Sulfuric acid thickening device and method for producing concentrated sulfuric acid by using same

Abstract

The invention relates to the technical field of concentrated sulfuric acid production, and particularly discloses a sulfuric acid thickening device which comprises a waste acid regeneration unit for burning sulfur-containing waste acid and acid gas to produce sulfuric acid and a sulfuric acid thickening unit for thickening the sulfuric acid generated by the waste acid regeneration unit, the sulfuric acid thickening unit comprises a combustion chamber, and liquid sulfur is combusted in the combustion chamber to generate sulfur dioxide. A steam generating device is arranged in the combustion chamber, the combustion chamber is connected with the reactor through a process gas conveying pipe, sulfur dioxide is subjected to a catalytic reaction in the reactor to generate sulfur trioxide, and the reactor is connected with the absorption tower through a process gas discharging pipe; unqualified sulfuric acid and reflux sulfuric acid in the waste acid regeneration unit absorb sulfur trioxide in an absorption tower to generate sulfuric acid, and the sulfuric acid is thickened; the invention also provides a method for producing concentrated sulfuric acid by using the device. According to the device, sulfuric acid with the concentration lower than 98wt% can be prepared into concentrated sulfuric acid with the concentration higher than 98wt%, the product income is increased, meanwhile, steam is generated as a byproduct, and the benefits of the device are increased.

Description

Technical Field

[0001] The present invention relates to the technical field of concentrated sulfuric acid production, and specifically to a sulfuric acid concentration increasing device and a method for producing concentrated sulfuric acid by using this device. Background Art

[0002] Conventional waste acid regeneration devices are designed to produce 98 wt% concentrated sulfuric acid, with raw materials being 90 wt% waste acid and acid gas. After being incinerated at 1100 °C in the waste acid incinerator, it generates sulfur dioxide-containing 2 acid gas. The acid gas enters the first-stage converter after being filtered for dust by a high-temperature filter. 95% of the sulfur dioxide in the acid gas in the first-stage converter 2 is converted into sulfur trioxide 3 , and then through the first-stage condenser, sulfur trioxide 3 is converted into 98 wt% sulfuric acid. The remaining 5% of sulfur dioxide in the acid gas 2 enters the second-stage converter to be converted into sulfur trioxide 3 , and then through the second-stage condenser, sulfur trioxide 3 is converted into 98 wt% sulfuric acid. The tail gas contains ppm-level sulfur dioxide 2 which is captured by an activated carbon reactor, and the purified tail gas is discharged to the atmosphere through a chimney.

[0003] In actual production, both the raw material acid gas and the waste acid carry a certain amount of hydrocarbon components, which generate water after being burned in the waste acid incinerator. This part of the water is condensed in the product sulfuric acid in the first-stage condenser and the second-stage condenser, resulting in the concentration of the concentrated sulfuric acid product being lower than 98 wt%, and the product concentration being unqualified. It can only be sold as 93 wt% national standard sulfuric acid, causing a large loss in device efficiency. Summary of the Invention

[0004] The first object of the present invention is to solve the problem that the concentration of concentrated sulfuric acid produced by the device for producing 98 wt% concentrated sulfuric acid from waste acid in the prior art is too low, and to provide a sulfuric acid concentration increasing device that can increase the sulfuric acid concentration. The concentrated sulfuric acid produced by this device is above 98 wt%, and it can generate steam using the heat generated by the device.

[0005] The second object of the present invention is to provide a method for producing concentrated sulfuric acid according to the above device.

[0006] To solve the above technical problems, the present invention includes a spent acid regeneration unit for producing sulfuric acid by burning sulfur-containing spent acid and acid gas. The spent acid regeneration unit includes a spent acid incinerator, which is connected with an air inlet pipe, a fuel gas inlet pipe, a spent acid inlet pipe, and an acid gas inlet pipe. The spent acid incinerator is also connected with an acid gas delivery pipe for discharging the sulfur dioxide-containing acid gas generated after incineration. At least one converter for converting sulfur dioxide into sulfur trioxide and a condenser corresponding to the converter one by one for condensing sulfur trioxide to generate sulfuric acid are provided on the acid gas delivery pipe. The condenser is connected with a sulfuric acid delivery pipe for discharging sulfuric acid. The last condenser is connected to a tail gas treatment device through a pipeline. Its structural feature is that the device also includes a sulfuric acid concentration unit for concentrating the sulfuric acid generated by the spent acid regeneration unit to obtain concentrated sulfuric acid with a concentration of more than 98 wt%. The sulfuric acid concentration unit includes a combustion chamber in which liquid sulfur burns to generate sulfur dioxide. The combustion chamber is connected with a liquid sulfur inlet pipe, a main fuel gas pipe, and a combustion-supporting air pipeline. The liquid sulfur inlet pipe is connected with an air pipeline for atomizing liquid sulfur. The combustion chamber is connected with a process gas delivery pipe for discharging the generated sulfur dioxide process gas. A steam generating device for generating steam by using the heat in the combustion chamber is provided in the combustion chamber. The steam generating device is connected with a deaerated water inlet pipe and a steam discharge pipeline. The process gas delivery pipe is connected to a reactor for catalytically generating sulfur trioxide from sulfur dioxide. The reactor is connected with a process gas discharge pipe for discharging the generated sulfur trioxide. The process gas discharge pipe is connected to the lower part of an absorption tower for sulfuric acid concentration. The top of the absorption tower is connected to the spent acid incinerator through an absorption tower tail gas discharge pipe. The bottom of the absorption tower is connected with a concentrated sulfuric acid discharge pipe. A sulfuric acid reflux pipe and a concentrated sulfuric acid external delivery valve are provided on the concentrated sulfuric acid discharge pipe along the flowing direction of the concentrated sulfuric acid. The sulfuric acid reflux pipe is connected to the upper part of the absorption tower. The sulfuric acid delivery pipe is connected to the upper part of the absorption tower.

[0007] After adopting the above structure, sulfur-containing waste acid, acid gas, combustion-supporting air, and fuel gas are respectively introduced into the waste acid incinerator through the waste acid inlet pipe, acid gas inlet pipe, air inlet pipe, and fuel gas inlet pipe. In the waste acid incinerator, the sulfur-containing substances in the sulfur-containing waste acid burn to generate sulfur dioxide. After the acid gas containing sulfur dioxide is discharged through the acid gas delivery pipe, it sequentially passes through at least one converter and at least one condenser. The converter is used to convert sulfur dioxide into sulfur trioxide, and the condenser is used to condense the generated sulfur trioxide to form sulfuric acid. The small amount of sulfur dioxide contained in the tail gas discharged from the last condenser is purified by the tail gas treatment equipment and then discharged. The sulfuric acid generated in the condenser is discharged into the sulfuric acid delivery pipe. Since the sulfur-containing waste acid and acid gas contain a certain amount of hydrocarbons, the hydrocarbons burn to generate water in the waste acid incinerator and enter the sulfuric acid generated in the condenser. Therefore, the sulfuric acid concentration discharged from the condenser is lower than 98 wt%, which cannot meet the quality requirements of 98 wt% concentrated sulfuric acid; liquid sulfur, dry air, and fuel gas respectively enter the combustion chamber through the liquid sulfur inlet pipe, combustion-supporting air pipeline, and fuel gas main pipe. The liquid sulfur burns in the combustion chamber to generate sulfur dioxide. The process gas containing sulfur dioxide enters the reactor through the process gas delivery pipe. The sulfur dioxide undergoes a catalytic reaction in the reactor to generate sulfur trioxide. The process gas containing sulfur trioxide is introduced into the absorption tower from the lower part through the process gas delivery pipe. The bottom of the absorption tower is connected with a concentrated sulfuric acid discharge pipe. The concentrated sulfuric acid discharged from the absorption tower can flow back into the absorption tower from the upper part through the sulfuric acid reflux pipe. The sulfuric acid in the sulfuric acid delivery pipe also enters the absorption tower from the upper part. The sulfur trioxide and sulfuric acid undergo countercurrent contact adsorption in the absorption tower, and the concentration of sulfuric acid increases. When the concentration of the concentrated sulfuric acid in the concentrated sulfuric acid discharge pipe reaches more than 98 wt%, the concentrated sulfuric acid external delivery valve is opened to send out the concentrated sulfuric acid product that meets the quality requirements. The tail gas generated by the absorption tower enters the waste acid incinerator through the absorption tower tail gas discharge pipe for incineration treatment; the deaerated water used for preparing steam enters the steam generating equipment through the deaerated water inlet pipe. The steam generating equipment uses the heat in the combustion chamber to generate steam, and the generated steam enters the steam discharge pipeline. The present invention uses the process of liquid sulfur combustion + sulfur dioxide conversion + absorption to concentrate the sulfuric acid generated by waste acid incineration, increases the concentration of the sulfuric acid generated by waste acid incineration to more than 98 wt%, improves the efficiency of the sulfuric acid product, and uses the heat in the combustion chamber to by-produce steam to realize the recovery and utilization of waste heat.

