Production process for preparing high-purity sulfur trioxide from high-efficiency pure oxygen through parallel double-furnace two-stage conversion method

Abstract

The invention discloses a production process for efficiently preparing high-purity sulfur trioxide from pure oxygen through a parallel double-furnace two-stage conversion method. The production process comprises the following steps: S1, preparing sulfur dioxide; s2, preparing sulfur trioxide; s3, condensing and separating sulfur trioxide; and S4, recovering the non-condensable gas to enter the next cycle. According to the method, pure oxygen and liquid sulfur are used as raw materials, the sulfur trioxide finished product is continuously produced, no by-product is generated, the yield of the finished product is close to 100%, and the product quality is pure. The gas circulation system is arranged, so that unreacted gas and uncondensed sulfur trioxide can be reused, the utilization rate of raw materials is increased, and space and capital investment are saved. The mode that the two sulfur burning furnaces are connected in parallel is arranged to burn liquid sulfur, the overall sulfur spraying amount of the device is guaranteed, and meanwhile the situation that due to the fact that a large amount of sulfur is sprayed in a single sulfur burning furnace for a short time, the furnace is overheated and overheated, and masonry equipment is damaged can be avoided.

Description

Technical Field

[0001] The invention relates to the technical field of sulfur trioxide preparation, and in particular to a production process for preparing high-purity sulfur trioxide by using pure oxygen in a highly efficient manner using a parallel double-furnace two-stage conversion method. Background Art

[0002] Existing pure sulfur trioxide products are mainly produced by the oleum method, and its core process is based on traditional sulfur or pyrite acid production units. This process usually prepares oleum by absorbing sulfur trioxide process gas with sulfuric acid, and then extracts sulfur trioxide gas through distillation. After the extracted sulfur trioxide gas is cooled and liquefied, the liquid pure sulfur trioxide product is finally obtained. However, this traditional process has obvious limitations.

[0003] In the traditional sulfuric acid production process, most of the sulfur trioxide generated by the catalytic oxidation process in the conversion section will react with the desalted water added to the dry absorption system to produce sulfuric acid or fuming sulfuric acid. This reaction greatly reduces the products that can be used to produce pure sulfur trioxide, making it difficult to significantly increase the output of finished products. At the same time, due to the inherent conversion efficiency problems of the process, the finished product yield of pure sulfur trioxide is extremely low, which limits the economic benefits of the process. In addition, the flue gas generated by the combustion reaction of air and liquid sulfur in the traditional process has a relatively complex composition and contains a large amount of by-products such as nitrogen oxides. The presence of these impurities not only increases the difficulty of sulfur trioxide purification in subsequent processes, but may also cause the purity of the finished product to fail to meet the standards.

[0004] For these reasons, the production of pure sulfur trioxide using the traditional oleum method is not only technically challenging, but also difficult to meet the needs of modern industry in terms of production efficiency and product quality. Therefore, improving the existing production process and increasing the output and purity of pure sulfur trioxide has become an urgent problem to be solved. Summary of the invention

[0005] Based on the problems existing in the background technology, the present invention provides a production process for preparing high-purity sulfur trioxide from pure oxygen by a parallel double-furnace two-stage conversion method with high efficiency. Pure oxygen and liquid sulfur are used as raw materials to continuously produce finished sulfur trioxide products without generating by-products. The finished product yield is close to 100%, and the product quality is pure.

[0006] The present invention is implemented by the following technical solutions:

[0007] A production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces, comprising the following steps:

[0008] S1. Preparation of sulfur dioxide: Liquid sulfur in the liquid sulfur tank and pure oxygen in the pure oxygen tank enter two parallel sulfur incinerators A and B, and the liquid sulfur is fully burned in the furnace to generate sulfur dioxide gas. The outlet smoke of sulfur incinerator A and sulfur incinerator B merges into one gas before the inlet of the combustion heat recovery device, and then enters the combustion heat recovery device for cooling;

