A continuous ammonium sulfate decomposition device with a hot air jacket

Abstract

This utility model discloses a continuous ammonium sulfate decomposition device with a hot air jacket, relating to the field of chemical equipment technology. The device includes an upper decomposition zone, a middle decomposition zone, a lower storage zone, and a hot air system. The upper decomposition zone has a first exhaust pipe at the top and a first slurry outlet at the bottom, and is internally equipped with a first rotary atomizer and a first stirrer. The middle decomposition zone includes multiple second rotary atomizers connected to a microwave heating device, a second exhaust pipe at the top, a second slurry outlet at the bottom connected to the lower storage zone, and a plasma generator at the top. This utility model is suitable for the direct decomposition of ammonium sulfate solution, completely changing the intermittent and inefficient operation mode of traditional devices that involve separate heating and decomposition of ammonia and SO3. Simultaneously, it enables continuous operation of the same device, solving the problem of low throughput in traditional intermittent devices.

Description

Technical Field

[0001] This utility model relates to the field of chemical equipment technology, specifically to a continuous ammonium sulfate decomposition device with a hot air jacket. Background Technology

[0002] Industrial by-product gypsum is a large amount of solid waste generated during industrial production. It mainly includes desulfurization gypsum emitted from coal-fired power plants, phosphogypsum produced from the phosphate fertilizer industry, and various types of gypsum emitted from citric acid plants and titanium dioxide plants. Among them, phosphogypsum and desulfurization gypsum are the types of industrial by-product gypsum generated in the largest quantities. Because these types of gypsum have a high CaSO4·2H2O content, they are suitable for decomposition and production of sulfuric acid co-production cement clinker (or lime) to achieve large-scale and high-value utilization.

[0003] In existing technologies, the production of sulfuric acid from industrial by-product gypsum mostly employs a reducing thermal decomposition process: gypsum is decomposed into SO2 gas through a high-temperature (typically >1200℃) reduction reaction, and then sulfuric acid is produced via a single-conversion-one-absorption, two-conversion-two-absorption, or three-conversion-three-absorption sulfuric acid production system. The solid product, CaO, is used to produce cement. Currently, the most widely used process is the "two-conversion-two-absorption" sulfuric acid production process, but it generally suffers from the following drawbacks:

[0004] (1) High energy consumption and cost: High-temperature reduction reaction requires a lot of energy, and the "two-conversion and two-absorption" acid production system has a large investment and high operating cost. Especially for low-concentration SO2 flue gas, the conversion rate is low and the energy consumption is further increased.

[0005] (2) Complex process flow: It requires multiple units such as gypsum reduction and decomposition device, gas purification, conversion and absorption, etc., with low equipment integration and large footprint.

[0006] (3) Environmental risks: SO2 gas leakage and exhaust gas treatment are difficult and can easily cause secondary pollution. In addition, the high-temperature reaction has strict requirements on the equipment materials and can easily cause equipment corrosion.

[0007] Therefore, developing a low-energy-consumption, low-cost, and simplified continuous ammonium sulfate decomposition (sulfuric acid production) device has become an urgent need to overcome existing technological bottlenecks. Utility Model Content

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a continuous ammonium sulfate decomposition device with a hot air jacket, which completely changes the intermittent and inefficient operation mode of "ammonia and SO3 being heated and decomposed separately" in the traditional device, and realizes continuous operation of the same device, thus solving the problem of small processing capacity of the traditional intermittent device.

[0009] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0010] A continuous ammonium sulfate decomposition device with a hot air jacket includes an upper decomposition zone, a middle decomposition zone, a lower storage zone, and a hot air system.

[0011] The top of the upper decomposition zone is provided with a first exhaust pipe, and the bottom is provided with a first slurry outlet. The interior is equipped with a first rotary atomizer and a first stirrer.

[0012] The first slurry outlet is connected to a microwave heating device via a pipe. The middle decomposition zone includes multiple second rotary atomizers connected to the microwave heating device inside it, a second exhaust pipe at its top, a second slurry outlet at its bottom connected to the lower storage zone, and a plasma generator installed at its top.

