Device for preparing ammonium sulfate from high-concentration ammonia-containing tail gas

Abstract

The utility model relates to a kind of high-concentration ammonia-containing tail gas preparation ammonium sulfate device, including the reaction absorption unit, vacuum reaction crystallization unit and separation and mother liquor circulation unit connected in turn, and the vacuum system connected with vacuum reaction crystallization unit.The reaction absorption unit includes the first reactor and the second reactor with Venturi structure, for carrying out staged absorption to ammonia-containing tail gas;The vacuum reaction crystallization unit includes reaction crystallizer and acid mixer, and the evaporation concentration and crystal growth of slurry are realized by using neutralization reaction heat under vacuum environment;The separation and mother liquor circulation unit realizes crystal product separation and mother liquor recycling.The utility model uses neutralization reaction heat as evaporation energy, and energy consumption is significantly reduced;By step-by-step acid addition and vacuum temperature control, the crystallization process is accurately controlled, and large-particle ammonium sulfate product is obtained;Meanwhile, low solid content operation and mother liquor circulation design are adopted, effectively solve the problem of equipment blockage, and improve the stability of device operation.

Description

Technical Field

[0001] This utility model relates to the field of chemical environmental protection technology, and in particular to a device for producing ammonium sulfate from high-concentration ammonia-containing tail gas. Background Technology

[0002] In the production processes of industries such as ammonia removal from ammonia nitrogen wastewater, aluminum ash treatment, and gold beneficiation agent synthesis, high-concentration ammonia-containing tail gas is generated. This tail gas has a strong odor, complex composition, and high water content. Once emissions exceed standards, it can easily lead to serious environmental accidents. Currently, the resource-based treatment of this tail gas (production of ammonium sulfate) remains a technical challenge. Existing technologies generally suffer from problems such as long process chains, large investments, high operating costs, difficulty in achieving water balance, high corrosiveness, and difficulty in meeting tail gas standards, failing to meet the requirements for long-term stable operation.

[0003] Specifically, existing mainstream technologies all have their own insurmountable drawbacks: while the saturator method has simple post-processing, the resulting ammonium sulfate crystals are small and mostly powdery, leading to difficulties in subsequent separation, drying, and packaging, as well as high equipment wear and energy consumption; the absorption tower + evaporation crystallization method can obtain large-particle crystals, but the evaporation crystallization process consumes a large amount of steam or electricity, resulting in excessive energy consumption; and the saturation tower absorption method using concentrated sulfuric acid, when processing high-concentration ammonia (>10%), causes a large amount of heat to be released by the violent reaction between sulfuric acid and ammonia, leading to excessively high and uncontrollable system temperatures (>80℃), high supersaturation of the solution, easy equipment blockage, unstable system operation, and frequent maintenance. Therefore, developing an integrated device that can shorten the process, reduce energy consumption, precisely control temperature, and produce large-particle ammonium sulfate crystals has become an urgent need in this field.

[0004] Chinese patent document CN203777925U discloses a system for treating ammonia-containing tail gas. This system includes an absorption system, a mother liquor preparation system, and an evaporation crystallization system. The absorption system includes a high-efficiency absorber and an absorption tower. The high-efficiency absorber has an air inlet at the top and a liquid inlet at the bottom, and is connected to the lower inlet of the absorption tower via a bottom outlet. The lower part of the absorption tower has a first gas distributor, the middle part of the absorption tower is filled with a packing layer, a liquid distributor is located above the packing layer, and the upper part of the absorption tower has a second gas distributor. Above the second gas distributor, a process water inlet, a spray system, and a demister are arranged sequentially. A chimney is located at the top of the absorption tower. The mother liquor preparation system includes a mother liquor protection high-level tank, a concentrated sulfuric acid tank, a concentrated sulfuric acid high-level tank, a dilution tank, and a mother liquor acidity adjustment tank. The evaporation crystallization system includes a secondary steam preheater, a heater, an evaporator, a crystallization tank, an ammonium sulfate separator, a dryer, and a secondary steam condensate tank.