[0009] S2. Preparation of sulfur trioxide: The gas at the outlet of the combustion heat recovery device is mixed with the pure oxygen in the pure oxygen tank and enters the first stage of the converter to undergo a catalytic oxidation reaction of sulfur dioxide. The gas at the outlet of the first stage of the converter enters the high-temperature heat recovery device for heat exchange and then enters the second stage of the converter to undergo a second stage of catalytic oxidation reaction. The gas at the outlet of the second stage of the converter enters the warm heat recovery device for heat exchange again. The gas at the outlet of the warm heat recovery device enters the economizer and the heat exchanger in sequence for heat exchange;

[0010] S3. Sulfur trioxide condensation and separation: The gas at the heat exchanger outlet enters the compressor for compression, the gas volume is reduced, and the temperature is increased. After the temperature is increased, the gas enters the heat recovery condensation device for compressor mechanical heat energy recovery and condensation with the finished pure sulfur trioxide. The gas is separated into pure sulfur trioxide products in the heat recovery condensation device and enters the pure sulfur trioxide tank;

[0011] S4. Recover the non-condensable gas and enter the next cycle: the remaining uncondensed gas in the heat recovery condensing device is treated as non-condensable gas and re-enters the sulfur incinerator through the gas phase outlet pipe of the heat recovery condensing device to participate in the next cycle of the process system and form a gas phase closed circulation system.

[0012] Furthermore, in step S1, liquid sulfur and pure oxygen enter two parallel incinerators A and sulfur incinerator B, including the non-condensable gas at the gas phase outlet of the heat recovery condensing device in step S4, and the ratio of the total amount of pure oxygen in the furnace to the amount of liquid sulfur is (1.1-1.3):1.

[0013] Furthermore, in step S1, the gas temperature is reduced to 400±10°C in the combustion heat recovery device.

[0014] Furthermore, in step S2, the combustion heat recovery device outlet gas is mixed with the pure oxygen in the pure oxygen tank at a volume ratio of (2.05-2.2):1.

[0015] Furthermore, in step S2, after the first-stage outlet gas of the converter enters the high-temperature heat recovery device for heat exchange, the gas temperature drops to 450±10°C.

[0016] Furthermore, in step S2, after the outlet gas of the second stage of the converter enters the warm heat recovery device for heat exchange again, the gas temperature drops to 200±10°C;

[0017] In step S2, the outlet gas of the medium-temperature heat recovery device enters the economizer and the heat exchanger in turn for heat exchange, and the gas temperature drops to 45-50°C;

[0018] In step S3, the gas at the heat exchanger outlet enters the compressor and is compressed to 2-3 MPa, and the gas temperature reaches 200-250°C;

[0019] In step S4, a tail gas discharge process is added on the way from the gas phase outlet pipeline of the heat recovery condensing device to the incinerator, and a small part of the non-condensable gas can be continuously or intermittently discharged to the tail gas absorption system for treatment.

[0020] Furthermore, the tail gas absorption system includes an absorption tank, an air inlet pipe is arranged at the right end of the absorption tank, the air inlet pipe is connected through the gas phase outlet pipe of the heat recovery condensing device, a liquid inlet pipe is connected through the upper end of the absorption tank, a valve one is arranged on the air inlet pipe, a valve two is arranged on the liquid inlet pipe, a fixed ring is fixedly arranged in the absorption tank, a plurality of stirring rods are rotatably arranged in the fixed ring, a rotating rod is fixedly arranged in the center of the plurality of stirring rods, a driving blade is arranged on the rotating rod, a filter screen is also fixedly arranged in the absorption tank, a liquid outlet pipe is arranged on the lower side of the absorption tank, a valve three is arranged in the liquid outlet pipe, and the liquid outlet pipe is located on the left side of the filter screen.

[0021] Furthermore, a fixed box is provided through the upper surface of the absorption tank, a controller is fixedly provided on the upper inner wall of the fixed box, a pressure sensor is provided on the lower surface of the controller, the controller is electrically connected to the pressure sensor, valve one, valve two and valve three, a slide plate is slidably provided in the fixed box, a spring is fixedly provided on the slide plate, the other end of the spring is fixedly connected to the lower surface of the controller, a moving rod is fixedly provided at the lower end of the slide plate, a floating plate is fixedly provided at the lower end of the moving rod, a scraper is fixedly provided at the left end of the floating plate, the scraper is abutted against the filter screen, and a discharge box is fixedly provided through the lower surface of the absorption tank.

