Sulfuric acid thickening device

Abstract

The utility model 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 produced by the waste acid regeneration unit, liquid sulfur combusts in a combustion chamber to generate sulfur dioxide, a steam generating device is arranged in the combustion chamber, the combustion chamber is connected with a reactor through a process gas conveying pipe, sulfur dioxide catalyzes and reacts in the reactor to generate sulfur trioxide, the reactor is connected with an absorption tower through a process gas discharge pipe, and the absorption tower is provided with a sulfuric acid return 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. 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 utility model relates to concentrated sulfuric acid production technical field, specifically is a sulfuric acid concentration increasing device. BACKGROUND

[0002] The conventional waste acid regenerating device designs and produces 98wt% concentrated sulfuric acid, the raw material is 90wt% waste acid and acid gas, generates the acid gas containing SO2 after 1100 DEG C incineration of waste acid incinerator, the acid gas after high temperature filter filter dust enters the primary converter.95% SO2 in the acid gas in the primary converter is converted into SO3, and then the SO3 is converted into 98wt% sulfuric acid through the primary condenser, the remaining 5% SO2 in the acid gas enters the secondary converter and is converted into SO3, and then the SO3 is converted into 98wt% sulfuric acid through the secondary condenser, and the ppm level SO2 in the tail gas is captured through the activated carbon reactor, and the purified tail gas is discharged to the atmosphere through the chimney.

[0003] In actual production, the raw material acid gas and waste acid carry a certain amount of hydrocarbon components, which are burned to generate water in the waste acid incinerator, and this part of water is condensed in the product sulfuric acid in the primary condenser and the secondary condenser, resulting in that the concentration of concentrated sulfuric acid product is lower than 98wt%, the product concentration is unqualified, and only 93wt% national standard sulfuric acid can be sold, and the device benefit is greatly lost. UTILITY MODEL CONTENTS

[0004] The first object of the utility model is to solve the problem of low concentration of concentrated sulfuric acid produced by the device for producing 98wt% concentrated sulfuric acid from waste acid in the prior art, and provide a sulfuric acid concentration increasing device capable of improving the concentration of sulfuric acid, the concentrated sulfuric acid produced by the device is above 98wt%, and steam can be generated by using the heat generated by the device.

[0005] The second object of the utility model is to provide a method for producing concentrated sulfuric acid by the above-mentioned device.

[0006] To solve the above-mentioned technical problems, this utility model includes a waste acid regeneration unit for producing sulfuric acid by incinerating sulfur-containing waste acid and acidic gas. The waste acid regeneration unit includes a waste acid incinerator connected to an air inlet pipe, a fuel gas inlet pipe, a waste acid inlet pipe, and an acidic gas inlet pipe. The waste acid incinerator is also connected to an acidic gas delivery pipe for discharging the sulfuric acid dioxide-containing gas generated after incineration. The acidic gas delivery pipe is equipped with at least one converter for converting sulfur dioxide to sulfur trioxide, and a condenser corresponding to each converter for condensing sulfur trioxide to generate sulfuric acid. The condenser is connected to a sulfuric acid delivery pipe for discharging the sulfuric acid. Finally, the condenser is connected to a tail gas treatment device via a pipeline. The structural feature is that the device also includes a sulfuric acid enrichment unit for enriching the sulfuric acid produced by the waste acid regeneration unit to obtain concentrated sulfuric acid with a content of 98 wt% or higher. The sulfuric acid enrichment unit includes a combustion chamber for burning liquid sulfur to generate sulfur dioxide, and the combustion chamber is connected to a liquid sulfur inlet pipe. The system includes a fuel gas main pipe and a combustion air pipeline. The liquid sulfur inlet pipe is connected to an air pipeline for atomizing the liquid sulfur. The combustion chamber is connected to a process gas delivery pipe for discharging the generated sulfur dioxide process gas. The combustion chamber is equipped with a steam generator that uses the heat inside the combustion chamber to generate steam. The steam generator is connected to a deoxygenated water inlet pipe and a steam outlet pipe. The process gas delivery pipe is connected to a reactor that catalytically generates sulfur trioxide from sulfur dioxide. The reactor is connected to a process gas outlet pipe for discharging the generated sulfur trioxide. The process gas outlet pipe is connected to the lower part of an absorption tower for sulfuric acid concentration. The top of the absorption tower is connected to a waste acid incinerator through an absorption tower tail gas outlet pipe. The bottom of the absorption tower is connected to a concentrated sulfuric acid outlet pipe. The concentrated sulfuric acid outlet pipe is equipped with a sulfuric acid reflux pipe and a concentrated sulfuric acid external valve arranged along the flow direction of 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] With the above structure, sulfur-containing waste acid, acidic gas, combustion air, and fuel gas are respectively introduced into the waste acid incinerator through the waste acid inlet pipe, acidic 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 are burned to generate sulfur dioxide. The acidic gas containing sulfur dioxide is discharged through the acidic gas conveying pipe and then 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 generate 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 before being discharged. The sulfuric acid generated in the condenser is discharged into the sulfuric acid conveying pipe. Because the sulfur-containing waste acid and acidic gas contain a certain amount of hydrocarbons, the hydrocarbons are burned in the waste acid incinerator to generate water, which enters the sulfuric acid generated in the condenser. Therefore, the concentration of sulfuric acid discharged from the condenser is less than 98 wt%, which cannot meet the quality requirements of 98 wt% concentrated sulfuric acid. Liquid sulfur, dry air, and fuel gas are respectively introduced through the liquid sulfur inlet pipe, combustion air pipeline, and fuel gas pipeline. The main pipe enters the combustion chamber, where liquid sulfur burns to produce sulfur dioxide. The process gas containing sulfur dioxide enters the reactor through the process gas delivery pipe. In the reactor, the sulfur dioxide undergoes a catalytic reaction to produce sulfur trioxide. The process gas containing sulfur trioxide is then fed into the absorption tower from the bottom through the process gas delivery pipe. The bottom of the absorption tower is connected to a concentrated sulfuric acid discharge pipe. The concentrated sulfuric acid discharged from the absorption tower can flow back into the absorption tower from the top through the sulfuric acid reflux pipe. The sulfuric acid in the sulfuric acid delivery pipe also enters the absorption tower from the top. The sulfur trioxide and sulfuric acid undergo countercurrent contact adsorption in the absorption tower, increasing the concentration of sulfuric acid. When the concentration of concentrated sulfuric acid in the concentrated sulfuric acid discharge pipe reaches 98 wt% or more, the concentrated sulfuric acid external 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 for incineration through the absorption tower tail gas discharge pipe. The deoxygenated water used to prepare steam enters the steam generating equipment through the deoxygenated water inlet pipe. The steam generating equipment uses the heat in the combustion chamber to generate steam, which then enters the steam discharge pipe. This invention utilizes a process of liquid sulfur combustion + sulfur dioxide conversion + absorption to concentrate sulfuric acid produced by waste acid incineration, increasing the concentration of sulfuric acid produced by waste acid incineration to over 98 wt%, thereby improving the efficiency of sulfuric acid products. Furthermore, it utilizes the heat from the combustion chamber to produce steam as a byproduct, achieving waste heat recovery and utilization.

