary sulfuric acid drying tower 4 is connected to the concentrated sulfuric acid high-level storage tank 16, and the sulfuric acid feed size is controlled by the sulfuric acid control regulating valve 17. If the feed is large, the sulfuric acid concentration monitored by the sulfuric acid online concentration meter 12 will be large, and if the feed is small, the sulfuric acid concentration monitored by the sulfuric acid online concentration meter 12 will be small.

[0031] The tail gas outlet of the secondary sulfuric acid drying tower 4 is connected to a chlorine circulation compressor 18 to provide power for chlorine circulation, and the recovered chlorine is returned to the chlorination reaction system for utilization.

[0032] In the initial state, the water absorption tower 2, the primary sulfuric acid drying tower 3 and the secondary sulfuric acid drying tower 4 all have a small amount of water and concentrated sulfuric acid to maintain the circulation of the water absorption circulation pump 7, the primary sulfuric acid circulation pump 11 and the secondary sulfuric acid circulation pump 15. The tail gas inlet pipe 1 is connected to the tail gas of the 2,3-dichloro-5-trichloromethylpyridine chlorination kettle. 2,3-dichloro-5-trichloromethylpyridine uses 2-chloro-5-chloromethylpyridine as a raw material to pass chlorine to react. The amount of chlorine in the reaction process is 3 times the molar mass in excess, and the tail gas contains a large amount of chlorine and hydrogen chloride.

[0033] The overflow hydrochloric acid concentration is controlled at 30% to 32% after absorption by the water absorption tower 2. The tap water regulating control valve 501 is linked with the hydrochloric acid online concentration meter 8 to control the tap water supply. The tap water supply is increased when the hydrochloric acid concentration is high, and the tap water supply is reduced when the hydrochloric acid concentration is low. Since hydrogen chloride releases heat when it meets water and concentrated sulfuric acid releases heat when it absorbs water, the water absorption condenser 6, the primary sulfuric acid condenser 10 and the secondary sulfuric acid condenser 14 all use circulating water for cooling.

[0034] The tail gas from the water absorption tower 2 enters the primary sulfuric acid drying tower 3 for preliminary drying, and the concentrated sulfuric acid high-level storage tank 16 continuously replenishes concentrated sulfuric acid to the secondary sulfuric acid drying tower 4. The replenishment amount is adjusted according to the sulfuric acid online concentration meter 12 and the sulfuric acid control regulating valve 17. The concentration of the overflowing dilute sulfuric acid is controlled at 85% to 88%. If the concentration is too high, the replenishment amount of concentrated sulfuric acid is reduced, and if the concentration is too low, the replenishment amount of concentrated sulfuric acid is increased. After being dried by the secondary sulfuric acid drying tower 4, the chlorine is compressed back into the reaction system by the chlorine circulation compressor 18 for reuse. When the liquid levels of the hydrochloric acid storage tank 9 and the dilute sulfuric acid storage tank 13 accumulate to a certain level, they are loaded and transported.

[0035] The above is only a preferred embodiment of the utility model, and does not impose any form of limitation on the utility model. Although the utility model has been disclosed as above in the preferred embodiment, it is not used to limit the utility model. Any technician familiar with this patent can make equivalent replacements or changes based on the technical solution and utility model concept of the utility model without departing from the scope of the technical solution of the utility model, which should be covered within the protection scope of the utility model.

Claims

1. A chlorine recovery device in chlorination reaction tail gas, characterized in that: The invention comprises a water absorption tower (2), a primary sulfuric acid drying tower (3) and a secondary sulfuric acid drying tower (4), wherein a first connecting pipe (19) is fixedly installed at the top of the water absorption tower (2) and is connected to the first connecting pipe (19), and the first connecting pipe (19) is fixedly connected and connected to the side end of the primary sulfuric acid drying tower (3); a second connecting pipe (20) is fixedly installed at the top of the primary sulfuric acid drying tower (3) and is connected to the second connecting pipe (20), and the second connecting pipe (20) is fixedly connected and connected to the side end of the secondary sulfuric acid drying tower (4); a tail gas inlet pipe (1) is fixedly installed at the side end of the water absorption tower (2) and is connected to the tail gas inlet pipe (1); a water inlet pipe (5) is fixedly installed at the side end of the tail gas inlet pipe (1) and is connected to the water inlet pipe (5), and a tap water regulating control valve (501) is fixedly installed on the water inlet pipe (5); a second sulfuric acid overflow pipe (21) is fixedly installed at the bottom side end of the primary sulfuric acid drying tower (3) and is connected to the second sulfuric acid overflow pipe (21), and the second sulfuric acid overflow pipe (21) is fixedly installed and connected to the bottom side end of the secondary sulfuric acid drying tower (4).

2. The chlorine recovery device in the chlorination reaction tail gas according to claim 1, characterized in that: A hydrochloric acid storage tank (9) is fixedly installed at the bottom side end of the water absorption tower (2) and is connected to the hydrochloric acid storage tank (9), and a hydrochloric acid online concentration meter (8) is fixedly installed at the output end of the hydrochloric acid storage tank (9).