[0022] Furthermore, an inclined plate is fixedly provided on the lower inner wall of the discharge box, a discharge port is provided at the right end of the discharge box, a special-shaped baffle is provided on the left side wall of the discharge box, a magnetic block is provided on the upper side of the special-shaped baffle, the magnetic block is fixedly provided on the inner wall of the left side wall of the discharge box, a metal baffle is hinged on the right inner wall of the discharge box, a torsion spring is provided at the hinge position between the discharge box and the metal baffle, the metal baffle is located between the magnetic block and the special-shaped baffle, and a push block is provided on the lower surface of the floating plate, and the push block cooperates with the metal baffle.

[0023] Furthermore, a tank body with an opening at the right end is provided on the left side wall of the absorption tank, a C-shaped connecting rod is fixedly provided on the right side of the tank body, a driving motor is provided on the left side of the tank body, the right output end of the driving motor is fixedly connected to a reciprocating screw rod, the reciprocating screw rod is rotatably connected to the tank body and the C-shaped connecting rod, a pushing plate is threadedly connected to the reciprocating screw rod, a vertically symmetrical rack is fixedly provided on the right side of the pushing plate, the rack slides through the C-shaped connecting rod, a vertically symmetrical hose is connected to the left side of the tank body, the hose is fixedly extended into the absorption tank, the absorption tank is rotatably connected to a vertically symmetrical rotating tube, a gear ring is fixedly provided in the center of the rotating tube, the rack is meshed with the gear ring, the rotating tube is through-connected with the hose, and a plurality of nozzles are provided on the rotating tube.

[0024] Beneficial effects of the present invention:

[0025] 1. The present invention uses pure oxygen and liquid sulfur as raw materials. Compared with air oxidation, it reduces the participation of unnecessary inert gases such as nitrogen, improves the utilization rate of oxygen and the reaction rate, continuously produces sulfur trioxide products, does not produce by-products, has a finished product yield of nearly 100%, and has pure product quality.

[0026] 2. The present invention sets up a dual sulfur incinerator in parallel mode to burn liquid sulfur, which ensures the overall sulfur injection amount of the device while avoiding the situation where a large amount of sulfur injection in a single sulfur incinerator in a short time causes overheating in the furnace and damages the masonry equipment.

[0027] 3. The gas circulation system provided in the present invention allows unreacted gas and uncondensed sulfur trioxide to be reused, thereby improving the utilization rate of raw materials. This design reduces the consumption and waste of raw materials, and due to the recycling of reactants, the scale of the device can be controlled, and no overly large equipment is required, thereby saving space and capital investment.

[0028] 4. In the present invention, the finished pure sulfur trioxide is separated from the system by first compressing the gas and then condensing it, which avoids the acid treatment step in the traditional oleum method, thereby simplifying the process flow and reducing the difficulty of operation. This method effectively reduces the corrosive load of the equipment and reduces the requirements for equipment materials, which is beneficial to extending the service life of the equipment. The efficient reaction and separation process reduces energy consumption, making the production more energy-saving and environmentally friendly. Reducing energy consumption not only helps to improve the economic benefits of the device, but also helps to reduce the negative impact on the environment. Through the method of gas compression and condensation separation, the optimization of process energy consumption further improves the economy of the overall device. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide further explanation of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0030] Figure 1 It is the material flow chart of the present invention;

[0031] Figure 2 It is a process flow chart of the present invention;

[0032] Figure 3 It is a structural schematic diagram of the absorption tank of the present invention;

[0033] Figure 4 It is a structural schematic diagram of the discharge box of the present invention;

[0034] Figure 5 It is a structural schematic diagram of the tank body of the present invention;

[0035] Figure 6 It is a structural schematic diagram of the rotating tube of the present invention;

[0036] Figure 7 This is a schematic diagram of the connection between the C-shaped connecting rod and the tank body of the present invention;

[0037] Figure 8 It is a schematic diagram of the internal structure of the fixing ring of the present invention.