[0008] The main fuel gas pipe is equipped with a fuel gas branch pipe, a fuel gas flow meter, and a fuel gas regulating valve arranged sequentially along the fuel gas flow direction. The fuel gas branch pipe is connected to the continuous lamp in the combustion chamber. The combustion chamber is equipped with a combustion chamber thermometer for detecting the furnace temperature. The combustion chamber thermometer is electrically connected to the fuel gas flow meter and the fuel gas regulating valve.

[0009] The process gas delivery pipe is connected to the top of the reactor. The reactor is equipped with 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 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. The combustion air branch pipe is connected to the combustion chamber. The dry air supply pipe connected to the air inlet of the air preheater is equipped with a dry air flow meter and a dry air regulating valve. The process gas delivery pipe is equipped with an oxygen analyzer for detecting the oxygen content in the process gas. The oxygen analyzer is electrically connected to the dry air flow meter and the dry air regulating valve.

[0010] The liquid sulfur inlet pipe is equipped with a liquid sulfur-steam heat exchanger, a liquid sulfur thermometer, a liquid sulfur flow meter, and a liquid sulfur feed regulating valve arranged sequentially along the liquid sulfur flow direction. The connection between the liquid sulfur atomizing air branch pipe and the liquid sulfur inlet 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 inlet pipe. The steam inlet pipe is equipped with a steam flow regulating valve, which is electrically connected to the liquid sulfur thermometer. The liquid sulfur flow meter is electrically connected to the liquid sulfur feed regulating valve.

[0011] The process gas conveying pipe is equipped with a deoxygenated water preheater for preheating the deoxygenated water used to generate steam. The inlet and outlet of the deoxygenated water preheater are both connected to the deoxygenated water supply pipe. The steam generating equipment includes a steam superheater and a steam generator arranged sequentially along the sulfur dioxide flow direction in the combustion chamber. The steam superheater and the steam generator are located near the outlet end of the sulfur dioxide process gas. The inlet of the steam generator is connected to the deoxygenated water supply pipe connected to the outlet of the deoxygenated water preheater. The steam outlet of the steam generator is connected to the steam superheater through a saturated steam pipe. The steam outlet of the steam superheater is connected to a superheated steam pipe.

[0012] A steam bypass is provided between the saturated steam pipeline and the superheated steam pipeline, and a bypass regulating valve is provided on the steam bypass; a deoxygenated water flow meter and a deoxygenated water regulating valve are provided on the deoxygenated water inlet pipe connected to the inlet of the deoxygenated water preheater, and the deoxygenated water flow meter and the deoxygenated water regulating valve are electrically connected.

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

[0014] The concentrated sulfuric acid discharge pipe is equipped with a circulating water cooler for cooling the concentrated sulfuric acid and a concentrated sulfuric acid thermometer for detecting the temperature of the concentrated sulfuric acid, which are arranged along the flow direction of the concentrated sulfuric acid. The circulating water cooler and the concentrated sulfuric acid thermometer are located in the section between the absorption tower and the sulfuric acid return pipe. The inlet and outlet of the circulating water cooler are connected to the circulating cooling water pipe. The circulating cooling water pipe connected to the outlet of the circulating water cooler is equipped with a circulating cooling water regulating valve, which is electrically connected to the concentrated sulfuric acid thermometer. The concentrated sulfuric acid discharge pipe is also equipped with a first online sulfuric acid concentration meter for real-time detection of the concentrated sulfuric acid concentration, which is electrically connected to the concentrated sulfuric acid delivery valve.