[0005] While the above-mentioned technical solutions can achieve the treatment of ammonia-containing tail gas and the recovery of ammonium sulfate, there are still problems such as high system energy consumption, small ammonium sulfate crystal particles leading to difficulties in subsequent separation and drying, and easy clogging of equipment under high concentration ammonia conditions. Therefore, it is necessary to develop a new device for producing ammonium sulfate from high concentration ammonia-containing tail gas, which can significantly reduce energy consumption and effectively control the stability of system operation while achieving efficient absorption and large-particle ammonium sulfate crystal production. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide a device for producing ammonium sulfate from high-concentration ammonia-containing tail gas, which can produce large-particle ammonium sulfate crystals, significantly reduce energy consumption, effectively control system temperature and supersaturation, prevent equipment blockage, and improve operational stability and reliability.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: the device for producing ammonium sulfate from high-concentration ammonia-containing tail gas includes a reaction absorption unit, a vacuum reaction crystallization unit, a separation and mother liquor circulation unit, and a vacuum system; the reaction absorption unit, the vacuum reaction crystallization unit, and the separation and mother liquor circulation unit are connected in sequence; the vacuum system is connected to the vacuum reaction crystallization unit.

[0008] Using the above technical solution, the device sequentially connects a reaction absorption unit, a vacuum reaction crystallization unit, and a separation and mother liquor circulation unit, working in conjunction with a vacuum system to form a complete high-concentration ammonia-containing tail gas treatment system. The reaction absorption unit is responsible for multi-stage absorption of the ammonia-containing tail gas, generating ammonium sulfate slurry; the vacuum reaction crystallization unit utilizes the heat of reaction in a vacuum environment to achieve evaporation and concentration of the slurry and crystal growth; the separation and mother liquor circulation unit separates the crystals from the mother liquor and enables the recycling of the mother liquor; the vacuum system provides stable vacuum conditions for the reaction crystallization unit. This integrated design significantly shortens the process chain, reduces external energy consumption, and simultaneously improves the stability of system operation and the quality of the crystalline product.

[0009] Preferably, the reaction absorption unit includes a primary reactor, a primary circulation pump, and an ammonium sulfate slurry pump; the upper part of the primary reactor is equipped with a Venturi structure, through which high-concentration ammonia-containing tail gas (5%~95%v) enters the primary reactor.

[0010] The Venturi structure is located at the top of the primary reactor and is connected to both the tail gas inlet pipe and the outlet pipe of the primary circulating pump, forming a gas-liquid mixing channel. High-concentration ammonia-containing tail gas enters the reactor through the Venturi structure, where it mixes vigorously with the circulating absorbent, enhancing gas-liquid contact efficiency and improving the ammonia absorption rate and reaction effect. The absorption reaction achieves initial rapid mixing and absorption within the Venturi structure, followed by sufficient reaction and residence within the main reactor space, thus extending the overall gas-liquid contact time and improving treatment efficiency.

[0011] Preferably, the bottom of the primary reactor is provided with a first outlet and a second outlet; the first outlet of the primary reactor is connected to the Venturi structure through the primary circulation pump; the second outlet of the primary reactor is connected to the inlet of the ammonium sulfate slurry pump.

[0012] The first outlet is located at the lowest point of the reactor and is connected to the venturi structure at the top via a primary circulation pump, forming a slurry circulation loop inside the reactor. This keeps the slurry flowing, prevents solid deposition, and maintains the uniformity and low solids content (3%~6%) of the slurry within the reactor. The second outlet directly and independently delivers the slurry generated in the reaction to the ammonium sulfate slurry pump, ensuring the stability of the slurry composition and flow rate delivered to the crystallization unit and avoiding interference with the circulation loop. This dual-outlet design effectively reduces the risk of equipment and pipeline blockage.

[0013] Preferably, the reaction absorption unit further includes a secondary reactor and a secondary circulation pump; the secondary reactor is provided with an acid inlet, an air inlet, a liquid inlet, and an air outlet; the air inlet of the secondary reactor is connected to the air outlet of the primary reactor, and the bottom outlet of the secondary reactor is connected to the liquid inlet of the secondary circulation pump; the liquid outlet of the secondary circulation pump is connected to the liquid inlet of the primary reactor and the liquid inlet of the secondary reactor, respectively.

[0014] The secondary reactor receives the tail gas treated by the primary reactor and replenishes it with sulfuric acid through the acid inlet for deep absorption, ensuring that residual ammonia in the tail gas is completely removed. A secondary circulation pump returns a portion of the circulating liquid to both the primary and secondary reactors, optimizing the distribution of the absorbent and reaction efficiency, thus improving the tail gas treatment effect. The outlet is located at the top of the secondary reactor; the final emitted tail gas, after undergoing two stages of absorption, has a significantly reduced ammonia content.