[0038] Among them, 1. Liquid sulfur tank, 2. Pure oxygen tank, 3. Sulfur incinerator A, 4. Sulfur incinerator B, 5. Combustion heat recovery device, 6. Converter stage 1, 7. High temperature heat recovery device, 8. Converter stage 2, 9. Medium temperature heat recovery device, 10. Economizer, 11. Heat exchanger, 12. Compressor, 13. Heat recovery condensing device, 14. Tail gas absorption system, 15. Pure sulfur trioxide tank, 16. Absorption tank, 17. Slide plate, 18. Fixed box, 19. Controller, 20. Floating plate, 21. Valve 2, 22. Liquid inlet pipe, 23. Drive blade, 24. .Intake pipe, 25. Valve one, 26. Rotating rod, 27. Fixed ring, 28. Moving rod, 29. Push block, 30. Scraper, 31. Valve three, 32. Liquid outlet pipe, 33. Hose, 34. Driving motor, 35. Reciprocating screw, 36. Metal baffle, 37. Discharge box, 38. Discharge port, 39. Inclined plate, 40. Special-shaped baffle, 41. Magnetic block, 42. Push plate, 43. C-shaped connecting rod, 44. Rack, 45. Gear ring, 46. Rotating tube, 47. Nozzle, 48. Tank, 49. Stirring rod, 50. Filter. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only partial embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] refer to Figure 1 and Figure 2 The present invention provides a production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces, comprising the following steps:

[0041] S1. Preparation of sulfur dioxide: The liquid sulfur in the liquid sulfur tank 1 and the pure oxygen in the pure oxygen tank 2 enter two parallel sulfur incinerators A3 and B4. The liquid sulfur is fully burned in the furnace to generate sulfur dioxide gas. The smoke at the outlets of the sulfur incinerators A3 and B4 merges into a gas before the inlet of the combustion heat recovery device 5, and then enters the combustion heat recovery device 5 for cooling. In order to avoid the generation of sublimated sulfur in the furnace, the liquid sulfur and pure oxygen enter the two parallel incinerators A3 and B4, including the non-condensable gas at the gas phase outlet of the heat recovery condensing device 13 in step S4, and the ratio of the total amount of pure oxygen in the furnace to the amount of liquid sulfur is (1.1-1.3):1.

[0042] S2. Preparation of sulfur trioxide: The gas at the outlet of the combustion heat recovery device 5 is mixed with the pure oxygen in the pure oxygen tank 2 at a volume ratio of (2.05-2.2):1, and enters the first stage of the converter 6 to undergo a catalytic oxidation reaction of sulfur dioxide. The gas at the outlet of the first stage of the converter 6 enters the high-temperature heat recovery device 7 for heat exchange, and then enters the second stage of the converter 8 for a second-stage catalytic oxidation reaction. The gas at the outlet of the second stage of the converter 8 enters the warm heat recovery device 9 for heat exchange again, and the gas at the outlet of the warm heat recovery device 9 enters the economizer 10 and the heat exchanger 11 in sequence for heat exchange.

[0043] S3. Sulfur trioxide condensation and separation: The gas at the outlet of the heat exchanger 11 enters the compressor 12 for compression, the gas volume is reduced, and the temperature is increased. After the temperature is increased, the gas enters the heat recovery condensation device 13 for compressor mechanical heat energy recovery and condensation with the finished pure sulfur trioxide. The gas is separated into pure sulfur trioxide products in the heat recovery condensation device and enters the pure sulfur trioxide tank 15.

[0044] S4. Recover the non-condensable gas and enter the next cycle: the remaining uncondensed gas in the heat recovery condensing device 13 is used as non-condensable gas, and re-enters the sulfur incinerator through the gas phase outlet pipe of the heat recovery condensing device 13 to participate in the next cycle of the process system, forming a gas phase closed circulation system. In order to ensure that the pressure lower than the external atmospheric pressure will not be formed in the system, in the process of gas circulation back to the sulfur incinerator, part of the uncondensed sulfur trioxide and unconverted sulfur dioxide are retained as non-condensable gas. This part of non-condensable gas plays the role of circulating gas and dilution gas. Returning to the sulfur incinerator can avoid the high oxygen content when pure oxygen is added to the furnace to form a high oxygen environment that damages the equipment in the furnace. In order to maintain the stability of the pressure and components of the gas circulation system, further, an exhaust gas discharge process is added on the way from the gas phase outlet pipe of the heat recovery condensing device 13 to the sulfur incinerator A3 and the sulfur incinerator B4, and a small part of the non-condensable gas can be continuously or intermittently discharged to the exhaust gas absorption system 14 for treatment.