[0015] A method for producing concentrated sulfuric acid, employing the apparatus described in any of the above-mentioned embodiments, wherein sulfur-containing waste acid and acidic gas are respectively introduced into a waste acid incinerator via waste acid inlet pipe and acidic gas inlet pipe, respectively; combustion air and fuel gas are respectively introduced into the waste acid incinerator via air inlet pipe and fuel gas inlet pipe, respectively; the sulfur-containing substances in the sulfur-containing waste acid and acidic gas are burned in the waste acid incinerator to generate sulfur dioxide; the acidic gas containing sulfur dioxide passes sequentially through a converter and a condenser via an acidic gas conveying pipe, wherein at least one converter and one condenser are provided, and the converter and condenser are arranged in a one-to-one correspondence; the sulfur dioxide reacts to generate sulfur trioxide in the converter, and the sulfur trioxide generates sulfuric acid in the condenser and enters the sulfuric acid conveying pipe, wherein the sulfuric acid concentration in the sulfuric acid conveying pipe is less than 98 wt%; the tail gas discharged from the last condenser is purified by a tail gas treatment device before being discharged; liquid sulfur enters the combustion chamber via a liquid sulfur inlet pipe, and dry air and fuel gas enter the combustion chamber via a combustion air pipeline and a fuel gas main pipeline, respectively; the liquid sulfur burns to generate sulfur dioxide in the combustion chamber, and the sulfur dioxide is generated in the combustion chamber. The process gas containing sulfur dioxide enters the reactor through the process gas delivery pipe. In the reactor, the sulfur dioxide undergoes a catalytic reaction to generate sulfur trioxide. The process gas containing sulfur trioxide generated in the reactor is then discharged into the absorption tower from the bottom through the process gas discharge pipe. Sulfuric acid from the sulfuric acid delivery pipe enters the absorption tower from the top. The sulfuric acid and sulfur trioxide undergo countercurrent contact adsorption in the absorption tower. After absorbing the sulfur trioxide, the sulfuric acid generates concentrated sulfuric acid, which enters the concentrated sulfuric acid discharge pipe. A portion of the concentrated sulfuric acid is returned to the absorption tower from the top through the sulfuric acid reflux pipe, where it undergoes a circulating countercurrent contact adsorption with the sulfur trioxide to increase the concentration of the concentrated sulfuric acid. When the concentration of concentrated sulfuric acid in the concentrated sulfuric acid discharge pipe reaches 98 wt% or higher, the concentrated sulfuric acid delivery valve is opened, and the concentrated sulfuric acid product with a concentration of 98 wt% or higher is discharged. 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 generator in the combustion chamber through the deoxygenated water inlet pipe. The steam generator absorbs heat from 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 waste acid regeneration unit does not meet the 98wt% concentrated sulfuric acid product requirement. This utility model discloses a sulfuric acid concentration device and a method for producing concentrated sulfuric acid using this device. The process involves liquid sulfur combustion + sulfur dioxide conversion + absorption to concentrate the sulfuric acid. 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 does not meet the product requirement are absorbed in a countercurrent contact in the absorption tower. After the sulfuric acid absorbs the sulfur trioxide, its concentration increases. When the sulfuric acid reaches the 98wt% concentrated sulfuric acid requirement, it is sent out as the product, improving the economic benefits of sulfuric acid production. The heat generated in the combustion chamber is used to produce superheated steam, realizing heat recovery and utilization, and improving the efficiency of the device. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] In the diagram: 1. Liquid sulfur inlet pipe; 11. Liquid sulfur-steam heat exchanger; 12. Liquid sulfur thermometer; 13. Liquid sulfur flow meter; 14. Liquid sulfur feed regulating valve; 2. Steam inlet pipe; 21. Steam flow regulating valve; 3. Fuel gas main pipe; 31. Fuel gas branch pipe; 32. Fuel gas flow meter; 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 flow meter; 43. Dry air flow meter; 44. Dry air regulating valve. 5. Control 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 delivery pipeline; 541. Deoxygenated water preheater; 542. Oxygen analyzer; 6. Deoxygenated water inlet pipe; 61. Deoxygenated water flow meter; 62. Deoxygenated water regulating valve; 7. Reactor; 71. Tail gas tube heat exchanger; 72. Air preheater; 73. Glass tube heat exchanger; 74. Process gas exhaust pipe; 8. 81. 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 reflux pipe; 815. First sulfuric acid online concentration meter; 816. Concentrated sulfuric acid external valve; 817. Circulating cooling water pipe; 818. Circulating cooling water regulating valve; 82. Absorption tower tail gas discharge pipe; 821. Tail gas fan; 100. Waste acid incinerator; 101. Air inlet pipe; 102. Fuel gas inlet pipe; 103. Waste acid inlet pipe; 104. Acidic gas inlet pipe; 105. First acid... 200, acidic gas delivery pipe; 300, filter; 301, primary converter; 301, second acidic gas delivery pipe; 400, primary condenser; 401, first sulfuric acid delivery pipe; 402, second sulfuric acid online concentration meter; 403, sulfuric acid flow meter; 404, sulfuric acid regulating valve; 405, third acidic gas delivery pipe; 500, secondary converter; 501, fourth acidic gas delivery pipe; 600, secondary condenser; 601, second sulfuric acid delivery pipe; 602, sulfur-containing tail gas discharge pipe; 700, activated carbon reactor; 701, tail gas discharge pipe. Detailed Implementation

