Anti-crystallization ammonium carbamate denitration agent pyrolysis box

Abstract

The invention discloses an ammonium carbamate denitration agent pyrolysis box for preventing crystallization. The ammonium carbamate denitration agent pyrolysis box comprises a box body, a conveying belt, a first heating assembly and a second heating assembly. The ammonium carbamate powder is heated from the upper portion of the ammonium carbamate powder through the first heating assembly, the ammonium carbamate powder is heated from the lower portion of the ammonium carbamate powder through the second heating assembly, it is effectively guaranteed that ammonium carbamate is completely decomposed on the conveying belt, and the defect that a medium can only be heated and decomposed from a single face through traditional heating equipment is overcome. Ammonium carbamate powder is fully pyrolyzed on the conveying belt, so that the problem of pipeline blockage caused by caking of ammonium carbamate in the flue gas denitration process is avoided. The box body can ensure that ammonium carbamate is fully decomposed to generate enough ammonia gas for denitration reaction, so that the denitration efficiency is improved. As the ammonium carbamate is directly decomposed in the box body, the ammonia preparation method does not need to be carried out under a high-temperature condition like the traditional urea ammonia preparation method, the ammonia preparation efficiency is improved by 5.9%-23.5% and averagely improved by 14.70% compared with the urea, and the ammonia preparation energy consumption is reduced by 48.0%-65.0%.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas denitration in coal-fired power plants, and in particular to a pyrolysis box for an ammonium carbamate denitrification agent used for preventing crystallization. Background Art

[0002] With growing awareness of environmental protection and the increasing demand for air pollution control, controlling NOx emissions from coal-fired power plants has become a key focus of environmental protection efforts. Selective catalytic reduction (SCR) flue gas denitrification technology is widely used in coal-fired power plants due to its proven effectiveness in controlling NOx emissions from coal-fired units. Urea, currently the most commonly used flue gas denitrification reducing agent, is a relatively mature and safe ammonia production process. However, the high temperature required to produce ammonia from urea increases the energy cost of the denitrification system.

[0003] In the related art, addressing the limitations of existing urea-ammonia production technology, the use of ammonium carbamate, an intermediate product in urea production, as the primary denitrification agent has been proposed, offering cost advantages. However, ammonium carbamate is prone to agglomeration during the selective catalytic denitrification of flue gas, leading to pipeline blockage and difficulty in decomposition. Summary of the Invention

[0004] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0005] To this end, an embodiment of the present invention provides an ammonium carbamate denitrification agent pyrolysis box for preventing crystallization.

[0006] The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to an embodiment of the present invention comprises:

[0007] A box body, wherein the box body has a pyrolysis chamber, and is provided with a feed pipe and an exhaust pipe connected to the pyrolysis chamber, wherein the feed pipe is used for the ammonium carbamate powder to enter the box body, and the exhaust pipe is used for exhausting carbon dioxide and ammonia generated by the pyrolysis of ammonium carbamate;

[0008] A conveyor belt is arranged in the box body, and one end of the conveyor belt is arranged below the discharge pipe to receive the ammonium carbamate powder falling from the discharge pipe;

[0009] A first heating component and a second heating component, the first heating component is arranged in the box and above the conveyor belt, the second heating component is arranged in the box and between the upper belt and the lower belt of the conveyor belt, the first heating component and the second heating component are both used to heat the ammonium carbamate powder transported on the conveyor belt to decompose the ammonium carbamate powder into carbon dioxide and ammonia.

[0010] In some embodiments, the first heating assembly includes a heating plate and an energy storage battery. The heating plate has a heating surface facing the conveyor belt. The heating surface is provided with a mounting hole for accommodating the energy storage battery. The energy storage battery is used to discharge to heat the heating surface.

[0011] In some embodiments, the inner diameter of the mounting hole is 2 cm to 5 cm.

[0012] In some embodiments, there are multiple heating plates, and the multiple heating plates are arranged at intervals along the conveying direction of the conveyor belt.

[0013] In some embodiments, the second heating assembly includes an electric heating rod and a heat dissipation sleeve, the axial direction of the electric heating rod is parallel to the conveying direction of the conveyor belt, and the heat dissipation sleeve is mounted on the electric heating rod to dissipate the heat generated by the electric heating rod.

[0014] In some embodiments, the distance between the heat dissipation sleeve and the upper belt and the lower belt of the conveyor belt is 0.1m to 0.15m.