[0045] The present invention also provides a heat recovery process, including a recovery device 5, a high-temperature heat recovery device 7, a medium-temperature heat recovery device 9, and a coal economizer 10. The chemical heat energy in the device of the present invention is only the heat of sulfur combustion and the heat of sulfur dioxide oxidation, and the mechanical heat energy is the internal energy of the gas converted after the compressor does work on the process gas. These heats can be recovered through the thermal equipment provided at the outlet of the sulfur incinerator, the outlets of each section of the converter, and the outlet of the compressor, so as to achieve efficient recovery and utilization of heat energy, increase the steam production per unit sulfur combustion of the device, and reduce its own steam energy consumption.

[0046] In step S1, the outlet temperature of sulfur dioxide gas from the sulfur incinerator is about 1300° C., and the gas temperature is reduced to 400±10° C. by the combustion heat recovery device 5. This temperature is beneficial to the subsequent catalytic reaction and can avoid high temperature damage to the equipment.

[0047] In step S2, the gas temperature at the outlet of the first stage 6 of the converter is about 620° C. After entering the high-temperature heat recovery device 7 for heat exchange, the gas temperature drops to 450±10° C. This temperature helps to optimize the subsequent catalytic reaction and improve the conversion efficiency.

[0048] In step S2, the outlet gas temperature of the second stage converter 8 is about 480° C. After entering the warm heat recovery device 9 for another heat exchange, the gas temperature drops to 200±10° C. This temperature adjustment helps further energy recovery and optimizes the final condensation step.

[0049] In step S2, the outlet gas of the heat recovery device 9 enters the economizer 10 and the heat exchanger 11 in turn for heat exchange, and the gas temperature drops to 45-50° C. This is to ensure that the heat energy of the gas is fully utilized before entering the compressor and is reduced to a temperature suitable for the compressor to handle.

[0050] In step S3, the gas at the outlet of the heat exchanger 11 enters the compressor 12 and is compressed to 2-3 MPa, and the gas temperature reaches 200-250° C. The compressor parameter range is sufficient to ensure that the gas is effectively condensed into liquid sulfur trioxide in the subsequent condensation step, while also maximizing the use of the mechanical heat energy generated in the compressor process.

[0051] In order to recover the mechanical energy of the compressor, the cold side medium in the heat recovery condensing device 13 is desalted water, which absorbs the heat energy in the process gas, increases the temperature of the desalted water, and saves the steam energy consumption of the system.

[0052] In addition to being applicable to the working condition where a mixture of sulfur trioxide and sulfur dioxide is used as the circulating gas, the present invention can also be applied to the working condition where sulfur dioxide and inert gas are used as the circulating gas. Figure 1As shown, using inert gas such as (CO2 or He) instead of sulfur trioxide as the main component of the circulating gas from the heat recovery condensing device 13 to the sulfur incinerator A3 and the sulfur incinerator B4 can reduce the oxygen concentration in the furnace and the sulfur trioxide concentration in each stage of the converter, and can also reduce the risk of overheating due to violent combustion of sulfur, and can improve the sulfur dioxide conversion rate in the converter, and the generated sulfur trioxide can be extracted and separated as a finished product of pure sulfur trioxide, but this operating condition may require larger equipment and pipelines for production at the same production capacity.

[0053] The sulfur trioxide product of the present invention is in liquid or critical gas state. The product is tested and the purity is 99.9%.

[0054] 1. The present invention uses pure oxygen to prepare pure sulfur trioxide. The process gas generated after the reaction, combustion and conversion of liquid sulfur and pure oxygen has low impurity content and no byproducts such as nitrogen oxides. It can meet the conditions of direct output of liquid after condensation after compression, and gets rid of the constraint of the traditional sulfur-based acid production process that the sulfur trioxide in the flue gas must be used to produce 98% sulfuric acid and oleum. The conversion rate of raw materials into pure sulfur trioxide products is extremely high, which can greatly expand the production capacity of pure sulfur trioxide;