[0008] A fuel gas branch pipe, a fuel gas flowmeter, and a fuel gas regulating valve are sequentially arranged on the fuel gas main pipe along the fuel gas flow direction. The fuel gas branch pipe is connected to the pilot burner of the combustion chamber. A combustion chamber thermometer for detecting the furnace temperature is provided on the combustion chamber. The combustion chamber thermometer is electrically connected to the fuel gas flowmeter and the fuel gas regulating valve.

[0009] The process gas transfer pipe is connected to the top of the reactor. Inside the reactor, there are a tail gas preheater for preheating the tail gas of the absorption tower and an air preheater for preheating the dry air entering the combustion chamber. The air inlet and outlet of the air preheater are connected to the dry air supply pipe. The end of the dry air supply pipe connected to the air outlet of the air preheater is connected to the combustion-supporting air branch pipe and the liquid sulfur atomizing air branch pipe. The liquid sulfur atomizing air branch pipe is connected to the liquid sulfur supply pipe, and the combustion-supporting air branch pipe is connected to the combustion chamber. On the dry air supply pipe connected to the air inlet of the air preheater, there are a dry air flowmeter and a dry air regulating valve. On the process gas transfer pipe, there is an oxygen analyzer for detecting the oxygen content in the process gas, and the oxygen analyzer is electrically connected to the dry air flowmeter and the dry air regulating valve.

[0010] On the liquid sulfur supply pipe, there are a liquid sulfur-steam heat exchanger, a liquid sulfur thermometer, a liquid sulfur flowmeter, and a liquid sulfur feed regulating valve arranged in sequence along the flowing direction of the liquid sulfur. The connection point of the liquid sulfur atomizing air branch pipe and the liquid sulfur supply pipe is located between the liquid sulfur feed regulating valve and the combustion chamber. The liquid sulfur-steam heat exchanger is also connected to the steam supply pipe. On the steam supply pipe, there is a steam flow regulating valve, and the steam flow regulating valve is electrically connected to the liquid sulfur thermometer. The liquid sulfur flowmeter is electrically connected to the liquid sulfur feed regulating valve.

[0011] On the process gas transfer pipe, there is a deaerated water preheater for preheating the deaerated water used for generating steam. The inlet and outlet of the deaerated water preheater are both connected to the deaerated water supply pipe. The steam generating equipment includes a steam superheater and a steam generator arranged in sequence along the flowing direction of sulfur dioxide in the combustion chamber. The steam superheater and the steam generator are arranged near the discharge end of the sulfur dioxide process gas. The water inlet of the steam generator is connected to the deaerated water supply pipe connected to the outlet of the deaerated water preheater. The steam outlet of the steam generator is connected to the steam superheater through a saturated steam pipeline, and the steam outlet of the steam superheater is connected to a superheated steam pipeline.

[0012] There is a steam bypass between the saturated steam pipeline and the superheated steam pipeline, and there is a bypass regulating valve on the steam bypass. On the deaerated water supply pipe connected to the water inlet of the deaerated water preheater, there are a deaerated water flowmeter and a deaerated water regulating valve, and the deaerated water flowmeter is electrically connected to the deaerated water regulating valve.

[0013] The tail gas preheater includes a tail gas bare tube heat exchanger and a glass tube heat exchanger. The tail gas bare tube heat exchanger, the air preheater, and the glass tube heat exchanger are arranged in sequence along the flowing direction of the process gas in the reactor. The absorption tower tail gas discharge pipe is connected to the glass tube heat exchanger and the tail gas bare tube heat exchanger in sequence along the flowing direction of the tail gas.

[0014] A circulating water cooler for cooling concentrated sulfuric acid and a concentrated sulfuric acid thermometer for detecting the temperature of concentrated sulfuric acid are provided on the concentrated sulfuric acid discharge pipe, and are arranged along the flowing direction of concentrated sulfuric acid. The circulating water cooler and the concentrated sulfuric acid thermometer are arranged in the section between the absorption tower and the sulfuric acid reflux pipe. The inlet and outlet of the circulating water cooler are connected to the circulating cooling water pipe. A circulating cooling water regulating valve is provided on the circulating cooling water pipe connected to the outlet of the circulating water cooler, and the circulating cooling water regulating valve is electrically connected to the concentrated sulfuric acid thermometer. A first online sulfuric acid concentration meter for real-time detecting the concentration of concentrated sulfuric acid is also provided on the concentrated sulfuric acid discharge pipe, and the first online sulfuric acid concentration meter is electrically connected to the concentrated sulfuric acid external delivery valve.

[0015] A method for producing concentrated sulfuric acid, using the device described in any one of the above. Sulfurous waste acid and acid gas are respectively introduced into the waste acid incinerator through the waste acid inlet pipe and the acid gas inlet pipe. Combustion-supporting air and fuel gas respectively enter the waste acid incinerator through the air inlet pipe and the fuel gas inlet pipe. The sulfur-containing substances in the sulfurous waste acid and acid gas burn in the waste acid incinerator to generate sulfur dioxide. The acid gas containing sulfur dioxide passes through the converter and the condenser in sequence through the acid gas delivery pipe. At least one converter and condenser are provided, and the converter and the condenser are arranged in one-to-one correspondence. Sulfur dioxide reacts in the converter to generate sulfur trioxide, and sulfur trioxide generates sulfuric acid in the condenser and enters the sulfuric acid delivery pipe. The sulfuric acid in the sulfuric acid delivery pipe has a concentration lower than 98 wt%. The tail gas discharged from the last condenser is purified by the tail gas treatment equipment and then discharged. Liquid sulfur enters the combustion chamber through the liquid sulfur inlet pipe. Dry air and fuel gas respectively enter the combustion chamber through the combustion-supporting air pipeline and the main fuel gas pipe. The liquid sulfur burns in the combustion chamber to generate sulfur dioxide. The process gas containing sulfur dioxide generated in the combustion chamber enters the reactor through the process gas delivery pipe. Sulfur dioxide undergoes a catalytic reaction in the reactor to generate sulfur trioxide. The process gas containing sulfur trioxide generated in the reactor enters the absorption tower from the lower part through the process gas discharge pipe. The sulfuric acid in the sulfuric acid delivery pipe enters the absorption tower from the upper part. Sulfuric acid and sulfur trioxide undergo countercurrent contact adsorption in the absorption tower. Sulfuric acid absorbs sulfur trioxide to generate concentrated sulfuric acid. The obtained concentrated sulfuric acid enters the concentrated sulfuric acid discharge pipe. Part of the concentrated sulfuric acid is refluxed from the upper part to the absorption tower through the sulfuric acid reflux pipe, and undergoes cyclic countercurrent contact adsorption with sulfur trioxide to increase the concentration of concentrated sulfuric acid. When the concentration of concentrated sulfuric acid in the concentrated sulfuric acid discharge pipe reaches more than 98 wt%, the concentrated sulfuric acid external delivery valve is opened, and the concentrated sulfuric acid product with a concentration of more than 98 wt% is sent out. The tail gas generated by the absorption tower enters the waste acid incinerator for treatment through the absorption tower tail gas discharge pipe. Deoxygenated water enters the steam generating equipment in the combustion chamber through the deoxygenated water inlet pipe. The steam generating equipment absorbs the heat in the combustion chamber to generate steam.