[0015] Preferably, the vacuum reaction crystallization unit includes a reaction crystallizer, a reaction circulation pump, an acid mixer, and a crystal discharge pump; the acid mixer is provided with a slurry inlet, a concentrated sulfuric acid inlet, and a mixed liquid outlet, the slurry inlet being connected to the outlet of the ammonium sulfate slurry pump; the first outlet is connected to the inlet of the reaction crystallizer through the reaction circulation pump and the acid mixer to form a slurry circulation; the second outlet is connected to the input end of the crystal discharge pump.

[0016] Ammonium sulfate slurry (3%–6% solids content), which has already partially absorbed ammonia from the primary reactor, is pumped to the acid mixer via an ammonium sulfate slurry pump. In the acid mixer, the slurry mixes rapidly and violently with the introduced concentrated sulfuric acid, completing the second step of the "stepwise acid addition" process. This invention achieves the technical effect of "stepwise acid addition" through a device structure consisting of a primary reactor, a secondary reactor, and a vacuum reaction crystallization unit, operating in a coordinated manner. The intense neutralization exothermic process is transferred to the vacuum reaction crystallizer, where the heat of reaction drives evaporation and concentration, concentrating the solids content to 8%–15%. The crystallization environment is precisely controlled by vacuum, thus significantly reducing external energy consumption while successfully producing large-particle ammonium sulfate crystals. This fundamentally solves the problems of temperature runaway and scaling / clogging caused by concentrated exothermic processes in traditional devices. A reaction circulation pump circulates the slurry, balancing system temperature and supersaturation, promoting ammonium sulfate crystal growth; a crystal discharge pump transports the concentrated slurry to the separation unit.

[0017] Preferably, the vacuum system is connected to the gas outlet of the reaction crystallizer to establish and maintain the vacuum state of the reaction crystallizer; the vacuum system is an adjustable vacuum system.

[0018] A vacuum system lowers the boiling point, enabling low-temperature evaporation. The system is adjustable, allowing the pumping rate of non-condensable gases to be changed by adjusting the frequency-controlled vacuum pump or the opening of the inlet valve connected to the system. This stabilizes the pressure within the crystallizer at a preset target value, precisely controlling the boiling point temperature of the slurry. Flexible vacuum control is crucial for ensuring the system's supersaturation is within the optimal range for crystal growth, thus producing large-particle ammonium sulfate crystals. The outlet is located at the top of the crystallizer, allowing the water vapor generated during evaporation to rise naturally into the vacuum system, eliminating the need for an additional gas-liquid separation device.

[0019] Preferably, the vacuum system is a vacuum condensation system, which includes a condenser, a vacuum buffer tank, a vacuum pump, a condensate tank, and a condensate pump; the outlet of the reaction crystallizer is connected to the vacuum buffer tank through the condenser, and the vacuum pump is connected to the vacuum buffer tank; the outlet of the vacuum buffer tank is connected to the inlet of the condensate tank, the outlet of the condensate tank is connected to the inlet of the condensate pump, and the outlet of the condensate pump is connected to each water point in the system.

[0020] A vacuum buffer tank is positioned between the condenser and the vacuum pump to separate gas and liquid and stabilize the vacuum level, preventing pressure fluctuations during vacuum pump operation. Condensate is collected in a condensate tank and then pumped back to the system for makeup or flushing, achieving energy and water recycling and further reducing operating costs.

[0021] Preferably, the separation and mother liquor circulation unit includes a buffer tank, a centrifuge, a mother liquor tank, and a mother liquor pump; the inlet of the buffer tank is connected to the outlet of the crystal discharge pump, the outlet of the buffer tank is connected to the inlet of the centrifuge through a first pipeline, and is connected to the inlet of the mother liquor tank through a second pipeline; the outlet of the centrifuge is connected to the inlet of the mother liquor tank, and the centrifuge is provided with an outlet for discharging wet ammonium sulfate crystals.

[0022] The buffer tank receives the slurry from the crystallization unit for initial thickening, and then enters the centrifuge for solid-liquid separation to obtain large-particle ammonium sulfate crystal wet material; the separated mother liquor enters the mother liquor tank to realize centralized management and recycling of the mother liquor, thereby improving resource utilization.

[0023] Preferably, the outlet of the mother liquor tank is connected to the inlet of the mother liquor pump, and the outlet of the mother liquor pump is connected to the Venturi structure.

[0024] The mother liquor pump returns the mother liquor from the mother liquor tank to the Venturi structure of the primary reactor to participate in the circulating absorption reaction, forming a closed-loop mother liquor circulation system. This reduces wastewater discharge and the amount of external absorbent used, lowers operating costs, and maintains the system's water balance.