[0020] Reference Figure 1A sulfuric acid concentration device includes a waste acid regeneration unit for producing sulfuric acid by incinerating sulfur-containing waste acid and acidic gas, and a sulfuric acid concentration unit for concentrating the sulfuric acid produced by the waste acid regeneration unit to obtain concentrated sulfuric acid with a content of 98 wt% or higher. The waste acid regeneration unit includes a waste acid incinerator 100, which is connected to an air inlet pipe 101, a fuel gas inlet pipe 102, a waste acid inlet pipe 103, and an acidic gas inlet pipe 104. The sulfur-containing waste acid and acidic gas are burned in the waste acid incinerator 100 to generate sulfur dioxide. The waste acid incinerator 100 is connected to at least one converter and at least one condenser through an acidic gas delivery 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 converter and condenser are arranged in a one-to-one correspondence. Figure 1 As shown, the waste acid regeneration unit includes a two-stage converter and a condenser, which is a conventional design in this field. Specifically, the waste acid incinerator 100 is connected to the first-stage converter 300 via a first acid gas delivery pipe 105. The first acid gas delivery pipe 105 is equipped with a filter 200 that is acid-resistant and high-temperature resistant, used to filter dust in the acid gas. The first-stage converter 300 is connected to the first-stage condenser 400 via a second acid gas delivery pipe 301. The first-stage condenser 400 is connected to the second-stage converter 500 via a third acid gas delivery pipe 405. The second-stage converter 500 is connected to the second-stage condenser 600 via a fourth acid gas delivery pipe 501. The second-stage condenser 600 is connected to the activated carbon reactor 700 via a sulfur-containing tail gas discharge pipe 602. The activated carbon reactor 700 is a tail gas treatment device capable of capturing... To purify the small amount of sulfur dioxide in the exhaust gas, the activated carbon reactor 700 is connected to the exhaust gas discharge pipe 701. The bottom of the primary condenser 400 is connected to the first sulfuric acid delivery pipe 401, and the bottom of the secondary condenser 600 is connected to the second sulfuric acid delivery pipe 601. The sulfuric acid produced by the primary condenser 400 and the secondary condenser 600 is discharged through the first sulfuric acid delivery pipe 401 and the second sulfuric acid delivery pipe 601, respectively. The second sulfuric acid delivery pipe 601 is connected to the first sulfuric acid delivery pipe 401, so that the two sulfuric acid streams are combined. The first sulfuric acid delivery pipe 401 is also equipped with a second sulfuric acid online concentration meter 402, a sulfuric acid flow meter 403, and a sulfuric acid regulating valve 404. The sulfuric acid flow meter 403 is electrically connected to the sulfuric acid regulating valve 404, and the flow rate of sulfuric acid entering the absorption tower 8 is controlled by adjusting the opening of the sulfuric acid regulating valve 404.

[0021] Reference Figure 1The 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 inlet pipe 1, a fuel gas main pipe 3, and an air supply pipe. The liquid sulfur inlet pipe 1 is connected to an air supply pipe for atomizing the liquid sulfur, which then enters the combustion chamber 5. The combustion chamber 5 is equipped with a steam generator that uses the heat within the combustion chamber 5 to generate steam. The steam generator is connected to a deoxygenated water inlet pipe 6 and a steam exhaust pipe. The combustion chamber 5 is connected to the top of a reactor 7 via a process gas supply pipe 54. The sulfur dioxide process gas generated from the combustion of liquid sulfur is introduced into the reactor 7 via the process gas supply pipe 54, where the sulfur dioxide undergoes a catalytic reaction to produce sulfur dioxide. The process gas produced in reactor 7 is converted into sulfur trioxide. A vanadium-based catalyst is installed in reactor 7, a standard feature in this field. The bottom of reactor 7 is connected to the lower part of absorption tower 8 via process gas discharge pipe 74. The sulfur trioxide process gas generated in reactor 7 is introduced into absorption tower 8 from the bottom via process gas discharge pipe 74. The top of absorption tower 8 is connected to waste acid incinerator 100 via absorption tower tail gas discharge pipe 82. Specifically, absorption tower tail gas discharge pipe 82 is connected to acid gas inlet pipe 104. The absorption tower tail gas enters waste acid incinerator 100 for incineration via acid gas inlet pipe 104. Alternatively, absorption tower tail gas discharge pipe 82 can be directly connected to waste acid incinerator 100. Figure 1 As shown, the bottom of the absorption tower 8 is connected to a concentrated sulfuric acid discharge pipe 81. The concentrated sulfuric acid discharge pipe 81 is equipped 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 is connected to the upper part of the absorption tower 8, and the sulfuric acid delivery pipe is also 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 is introduced into the absorption tower 8 from the top through the sulfuric acid reflux pipe 814. A check valve is installed 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 from bottom to top in the absorption tower 8, and the sulfuric acid flows from top to bottom in the absorption tower 8. The sulfuric acid and sulfur trioxide undergo countercurrent contact adsorption. Water absorbs sulfur trioxide to generate sulfuric acid, and the concentration of sulfuric acid increases. When the concentration of sulfuric acid in the concentrated sulfuric acid discharge pipe 81 reaches 98wt% or more, the concentrated sulfuric acid delivery valve 816 is opened to send out the qualified concentrated sulfuric acid product.

[0022] Reference Figure 1The fuel gas main pipe 3 is equipped with a fuel gas branch pipe 31, a fuel gas flow meter 32, and a fuel gas regulating valve 33 arranged sequentially along the fuel gas flow direction. The fuel gas branch pipe 31 is connected to the continuous lamp of the combustion chamber 5. The combustion chamber 5 is equipped 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. The flow rate of fuel gas entering the combustion chamber 5 is controlled by adjusting the opening of the fuel gas regulating valve 33, and the temperature of the combustion chamber 5 is controlled in cascade at 1000℃. A circulating water cooler 811 and a concentrated sulfuric acid thermometer 812 are installed on the concentrated sulfuric acid discharge pipe 81, arranged along the flow direction of the concentrated sulfuric acid. The circulating water cooler 811 cools the concentrated sulfuric acid, and 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 located in the section between the absorption tower 8 and the sulfuric acid return pipe 814. The inlet and outlet of the circulating water cooler 811 are connected to the circulating cooling water pipe 817. The circulating cooling water pipe 817, connected to the outlet of the circulating water cooler 811, is equipped with a circulating cooling water regulating valve 818. The concentrated sulfuric acid thermometer 812 is electrically connected to the circulating cooling water regulating valve 818. The temperature of the concentrated sulfuric acid is controlled by adjusting the opening of the circulating cooling water regulating valve 818, so that the temperature of the cooled concentrated sulfuric acid is maintained at 40°C. The concentrated sulfuric acid discharge pipe 81 is also equipped with a device that can detect the temperature of the concentrated sulfuric acid in real time. The first online sulfuric acid concentration meter 815 is installed between the sulfuric acid reflux pipe 814 and the concentrated sulfuric acid delivery valve 816. The first online sulfuric acid concentration meter 815 is electrically connected to the concentrated sulfuric acid delivery valve 816. When the first online sulfuric acid concentration meter 815 detects that the sulfuric acid concentration is above 98wt%, the concentrated sulfuric acid delivery valve 816 is automatically opened to deliver qualified concentrated sulfuric acid product. For example, when the first online sulfuric acid concentration meter 815 detects that the concentrated sulfuric acid concentration reaches 99wt%, the concentrated sulfuric acid delivery valve 816 is opened. When the first online sulfuric acid concentration meter 815 detects that the concentrated sulfuric acid concentration is below 98wt%, the concentrated sulfuric acid delivery valve 816 is closed, so that the concentration of the discharged concentrated sulfuric acid product meets the quality standard. The concentrated sulfuric acid discharge pipe 81 is also equipped with a concentrated sulfuric acid circulation pump 813 to provide power for the circulation of concentrated sulfuric acid.