3. The chlorine recovery device in the chlorination reaction tail gas according to claim 2, characterized in that: A water absorption circulation pump (7) is fixedly installed at the bottom side end of the water absorption tower (2) and is connected to the water absorption circulation pump (7), an output end of the water absorption circulation pump (7) is fixedly installed and is connected to a water absorption condenser (6), and an output end of the water absorption condenser (6) is fixedly connected to and connected to the side end of the water absorption tower (2).

4. The chlorine recovery device in the chlorination reaction tail gas according to claim 3, characterized in that: The connection point between the water inlet pipe (5) and the water absorption tower (2) and the connection point between the water absorption condenser (6) and the water absorption tower (2) are both higher than the connection point between the tail gas inlet pipe (1) and the water absorption tower (2); the connection point between the tail gas inlet pipe (1) and the water absorption tower (2) is higher than the connection point between the hydrochloric acid storage tank (9) and the water absorption tower (2); and the connection point between the hydrochloric acid storage tank (9) and the water absorption tower (2) is higher than the connection point between the water absorption circulation pump (7) and the water absorption tower (2).

5. The chlorine recovery device in the chlorination reaction tail gas according to claim 1, characterized in that: A dilute sulfuric acid storage tank (13) is fixedly installed at the bottom side end of the primary sulfuric acid drying tower (3) and is connected to the dilute sulfuric acid storage tank (13), and a sulfuric acid online concentration meter (12) is fixedly installed at the output end of the dilute sulfuric acid storage tank (13).

6. The chlorine recovery device in the chlorination reaction tail gas according to claim 5, characterized in that: A primary sulfuric acid circulation pump (11) is fixedly installed at the bottom side end of the primary sulfuric acid drying tower (3) and is in communication with the primary sulfuric acid circulation pump (11); an output end of the primary sulfuric acid circulation pump (11) is fixedly installed and in communication with a primary sulfuric acid condenser (10); and an output end of the primary sulfuric acid condenser (10) is fixedly connected and in communication with the side end of the primary sulfuric acid drying tower (3).

7. The chlorine recovery device in the chlorination reaction tail gas according to claim 6, characterized in that: The high pressure at the connection point between the primary sulfuric acid condenser (10) and the primary sulfuric acid drying tower (3) is higher than the connection point between the first connecting pipe (19) and the primary sulfuric acid drying tower (3); the connection point between the first connecting pipe (19) and the primary sulfuric acid drying tower (3) is higher than the connection point between the dilute sulfuric acid storage tank (13) and the primary sulfuric acid drying tower (3); the connection point between the dilute sulfuric acid storage tank (13) and the primary sulfuric acid drying tower (3) is higher than the connection point between the primary sulfuric acid circulation pump (11) and the primary sulfuric acid drying tower (3); and the connection point between the second sulfuric acid overflow pipe (21) and the primary sulfuric acid drying tower (3) is higher than the connection point between the primary sulfuric acid circulation pump (11) and the primary sulfuric acid drying tower (3).

8. The chlorine recovery device in the chlorination reaction tail gas according to claim 1, characterized in that: The top of the secondary sulfuric acid drying tower (4) is fixedly installed and connected to a chlorine circulation compressor (18), the side end of the secondary sulfuric acid drying tower (4) is fixedly installed and connected to a concentrated sulfuric acid high-position storage tank (16), and the output end of the concentrated sulfuric acid high-position storage tank (16) is fixedly installed with a sulfuric acid control regulating valve (17).

9. The chlorine recovery device in the chlorination reaction tail gas according to claim 8, characterized in that: A secondary sulfuric acid circulation pump (15) is fixedly installed at the bottom side end of the secondary sulfuric acid drying tower (4) and is in communication with the secondary sulfuric acid circulation pump (15); an output end of the secondary sulfuric acid circulation pump (15) is fixedly installed and in communication with a secondary sulfuric acid condenser (14); and an output end of the secondary sulfuric acid condenser (14) is fixedly connected and in communication with the side end of the secondary sulfuric acid drying tower (4).

10. The chlorine recovery device in the tail gas of a chlorination reaction according to claim 9, characterized in that: The connection point between the concentrated sulfuric acid high-position storage tank (16) and the secondary sulfuric acid drying tower (4) and the connection point between the secondary sulfuric acid condenser (14) and the secondary sulfuric acid drying tower (4) are both higher than the connection point between the second connecting pipe (20) and the secondary sulfuric acid drying tower (4); the connection point between the second connecting pipe (20) and the secondary sulfuric acid drying tower (4) is higher than the connection point between the second sulfuric acid overflow pipe (21) and the secondary sulfuric acid drying tower (4); and the connection point between the second sulfuric acid overflow pipe (21) and the secondary sulfuric acid drying tower (4) is higher than the connection point between the secondary sulfuric acid circulation pump (15) and the secondary sulfuric acid drying tower (4).

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