[0025] Compared with the prior art, the beneficial effects of this utility model are: (1) Significantly reduced energy consumption: This invention creatively utilizes the heat released from the neutralization reaction of ammonia and sulfuric acid as the driving energy for evaporation and concentration by integrating the vacuum reaction crystallization unit with the reaction absorption unit, thereby replacing or significantly reducing the dependence on external steam or electric heating. At the same time, by lowering the boiling point of the slurry in the reaction crystallizer through the vacuum system, low-temperature evaporation is achieved, further reducing the overall energy consumption of the system.

[0026] (2) Significantly Improved Crystallization Quality: This invention, through a "stepwise acid addition" design, places the main acidification and exothermic reactions in a dedicated vacuum reaction crystallization unit. Combined with an adjustable vacuum system, the operating temperature within the crystallizer is precisely controlled, thereby stabilizing the supersaturation during crystallization within the optimal range. This effectively promotes the growth of ammonium sulfate crystals, inhibits the formation of excessive fine crystal nuclei, and ultimately yields large-particle ammonium sulfate crystals with larger particle size and more uniform distribution, greatly improving the operability of subsequent separation, drying, and packaging.

[0027] (3) High operational stability and effective prevention of equipment blockage: This utility model adopts a synergistic design of two-stage reaction absorption and vacuum crystallization separation. The solid content (3%~6%) in the first-stage reactor is maintained by slurry circulation, which fundamentally reduces the risk of blockage in the upstream equipment and pipelines. At the same time, the crystallization process, which is highly exothermic and prone to scaling, is moved to an independent reaction crystallizer, and water and material balance is achieved through a closed-loop mother liquor circulation system. This avoids scaling and blockage caused by excessive local supersaturation in the absorption tower, and significantly improves the stability and reliability of the device during long-term operation.

[0028] (4) Precise and effective temperature control: In response to the industry problem of large heat release and drastic temperature rise during the treatment of high-concentration ammonia tail gas, this utility model disperses the reaction points by "step-by-step acid addition" and uses vacuum evaporation to efficiently transfer heat, thereby achieving precise and flexible control of the system temperature, especially the temperature inside the reaction crystallizer, and completely solving the pain point of temperature runaway (>80℃) caused by concentrated heat release in traditional devices.

[0029] (5) High system integration and improved resource utilization: This utility model shortens the process flow through the efficient connection and coupling of various functional units. The closed-loop circulation of the mother liquor reduces wastewater discharge and the amount of fresh absorbent used; the condensate generated by the vacuum system is recycled for system water replenishment and rinsing, realizing the maximum utilization of resources and further reducing operating costs and environmental impact. Attached Figure Description

[0030] The technical solution of this utility model is further described below with reference to the accompanying drawings: Figure 1 This is a schematic diagram of the process flow for the device for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to this utility model. Wherein: 1- Primary reactor; 2- Primary circulating pump; 3- Ammonium sulfate slurry pump; 4- Secondary reactor; 5- Secondary circulating pump; 6- Reaction crystallizer; 7- Reaction circulating pump; 8- Acid mixer; 9- Condenser; 10- Vacuum buffer tank; 11- Vacuum pump; 12- Condensate tank; 13- Condensate pump; 14- Crystal discharge pump; 15- Buffer tank; 16- Centrifuge; 17- Mother liquor tank; 18- Mother liquor pump; 101- High-concentration ammonia-containing tail gas; 102- Sulfuric acid; 103- Compliant tail gas; 104- Wet ammonium sulfate crystals. Detailed Implementation

[0031] To enhance understanding of this utility model, it will be described in further detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to explain this utility model and do not limit the scope of protection of this utility model.

[0032] Example 1: As Figure 1 As shown, the ammonium sulfate production device from high-concentration ammonia-containing tail gas includes a reaction absorption unit, a vacuum reaction crystallization unit, a separation and mother liquor circulation unit, and a vacuum system. The reaction absorption unit includes a primary reactor 1, a primary circulation pump 2, an ammonium sulfate slurry pump 3, a secondary reactor 4, and a secondary circulation pump 5. A Venturi structure is installed at the top of the primary reactor 1, through which the high-concentration ammonia-containing tail gas 101 (5%~95%v) enters the primary reactor 1. A first outlet and a second outlet are located at the bottom of the primary reactor 1. The first outlet is connected to the Venturi structure via the primary circulation pump 2, forming a slurry circulation loop; the second outlet is connected to the inlet of the ammonium sulfate slurry pump 3.