[0013] The hot air system includes an upper jacket located outside the upper decomposition zone, a middle jacket located outside the middle decomposition zone, and multiple transition pipes connecting the upper jacket and the middle jacket.

[0014] Furthermore, an ammonia gas guide hood is provided at the top of the interior of the upper decomposition zone.

[0015] Furthermore, an ammonia absorption tower and an ammonia storage tank are connected in series with the first exhaust pipe.

[0016] Furthermore, a first raw liquid pump is provided outside the upper decomposition zone and connected to the first rotary atomizer via a pipeline; a second raw liquid pump is installed at the first slurry outlet; a third slurry outlet is provided at the lower end of the lower storage zone, and a mother liquor pump is provided connected to the third slurry outlet.

[0017] Furthermore, multiple second rotary atomizers are arranged in multiple layers inside the middle decomposition zone; and the nozzles of the second rotary atomizers are made of ceramic materials such as Al2O3-ZrO2 composite ceramics.

[0018] Furthermore, a quench tower, an electrostatic precipitator, a sulfuric acid absorption tower, and a sulfuric acid storage tank are connected in series with the second exhaust pipe.

[0019] Furthermore, the lower end of the middle section decomposition zone is conical, and an ultrasonic transducer is installed on the conical sidewall.

[0020] Furthermore, hot air inlets are provided at the lower ends of both the middle and upper jacket sections, and hot air ducts are provided at each hot air inlet. Electric butterfly valves for mixing cold air are also provided on the hot air ducts.

[0021] Furthermore, both the middle and upper jackets are equipped with guide vanes that can guide the high-temperature hot air to rise in a spiral shape.

[0022] Furthermore, a hot air outlet is located at the upper end of the upper jacket, and an exhaust fan is installed at the hot air outlet.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] (1) This utility model is applicable to the direct decomposition of ammonium sulfate solution. It adopts a segmented structure of "upper section (ammonia decomposition at 180-200℃) + middle section (SO3 decomposition at 350℃) + lower section (mother liquor storage)". Through independent temperature control, it realizes the directional separation and separate discharge of ammonia (decomposition rate > 85%) and SO3, which completely changes the intermittent and inefficient operation mode of "ammonia and SO3 are heated and decomposed separately" in traditional devices. At the same time, the three sections form a whole. The ammonium sulfate raw solution directly enters the device for decomposition, and the low-concentration mother liquor is automatically returned to the ammoniation system for circulation, realizing continuous operation of the same device. It solves the problem of small processing capacity of traditional intermittent devices and creates the core conditions for large-scale equipment (suitable for large-scale treatment of industrial by-product gypsum).

[0025] (2) The ammonium sulfate aqueous solution itself has extremely low impurity content, so there is no need to add an additional gas purification unit. At the same time, the device provided by this utility model adopts a "hot air jacket heat transfer" design, in which high-temperature hot air only flows within the jacket and does not come into contact with the ammonium sulfate solution at all, thus avoiding the contamination of the product by dust or impurities carried by the hot air from the source. The sulfuric acid obtained after rapid cooling and absorption can reach a purity of 93-98%, and does not contain trace impurities brought about by SO2 conversion in traditional processes. It can be directly used for phosphate fertilizer production or industrial-grade sulfuric acid sales, and the quality stability of sulfuric acid is significantly better than that of traditional acid production devices.

[0026] (3) The maximum operating temperature of this invention is only 350-400℃ (the core temperature of SO3 decomposition in the middle stage is 350℃), which is significantly lower than the 520℃ of traditional granular ammonium sulfate (dry method) decomposition; at the same time, this invention is coupled with microwave heating technology, which selectively heats NH4 + SO4 2- Ions induce localized overheating, further reducing the apparent activation energy of the reaction and lowering the overall energy consumption by 40% compared to traditional high-temperature decomposition processes. This significantly reduces the energy consumption cost of sulfuric acid production from industrial by-product gypsum, aligning with the energy-saving requirements under the "dual carbon" target.