[0023] Reference Figure 1The reactor 7 is equipped with a tail gas preheater and an air preheater 72. 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 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. Dry air enters the liquid sulfur supply pipe 1 and atomizes the liquid sulfur. The liquid sulfur atomizing air branch pipe 42 is equipped with a liquid sulfur atomizing air regulating valve 421 and a liquid sulfur atomizing air flow meter 422. The liquid sulfur atomizing air regulating valve 421 is connected to the liquid sulfur supply pipe 1. A sulfur atomizing air flow meter 422 is electrically connected. The air flow rate into the liquid sulfur supply pipe 1 is controlled by adjusting the opening of the liquid sulfur atomizing air regulating valve 421, maintaining a certain ratio between the atomizing air flow rate and the liquid sulfur. The combustion air branch pipe 41 is connected to the combustion chamber 5 and serves as the combustion air for liquid sulfur combustion. A dry air flow meter 43 and a dry air regulating valve 44 are installed on the dry air supply pipe 4 connected to the air inlet of the air preheater 72. An oxygen analyzer 542 is installed on the process gas delivery pipe 54. The oxygen analyzer 542 detects the oxygen content of the process gas in the pipe. The oxygen analyzer 542 is electrically connected to the dry air flow meter 43 and the dry air regulating valve 44, cascading control of the oxygen content in the process gas delivery pipe 54. Figure 1 As shown, the liquid sulfur inlet pipe 1 is equipped with a liquid sulfur-steam heat exchanger 11, a liquid sulfur thermometer 12, a liquid sulfur flow meter 13, and a liquid sulfur feed regulating valve 14 arranged sequentially along the liquid sulfur flow direction. The connection 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 a graphite heat exchanger. The liquid sulfur flow meter 13 is electrically connected to the liquid sulfur feed regulating valve 14. The liquid sulfur flow rate is controlled by adjusting the opening of the liquid sulfur feed regulating valve 14. The steam heat exchanger 11 is also connected to a steam pipe 2 for heating the liquid sulfur in the liquid sulfur inlet pipe 1. When the liquid sulfur flows through the liquid sulfur-steam heat exchanger 11, it absorbs heat from the steam to keep the liquid sulfur in a liquid state. The steam pipe 2 is equipped with a steam flow regulating valve 21, which is electrically connected to the liquid sulfur thermometer 12. By adjusting the opening of the steam flow regulating valve 21, the steam flow is controlled, thereby controlling the heat exchange between the steam and the liquid sulfur and the temperature of the liquid sulfur after heating, so that the temperature of the heated liquid sulfur is 140℃.

[0024] Reference Figure 1A deoxygenated water preheater 541 is installed on the process gas conveying pipe 54. The deoxygenated water preheater 541 uses the waste heat of the process gas to preheat the deoxygenated water used for steam production. The inlet and outlet of the deoxygenated water preheater 541 are both connected to the deoxygenated water supply pipe 6. The deoxygenated water and the process gas exchange heat in the deoxygenated water preheater 541. The deoxygenated water absorbs the heat of the process gas and rises to 140°C. After the process gas releases heat, its temperature drops to 440°C. The steam generating equipment includes a steam superheater 52 and a steam generator 53 arranged sequentially in the direction of sulfur dioxide flow in the combustion chamber 5. The steam superheater 52 and the steam generator 53 are located near the outlet end of the sulfur dioxide process gas. The inlet of the steam generator 53 is connected to the deoxygenated water supply pipe 6 connected to the outlet of the deoxygenated water preheater 541. The steam outlet of 53 is connected to the steam inlet of the steam superheater 52 via the saturated steam pipe 531. The steam outlet of the steam superheater 52 is connected to the superheated steam pipe 521. The superheated steam generated by the steam superheater 52 is sent out through the hot steam pipe 521. A steam bypass 532 is provided between the saturated steam pipe 531 and the superheated steam pipe 521. A bypass regulating valve 533 is provided on the steam bypass 532. The temperature of the superheated steam is controlled by adjusting the opening of the bypass regulating valve 533. The deoxygenated water preheater 541 is connected to the deoxygenated water supply pipe 6, which is equipped with a deoxygenated water flow meter 61 and a deoxygenated water regulating valve 62. The deoxygenated water flow meter 61 is electrically connected to the deoxygenated water regulating valve 62. The flow rate of the deoxygenated water and the steam output are controlled by adjusting the opening of the deoxygenated water regulating valve 62. The exhaust gas preheater includes an exhaust gas bare tube heat exchanger 71 and a glass tube heat exchanger 73. The exhaust gas bare tube heat exchanger 71, air preheater 72, and glass tube heat exchanger 73 are arranged sequentially in the reactor 7 along the flow direction of the process gas. The exhaust gas discharge pipe 82 of the absorber tower is connected sequentially to the glass tube heat exchanger 73 and the exhaust gas bare tube heat exchanger 71 along the flow direction of the exhaust gas. The exhaust gas from the absorber 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 exhaust gas bare tube heat exchanger 71 to exchange heat with the reactor 7. The process gas heat exchange increases the temperature of the absorber tower tail gas entering the waste acid incinerator 100; the tail gas outlet of the tail gas tube heat exchanger 71 is connected to the absorber tower tail gas discharge pipe 82, which is also equipped with a tail gas fan 821 for extracting the absorber tower tail gas. 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 to keep the furnace of the combustion chamber 5 under a slight negative pressure (-0.5kPa to -0.05kPa) to prevent harmful gases from escaping and polluting the environment.