[0033] The secondary reactor 4 is equipped with an acid inlet, an air inlet, a liquid inlet, and an air outlet. Its air inlet is connected to the air outlet of the primary reactor 1, and its bottom outlet is connected to the liquid inlet of the secondary circulation pump 5. The liquid outlet of the secondary circulation pump 5 is connected to the liquid inlets of both the primary reactor 1 and the secondary reactor 4. The vacuum reaction crystallization unit includes a reaction crystallizer 6, a reaction circulation pump 7, an acid mixer 8, and a crystal discharge pump 14.

[0034] The acid mixer 8 is equipped with a slurry inlet, a concentrated sulfuric acid inlet, and a mixed liquid outlet. Its slurry inlet is connected to the outlet of the ammonium sulfate slurry pump 3. The upper part of the reaction crystallizer 6 is equipped with a liquid inlet and a gas outlet, while the lower part is equipped with a first liquid outlet and a second liquid outlet. The first liquid outlet is connected to the liquid inlet of the reaction crystallizer 6 via the reaction circulation pump 7 and the acid mixer 8, forming a slurry circulation loop. The second liquid outlet is connected to the input end of the crystal discharge pump 14. The vacuum system is connected to the gas outlet of the reaction crystallizer 6 and is used to establish and maintain the vacuum state of the reaction crystallizer 6.

[0035] The vacuum system is a vacuum condensation system, comprising a condenser 9, a vacuum buffer tank 10, a vacuum pump 11, a condensate tank 12, and a condensate pump 13. The outlet of the reaction crystallizer 6 is connected to the vacuum buffer tank 10 via the condenser 9, and the vacuum pump 11 is also connected to the vacuum buffer tank 10. The outlet of the vacuum buffer tank 10 is connected to the inlet of the condensate tank 12, and the outlet of the condensate tank 12 is connected to the inlet of the condensate pump 13. The outlet of the condensate pump 13 is connected to each water point in the system. The separation and mother liquor circulation unit includes a buffer tank 15, a centrifuge 16, a mother liquor tank 17, and a mother liquor pump 18.

[0036] The inlet of the buffer tank 15 is connected to the outlet of the crystal discharge pump 14. The outlet of the buffer tank 15 is connected to the inlet of the centrifuge 16 via a first pipeline and to the inlet of the mother liquor tank 17 via a second pipeline. The centrifuge 16 is provided with an outlet for discharging wet ammonium sulfate crystals 104, and its outlet is connected to the inlet of the mother liquor tank 17. The outlet of the mother liquor tank 17 is connected to the inlet of the mother liquor pump 18, and the outlet of the mother liquor pump 18 is connected to the Venturi structure at the top of the primary reactor 1.

[0037] The operating process of the device is as follows: High-concentration ammonia-containing tail gas 101 with a concentration of 10%~15% first enters the system through the Venturi structure at the top of the primary reactor 1. The tail gas comes into full contact with the circulating mother liquor from the primary circulation pump 2, completing the preliminary absorption reaction. The tail gas after primary treatment enters the secondary reactor 4, where concentrated sulfuric acid 102 is added through the acid addition port at the top. Under the action of the secondary circulation pump 5, the reaction is further carried out to ensure that the tail gas 103 meets the emission standards. The first liquid outlet at the bottom of the primary reactor 1 maintains the internal circulation of the slurry through the primary circulation pump 2, and the second liquid outlet transports ammonium sulfate slurry with a solid content of 3%~6% to the acid mixer 8 through the ammonium sulfate slurry pump 3.

[0038] The slurry, after being mixed with concentrated sulfuric acid in acid mixer 8, enters reaction crystallizer 6. The absolute pressure within reaction crystallizer 6 is maintained at 0.01~0.03 MPa using a vacuum system, and the operating temperature is controlled at 50~65℃. The heat of neutralization reaction drives the slurry to evaporate and concentrate, increasing the solid content to 8%~15%. The concentrated slurry is thickened by crystal discharge pump 14 into buffer tank 15, and then separated in centrifuge 16 to obtain wet ammonium sulfate crystals 104. The separated mother liquor is returned to mother liquor tank 17 and then pumped back to primary reactor 1 for recycling via mother liquor pump 18. The condensate generated by the vacuum system is collected in condensate tank 12 via condenser 9 and vacuum buffer tank 10, and then pumped back to the system for makeup water by condensate pump 13.