[0016] The temperature of the liquid sulfur in the liquid sulfur inlet pipe is 140 °C. The temperature of the process gas containing sulfur dioxide entering the reactor is 440 °C.

[0017] The sulfuric acid concentration produced by the spent acid regeneration unit fails to meet the requirements of 98wt% concentrated sulfuric acid product. For the sulfuric acid concentration device of the present invention and the method for producing concentrated sulfuric acid using this device, the sulfuric acid is concentrated by adopting the process of liquid sulfur combustion + sulfur dioxide conversion + absorption. The liquid sulfur vaporizes and enters the combustion chamber to burn and generate sulfur dioxide. The sulfur dioxide undergoes a catalytic reaction in the converter to generate sulfur trioxide. The sulfur trioxide and the sulfuric acid that fails to meet the product requirements are in countercurrent contact absorption in the absorption tower. After the sulfuric acid absorbs the sulfur trioxide, its concentration increases. When the sulfuric acid meets the requirements of 98wt% concentrated sulfuric acid, it is sent out as a product, improving the economic benefits of the sulfuric acid product; the heat in the combustion chamber is used to by-produce superheated steam to realize heat recovery and utilization, improving the device efficiency. Brief Description of the Drawings

[0018] Figure 1 It is a schematic structural diagram of the present invention;

[0019] In the figure: 1. Liquid sulfur inlet pipe; 11. Liquid sulfur - steam heat exchanger; 12. Liquid sulfur thermometer; 13. Liquid sulfur flowmeter; 14. Liquid sulfur feed regulating valve; 2. Steam inlet pipe; 21. Steam flow regulating valve; 3. Main fuel gas pipe; 31. Fuel gas branch pipe; 32. Fuel gas flowmeter; 33. Fuel gas regulating valve; 4. Dry air inlet pipe; 41. Combustion air branch pipe; 42. Liquid sulfur atomizing air branch pipe; 421. Liquid sulfur atomizing air regulating valve; 422. Liquid sulfur atomizing air flowmeter; 43. Dry air flowmeter; 44. Dry air regulating valve; 5. Combustion chamber; 51. Combustion chamber thermometer; 52. Steam superheater; 521. Superheated steam pipeline; 53. Steam generator; 531. Saturated steam pipeline; 532. Steam bypass; 533. Bypass regulating valve; 54. Process gas transfer pipe; 541. Deaerated water preheater; 542. Oxygen analyzer; 6. Deaerated water inlet pipe; 61. Deaerated water flowmeter; 62. Deaerated water regulating valve; 7. Reactor; 71. Tail gas bare tube heat exchanger; 72. Air preheater; 73. Glass tube heat exchanger; 74. Process gas discharge pipe; 8. Absorption tower; 81. Concentrated sulfuric acid discharge pipe; 811. Circulating water cooler; 812. Concentrated sulfuric acid thermometer; 813. Concentrated sulfuric acid circulating pump; 814. Sulfuric acid return pipe; 815. First sulfuric acid on - line concentration meter; 816. Concentrated sulfuric acid external delivery valve; 817. Circulating cooling water pipe; 818. Circulating cooling water regulating valve; 82. Absorption tower tail gas discharge pipe; 821. Tail gas fan; 100. Spent acid incinerator; 101. Air inlet pipe; 102. Fuel gas inlet pipe; 103. Spent acid inlet pipe; 104. Acid gas inlet pipe; 105. First acid gas transfer pipe; 200. Filter; 300. First - stage converter; 301. Second acid gas transfer pipe; 400. First - stage condenser; 401. First sulfuric acid transfer pipe; 402. Second sulfuric acid on - line concentration meter; 403. Sulfuric acid flowmeter; 404. Sulfuric acid regulating valve; 405. Third acid gas transfer pipe; 500. Second - stage converter; 501. Fourth acid gas transfer pipe; 600. Second - stage condenser; 601. Second sulfuric acid transfer pipe; 602. Sulfur - containing tail gas discharge pipe; 700. Activated carbon reactor; 701. Tail gas discharge pipe. Detailed implementation manners

[0020] Refer to Figure 1, a sulfuric acid concentration device, including a spent acid regeneration unit for incinerating sulfur-containing spent acid and acid gas to produce sulfuric acid, and a sulfuric acid concentration unit for concentrating the sulfuric acid produced by the spent acid regeneration unit to obtain concentrated sulfuric acid with a concentration of more than 98 wt%. The spent acid regeneration unit includes a spent acid incinerator 100, which is connected with an air inlet pipe 101, a fuel gas inlet pipe 102, a spent acid inlet pipe 103 and an acid gas inlet pipe 104. The sulfur-containing spent acid and acid gas burn in the spent acid incinerator 100 to generate sulfur dioxide. The spent acid incinerator 100 is connected with at least one converter and at least one condenser through an acid gas transmission pipe. The converter converts sulfur dioxide into sulfur trioxide, and the condenser condenses the sulfur trioxide generated by the converter to produce sulfuric acid. The converters and condensers are arranged in one-to-one correspondence. As Figure 1 shown, the spent acid regeneration unit includes two-stage converters and condensers, which is a conventional design in the art. Specifically, the spent acid incinerator 100 is connected with a first-stage converter 300 through a first acid gas transmission pipe 105. A filter 200 for filtering dust in the acid gas and resistant to acid and high temperature is provided on the first acid gas transmission pipe 105. The first-stage converter 300 is connected with a first-stage condenser 400 through a second acid gas transmission pipe 301. The first-stage condenser 400 is connected with a second-stage converter 500 through a third acid gas transmission pipe 405. The second-stage converter 500 is connected with a second-stage condenser 600 through a fourth acid gas transmission pipe 501. The second-stage condenser 600 is connected with an activated carbon reactor 700 through a sulfur-containing tail gas discharge pipe 602. The activated carbon reactor 700 is a tail gas treatment device that can capture and purify a small amount of sulfur dioxide in the tail gas. The activated carbon reactor 700 is connected with a tail gas discharge pipe 701. The bottom of the first-stage condenser 400 is connected with a first sulfuric acid transmission pipe 401. The bottom of the second-stage condenser 600 is connected with a second sulfuric acid transmission pipe 601. The sulfuric acid produced by the first-stage condenser 400 and the second-stage condenser 600 is discharged through the first sulfuric acid transmission pipe 401 and the second sulfuric acid transmission pipe 601 respectively. The second sulfuric acid transmission pipe 601 is connected to the first sulfuric acid transmission pipe 401 to merge the two streams of sulfuric acid. A second sulfuric acid on-line concentration meter 402, a sulfuric acid flow meter 403 and a sulfuric acid regulating valve 404 are also provided on the first sulfuric acid transmission pipe 401. The sulfuric acid flow meter 403 is electrically connected with the sulfuric acid regulating valve 404, and the flow rate of the sulfuric acid entering the absorption tower 8 is controlled by adjusting the opening of the sulfuric acid regulating valve 404.