[0027] (4) The synergistic effect of microwave and plasma technologies in this invention: Microwaves overcome thermodynamic limitations through bulk heating, reducing the decomposition temperature of ammonium sulfate from 520℃ to 300-400℃, thus avoiding the aggravation of side reactions at high temperatures; the high-energy electrons generated by plasma can precisely break the molecular bonds of (NH4)2SO4, directionally promoting its conversion into NH3 and SO3 (rather than SO2), while simultaneously generating H· free radicals to inhibit SO2 generation. Ultimately, a near-zero emission effect is achieved with SO2 by-product rate <1% and ammonium sulfate decomposition rate >95%, which reduces the pressure of tail gas treatment and improves the utilization rate of raw materials.

[0028] (5) The traditional “two-stage conversion and two-stage absorption” acid production process requires complex equipment such as gypsum reduction and decomposition device, gas purification tower, and multi-stage converter, which has a large investment and high operating costs (especially when the conversion rate is low and energy consumption is increased when the SO2 concentration is low); while the device provided by this utility model directly decomposes SO3, and can directly generate 98% high-concentration finished sulfuric acid through quench tower → electrostatic precipitator → sulfuric acid absorption tower, which can save the equipment of “SO2 multi-stage conversion”. Attached Figure Description

[0029] Figure 1 A schematic diagram of the overall structure of the device provided by this utility model.

[0030] The corresponding names of the attached figures are as follows: 1-Upper decomposition zone, 2-Middle decomposition zone, 3-Lower storage zone, 41-First raw liquid pump, 42-Second raw liquid pump, 43-Mother liquor pump, 51-First stirrer, 52-Second stirrer, 6-Ammonia gas guide hood, 7-First rotary atomizer, 8-Upper jacket, 9-Plasma generator, 10-Transition pipe, 11-Microwave heating device, 12-Middle jacket, 13-Second rotary atomizer, 14-Electric valve, 15-Exhaust fan, 16-First exhaust pipe, 17-Ammonia absorption tower, 18-Ammonia water storage tank, 19-First slurry outlet, 20-Second exhaust pipe, 21-Third slurry outlet, 22-Hot air pipe. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0032] This embodiment provides a continuous ammonium sulfate decomposition device with a hot air jacket. Its core lies in utilizing the unique physicochemical properties of ammonia. Through optimized gas-solid-liquid three-phase reaction conditions and a specialized device design, industrial by-product gypsum is decomposed into ammonium sulfate intermediates at low or even room temperature. This intermediates are then used to produce sulfuric acid through secondary decomposition, along with high-value-added carbonate products. In terms of technical approach, this embodiment simplifies the process flow by finding a suitable technical route, achieving modular and integrated design. Furthermore, it fully considers the goals of new energy consumption and carbon neutrality, further optimizing the environmental friendliness and economy of the process route, resulting in a more complete process.

[0033] Based on the decomposition characteristics of ammonium sulfate, this invention innovatively employs segmented material distribution and segmented temperature control technology to achieve efficient separation of decomposition products, and couples microwave heating and plasma technology to enhance reaction efficiency. The continuous ammonium sulfate decomposition device provided in this embodiment consists of an upper decomposition zone 1, a middle decomposition zone 2, a lower storage zone 3, and a hot air system, wherein the upper decomposition zone 1, the middle decomposition zone 2, and the lower storage zone 3 are connected by flanges to form a whole.

[0034] This device is a jacketed, segmented ammonium sulfate decomposition reactor that uses hot air as the heat transfer medium. The hot air does not come into contact with the solution, ensuring the quality of the sulfuric acid. The specific operation and design are as follows:

[0035] (1) Upper section: 180-200℃ ammonia decomposition section

[0036] The upper decomposition zone 1 is located at the top of the device. Inside it are a first rotary atomizer 7 and a first stirrer 51. An ammonia gas guide hood 6 is installed at the top of the upper decomposition zone 1 to effectively prevent solution droplets from being carried away by ammonia gas. The first stirrer 51 is used to stir the solution within the upper decomposition zone 1. Outside the upper decomposition zone 1, a first raw material pump 41, connected to the first rotary atomizer 7 via a pipe, is installed to pressurize the solution from the ammonium sulfate raw material tank and the catalyst solution.