[0039] Example 2: This example provides a more optimized and specific implementation scheme based on Example 1. In this example, the operation of the primary reactor 1 is finely controlled, and the solid content of the slurry discharged from its bottom is strictly controlled within the range of 4%~5%. The vacuum reaction crystallization unit adopts an adjustable vacuum system, and the absolute pressure in the reaction crystallizer 6 is precisely stabilized between 0.015~0.025MPa by a frequency-controlled vacuum pump 11, and the corresponding operating temperature is stabilized between 58~62℃. Under these optimized conditions, the solid content of the slurry discharged from the reaction crystallizer 6 can be increased to 12%~15%. In the separation unit, a horizontal screw discharge centrifuge 16 is used, and the residence time of the buffer tank 15 is optimized to ensure that the moisture content of the ammonium sulfate crystal wet material 104 is ≤4%. The mother liquor circulation system controls the ratio of mother liquor return flow to fresh replenishment absorption liquid within the range of (6~10):1, effectively ensuring the stability of the system's long-term operation.

[0040] For those skilled in the art, the specific embodiments are merely exemplary descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A device for producing ammonium sulfate from high-concentration ammonia-containing tail gas, characterized in that, It includes a reaction absorption unit, a vacuum reaction crystallization unit, a separation and mother liquor circulation unit, and a vacuum system; the reaction absorption unit, the vacuum reaction crystallization unit, and the separation and mother liquor circulation unit are connected in sequence; the vacuum system is connected to the vacuum reaction crystallization unit.

2. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 1, characterized in that, The reaction absorption unit includes a primary reactor, a primary circulation pump, and an ammonium sulfate slurry pump; the upper part of the primary reactor is equipped with a Venturi structure, through which high-concentration ammonia-containing tail gas of 5%~95%v enters the primary reactor.

3. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 2, characterized in that, The bottom of the primary reactor is provided with a first outlet and a second outlet; the first outlet of the primary reactor is connected to the Venturi structure through the primary circulation pump; the second outlet of the primary reactor is connected to the inlet of the ammonium sulfate slurry pump.

4. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 2, characterized in that, The reaction absorption unit further includes a secondary reactor and a secondary circulation pump; the secondary reactor is provided with an acid inlet, an air inlet, a liquid inlet, and an air outlet; the air inlet of the secondary reactor is connected to the air outlet of the primary reactor, and the bottom outlet of the secondary reactor is connected to the liquid inlet of the secondary circulation pump; the liquid outlet of the secondary circulation pump is connected to the liquid inlet of the primary reactor and the liquid inlet of the secondary reactor, respectively.

5. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 3, characterized in that, The vacuum reaction crystallization unit includes a reaction crystallizer, a reaction circulation pump, an acid mixer, and a crystal discharge pump. The acid mixer is provided with a slurry inlet, a concentrated sulfuric acid inlet, and a mixed liquid outlet. The slurry inlet is connected to the outlet of the ammonium sulfate slurry pump. The first outlet is connected to the inlet of the reaction crystallizer through the reaction circulation pump and the acid mixer to form a slurry circulation. The second outlet is connected to the input end of the crystal discharge pump.

6. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 5, characterized in that, The vacuum system is connected to the outlet of the reaction crystallizer and is used to establish and maintain the vacuum state of the reaction crystallizer; the vacuum system is an adjustable vacuum system.

7. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 5, characterized in that, The vacuum system is a vacuum condensation system, which includes a condenser, a vacuum buffer tank, a vacuum pump, a condensate tank, and a condensate pump. The outlet of the reaction crystallizer is connected to the vacuum buffer tank through the condenser, and the vacuum pump is connected to the vacuum buffer tank. The outlet of the vacuum buffer tank is connected to the inlet of the condensate tank, the outlet of the condensate tank is connected to the inlet of the condensate pump, and the outlet of the condensate pump is connected to each water point in the system.

8. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 5, characterized in that, The separation and mother liquor circulation unit includes a buffer tank, a centrifuge, a mother liquor tank, and a mother liquor pump; the inlet of the buffer tank is connected to the outlet of the crystal discharge pump, the outlet of the buffer tank is connected to the inlet of the centrifuge through a first pipeline, and is connected to the inlet of the mother liquor tank through a second pipeline; the outlet of the centrifuge is connected to the inlet of the mother liquor tank, and the centrifuge is provided with an outlet for discharging wet ammonium sulfate crystals.

9. The apparatus for producing ammonium sulfate from high-concentration ammonia-containing tail gas according to claim 8, characterized in that, The outlet of the mother liquor tank is connected to the inlet of the mother liquor pump, and the outlet of the mother liquor pump is connected to the Venturi structure.

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