[0055] 2. The present invention gets rid of the water replenishment process of the traditional sulfuric acid production process, avoids the waste of low-temperature heat from the reaction of SO3 and H20, and the chemical heat energy in the device is only the heat of sulfur combustion and the heat of sulfur dioxide oxidation. The mechanical heat energy is the internal energy of the gas converted after the compressor does work on the process gas. This heat can be recovered through the thermal equipment set at the outlet of the sulfur incinerator, the outlets of each section of the converter, and the outlet of the compressor, so as to achieve efficient recovery and utilization of heat energy, increase the unit sulfur combustion steam production of the device, and reduce its own steam energy consumption;

[0056] 3. Pure sulfur trioxide is produced by the sulfur dioxide / sulfur trioxide cycle process. Compared with the nitrogen component that accounts for about 80% in the traditional sulfuric acid plant, the total gas volume in the plant is smaller, which can reduce the scale of equipment and pipelines, and have a smaller footprint and construction consumables at the same capacity. It can also reduce the proportion of oxygen content in each sulfur incinerator, avoiding the high oxygen over-temperature environment that damages the equipment after pure oxygen is transported into the furnace.

[0057] 4. The present invention can take into account both production output and equipment life. A double sulfur incinerator is set up to burn liquid sulfur in parallel. While ensuring the overall sulfur injection amount of the device, it can avoid the situation where a large amount of sulfur injection in a single sulfur incinerator in a short time causes overheating in the furnace and damages the masonry equipment. It reduces the risk of melting and oxidation of equipment in the furnace, ensures the life of the device in actual production operation, avoids frequent maintenance / replacement of equipment, and ensures the production start-up rate.

[0058] refer to Figures 3 to 8The tail gas absorption system 14 includes an absorption tank 16, an air inlet pipe 24 is arranged at the right end of the absorption tank 16, and the air inlet pipe 24 is connected with the gas phase outlet pipe of the heat recovery condensing device 13, and the upper end of the absorption tank 16 is connected with a liquid inlet pipe 22, and the air inlet pipe 24 is provided with a valve 1 25, and the liquid inlet pipe 22 is provided with a valve 21, a fixed ring 27 is fixedly arranged in the absorption tank 16, and a plurality of stirring rods 49 are rotatably arranged in the fixed ring 27, and a rotating rod 26 is fixedly arranged in the center of the plurality of stirring rods 49, and a driving blade 23 is arranged on the rotating rod 26, and a filter screen 50 is also fixedly arranged in the absorption tank 16, and a liquid outlet pipe 32 is arranged at the lower side of the absorption tank 16, and a valve 3 31 is arranged in the liquid outlet pipe 32, and the liquid outlet pipe 32 is located on the left side of the filter screen 50.

[0059] Among them, a fixed box 18 is provided through the upper surface of the absorption tank 16, a controller 19 is fixedly provided on the upper inner wall of the fixed box 18, a pressure sensor is provided on the lower surface of the controller 19, the controller 19 is electrically connected to the pressure sensor, valve one 25, valve two 21 and valve three 31, a slide plate 17 is slidably provided in the fixed box 18, a spring is fixedly provided on the slide plate 17, the other end of the spring is fixedly connected to the lower surface of the controller, a moving rod 28 is fixedly provided at the lower end of the slide plate 17, a floating plate 20 is fixedly provided at the lower end of the moving rod 28, a scraper 30 is fixedly provided at the left end of the floating plate 20, the scraper 30 is abutted against the filter screen 50, and a discharge box 37 is fixedly provided through the lower surface of the absorption tank 16.

[0060] When tail gas absorption and discharge is required, valve one 25 and valve two 21 are started by controller 19, non-condensable gas and tail gas enter into absorption tank 16 through air inlet pipe 24, and treatment liquid enters into absorption tank 16 through liquid inlet pipe 22. By mixing treatment liquid with non-condensable gas and tail gas, non-condensable gas can be deacidified and deodorized, and tail gas can be absorbed (the type of treatment liquid can be selected by technicians in this field). Then, as the liquid content in absorption tank 16 increases, the water level rises, which drives floating plate 20 to rise. The rising of floating plate 20 drives moving rod 28 to rise. Moving rod 28 drives slide plate 17 to rise. Slide plate 17 will eventually hit the pressure sensor. Then controller 19 starts valve three 31, and liquid outlet pipe 32 starts to discharge liquid. The water level in absorption tank 16 is filtered by filter screen 50 and discharged through liquid outlet pipe 32. Then the water level gradually drops. Slide plate 17 is reset under the action of spring, driving floating plate 20 to move downward together.