[0021] Refer to Figure 1, the sulfuric acid concentration increasing unit includes a combustion chamber 5 where liquid sulfur burns to generate sulfur dioxide. The combustion chamber 5 is connected to a liquid sulfur inlet pipe 1, a main fuel gas pipe 3, and a combustion air pipeline. The liquid sulfur inlet pipe 1 is connected to an air pipeline for atomizing the liquid sulfur. After the liquid sulfur is atomized, it enters the combustion chamber 5. Inside the combustion chamber 5, there is a steam generating device that uses the heat in the combustion chamber 5 to generate steam. The steam generating device is connected to a deaerated water inlet pipe 6 and a steam discharge pipeline. The combustion chamber 5 is connected to the top of a reactor 7 through a process gas transfer pipe 54. The sulfur dioxide process gas generated by the combustion of liquid sulfur passes through the process gas transfer pipe 54 and enters the reactor 7. Sulfur dioxide undergoes a catalytic reaction in the reactor 7 to generate sulfur trioxide. Inside the reactor 7, there is a vanadium-based catalyst, which is a conventional setting in the art. The bottom of the reactor 7 is connected to the lower part of an absorption tower 8 through a process gas discharge pipe 74. The sulfur trioxide process gas generated inside the reactor 7 passes through the process gas discharge pipe 74 and enters the absorption tower 8 from the lower part. The top of the absorption tower 8 is connected to a waste acid incinerator 100 through an absorption tower tail gas discharge pipe 82. Specifically, the absorption tower tail gas discharge pipe 82 is connected to an acid gas inlet pipe 104. The absorption tower tail gas enters the waste acid incinerator 100 through the acid gas inlet pipe 104 for incineration treatment. Of course, the absorption tower tail gas discharge pipe 82 can also be directly connected to the waste acid incinerator 100; as Figure 1 shown, the bottom of the absorption tower 8 is connected to a concentrated sulfuric acid discharge pipe 81. On the concentrated sulfuric acid discharge pipe 81, there is a sulfuric acid reflux pipe 814 and a concentrated sulfuric acid external delivery valve 816 arranged along the flow direction of the concentrated sulfuric acid. The sulfuric acid reflux pipe 814 is connected to the upper part of the absorption tower 8. The sulfuric acid delivery pipe is connected to the upper part of the absorption tower 8. Specifically, the sulfuric acid delivery pipe is connected to the sulfuric acid reflux pipe 814. The sulfuric acid in the sulfuric acid delivery pipe passes through the sulfuric acid reflux pipe 814 and enters the absorption tower 8 from the upper part. A check valve is set on the sulfuric acid reflux pipe 814 to prevent backflow. Of course, the sulfuric acid delivery pipe can also be directly connected to the upper part of the absorption tower 8. The sulfur trioxide process gas flows upward in the absorption tower 8 from the bottom, and the sulfuric acid flows downward in the absorption tower 8 from the top. The sulfuric acid and sulfur trioxide undergo countercurrent contact adsorption. The water absorbs sulfur trioxide to form sulfuric acid, and the concentration of the sulfuric acid increases. When the concentration of the sulfuric acid in the concentrated sulfuric acid discharge pipe 81 reaches more than 98 wt%, the concentrated sulfuric acid external delivery valve 816 is opened to send out the qualified concentrated sulfuric acid product.

[0022] Refer to Figure 1, a fuel gas main pipe 3 is provided with a fuel gas branch pipe 31, a fuel gas flowmeter 32, and a fuel gas regulating valve 33 arranged in sequence along the fuel gas flow direction. The fuel gas branch pipe 31 is connected to the pilot burner of the combustion chamber 5. A combustion chamber thermometer 51 for detecting the furnace temperature is arranged in the combustion chamber 5. The combustion chamber thermometer 51 is electrically connected to the fuel gas flowmeter 32 and the fuel gas regulating valve 33. By adjusting the opening degree of the fuel gas regulating valve 33, the fuel gas flow rate into the combustion chamber 5 is controlled, and the temperature of the combustion chamber 5 is cascade-controlled at 1000 °C. A circulating water cooler 811 and a concentrated sulfuric acid thermometer 812 are arranged on the concentrated sulfuric acid discharge pipe 81 along the flow direction of the concentrated sulfuric acid. The circulating water cooler 811 cools down the concentrated sulfuric acid. The concentrated sulfuric acid thermometer 812 detects the temperature of the concentrated sulfuric acid. The circulating water cooler 811 and the concentrated sulfuric acid thermometer 812 are arranged in the section between the absorption tower 8 and the sulfuric acid return pipe 814. The water inlet and outlet of the circulating water cooler 811 are connected to the circulating cooling water pipe 817. A circulating cooling water regulating valve 818 is arranged on the circulating cooling water pipe 817 connected to the outlet of the circulating water cooler 811. The concentrated sulfuric acid thermometer 812 is electrically connected to the circulating cooling water regulating valve 818. By adjusting the opening degree of the circulating cooling water regulating valve 818, the temperature of the concentrated sulfuric acid is controlled to make the temperature of the cooled concentrated sulfuric acid at 40 °C. A first online sulfuric acid concentration meter 815 capable of detecting the concentration of concentrated sulfuric acid in real time is also arranged on the concentrated sulfuric acid discharge pipe 81. The first online sulfuric acid concentration meter 815 is arranged between the sulfuric acid return pipe 814 and the concentrated sulfuric acid external delivery valve 816. The first online sulfuric acid concentration meter 815 is electrically connected to the concentrated sulfuric acid external delivery valve 816. When the first online sulfuric acid concentration meter 815 detects that the sulfuric acid concentration is above 98 wt%, the concentrated sulfuric acid external delivery valve 816 is automatically opened to send out the qualified concentrated sulfuric acid product. For example, when the first online sulfuric acid concentration meter 815 detects that the concentrated sulfuric acid concentration reaches 99 wt%, the concentrated sulfuric acid external delivery valve 816 is opened. When the first online sulfuric acid concentration meter 815 detects that the concentrated sulfuric acid concentration is below 98 wt%, the concentrated sulfuric acid external delivery valve 816 is closed to make the concentration of the discharged concentrated sulfuric acid product meet the quality standard. A concentrated sulfuric acid circulation pump 813 is also arranged on the concentrated sulfuric acid discharge pipe 81 to provide power for the concentrated sulfuric acid circulation.