[0025] It should be noted that the actual combustion chamber 5, reactor 7, absorption tower 8, waste acid incinerator 100, converter, and condenser are also equipped with accessories such as pressure gauges and thermometers, and the pipelines are also equipped with accessories such as hand valves, pumps, fans, and instruments, which are not shown in the drawings or text and are conventional settings in this field; the equipment involved in this utility model is prior art and can be purchased from relevant enterprises with design and production qualifications.

[0026] The method for producing concentrated sulfuric acid using the above-mentioned apparatus comprises the following steps:

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

[0028] The 98wt% sulfuric acid catalyst used in the alkylation unit loses its catalytic effect after the alkylation reaction, with the sulfuric acid concentration dropping to 90wt%. It is discharged as waste acid from the alkylation unit. The waste acid regeneration unit uses this 90% sulfuric acid and acidic gas (H2S) from the sulfur unit as feedstock.

[0029] Sulfur-containing waste acid and acidic gas are introduced into the waste acid incinerator 100 via waste acid inlet pipe 103 and acidic gas inlet pipe 104, respectively. Combustion air and fuel gas are introduced into the waste acid incinerator 100 via air inlet pipe 101 and fuel gas inlet pipe 102, respectively. The sulfur-containing waste acid is incinerated at 1100℃ to generate sulfur dioxide, undergoing reactions ① and ②. The acidic gas is incinerated at 1100℃ to generate sulfur dioxide, undergoing reaction ③.

[0030] H₂SO₄ 1100℃→ SO₃+H₂O ①

[0031] 2SO3 1100℃→ 2SO2+O2 ②

[0032] 2H2S+3O2 1100℃→ 2SO2+2H2O ③

[0033] Acidic gas containing sulfur dioxide is filtered through filter 200 to remove dust, and its temperature is reduced to 440℃. It then enters the primary converter 300, where 95% of the sulfur dioxide is converted to sulfur trioxide. After passing through the primary condenser 400, the sulfur trioxide is converted to sulfuric acid. The remaining 5% of sulfur dioxide in the acidic gas enters the secondary converter 500 to be converted back to sulfur trioxide, and then through the secondary condenser 600 to be converted back to sulfuric acid. The tail gas, containing sulfur dioxide at the ppm level, is captured by the activated carbon reactor 700. The purified tail gas is then discharged into the atmosphere through a chimney. (Waste acid...) The incineration design is for producing 98wt% concentrated sulfuric acid. However, since the raw material waste acid and acidic gas both carry hydrocarbon components, they are burned in the waste acid incinerator 100 to produce water. This water is condensed in the product sulfuric acid in the primary condenser 400 and the secondary condenser 600, producing substandard concentrated sulfuric acid with an actual concentration of about 97wt%. The concentrated sulfuric acid produced by the primary condenser 400 and the secondary condenser 600 is combined and enters the first sulfuric acid conveying pipe 401. After passing through the second sulfuric acid online concentration meter 402, sulfuric acid flow meter 403, and sulfuric acid regulating valve 404, it is sent to the absorption tower 8 of the newly added sulfuric acid concentration unit.

[0034] 2. Flowchart of the sulfuric acid concentration unit

[0035] (1) Liquid sulfur incineration

[0036] Liquid sulfur from upstream enters the liquid sulfur inlet pipe 1. The liquid sulfur and steam exchange heat in the liquid sulfur-steam heat exchanger 11. The liquid sulfur temperature is controlled at 140℃ by the steam flow regulating valve 21 to maintain the liquefied state of the sulfur. After being metered by the liquid sulfur flow meter 13 and the liquid sulfur feed regulating valve 14, the liquid sulfur is then sent into the combustion chamber 5 through the air atomization introduced by the liquid sulfur atomization air branch pipe 42.

[0037] The fuel gas from the fuel gas pipeline is divided into two paths. The main branch is the fuel gas main pipe 3, through which the fuel gas flows into the combustion chamber 5 after passing through the fuel gas flow meter 32, the fuel gas regulating valve 33, and the main burner (not shown in the figure). The secondary branch is the fuel gas branch pipe 31, through which the fuel gas enters the combustion chamber 5 via the continuous light (not shown in the figure). The fuel gas burns in the combustion chamber 5, raising the furnace temperature to 1000℃, providing a site for the liquid sulfur reaction. The combustion chamber thermometer 51 detects the furnace temperature, and the fuel gas flow is controlled by the fuel gas regulating valve 33, cascading control of the furnace temperature of the combustion chamber 5 to the target temperature of 1000℃.

[0038] The air in the dry air supply pipe 4 is metered by the dry air flow meter 43 and the dry air regulating valve 44, and preheated by the air preheater 72. It is 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. The other path enters the liquid sulfur atomizing air branch pipe 42, and after passing through the liquid sulfur atomizing air regulating valve 421 and the liquid sulfur atomizing air flow meter 422, it enters the liquid sulfur supply pipe 1. A certain proportion is controlled according to the liquid sulfur feed rate for liquid sulfur atomization. To ensure the best product quality, the dry air uses purified air with a dew point below -60℃. The dry air used for combustion is preheated to 150℃ by the air preheater 72 before entering the combustion chamber 5 to reduce the energy consumption of the device. The amount of dry air entering the combustion chamber 5 is automatically controlled by the dry air flow meter 43 and the dry air regulating valve 44. The excess oxygen content in the process air is controlled in a cascade manner according to the measurement value of the oxygen analyzer 542 to be within the range of 2-5%V index.