[0037] After being pressurized by the first stock solution pump, the ammonium sulfate stock solution is sprayed into the upper decomposition zone 1 of the device through the first rotary atomizer 7. The sprayed solution is in the form of a mist (the droplet size after atomization is 50-80μm), which greatly increases the gas-liquid contact area and enhances the decomposition reaction efficiency. Under an environment of 180-200℃, the ammonium sulfate solution is rapidly decomposed into ammonia and water vapor. The ammonia decomposition rate in this section is >85%.

[0038] A first exhaust pipe 16 is installed at the top of the upper decomposition zone 1. The decomposed ammonia gas and water vapor are transported through the top first exhaust pipe 16 to the ammonia absorption tower 17 (for dilute sulfuric acid washing and recovery), and finally enter the ammonia water storage tank 18 for recycling in the ammoniation system. This section is equipped with a pH interlock system (to monitor undecomposed NH4). + (Concentration, feedback adjustment temperature). A first slurry outlet 19 is provided at the lower end of the upper decomposition zone 1, and the slurry that has been decomposed is discharged from the first slurry outlet 19 at the lower end.

[0039] (2) Middle section: SO3 decomposition section at 350℃

[0040] A second raw material pump 42 is installed at the first slurry outlet 19 of the upper decomposition zone 1, and a microwave heating device 11 is connected to the second raw material pump 42 via a pipeline. The middle decomposition zone 2 is located below the upper decomposition zone 1, and multiple second rotary atomizers 13 connected to the microwave heating device 11 via pipelines are installed inside the middle decomposition zone 2. These second rotary atomizers 13 are arranged in multiple layers inside the middle decomposition zone 2. The slurry after decomposition in the upper decomposition zone 1 is pressurized by the second raw material pump 42 and sent to the microwave heating device 11 via pipeline. The microwaves stimulate the ammonium sulfate ions (NH4+) to react with the slurry. + SO4 2-Selective heating induces localized overheating (>300℃), reducing the apparent activation energy. Furthermore, under microwave action, the decomposition temperature of ammonium sulfate is significantly reduced, controllable between 300-400℃. Simultaneously, compared to traditional high-temperature decomposition processes, overall energy consumption is reduced by 40%, achieving substantial energy savings while improving decomposition efficiency. The microwave-heated slurry is transported via pipeline to the second rotary atomizer 13, where it is sprayed as a mist into the intermediate decomposition zone 2. At 350℃, the ammonium sulfate solution rapidly decomposes into SO3 and water vapor, which are the decomposition products of this stage.

[0041] To address the high corrosiveness of SO3 to materials at high temperatures (especially when containing trace amounts of water, it easily generates sulfuric acid), the lining of the middle decomposition zone is made of a composite layer of borosilicate glass and Hastelloy C-276, which can withstand the corrosion of SO3 at high temperatures; the nozzle of the second rotary atomizer is made of ceramic materials such as Al2O3-ZrO2 composite ceramic, which has both high temperature resistance and corrosion resistance.

[0042] A second exhaust pipe 20 is installed at the top of the intermediate decomposition zone 2. SO3 and water vapor are transported through this top second exhaust pipe to the quench tower, electrostatic precipitator, and sulfuric acid absorption tower, where they are absorbed by dilute sulfuric acid to produce finished sulfuric acid, which finally enters the sulfuric acid storage tank. The second exhaust pipe (SO3 pipe) is electrically heated to maintain the pipe temperature at 120-150℃, preventing SO3 condensation and blockage. An emergency nitrogen purging system is also installed, which automatically activates when the oxygen content in the pipe exceeds 5%, mitigating safety risks. To prevent SO3 pipe blockage, the pipe is designed with an inclination angle of ≥30°, and a steam purging port is installed every 3 meters.

[0043] The lower end of the middle decomposition zone 2 is conical (the angle of the cone bottom is ≥70°). At the same time, an ultrasonic transducer is installed on the side wall to prevent the solution from crystallizing and accumulating at the bottom through vibration. A second slurry outlet is opened at the bottom of the cone, and an electric valve 14 whose opening is controlled by DCS is installed at the second slurry outlet.