[0023] Refer to Figure 1, there is a tail gas preheater and an air preheater 72 in the reactor 7. The tail gas preheater 72 preheats the tail gas from the absorption tower, and the air preheater preheats the dry air entering the combustion chamber 5. The air inlet and outlet of the air preheater 72 are connected to the dry air supply pipe 4. The end of the dry air supply pipe 4 connected to the air outlet of the air preheater 72 is connected to the combustion-supporting air branch pipe 41 and the liquid sulfur atomizing air branch pipe 42. The liquid sulfur atomizing air branch pipe 42 is connected to the liquid sulfur supply pipe 1. The dry air enters the liquid sulfur supply pipe 1 to atomize the liquid sulfur. There are a liquid sulfur atomizing air regulating valve 421 and a liquid sulfur atomizing air flowmeter 422 on the liquid sulfur atomizing air branch pipe 42. The liquid sulfur atomizing air regulating valve 421 is electrically connected to the liquid sulfur atomizing air flowmeter 422. By adjusting the opening of the liquid sulfur atomizing air regulating valve 421, the air flow rate into the liquid sulfur supply pipe 1 is controlled to keep a certain ratio between the atomizing air flow rate and the liquid sulfur. The combustion-supporting air branch pipe 41 is connected to the combustion chamber 5 and serves as the combustion-supporting air for liquid sulfur combustion. There are a dry air flowmeter 43 and a dry air regulating valve 44 on the dry air supply pipe 4 connected to the air inlet of the air preheater 72. There is an oxygen analyzer 542 on the process gas transfer pipe 54. The oxygen analyzer 542 detects the oxygen content of the process gas in the pipeline. The oxygen analyzer 542 is electrically connected to the dry air flowmeter 43 and the dry air regulating valve 44 to cascade-control the oxygen content in the process gas transfer pipe 54. As Figure 1 shown, there are a liquid sulfur-steam heat exchanger 11, a liquid sulfur thermometer 12, a liquid sulfur flowmeter 13, and a liquid sulfur feed regulating valve 14 arranged in sequence along the liquid sulfur flow direction on the liquid sulfur supply pipe 1. The connection point of the liquid sulfur atomizing air branch pipe 42 and the liquid sulfur supply pipe 1 is located between the liquid sulfur feed regulating valve 14 and the combustion chamber 5. The liquid sulfur-steam heat exchanger 11 uses a graphite heat exchanger. The liquid sulfur flowmeter 13 is electrically connected to the liquid sulfur feed regulating valve 14. By adjusting the opening of the liquid sulfur feed regulating valve 14, the liquid sulfur flow rate is controlled. The liquid sulfur-steam heat exchanger 11 is also connected to a steam supply pipe 2 for heating the liquid sulfur in the liquid sulfur supply pipe 1. When the liquid sulfur flows through the liquid sulfur-steam heat exchanger 11, it absorbs the heat in the steam to keep the liquid sulfur in a liquid state. There is a steam flow regulating valve 21 on the steam supply pipe 2. The steam flow regulating valve 21 is electrically connected to the liquid sulfur thermometer 12. By adjusting the opening of the steam flow regulating valve 21, the steam flow rate is controlled, and thus the heat exchange amount between the steam and the liquid sulfur and the temperature of the heated liquid sulfur are controlled to make the temperature of the heated liquid sulfur 140 °C.

[0024] Refer to Figure 1, a deaerated water preheater 541 is provided on the process gas transfer pipe 54. The deaerated water preheater 541 uses the waste heat of the process gas to preheat the deaerated water for producing steam. Both the inlet and outlet of the deaerated water preheater 541 are connected to the deaerated water supply pipe 6. The deaerated water and the process gas exchange heat in the deaerated water preheater 541. The deaerated water absorbs the heat of the process gas and is heated to 140 °C, and the temperature of the process gas drops to 440 °C after releasing heat. The steam generating equipment includes a steam superheater 52 and a steam generator 53 arranged in sequence along the flow direction of sulfur dioxide in the combustion chamber 5. The steam superheater 52 and the steam generator 53 are arranged near the discharge end of the sulfur dioxide process gas. The water inlet of the steam generator 53 is connected to the deaerated water supply pipe 6 connected to the outlet of the deaerated water preheater 541. The steam outlet of the steam generator 53 is connected to the steam inlet of the steam superheater 52 through a saturated steam pipe 531. The steam outlet of the steam superheater 52 is connected to a superheated steam pipe 521. The superheated steam generated by the steam superheater 52 is sent out through the superheated steam pipe 521. A steam bypass 532 is provided between the saturated steam pipe 531 and the superheated steam pipe 521, and a bypass regulating valve 533 is provided on the steam bypass 532. The temperature of the superheated steam is controlled by adjusting the opening degree of the bypass regulating valve 533; a deaerated water flowmeter 61 and a deaerated water regulating valve 62 are provided on the deaerated water supply pipe 6 connected to the inlet of the deaerated water preheater 541. The deaerated water flowmeter 61 is electrically connected to the deaerated water regulating valve 62. The flow rate of the deaerated water and the steam output are controlled by adjusting the opening degree of the deaerated water regulating valve 62. The tail gas preheater includes a tail gas bare tube heat exchanger 71 and a glass tube heat exchanger 73. The tail gas bare tube heat exchanger 71, the air preheater 72, and the glass tube heat exchanger 73 are arranged in sequence along the flow direction of the process gas in the reactor 7. The tail gas discharge pipe 82 of the absorption tower is connected to the glass tube heat exchanger 73 and the tail gas bare tube heat exchanger 71 in sequence along the flow direction of the tail gas. The tail gas of the absorption tower first flows through the glass tube heat exchanger 73 to exchange heat with the process gas in the reactor 7, and then flows through the tail gas bare tube heat exchanger 71 to exchange heat with the process gas in the reactor 7, so as to increase the temperature of the tail gas of the absorption tower entering the waste acid incinerator 100; a tail gas fan 821 for extracting the tail gas of the absorption tower is also provided on the tail gas discharge pipe 82 connected to the tail gas outlet of the tail gas bare tube heat exchanger 71. The tail gas fan 821 is a variable frequency fan. The furnace pressure of the combustion chamber 5 is controlled by the tail gas fan 821, so that the furnace of the combustion chamber 5 maintains a slight negative pressure (-0.5 kPa to -0.05 kPa), avoiding the escape of harmful gases and polluting the environment.

[0025] It should be noted that: actual pressure gauges, thermometers and other accessories are also provided on the combustion chamber 5, reactor 7, absorption tower 8, waste acid incinerator 100, converter, and condenser, and hand valves, pumps, fans, instruments and other accessories are also provided on the pipelines, which are not shown in the figures or texts and are conventional settings in the art; the equipment involved in the present invention is prior art and can be purchased from relevant enterprises with design and production qualifications.

[0026] A method for producing concentrated sulfuric acid using the above device adopts the following processes:

[0027] 1. Process flow of the spent acid regeneration unit

[0028] The 98 wt% sulfuric acid catalyst used in the alkylation unit has its sulfuric acid concentration decreased to 90 wt% after the alkylation reaction and loses its catalytic effect, and is discharged as the spent acid of the alkylation unit. The raw materials of the spent acid regeneration unit are sulfuric acid with a mass content of 90% and acidic gas with a composition of H2S from the sulfur plant.