[0039] Liquid sulfur is burned in combustion chamber 5 to generate high-temperature process gas containing sulfur dioxide at 1000℃. The gas then passes through steam superheater 52 and steam generator 53 before entering process gas delivery pipe 54. Steam superheater 52 and steam generator 53 absorb heat from the high-temperature process gas to generate superheated steam. The high-temperature process gas then passes through deaerator water preheater 541 and its temperature drops to 440℃ before entering downstream reactor 7. To prevent harmful gases from escaping and polluting the environment, combustion chamber 5 operates at a slight negative pressure (-0.5kPa to -0.05kPa), and the furnace negative pressure is controlled by the frequency converter of exhaust gas fan 821.

[0040] (2) Sulfur dioxide conversion

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

[0042] Oxidation (conversion rate approximately 90%)

[0043] The oxidation reaction of sulfur dioxide is an exothermic reaction. After passing through the catalyst bed, the process gas temperature rises from 440°C to 450°C. The process gas (SO2+SO3) after the reaction passes through the tail gas tube heat exchanger 71, the air preheater 72, and the glass tube heat exchanger 73 in sequence, and the temperature drops to about 130°C. Then, it 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 concentrated sulfuric acid produced enters the concentrated sulfuric acid discharge pipe 81 and is cooled to 40°C by the circulating water cooler 811. 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 circulation pump 813, the concentrated sulfuric acid is divided into two branches. In the external delivery branch, when the sulfuric acid concentration meter 815 shows that the sulfuric acid concentration reaches 99wt%, the concentrated sulfuric acid external delivery valve 816 is automatically opened. When the concentration is lower than 98wt%, the concentrated sulfuric acid external delivery valve 816 is closed. The concentrated sulfuric acid in the circulation branch enters the sulfuric acid return pipe 814. The check valve prevents the sulfuric acid from flowing back. After mixing with the unqualified sulfuric acid from the waste acid regeneration unit, it enters the absorption tower 8 from the top and is distributed by the top distributor. It is 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 comes into countercurrent contact with the sulfuric acid from top to bottom for adsorption. During the contact process, sulfur trioxide combines with water in the low-concentration sulfuric acid to produce sulfuric acid, achieving the purpose of removing moisture and concentrating sulfuric acid.

[0046] SO3(g) + H2O(g) → H2SO4(g) (Hydration efficiency 100%)

[0047] (4) Exhaust gas treatment

[0048] The exhaust gas from the absorption tower contains sulfur dioxide and sulfur trioxide. It is drawn out by the exhaust gas fan 821 and enters the exhaust gas discharge pipe 82 of the absorption tower. After being preheated by the glass tube heat exchanger 73 and the exhaust gas bare tube heat exchanger 71, it is sent to the waste acid incinerator 100. It is converted into sulfuric acid by the waste acid regeneration unit, which reduces the emission of sulfur-containing exhaust gas and improves the sulfur recovery efficiency.

[0049] (5) Steam production

[0050] Deoxygenated water enters the deoxygenated water inlet pipe 6 and is heated from 100°C to 150-160°C by the deoxygenated water preheater 541. The heated deoxygenated water then enters the steam generator 53 to generate 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 generated 1.0 MPa steam is sent to the plant's low-pressure superheated steam network. A steam bypass 532 is provided between the saturated steam pipeline 531 and the superheated steam pipeline 521. A bypass regulating valve 533 is provided on the steam bypass 532 to control the temperature of the steam entering the low-pressure superheated steam network.

[0051] (6) Scheme for controlling the amount of sulfuric acid feed in the sulfuric acid concentration unit

[0052] Off-specification sulphuric acid concentration Target product sulphuric acid concentration Difference Y％ 99％ (99-Y)％

[0053] The target product's sulfuric acid molar amount is calculated as: sulfur molar amount in substandard sulfuric acid + sulfur in the replenishing solution * 90% molar amount.

[0054] Let the amount of liquid sulfur fed be x, then the sulfur balance per unit mass (t) of product 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 1tY% sulfuric acid to 99%, it is necessary to replenish (99-Y)%*0.3628(t) liquid sulfur.

[0058] In practice, the liquid sulfur feed rate X is set as a formula in the DCS (not shown in the figure, this is a standard setting in this field). The value Y provided by the online non-compliance concentration meter is substituted into the formula (99-Y)%*0.3628, and the result is used as the input value for the liquid sulfur feed rate X.

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

[0060] (1) The sulfuric acid concentration unit increases the acid concentration of the product by 1-2w to obtain concentrated sulfuric acid of more than 98w%, which increases the flexibility of product sales, improves economic benefits, and the sulfuric acid concentration unit is simple, effective and has low investment cost.

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

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

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

[0064] (5) The low-pressure superheated steam produced as a by-product can provide a high-quality heat source and kinetic energy, increasing the efficiency of the plant.