[0015] In some embodiments, the pyrolysis temperature in the box is 180℃~240℃

[0016] In some embodiments, the discharge end of the discharge pipe extends into the pyrolysis chamber and has a flared portion, and the cross-sectional area of ​​the flared portion gradually increases along the discharge direction of the discharge pipe.

[0017] In some embodiments, the mass flux of ammonium carbamate powder in the feed pipe is 0-500 kg·m~2·s~1; and / or the gas flow rate in the gas outlet pipe is 10-15 m·s~1.

[0018] In some embodiments, the box is generally rectangular, the conveying direction of the conveyor belt is parallel to the length direction of the box, the ratio of the length: width: height of the conveyor belt is (5-6): (1-1.5): (1.2-1.5), the distance between the conveyor belt and the long side of the box is 0.5m-1.0m, the distance between the conveyor belt and the wide side of the box is 1m-2m, and the height of the box is 1.8m-2.5m.

[0019] The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization of the present invention utilizes a first heating component to heat the ammonium carbamate powder from above and a second heating component to heat the ammonium carbamate powder from below, effectively ensuring that the ammonium carbamate is completely decomposed on the conveyor belt. This overcomes the drawback of conventional heating equipment that only heats and decomposes the medium from a single side. The ammonium carbamate powder is fully pyrolyzed on the conveyor belt, avoiding the problem of pipe blockage caused by ammonium carbamate agglomeration during the flue gas denitrification process. The box ensures that ammonium carbamate is fully decomposed, generating sufficient ammonia for the denitrification reaction, thereby improving denitrification efficiency. Because ammonium carbamate decomposes directly within the box, it does not need to be carried out under high temperature conditions like traditional urea ammonia production. This reduces the energy consumption cost of the denitrification system and avoids the potential safety hazards of urea ammonia production under high temperature conditions, thereby improving the safety performance of the system. As a denitrification agent component, ammonium carbamate has a lower production cost than urea and reduces material waste caused by crystallization, further reducing operating costs. The ammonia production efficiency of the ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to the embodiment of the present invention is increased by 5.9% to 23.5% compared with urea, with an average increase of 14.70%, and the energy consumption for ammonia production is reduced by 48.0% to 65.0%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a box body according to an embodiment of the present invention.

[0021] Figure 2 2 is a top view of the box body according to the embodiment of the present invention.

[0022] Figure 3 Schematic diagram of the structure of the first heating component of an embodiment of the present invention.

[0023] Reference numerals:

[0024] 1. Box body; 101. Pyrolysis chamber; 2. Feeding pipe; 201. Expanding portion; 3. Exhaust pipe; 4. Conveyor belt; 5. First heating component; 501. Heating plate; 5011. Heating surface; 5012. Mounting hole; 6. Second heating component; 601. Electric heating rod; 602. Heat dissipation sleeve. DETAILED DESCRIPTION

[0025] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0026] like Figures 1 to 3As shown, the ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to an embodiment of the present invention comprises a box body 1, a conveyor belt 4, a first heating assembly 5, and a second heating assembly 6. The box body 1 has a pyrolysis chamber 101. A feed pipe 2 and an exhaust pipe 3 are provided on the box body 1, communicating with the pyrolysis chamber 101. The feed pipe 2 allows ammonium carbamate powder to enter the box body 1, while the exhaust pipe 3 is used to discharge the carbon dioxide and ammonia generated by the pyrolysis of ammonium carbamate. The conveyor belt 4 is disposed within the box body 1, with one end of the conveyor belt 4 positioned below the feed pipe 2 to receive the ammonium carbamate powder falling from the feed pipe 2.

[0027] The first heating component 5 is arranged in the box body 1 and is located above the conveyor belt 4. The second heating component 6 is arranged in the box body 1 and is located between the upper belt and the lower belt of the conveyor belt 4. The first heating component 5 and the second heating component 6 are both used to heat the ammonium carbamate powder transported on the conveyor belt 4 to decompose the ammonium carbamate powder into carbon dioxide and ammonia.