[0029] The sulfur-containing spent acid and the acidic gas are respectively introduced into the spent acid incinerator 100 through the spent acid inlet pipe 103 and the acidic gas inlet pipe 104, and the combustion-supporting air and the fuel gas are respectively introduced into the spent acid incinerator 100 through the air inlet pipe 101 and the fuel gas inlet pipe 102. The sulfur-containing spent acid is incinerated at 1100 °C to generate sulfur dioxide, and reactions ① and ② occur. The acidic gas is incinerated at 1100 °C to generate sulfur dioxide, and reaction ③ occurs:

[0030] H 2 SO 4 1100 °C → SO 3 +H 2 O ①

[0031] 2SO 3 1100 °C → 2SO 2 +O 2 ②

[0032] 2H 2 S+3O 2 1100 °C → 2SO 2 +2H 2 O ③

[0033] The acidic gas containing sulfur dioxide is filtered by the filter 200 to remove dust, and its temperature drops to 440°C. Then it enters the first-stage converter 300, where 95% of the sulfur dioxide in the acidic gas is converted into sulfur trioxide. After passing through the first-stage condenser 400, the sulfur trioxide is converted into sulfuric acid. The remaining 5% of the sulfur dioxide in the acidic gas enters the second-stage converter 500 to be converted into sulfur trioxide, and then through the second-stage condenser 600, the sulfur trioxide is converted into sulfuric acid. The tail gas containing sulfur dioxide at the ppm level is captured by the activated carbon reactor 700, and the purified tail gas is discharged into the atmosphere through the chimney. The waste acid incineration is designed to produce 98 wt% concentrated sulfuric acid. Since both the raw material waste acid and the acidic gas carry hydrocarbon components, water is generated by burning in the waste acid incinerator 100. This part of the water is condensed in the product sulfuric acid in the first-stage condenser 400 and the second-stage condenser 600, resulting in unqualified concentrated sulfuric acid with an actual concentration of about 97 wt%. The concentrated sulfuric acid produced by the first-stage condenser 400 and the second-stage condenser 600 is combined and enters the first sulfuric acid transfer pipe 401, and after passing through the second online sulfuric acid concentration meter 402, the sulfuric acid flow meter 403, and the sulfuric acid regulating valve 404, it is sent to the absorption tower 8 of the newly added sulfuric acid concentration unit described below.

[0034] 2. Process of sulfuric acid concentration unit

[0035] (1) Liquid sulfur incineration

[0036] The liquid sulfur coming from upstream enters the liquid sulfur supply pipe 1. The liquid sulfur exchanges heat with steam in the liquid sulfur-steam heat exchanger 11. The temperature of the liquid sulfur is controlled at 140°C by the steam flow regulating valve 21 to maintain the liquefied state of sulfur. After being metered by the liquid sulfur flow meter 13 and the liquid sulfur feed regulating valve 14, it is atomized and sent into the combustion chamber 5 by the air atomization through the liquid sulfur atomizing air branch pipe 42.

[0037] The fuel gas coming from the fuel gas pipeline network is divided into two paths. The main branch is the fuel gas main pipe 3. The fuel gas passes through the fuel gas flow meter 32, the fuel gas regulating valve 33, and the main burner (not shown in the figure) and then enters the combustion chamber 5. The secondary branch is the fuel gas branch pipe 31. The fuel gas enters the combustion chamber 5 through the pilot burner (not shown in the figure) of the combustion chamber 5. The fuel gas burns in the combustion chamber 5, raising the furnace temperature to 1000°C, providing a place for the liquid sulfur reaction. The furnace temperature of the combustion chamber 5 is detected by the furnace temperature thermometer 51, and the fuel gas flow is controlled by the fuel gas regulating valve 33 to cascade-control the furnace temperature of the combustion chamber 5 at the target temperature of 1000°C.

[0038] The air in the dry air supply pipe 4 is metered by the dry air flowmeter 43 and the dry air regulating valve 44, preheated by the air preheater 72, and then divided into two paths. One path enters the combustion chamber 5 through the combustion air branch pipe 41 to provide the oxygen required for combustion, and the other path enters the liquid sulfur atomizing air branch pipe 42. After passing through the liquid sulfur atomizing air regulating valve 421 and the liquid sulfur atomizing air flowmeter 422, it enters the liquid sulfur supply pipe 1, and a certain proportion is controlled according to the liquid sulfur feed rate for liquid sulfur atomization. To ensure the best quality of the product, the dry air uses purified air with a dew point lower than -60°C. The dry air for combustion is preheated to 150°C by the air preheater 72 and then enters the combustion chamber 5 to reduce the energy consumption of the device. The dry air automatically controls the air volume entering the combustion chamber 5 through the dry air flowmeter 43 and the dry air regulating valve 44, and cascades to control the excess oxygen content in the process gas within the range of 2 - 5%V according to the measurement value of the oxygen analyzer 542.

[0039] After the liquid sulfur burns in the combustion chamber 5, high-temperature process gas containing sulfur dioxide at 1000°C is generated. It passes through the steam superheater 52 and the steam generator 53 in sequence and then enters the process gas transfer pipe 54. The steam superheater 52 and the steam generator 53 absorb the heat of the high-temperature process gas to generate superheated steam. The high-temperature process gas then enters the deaerated water preheater 541 and the temperature drops to 440°C, and then enters the downstream reactor 7. To avoid the escape of harmful gases and pollute the environment, the combustion chamber 5 operates at a slight negative pressure (-0.5 kPa to -0.05 kPa), and the furnace negative pressure is controlled by the frequency converter of the tail gas fan 821.

[0040] (2) Sulfur Dioxide Conversion

[0041] In the reactor 7, under the catalytic action of the vanadium-based catalyst, the sulfur dioxide in the sulfur dioxide process gas undergoes a catalytic oxidation reaction to generate sulfur trioxide, and the conversion rate is close to 90%. The reaction is as follows:

[0042] Oxidation (conversion rate about 90%)

[0043] The sulfur dioxide oxidation reaction is an exothermic reaction. After passing through the catalyst bed, the temperature of the process gas rises from 440°C to 450°C. The reacted process gas (SO 2 +SO 3 ) passes through the tail gas bare tube heat exchanger 71, the air preheater 72, and the glass tube heat exchanger 73 for three-stage heat exchange in sequence, and the temperature drops to about 130°C, and then is introduced into the lower part of the absorption tower 8 through the process gas discharge pipe 74.

[0044] (3) Absorption

[0045] The absorption tower 8 is equipped with an internal circulation system. The produced concentrated sulfuric acid enters the concentrated sulfuric acid discharge pipe 81, is cooled to 40°C by the circulating water cooler 811, and the temperature of the concentrated sulfuric acid after cooling is controlled by the circulating cooling water regulating valve 818. After passing through the concentrated sulfuric acid circulating pump 813, the concentrated sulfuric acid is divided into two branches. In the external delivery branch, when the first sulfuric acid on-line concentration meter 815 shows that the sulfuric acid concentration reaches 99 wt%, the concentrated sulfuric acid external delivery valve 816 is automatically opened, and when the concentration is lower than 98 wt%, the concentrated sulfuric acid external delivery valve 816 is closed. The concentrated sulfuric acid in the circulating branch enters the sulfuric acid return pipe 814, and the check valve prevents the sulfuric acid from flowing back. After mixing with the unqualified sulfuric acid from the spent acid regeneration unit, it enters the absorption tower 8 from the upper part, is distributed by the tower top distributor, and evenly sprayed onto the packing layer to maintain the humidity of the packing surface and achieve the maximum sulfur trioxide absorption performance. The process gas from the reactor 7 enters the absorption tower 8 from bottom to top, and contacts and adsorbs countercurrently with the sulfuric acid flowing from top to bottom. During the contact process, sulfur trioxide combines with the water in the low-concentration sulfuric acid to produce sulfuric acid, achieving the purpose of removing moisture and concentrating sulfuric acid.