[0061] A small portion of the non-condensable gas can continuously or intermittently enter the absorption tank 16 through the air inlet pipe 24. When a small portion of the non-condensable gas is continuously discharged, it is necessary to make the liquid inlet speed of the liquid inlet pipe 22 less than the liquid discharge speed of the liquid outlet pipe 32, so that the non-condensable gas can be treated more fully; but in general, a small portion of the non-condensable gas will be intermittently discharged into the absorption tank 16, which is achieved by pressing the pressure sensor by the slide plate 17. The discharge of the liquid in the absorption tank 16 makes the treatment liquid treat the non-condensable gas and tail gas more fully;

[0062] Among them, an inclined plate 39 is fixedly provided on the lower inner wall of the discharge box 37, a discharge port 38 is provided at the right end of the discharge box 37, a special-shaped baffle 40 is provided on the left side wall of the discharge box 37, a magnetic block 41 is provided on the upper side of the special-shaped baffle 40, the magnetic block 41 is fixedly provided on the inner wall of the left side wall of the discharge box 37, a metal baffle 36 is hinged on the right inner wall of the discharge box 37, a torsion spring is provided at the hinge position between the discharge box 37 and the metal baffle 36, the metal baffle 36 is located between the magnetic block 41 and the special-shaped baffle 40, and a push block 29 is provided on the lower surface of the floating plate 20, and the push block 29 cooperates with the metal baffle 36.

[0063] Among them, a tank body 48 with an opening at the right end is provided on the left side wall of the absorption tank 16, a C-shaped connecting rod 43 is fixedly provided on the right side of the tank body 48, a driving motor 34 is provided on the left side of the tank body 48, and a reciprocating screw rod 35 is fixedly connected to the output end on the right side of the driving motor 34. The reciprocating screw rod 35 is rotatably connected to the tank body 48 and the C-shaped connecting rod 43. A pushing plate 42 is threadedly connected to the reciprocating screw rod 35, and a rack 44 symmetrically arranged on the right side of the pushing plate 42 is fixedly provided, and the rack 44 slides through the C-shaped connecting rod 43. A hose 33 symmetrically arranged on the left side of the tank body 48 is connected, and the hose 33 is fixedly extended into the absorption tank 16. The absorption tank 16 is rotatably connected with a rotating tube 46 symmetrically arranged on the top and bottom, and a gear ring 45 is fixedly provided in the center of the rotating tube 46. The rack 44 is meshed and connected with the gear ring 45. The rotating tube 46 is connected to the hose 33, and a plurality of nozzles 47 are provided on the rotating tube 46.

[0064] When the slide plate 17 is reset under the action of the spring, the scraper 30 on the floating plate 20 will clean the filter 50. As the floating plate 20 gradually descends, the impurities on the filter 50 will also be scraped off. When the floating plate 20 descends to the lowest position, the push block 29 will push open the metal baffle 36, and the impurities will fall onto the special-shaped baffle 40. At this time, the metal baffle 36 will press against the special-shaped baffle 40 to seal the discharge box 37, and then discharge the scraped impurities through the discharge port 38. When the floating plate 20 rises with the rise of the water level, the metal baffle 36 is reset under the action of the torsion spring, and some liquid will be flushed onto the special-shaped baffle 40, thereby flushing the impurities onto the inclined plate 39, waiting for the next opening of the discharge port 38.

[0065] As the water level in the absorption tank 16 continues to rise, the liquid will enter the tank body 48, and then the drive motor 34 will be started intermittently, the drive motor 34 will drive the reciprocating screw 35, and the reciprocating screw 35 will drive the push plate 42 to move back and forth. The water in the tank body 48 will enter the hose 33 through the squeezing of the push plate 42, and then enter the rotating tube 46 and be sprayed out through a plurality of nozzles 47. In the process of the movement of the push plate 42, the push plate 42 drives the rack 44 to move, and the rack 44 drives the gear ring 45 to rotate, thereby effectively changing the spraying angle of the nozzle 47, and effectively cleaning the filter screen 50, with high cleanliness and strong practicality.