[0044] Additionally, a plasma generator is installed at the top of the intermediate decomposition zone 2. The plasma torch it produces can regulate the gas reaction path within the decomposition device, suppressing the formation of sulfur dioxide (SO2) by generating H· free radicals. Furthermore, during the decomposition of ammonium sulfate, the plasma can generate high-energy electrons, which can precisely cleave ammonium sulfate (NH4)2. + SO4 2- The chemical bonds in the molecule direct its conversion into ammonia (NH3) and sulfur trioxide (SO3), rather than producing byproducts such as sulfur dioxide (SO2). This directional reaction control effectively suppresses the side reaction that produces SO2, ensuring the direction and purity of the target product.

[0045] Under the action of plasma, the generation rate of sulfur dioxide (SO2), a byproduct of ammonium sulfate decomposition, can be controlled to below 1%, greatly reducing the generation of ineffective byproducts. At the same time, the decomposition rate of ammonium sulfate (NH4)2SO4 itself can reach more than 95%, significantly improving the utilization rate of raw materials and the production efficiency of target products, and further optimizing the performance of the overall decomposition process.

[0046] (3) Lower section: Mother liquor storage section

[0047] The lower storage zone 3 is located below the intermediate decomposition zone 2. The second slurry outlet is connected to the lower storage zone 3, allowing the (low-concentration) mother liquor, after decomposition in the intermediate decomposition zone 2, to flow into the lower storage zone 3 by gravity. This section primarily stores the mother liquor; it is not jacketed, does not require heating, and cools naturally. The mother liquor may contain undecomposed ammonium bisulfate (NH4HSO4), which is highly corrosive and prone to crystallization. Therefore, a second agitator 52 is installed at the top to forcibly agitate the slurry and prevent crystallization. The agitator is a variable-diameter screw type (with a 20% increase in bottom diameter to enhance bottom cleaning ability).

[0048] A third slurry outlet 21 is provided at the lower end of the lower storage zone 3. A mother liquor pump 43 is connected to the third slurry outlet 21 to transport the slurry in the lower storage zone 3 to the ammoniation system for recycling. In terms of operation and control, the mother liquor pump adopts frequency conversion control (adjusting the flow rate according to the liquid level) and is equipped with an online density meter (monitoring the crystallization trend).

[0049] In addition, to prevent the mother liquor pump from corroding and failing, a magnetic pump with silicon carbide bearings can be used (mechanical seals are prohibited), or a pneumatic mother liquor delivery system (without moving parts) can be installed.

[0050] (4) Hot air system

[0051] The hot air system includes an upper jacket 8 located outside the upper decomposition zone 1 and a middle jacket 12 located outside the middle decomposition zone 2. High-temperature hot air enters from the lower end of the jacket and exits from the upper end. Therefore, an outlet is provided at the upper end and an inlet at the lower end of the jacket. The outlet of the middle jacket 12 is connected to the inlet of the upper jacket 8 through multiple transition pipes 10. A hot air duct 22 is connected at the lower inlet of the middle jacket 12, and an electric butterfly valve for mixing cold air is provided on the hot air duct 22. This electric butterfly valve is controlled by a DCS to precisely regulate the temperature inside the jacket and meet the temperature requirements of the middle decomposition zone.

[0052] High-temperature hot air at 600℃ (sourced from high-temperature hot air cooling clinker in the cement kiln system, high-temperature carbon dioxide gas, etc.) supplied externally enters the intermediate jacket 12 of the intermediate decomposition zone 2 tangentially through hot air duct 22. The intermediate jacket 12 is equipped with guide vanes to guide the high-temperature hot air upwards in a spiral shape, thereby maximizing the residence time of the hot air within the jacket and ensuring optimal heat exchange. After being cooled by heat exchange in the intermediate jacket 12, the hot air enters the upper jacket 8 of the upper decomposition zone 1 in a spiral shape through multiple transition pipes 10. The upper jacket 8 is designed identically to the intermediate jacket 12, and also has guide vanes inside to maintain the hot air in a spiral upward state, further extending the residence time and ensuring temperature stability in the upper 180-200℃ ammonia decomposition section. Furthermore, a hot air duct is also connected to the lower inlet of the upper jacket 8, equipped with a DCS-controlled electric butterfly valve for precise temperature regulation within the upper jacket. An exhaust fan 15 is installed at the upper outlet of the upper jacket 8. The hot air that has completed the heat exchange and cooling in the upper section is transported to the heat exchanger by the exhaust fan 15 for subsequent heat recovery and utilization, which can achieve efficient energy circulation. The hot air after heat recovery is purified to meet emission standards before being discharged, reducing the impact on the environment. In this embodiment, thermal insulation material is provided on the outer surface of both the upper and middle jackets.