[0046] SO 3 (g)+H 2 O(g)→H 2 SO 4 (g) Hydration (efficiency 100%)

[0047] (4) Tail gas treatment

[0048] The tail gas of the absorption tower contains sulfur dioxide and sulfur trioxide, which is extracted by the tail gas fan 821 and enters the absorption tower tail gas discharge pipe 82. After being preheated and heated up by the glass tube heat exchanger 73 and the tail gas bare tube heat exchanger 71, it is sent to the spent acid incinerator 100, and is converted into sulfuric acid by the spent acid regeneration unit, reducing the sulfur-containing tail gas emission and improving the sulfur recovery efficiency.

[0049] (5) Steam production

[0050] The deaerated water enters the deaerated water supply pipe 6, is heated from 100°C to 150 - 160°C by the deaerated water preheater 541. The heated deaerated water enters the steam generator 53 to produce saturated steam at 1.0 Mpa and 185°C. The saturated steam enters the steam superheater 52 and is heated to 410 - 440°C by the high-temperature process gas. The produced 1.0 Mpa is sent to the plant's low-pressure superheated steam pipe network. There is a steam bypass 532 between the saturated steam pipe 531 and the superheated steam pipe 521, and a bypass regulating valve 533 is installed on the steam bypass 532 to control the steam temperature entering the low-pressure superheated steam pipe network through the bypass regulating valve 533.

[0051] (6) Control scheme for the liquid sulfur feed rate of the sulfuric acid concentration unit

[0052] Unqualified sulfuric acid concentration Sulfuric acid concentration of the target product Difference Y％ 99％ (99-Y)％

[0053] According to the sulfur molar amount in the target product sulfuric acid = the sulfur molar amount in the unqualified sulfuric acid + 90% of the sulfur molar amount in the supplementary liquid sulfur.

[0054] Let the feed rate of liquid sulfur be x, then the sulfur balance in the product per unit mass (t) is:

[0055] 1 * 99% / 98 = 1 * Y% / 98 + X * 90% / 32

[0056] x = (99 - Y)% * 32 / 98 / 90% = (99 - Y)% * 0.3628 (t)

[0057] That is: To increase the concentration of 1t of Y% sulfuric acid to 99%, (99 - Y)% * 0.3628 (t) of liquid sulfur needs to be supplemented.

[0058] In actual operation, set the formula for the liquid sulfur feed rate X in the DCS (not shown in the figure, which is a conventional setting in the art). Substitute the value Y provided by the on-line unqualified concentration meter into the formula (99 - Y)% * 0.3628, and calculate the result as the input value of the liquid sulfur feed rate X.

[0059] The sulfuric acid concentration increasing device of the present invention has the following beneficial effects:

[0060] (1) The sulfuric acid concentration increasing unit increases the product acid concentration by 1 - 2 w%, obtaining concentrated sulfuric acid with a concentration above 98 w%, increasing the flexibility of product sales, improving economic benefits, and the sulfuric acid concentration increasing unit is simple and effective with low investment cost;

[0061] (2) The sulfuric acid concentration increasing unit can be simply integrated into the existing waste acid regeneration unit;

[0062] (3) The sulfuric acid that needs to be concentrated by the sulfuric acid concentration increasing unit can be directly supplied by the waste acid regeneration unit, avoiding the energy consumption required for the transportation between upstream and downstream devices;

[0063] (4) The concentration of the product sulfuric acid can reach 99 wt%, higher than the national standard of 98 wt%, increasing the flexibility of product sales;

[0064] (5) The by-produced low-pressure superheated steam can provide high-quality heat source and kinetic energy, increasing the device benefits.

Claims

1. A sulfuric acid concentration device, comprising a waste acid regeneration unit for incinerating sulfur-containing waste acid and acid gas to produce sulfuric acid, the waste acid regeneration unit comprising a waste acid incinerator (100), the waste acid incinerator (100) being connected to an air supply pipe (101), a fuel gas supply pipe (102), a waste acid supply pipe (103), and an acid gas supply pipe (104), the waste acid incinerator (100) being further connected to an acid gas delivery pipe for discharging sulfuric acid gas containing sulfur dioxide generated after incineration, the acid gas delivery pipe being provided with at least one converter for converting sulfur dioxide into sulfur trioxide and a condenser arranged in a one-to-one correspondence with the converter and for condensing sulfur trioxide to generate sulfuric acid, the condenser being connected to a sulfuric acid delivery pipe for discharging sulfuric acid, the last condenser being connected to an exhaust gas treatment device via a pipeline, wherein: The device also includes a sulfuric acid concentration unit for concentrating sulfuric acid generated by the waste acid regeneration unit to obtain concentrated sulfuric acid with a concentration of more than 98 wt%. The sulfuric acid concentration unit includes a combustion chamber (5) for burning liquid sulfur to generate sulfur dioxide. The combustion chamber (5) is connected to a liquid sulfur supply pipe (1), a fuel gas main pipe (3) and a combustion-supporting air pipeline. The liquid sulfur supply pipe (1) is connected to an air pipeline for atomizing the liquid sulfur. The combustion chamber (5) is connected to a process gas delivery pipe (54) for discharging the generated sulfur dioxide process gas. A steam generating device for generating steam using the heat in the combustion chamber (5) is provided in the combustion chamber (5). The steam generating device is connected to a deoxygenated water supply pipe (6) and a steam discharge pipeline. The process gas delivery pipe (54) is connected to a deoxygenated water supply pipe (6) and a steam discharge pipeline. A reactor (7) for catalytically generating sulfur trioxide from sulfur dioxide, the reactor (7) being connected to a process gas discharge pipe (74) for discharging the generated sulfur trioxide, the process gas discharge pipe (74) being connected to the lower part of an absorption tower (8) for concentrating sulfuric acid, the top of the absorption tower (8) being connected to a waste acid incinerator (100) via an absorption tower tail gas discharge pipe (82), the bottom of the absorption tower (8) being connected to a concentrated sulfuric acid discharge pipe (81), the concentrated sulfuric acid discharge pipe (81) being provided with a sulfuric acid reflux pipe (814) and a concentrated sulfuric acid delivery valve (816) arranged along the flow direction of the concentrated sulfuric acid, the sulfuric acid reflux pipe (814) being connected to the upper part of the absorption tower (8), and the sulfuric acid delivery pipe being connected to the upper part of the absorption tower (8).

2. The sulfuric acid concentration device according to claim 1, characterized in that: The fuel gas main pipe (3) is provided with a fuel gas branch pipe (31), a fuel gas flow meter (32), and a fuel gas regulating valve (33) which are arranged in sequence along the flow direction of the fuel gas; the fuel gas branch pipe (31) is connected to a permanent lamp of the combustion chamber (5); the combustion chamber (5) is provided with a combustion chamber thermometer (51) for detecting the furnace temperature; the combustion chamber thermometer (51) is electrically connected to the fuel gas flow meter (32) and the fuel gas regulating valve (33).

3. The sulfuric acid concentration device according to claim 1, characterized in that: The process gas delivery pipe (54) is connected to the top of the reactor (7). The reactor (7) is provided with a tail gas preheater for preheating the tail gas from the absorption tower and an air preheater (72) for preheating the dry air entering the combustion chamber (5). The air inlet and outlet of the air preheater (72) are connected to the dry air supply pipe (4). The end of the dry air supply pipe (4) connected to the air outlet of the air preheater (72) is connected to the combustion air branch pipe (41) and the liquid sulfur atomization air branch pipe (42). The liquid sulfur atomizing air branch pipe (42) is connected to the liquid sulfur inlet pipe (1), the combustion-supporting air branch pipe (41) is connected to the combustion chamber (5), the dry air inlet pipe (4) connected to the air inlet of the air preheater (72) is provided with a dry air flow meter (43) and a dry air regulating valve (44), the process gas delivery pipe (54) is provided with an oxygen analyzer (542) for detecting the oxygen content in the process gas, and the oxygen analyzer (542) is electrically connected to the dry air flow meter (43) and the dry air regulating valve (44).