[0028] When the ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to the embodiment of the present invention is in use, the ammonium carbamate powder enters the pyrolysis chamber 101 in the box body 1 through the discharge pipe 2, and the ammonium carbamate powder falls on the conveyor belt 4, which transports the ammonium carbamate powder to the pyrolysis area. The first heating component 5 is located above the conveyor belt 4 to heat the ammonium carbamate powder, and the second heating component 6 is located between the upper belt and the lower belt of the conveyor belt 4 to further heat the ammonium carbamate powder. Through the combined action of the first heating component 5 and the second heating component 6, the ammonium carbamate powder is heated to the decomposition temperature and decomposed into carbon dioxide and ammonia. The carbon dioxide and ammonia produced by the decomposition are discharged from the box body 1 through the exhaust pipe 3 and can then be used in the flue gas denitrification process.

[0029] The ammonium carbamate denitrification chamber for preventing crystallization of the present invention utilizes a first heating element 5 to heat the ammonium carbamate powder from above and a second heating element 6 to heat the ammonium carbamate powder from below, effectively ensuring complete decomposition of the ammonium carbamate on the conveyor belt 4. This overcomes the drawback of conventional heating equipment that only heats and decomposes the medium from a single surface. The ammonium carbamate powder undergoes thorough pyrolysis on the conveyor belt 4, preventing pipe blockage caused by ammonium carbamate agglomeration during the flue gas denitrification process. The chamber 1 ensures the complete decomposition of ammonium carbamate, generating sufficient ammonia for the denitrification reaction, thereby improving denitrification efficiency. Because ammonium carbamate decomposes directly within the chamber 1, it does not require high-temperature conditions like conventional urea-based ammonia production. This reduces the energy consumption of the denitrification system and avoids potential safety hazards associated with high-temperature urea-based ammonia production, thereby improving the system's safety performance. As a denitrification agent component, ammonium carbamate has a lower production cost than urea and reduces material waste caused by crystallization, further reducing operating costs. The ammonia production efficiency of the ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to the embodiment of the present invention is increased by 5.9% to 23.5% compared with urea, with an average increase of 14.70%, and the energy consumption for ammonia production is reduced by 48.0% to 65.0%.

[0030] In some embodiments, the first heating assembly 5 includes a heating plate 501 and an energy storage battery. The heating plate 501 has a heating surface 5011 facing the conveyor belt 4. The heating surface 5011 is provided with a mounting hole 5012 for accommodating the energy storage battery. The energy storage battery is used to discharge to heat the heating surface 5011.

[0031] Specifically, if Figure 2 and Figure 3 As shown, when ammonium carbamate powder enters the housing 1 through the discharge pipe 2 and lands on the conveyor belt 4, the heating plate 501 begins operating, the energy storage battery discharges, and current flows through the heating plate 501, generating heat and raising the temperature of the heating surface 5011. The heat from the heating surface 5011 is transferred to the ammonium carbamate powder on the conveyor belt 4, promoting its decomposition. The discharge of the energy storage battery can be adjusted as needed to control the temperature of the heating plate 501 and the decomposition rate of the ammonium carbamate powder.

[0032] Since the energy storage battery can adjust the discharge rate, the temperature control of the heating plate 501 is more precise, which is conducive to achieving the best decomposition effect of the ammonium carbamate powder. The use of the energy storage battery allows the heating component to operate without an external power supply, which is suitable for different environments and conditions, especially in temporary or mobile flue gas denitrification applications. The energy storage battery can be charged during periods of low electricity prices and discharged quickly when heating is required, which helps to reduce energy costs. The design of the heating plate 501 and the energy storage battery can include safety measures, such as overheating protection and a battery management system to ensure stable operation of the system. Since the energy storage battery can be installed in the mounting hole 5012 on the heating plate 501, maintenance and replacement of the battery are more convenient.

[0033] In some embodiments, the inner diameter of the mounting hole 5012 is 2 cm to 5 cm.

[0034] For example, the inner diameter of the mounting hole 5012 is 2 cm, 3 cm, or 5 cm.

[0035] The inner diameter range of the mounting hole 5012 is to ensure that the energy storage battery can be properly installed on the heating plate 501. The range of 2cm to 5cm can accommodate energy storage batteries of different sizes and capacities, providing design flexibility. The selection of the inner diameter also needs to consider the structural strength and stability of the heating plate 501. If the mounting hole 5012 is too large, it may weaken the strength of the heating plate 501, and if it is too small, it may affect the installation and heat dissipation of the energy storage battery. Energy storage batteries of different capacities can be installed according to actual needs, allowing system designers to adjust the heating capacity according to the specific requirements and operating conditions of the box 1. The appropriate inner diameter makes the installation and maintenance of the energy storage battery easier, and technicians can quickly replace the battery to reduce downtime.