[0053] To match the different temperature requirements of the upper and middle sections, the hot air system adopts a graded control strategy:

[0054] Upper section: 200℃ hot air (all from the waste heat of the exhaust gas after the hot air heat exchange in the middle section, DCS control to add cold air to ensure the stability of the temperature inside the jacket);

[0055] Middle section: Independent 450℃ high-temperature hot air (based on 600℃ high-temperature hot air, DCS control adds cold air to ensure the stability of temperature inside the jacket);

[0056] Air volume distribution ratio: 30% in the upper section and 70% in the middle section, to meet the different heat load requirements of the two sections.

[0057] The control logic of the DCS is as follows:

[0058] A [Ammonium sulfate feed flow rate] --> B (Upper section temperature PID control)

[0059] B-->C{Ammonia Concentration Analysis}

[0060] C --> |Too low|D [Increase the upper temperature setting by 5℃]

[0061] C --> Normal | E [Maintain mid-section hot air volume]

[0062] E-->F (Calculation of SO3 yield in the middle section)

[0063] F --> | Descend | G [Activate secondary hot air injection]

[0064] This device is specifically designed for the direct decomposition of ammonium sulfate solution (simplifying the solution drying and crystallization process). After the ammonium sulfate stock solution is decomposed in this device, the remaining low-concentration mother liquor is returned to the ammoniation system for continued recycling. To prevent excessive pressure difference between the upper and middle sections from affecting reaction stability, a pressure buffer pipeline is installed between the upper and middle sections (maintaining a pressure difference ≤0.5 kPa). The entire system operates under slight negative pressure (pressure controlled between -1 and -2 kPa) to effectively prevent gas leakage within the reactor and ensure a safe production environment. The diameter ratio of the three reactor sections (upper decomposition zone, middle decomposition zone, and lower storage zone) is approximately 1:1.2:0.8, and the height ratio is approximately 1:1.5:0.5, adapting to the reaction requirements and material throughput of each section.

[0065] The reaction principle and subsequent processes involved in this embodiment are explained below:

[0066] Under high-temperature reaction conditions, ammonium sulfate rapidly decomposes into ammonia (NH3) and sulfuric acid (H2SO4), as follows:

[0067] (NH4)2SO4→H2SO4+2NH3↑

[0068] Alternatively, it can be expressed as: (NH4)2SO4→SO3↑+H2O+2NH3↑

[0069] Therefore, in this process, ammonium sulfate does not exist in solid form, but decomposes directly into gaseous sulfuric acid (H2SO4) and ammonia (NH3), which are discharged with the flue gas.

[0070] Subsequent rapid cooling and gas collection: Since sulfuric acid exists in a gaseous state (H2SO4(g)) at high temperatures, and ammonia (NH3) is also discharged with the flue gas, rapid cooling is required to prevent the sulfuric acid from recombining into ammonium sulfate ((NH4)2SO4) or forming sulfuric acid mist (H2SO4 droplets) at low temperatures. Specific measures include:

[0071] 1.Quick cooling tower

[0072] Function: To rapidly cool high-temperature flue gas to below 200°C, causing gaseous sulfuric acid to condense into liquid sulfuric acid (H2SO4(l)), while preventing ammonia from reacting with sulfuric acid again.

[0073] Cooling medium: Usually a circulating dilute sulfuric acid solution is used (the spray volume needs to be controlled to avoid excessive dilution of the sulfuric acid).