4. The sulfuric acid concentration device according to claim 3 is characterized in that: The liquid sulfur inlet pipe (1) is provided with a liquid sulfur-steam heat exchanger (11), a liquid sulfur thermometer (12), a liquid sulfur flowmeter (13), and a liquid sulfur feed regulating valve (14) which are arranged in sequence along the liquid sulfur flow direction; the connection point between the liquid sulfur atomizing air branch pipe (42) and the liquid sulfur inlet pipe (1) is located between the liquid sulfur feed regulating valve (14) and the combustion chamber (5); the liquid sulfur-steam heat exchanger (11) is also connected to the steam inlet pipe (2); the steam inlet pipe (2) is provided with a steam flow regulating valve (21); the steam flow regulating valve (21) is electrically connected to the liquid sulfur thermometer (12); and the liquid sulfur flowmeter (13) is electrically connected to the liquid sulfur feed regulating valve (14).

5. The sulfuric acid concentration device according to claim 3 is characterized in that: The process gas delivery pipe (54) is provided with a deoxygenated water preheater (541) for preheating deoxygenated water for generating steam. The water inlet and outlet of the deoxygenated water preheater (541) are both connected to the deoxygenated water supply pipe (6). The steam generating equipment comprises a steam superheater (52) and a steam generator (53) which are arranged in sequence along the flow direction of sulfur dioxide in the combustion chamber (5). The steam superheater (52) and the steam generator (53) are arranged near the discharge end of the sulfur dioxide process gas. The water inlet of the steam generator (53) is connected to the deoxygenated water supply pipe (6) connected to the water outlet of the deoxygenated water preheater (541). The steam outlet of the steam generator (53) is connected to the steam superheater (52) through a saturated steam pipe (531). The steam outlet of the steam superheater (52) is connected to the superheated steam pipe (521).

6. The sulfuric acid concentration device according to claim 5 is characterized in that: A steam bypass (532) is provided between the saturated steam pipeline (531) and the superheated steam pipeline (521), and a bypass regulating valve (533) is provided on the steam bypass (532); a deoxygenated water inlet pipe (6) connected to the water inlet of the deoxygenated water preheater (541) is provided with a deoxygenated water flow meter (61) and a deoxygenated water regulating valve (62), and the deoxygenated water flow meter (61) is electrically connected to the deoxygenated water regulating valve (62).

7. The sulfuric acid concentration device according to claim 3 is characterized in that: The tail gas preheater comprises a tail gas light tube heat exchanger (71) and a glass tube heat exchanger (73); the tail gas light tube heat exchanger (71), the air preheater (72), and the glass tube heat exchanger (73) are arranged in sequence along the flow direction of the process gas in the reactor (7); and the absorption tower tail gas discharge pipe (82) is connected to the glass tube heat exchanger (73) and the tail gas light tube heat exchanger (71) in sequence along the flow direction of the tail gas.

8. The sulfuric acid concentration device according to claim 1 is characterized in that: The concentrated sulfuric acid discharge pipe (81) is provided with a circulating water cooler (811) arranged along the flow direction of the concentrated sulfuric acid and used to cool the concentrated sulfuric acid, and a concentrated sulfuric acid thermometer (812) for detecting the temperature of the concentrated sulfuric acid. The circulating water cooler (811) and the concentrated sulfuric acid thermometer (812) are arranged in the section between the absorption tower (8) and the sulfuric acid reflux pipe (814). The water inlet and outlet of the circulating water cooler (811) are connected to a circulating cooling water pipe (817). The circulating cooling water pipe (817) connected to the water outlet of the circulating water cooler (811) is provided with a circulating cooling water regulating valve (818). The circulating cooling water regulating valve (818) is electrically connected to the concentrated sulfuric acid thermometer (812). The concentrated sulfuric acid discharge pipe (81) is also provided with a first sulfuric acid online concentration meter (815) for real-time detection of the concentration of the concentrated sulfuric acid. The first sulfuric acid online concentration meter (815) is electrically connected to the concentrated sulfuric acid delivery valve (816).

9. A method for producing concentrated sulfuric acid, characterized in that: The device according to any one of claims 1 to 8 is used, the sulfur-containing waste acid and acid gas are introduced into the waste acid incinerator (100) through the waste acid inlet pipe (103) and the acid gas inlet pipe (104), respectively, the combustion air and the fuel gas enter the waste acid incinerator (100) through the air inlet pipe (101) and the fuel gas inlet pipe (102), respectively, the sulfur-containing substances in the sulfur-containing waste acid and the acid gas are burned in the waste acid incinerator (100) to generate sulfur dioxide, the acid gas containing sulfur dioxide passes through the converter and the condenser in sequence through the acid gas delivery pipe, at least one of the converter and the condenser is provided, and the converter and the condenser are connected to each other. The condensers are arranged one by one, sulfur dioxide reacts in the converter to generate sulfur trioxide, sulfur trioxide generates sulfuric acid in the condenser and enters the sulfuric acid delivery pipe, the sulfuric acid concentration in the sulfuric acid delivery pipe is lower than 98wt%, and the tail gas discharged from the last condenser is purified by the tail gas treatment equipment before being discharged; liquid sulfur enters the combustion chamber (5) through the liquid sulfur inlet pipe (1), dry air and fuel gas enter the combustion chamber (5) through the combustion air pipeline and the fuel gas main pipe (3) respectively, the liquid sulfur is burned in the combustion chamber (5) to generate sulfur dioxide, and the process containing sulfur dioxide generated in the combustion chamber (5) The gas enters the reactor (7) through the process gas delivery pipe (54), the sulfur dioxide undergoes a catalytic reaction in the reactor (7) to generate sulfur trioxide, the process gas containing sulfur trioxide generated in the reactor (7) is passed from the bottom to the absorption tower (8) through the process gas discharge pipe (74), the sulfuric acid in the sulfuric acid delivery pipe is passed from the top of the absorption tower (8), the sulfuric acid and sulfur trioxide undergo countercurrent contact adsorption in the absorption tower (8), the sulfuric acid absorbs the sulfur trioxide to generate concentrated sulfuric acid, the concentrated sulfuric acid is passed into the concentrated sulfuric acid discharge pipe (81), and part of the concentrated sulfuric acid is discharged from the top through the sulfuric acid reflux pipe (814). The sulfuric acid is refluxed to the absorption tower (8) to react with sulfur trioxide in a countercurrent contact adsorption cycle to increase the concentration of the concentrated sulfuric acid. When the concentration of the concentrated sulfuric acid in the concentrated sulfuric acid discharge pipe (81) reaches above 98 wt %, the concentrated sulfuric acid delivery valve (816) is opened to deliver the concentrated sulfuric acid product having a concentration of above 98 wt %. The tail gas generated by the absorption tower (8) enters the waste acid incinerator (100) through the absorption tower tail gas discharge pipe (82) for treatment. The deoxygenated water enters the steam generating device in the combustion chamber (5) through the deoxygenated water inlet pipe (6). The steam generating device absorbs the heat in the combustion chamber (5) to generate steam.

10. The method for producing concentrated sulfuric acid according to claim 9, wherein: The temperature of the liquid sulfur in the liquid sulfur inlet pipe (1) is 140°C; the temperature of the sulfur dioxide-containing process gas entering the reactor (7) is 440°C.

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