[0036] In some embodiments, there are multiple heating plates 501 , and the multiple heating plates 501 are arranged at intervals along the conveying direction of the conveyor belt 4 .

[0037] For example, Figure 1As shown, the arrangement of multiple heating plates 501 can improve the uniformity of heating the ammonium carbamate powder. Because the heating plates 501 are spaced apart along the conveyor belt 4, each heating plate 501 can heat the passing ammonium carbamate powder, ensuring more uniform heating of the material and avoiding local overheating or insufficient heating. By controlling the temperature and heating time of different heating plates 501, the pyrolysis process of the ammonium carbamate powder can be flexibly adjusted to suit different process requirements and operating conditions. The arrangement of multiple heating plates 501 can form a temperature gradient along the conveyor belt 4, helping the ammonium carbamate powder to gradually heat up during transportation, thereby better controlling the rate and extent of the decomposition reaction. The design of multiple heating plates 501 can accelerate the pyrolysis rate of the ammonium carbamate powder, improve pyrolysis efficiency, and reduce pyrolysis time, thereby increasing the processing capacity of the entire denitrification system. Increasing the number of heating plates 501 can enhance the system's pyrolysis capacity, making the system more scalable to meet larger-scale or more demanding flue gas denitrification needs. Since the heating plates 501 can be arranged in a dispersed manner, the system can adjust the power of each heating plate 501 according to actual needs to avoid energy waste. If a heating plate 501 fails, it can be maintained or replaced separately without affecting the normal operation of other heating plates 501.

[0038] In some embodiments, the second heating component 6 includes an electric heating rod 601 and a heat dissipation sleeve 602. The axial direction of the electric heating rod 601 is parallel to the conveying direction of the conveyor belt 4. The heat dissipation sleeve 602 is mounted on the electric heating rod 601 to dissipate the heat generated by the electric heating rod 601.

[0039] like Figure 1 As shown, electric heating rod 601 serves as the primary heat source for second heating assembly 6 , with its axis parallel to the conveying direction of conveyor belt 4 . This ensures even heat distribution along conveyor belt 4 , facilitating uniform heating of the ammonium carbamate powder. A heat dissipation sleeve 602 is mounted over electric heating rod 601 . Its primary function is to effectively dissipate the heat generated by electric heating rod 601 and transfer it to the ammonium carbamate powder on conveyor belt 4 , while preventing heat concentration and localized overheating.

[0040] The combination of electric heating rod 601 and heat dissipation sleeve 602 provides a more uniform heating effect, which helps ensure uniform decomposition of the ammonium carbamate powder throughout the entire conveying process. By adjusting the power of electric heating rod 601, the heat output can be precisely controlled, making the pyrolysis process of the ammonium carbamate powder more stable and controllable. The heat dissipation sleeve 602 helps to quickly disperse the heat generated by electric heating rod 601, reducing the risk of overheating and improving system safety. The presence of heat dissipation sleeve 602 enhances heat transfer efficiency, allowing the ammonium carbamate powder to absorb heat more quickly, thereby improving pyrolysis efficiency.

[0041] For example, the electric heating rod 601 can be made of metal or non-metal materials. Metal materials include nickel-chromium alloys (such as Cr20Ni80), iron-chromium-aluminum alloys (such as FeCrAl), tungsten (W), and molybdenum (Mo). Non-metal materials include silicon carbide (SiC), PTC ceramics (positive temperature coefficient ceramics), and graphite. The electric heating rod 601 is connected to a power source via wires and generates heat through electrical heating.

[0042] The heat dissipation sleeve 602 can be made of metal materials such as copper (Cu), aluminum (Al) and silver (Ag); non-metallic materials can be graphene / carbon nanotubes, diamond and ceramics (AlN, BeO); composite materials can be aluminum-graphite composite materials and heat pipes (internal working fluid + copper shell), etc.

[0043] In some embodiments, the distance between the heat dissipation sleeve 602 and the upper belt and the lower belt of the conveyor belt 4 is 0.1m to 0.15m.