[0074] Temperature control: The temperature of the cooled flue gas should be below 150℃ to reduce the regeneration of ammonium sulfate.

[0075] 2. Sulfuric acid condensation and collection

[0076] Condenser: The condenser is made of fiberglass (FRP) or high-silicon cast iron, which is corrosion resistant and can efficiently recover sulfuric acid.

[0077] Sulfuric acid concentration adjustment: By controlling the cooling rate and the circulation volume of the absorbent, 93-98% industrial concentrated sulfuric acid can be obtained, which can be directly used in the production or sale of phosphate fertilizer.

[0078] 3. Ammonia recovery

[0079] Ammonia absorption tower: Residual ammonia (NH3) that is not absorbed by sulfuric acid can be recovered by water washing or acid washing (such as phosphoric acid absorption to produce ammonium phosphate), avoiding pollution emissions.

[0080] Exhaust gas treatment: If there is still a small amount of unreacted ammonia and SO2, wet desulfurization (such as limestone-gypsum method) can be used for further purification to meet emission standards.

[0081] The above embodiments are merely one of the preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but solve the same technical problem as this utility model, should be included within the scope of protection of this utility model.

Claims

1. A continuous ammonium sulfate decomposition device with a hot air jacket, characterized in that, It includes an upper decomposition zone (1), a middle decomposition zone (2), a lower storage zone (3), and a hot air system; The top of the upper decomposition zone (1) is provided with a first exhaust pipe (16), the lower end is provided with a first slurry outlet (19), and the interior is equipped with a first rotary atomizer (7) and a first stirrer (51). The first slurry outlet (19) is connected to a microwave heating device (11) via a pipe. The middle section decomposition zone (2) includes multiple second rotary atomizers (13) connected to the microwave heating device (11) inside it, a second exhaust pipe (20) at its top, a second slurry outlet at its bottom connected to the lower section storage zone (3), and a plasma generator (9) installed at its top. The hot air system includes an upper jacket (8) located outside the upper decomposition zone (1), a middle jacket (12) located outside the middle decomposition zone (2), and a multi-strand transition pipe (10) for connecting the upper jacket (8) and the middle jacket (12).

2. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 1, characterized in that, An ammonia gas guide hood (6) is provided at the top of the interior of the upper decomposition zone (1).

3. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 2, characterized in that, An ammonia absorption tower (17) and an ammonia water storage tank (18) are connected in series with the first exhaust pipe (16).

4. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 3, characterized in that, A first raw liquid pump (41) is provided outside the upper decomposition zone (1) and connected to the first rotary atomizer (7) through a pipe; a second raw liquid pump (42) is installed at the first slurry outlet (19); a third slurry outlet (21) is opened at the lower end of the lower storage zone (3), and a mother liquor pump (43) is provided connected to the third slurry outlet (21).

5. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 4, characterized in that, Multiple second rotary atomizers (13) are arranged in multiple layers inside the middle section decomposition zone (2); and the nozzles of the second rotary atomizers are made of Al2O3-ZrO2 composite ceramic.

6. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 5, characterized in that, A quench tower, an electrostatic precipitator, a sulfuric acid absorption tower, and a sulfuric acid storage tank are connected in series with the second exhaust pipe (20).

7. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 6, characterized in that, The lower end of the middle section decomposition zone (2) is conical, and an ultrasonic transducer is installed on the conical sidewall.

8. The ammonium sulfate continuous decomposition device with a hot air jacket according to claim 7, characterized in that, Hot air inlets are provided at the lower ends of the middle jacket (12) and the upper jacket (8), and hot air pipes (22) are provided at the hot air inlets. Electric butterfly valves for mixing cold air are provided on the hot air pipes (22).

9. A continuous ammonium sulfate decomposition device with a hot air jacket according to claim 8, characterized in that, The interior of both the middle jacket (12) and the upper jacket (8) is provided with a guide plate that can guide the high-temperature hot air to rise in a spiral shape.

10. A continuous ammonium sulfate decomposition device with a hot air jacket according to claim 9, characterized in that, The upper end of the upper jacket (8) is the hot air outlet, and an exhaust fan (15) is installed at the hot air outlet.

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