[0066] Finally, it should be noted that the above-mentioned embodiments only express several implementation methods of the present invention and are not intended to limit the invention. For those skilled in the art, any modification, equivalent replacement, improvement, etc. made without departing from the concept of the present invention should be included in the protection scope of the invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces, characterized in that: The following steps are involved: S1. Preparation of sulfur dioxide: Liquid sulfur in the liquid sulfur tank (1) and pure oxygen in the pure oxygen tank (2) enter two parallel sulfur incinerators A (3) and sulfur incinerators B (4), and the liquid sulfur is fully burned in the furnace to generate sulfur dioxide gas. The outlet smoke of the sulfur incinerators A (3) and sulfur incinerators B (4) merges into a gas before the inlet of the combustion heat recovery device (5), and then enters the combustion heat recovery device (5) for cooling; S2. Preparation of sulfur trioxide: The gas at the outlet of the combustion heat recovery device (5) is mixed with the pure oxygen in the pure oxygen tank (2) and enters the first converter (6) to undergo a catalytic oxidation reaction of sulfur dioxide. The gas at the outlet of the first converter (6) enters the high-temperature heat recovery device (7) for heat exchange and then enters the second converter (8) for a second-stage catalytic oxidation reaction. The gas at the outlet of the second converter (8) enters the warm heat recovery device (9) for heat exchange again. The gas at the outlet of the warm heat recovery device (9) enters the economizer (10) and the heat exchanger (11) in sequence for heat exchange; S3. Sulfur trioxide condensation and separation: The gas at the outlet of the heat exchanger (11) enters the compressor (12) for compression, the gas volume is reduced, and the temperature is increased. After the temperature is increased, the gas enters the heat recovery condensation device (13) for compressor mechanical heat recovery and condensation of the finished pure sulfur trioxide. The gas is separated into pure sulfur trioxide products in the heat recovery condensation device and enters the pure sulfur trioxide tank (15); S4. Recover the non-condensable gas and enter the next cycle: the remaining uncondensed gas in the heat recovery condensation device (13) is treated as non-condensable gas and re-enters the sulfur incinerator through the gas phase outlet pipeline of the heat recovery condensation device (13) to participate in the next cycle of the process system, forming a gas phase closed circulation system.

2. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1 is characterized in that: In step S1, liquid sulfur and pure oxygen enter two parallel incinerators A (3) and sulfur incinerator B (4), including the non-condensable gas at the gas phase outlet of the heat recovery condensation device (13) in step S4. The ratio of the total amount of pure oxygen in the furnace to the amount of liquid sulfur is (1.1-1.3):

1.

3. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1 is characterized in that: In step S1, the gas temperature is reduced to 400±10°C in the combustion heat recovery device (5).

4. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1, characterized in that: In step S2, the outlet gas of the combustion heat recovery device (5) is mixed with the pure oxygen in the pure oxygen tank (2) at a volume ratio of (2.05-2.2):

1.

5. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1, characterized in that: In step S2, the outlet gas of the first stage (6) of the converter enters the high-temperature heat recovery device (7) for heat exchange, and the gas temperature drops to 450±10°C.

6. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1, characterized in that: In step S2, the outlet gas of the second stage (8) of the converter enters the warm heat recovery device (9) for heat exchange again, and the gas temperature drops to 200±10°C.

7. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1, characterized in that: In step S2, the outlet gas of the medium-temperature heat recovery device (9) enters the economizer (10) and the heat exchanger (11) in sequence for heat exchange, and the gas temperature drops to 45-50°C.

8. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1 is characterized in that: In step S3, the gas at the outlet of the heat exchanger (11) enters the compressor (12) and is compressed to 2-3 MPa, and the gas temperature reaches 200-250°C.

9. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 1, characterized in that: In step S4, an exhaust gas discharge process is added on the way from the gas phase outlet pipeline of the heat recovery condensing device (13) to the incinerator.

10. The production process for preparing high-purity sulfur trioxide from pure oxygen using a two-stage conversion method with two parallel furnaces according to claim 9, characterized in that: A small portion of the non-condensable gas can be continuously or intermittently discharged to the tail gas absorption system (14) for treatment.

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