Claims

1. A sulfuric acid concentration device, comprising a waste acid regeneration unit for producing sulfuric acid by incinerating sulfur-containing waste acid and acid gas, the waste acid regeneration unit comprising a waste acid incinerator (100) connected with an air inlet pipe (101), a fuel gas inlet pipe (102), a waste acid inlet pipe (103), an acid gas inlet pipe (104), and further 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 being arranged on the acid gas delivery pipe, and a condenser corresponding to each converter for condensing sulfur trioxide into sulfuric acid, the condenser being connected with a sulfuric acid delivery pipe for discharging sulfuric acid, and the last condenser being connected with a tail gas treatment device through a pipe, characterized in that: The device also comprises a sulfuric acid concentration unit for increasing the concentration of sulfuric acid produced by the waste acid regeneration unit to more than 98wt% concentrated sulfuric acid, the sulfuric acid concentration unit comprising a combustion chamber (5) for generating sulfur dioxide by burning liquid sulfur, the combustion chamber (5) being connected with a liquid sulfur inlet pipe (1), a fuel gas main pipe (3) and a combustion air pipe, the liquid sulfur inlet pipe (1) being connected with an air pipe for atomizing liquid sulfur, the combustion chamber (5) being connected with a process gas delivery pipe (54) for discharging generated sulfur dioxide process gas, the combustion chamber (5) being provided with a steam generating device for generating steam by using heat in the combustion chamber (5), the steam generating device being connected with a deoxygenated water inlet pipe (6) and a steam discharge pipe, the process gas delivery pipe (54) being connected to a reactor (7) for catalytically generating sulfur trioxide from sulfur dioxide, the reactor (7) being connected with a process gas discharge pipe (74) for discharging generated sulfur trioxide, the process gas discharge pipe (74) being connected to the lower part of an absorption tower (8) for sulfuric acid concentration, the top of the absorption tower (8) being connected to a waste acid incinerator (100) through an absorption tower tail gas discharge pipe (82), the bottom of the absorption tower (8) being connected with a concentrated sulfuric acid discharge pipe (81), the concentrated sulfuric acid discharge pipe (81) being provided with a sulfuric acid return pipe (814) and a concentrated sulfuric acid delivery valve (816) arranged along the flow direction of the concentrated sulfuric acid, the sulfuric acid return pipe (814) being connected to the upper part of the absorption tower (8), the sulfuric acid delivery pipe being connected to the upper part of the absorption tower (8).

2. The sulfuric acid concentration plant 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) arranged in sequence along the flow direction of the fuel gas, the fuel gas branch pipe (31) being connected to the pilot light of the combustion chamber (5), the combustion chamber (5) being provided with a combustion chamber thermometer (51) for detecting the temperature of the combustion chamber, the combustion chamber thermometer (51) being electrically connected with the fuel gas flow meter (32) and the fuel gas regulating valve (33).

3. The sulfuric acid concentration plant 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) being provided with a tail gas preheater for preheating absorption tower tail gas and an air preheater (72) for preheating dry air entering the combustion chamber (5), the air inlet and outlet of the air preheater (72) being connected with a dry air inlet pipe (4), the end of the dry air inlet pipe (4) connected to the air outlet of the air preheater (72) being connected with a combustion air branch pipe (41) and a liquid sulfur atomizing air branch pipe (42), the liquid sulfur atomizing air branch pipe (42) being connected to the liquid sulfur inlet pipe (1), the combustion air branch pipe (41) being connected to the combustion chamber (5), the dry air inlet pipe (4) connected to the air inlet of the air preheater (72) being provided with a dry air flow meter (43) and a dry air regulating valve (44), the process gas delivery pipe (54) being provided with an oxygen analyzer (542) for detecting the oxygen content in the process gas, the oxygen analyzer (542) being electrically connected with the dry air flow meter (43) and the dry air regulating valve (44).

4. The sulfuric acid concentration plant according to claim 3, characterized in that: The liquid sulfur comes to the pipe (1) is equipped with along the liquid sulfur flow direction in proper order liquid sulfur-steam heat exchanger (11), liquid sulfur thermometer (12), liquid sulfur flowmeter (13), liquid sulfur feed adjusting valve (14), the liquid sulfur atomization air branch pipe (42) and liquid sulfur come to the pipe (1) connection between the liquid sulfur feed adjusting valve (14) and combustion chamber (5), the liquid sulfur-steam heat exchanger (11) still with steam come to the pipe (2) connection, the steam come to the pipe (2) is equipped with steam flow adjusting valve (21), the steam flow adjusting valve (21) and liquid sulfur thermometer (12) electricity is connected, the liquid sulfur flowmeter (13) and liquid sulfur feed adjusting valve (14) electricity is connected.

5. The sulfuric acid concentration plant according to claim 3, characterized in that: The process gas delivery pipe (54) is equipped with deaerated water preheater (541) for preheating deaerated water for generating steam, the inlet and outlet of the deaerated water preheater (541) are connected with the deaerated water pipe (6), the steam generating device includes steam superheater (52) and steam generator (53) arranged in the combustion chamber (5) along the flow direction of sulfur dioxide, the steam superheater (52) and steam generator (53) are arranged near the discharge end of sulfur dioxide process gas, the inlet of the steam generator (53) is connected with the deaerated water pipe (6) connected with the outlet of the deaerated water preheater (541), the steam outlet of the steam generator (53) is connected with the steam superheater (52) through saturated steam pipeline (531), and the steam outlet of the steam superheater (52) is connected with superheated steam pipeline (521).

6. The sulfuric acid concentration plant according to claim 5, characterized in that: The saturated steam pipeline (531) and the superheated steam pipeline (521) are provided with a steam bypass (532), and the steam bypass (532) is provided with a bypass adjusting valve (533); the deaerated water pipe (6) connected with the inlet of the deaerated water preheater (541) is provided with a deaerated water flowmeter (61) and a deaerated water adjusting valve (62), and the deaerated water flowmeter (61) is electrically connected with the deaerated water adjusting valve (62).

7. The sulfuric acid concentration plant according to claim 3, characterized in that: The tail gas preheater includes 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 with 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 plant according to claim 1, 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 for cooling 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 inlet and outlet of the circulating water cooler (811) are connected with a circulating cooling water pipe (817), the circulating cooling water pipe (817) connected with the 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 with the concentrated sulfuric acid thermometer (812); the concentrated sulfuric acid discharge pipe (81) is also provided with a first sulfuric acid online concentration instrument (815) for detecting the concentration of the concentrated sulfuric acid in real time, the first sulfuric acid online concentration instrument (815) is electrically connected with a concentrated sulfuric acid delivery valve (816).

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