[0044] The distance between the heat dissipation jacket 602 and the conveyor belt 4 has a significant impact on heat transfer efficiency. Too little distance may result in heat being concentrated in a small area, while too much distance may reduce effective heat transfer. Maintaining a certain distance prevents ammonium carbamate powder or decomposition products from becoming trapped between the heat dissipation jacket 602 and the conveyor belt 4, ensuring smooth system operation. Sufficient spacing between the heat dissipation jacket 602 and the conveyor belt 4 is required to ensure that heat can be effectively dissipated into the ammonium carbamate powder on the conveyor belt 4.

[0045] In some embodiments, the pyrolysis temperature in the box 1 is 180°C to 240°C.

[0046] The pyrolysis reaction of ammonium carbamate typically requires a certain temperature for efficient operation. A temperature range of 180°C to 240°C ensures that ammonium carbamate fully decomposes into carbon dioxide and ammonia, two reducing agents required in flue gas denitrification. Within this temperature range, the reaction rate can be adjusted to ensure an efficient and stable denitrification process. Excessively high or low temperatures can affect the reaction rate and decomposition efficiency. Setting a reasonable temperature range prevents overheating, which can cause side reactions or equipment damage, and also reduces energy consumption. Maintaining an appropriate temperature within chamber 1 reduces the risk of equipment fatigue and damage caused by excessive temperatures, thereby increasing equipment lifespan and safety. The temperature range of 180°C to 240°C provides sufficient flexibility to adjust the pyrolysis temperature according to different denitrification requirements and operating conditions. This temperature range reduces the likelihood of ammonium carbamate coking and ash accumulation within chamber 1, thereby reducing the frequency and cost of system maintenance.

[0047] In some embodiments, the discharge end of the discharge pipe 2 extends into the pyrolysis chamber 101 and has a flared portion 201 , and the cross-sectional area of ​​the flared portion 201 gradually increases along the discharge direction of the discharge pipe 2 .

[0048] For example, Figure 1 As shown, the provision of the flared portion 201 can slow the rate at which the ammonium carbamate powder flows from the discharge pipe 2 to the pyrolysis chamber 101, preventing the material from directly impacting the conveyor belt 4 at high speed and reducing wear on the conveyor belt 4. The flared portion 201 disperses the ammonium carbamate powder during its fall, facilitating even distribution within the pyrolysis chamber 101 and improving pyrolysis efficiency. The flared portion 201 also reduces material agglomeration during its fall, preventing pipe blockage caused by agglomeration.

[0049] Optionally, the mass flux of the ammonium carbamate powder in the discharge pipe 2 is 0 to 500 kg·m~2·s~1.

[0050] Mass flux is the mass of material passing through a unit area per unit time, which directly affects the transport speed and pyrolysis efficiency of ammonium carbamate powder. A lower mass flux (close to 0) may mean slower material transport, while a higher mass flux (close to 500 kg·m~2·s~1) means faster material transport. Appropriate mass flux selection can ensure that ammonium carbamate powder is evenly and effectively transported to the pyrolysis chamber 101 for sufficient pyrolysis reaction. Excessively high mass flux may cause material agglomeration or blockage during transportation, while too low mass flux may result in insufficient system processing capacity.

[0051] Optionally, the gas flow rate in the gas outlet pipe 3 is 10-15 m·s~1.

[0052] The gas flow rate is the ratio of the volumetric flow rate of gas passing through the outlet pipe 3 per unit time to the cross-sectional area of ​​the outlet pipe 3. An appropriate gas flow rate ensures that gases such as ammonia and carbon dioxide are quickly discharged from the pyrolysis chamber 101, preventing these gases from accumulating within the chamber and affecting the pyrolysis effect. A too low gas flow rate may cause gas to remain within the pyrolysis chamber 101, increasing the risk of ammonia escape and reducing denitrification efficiency. Excessively high gas flow rates may increase energy consumption and may affect the structural stability of the outlet pipe 3 and the entire system.

[0053] In some embodiments, the box body 1 is generally rectangular, the conveying direction of the conveyor belt 4 is parallel to the length direction of the box body 1, the ratio of the length: width: height of the conveyor belt 4 is (5-6): (1-1.5): (1.2-1.5), the distance between the conveyor belt 4 and the long side of the box body 1 is 0.5m-1.0m, the distance between the conveyor belt 4 and the wide side of the box body 1 is 1m-2m, and the height of the box body 1 is 1.8m-2.5m.

[0054] like Figure 1 and Figure 2 As shown, a rational design of the housing 1 and conveyor belt 4 can improve the system's processing capacity and denitrification efficiency while ensuring system safety and environmental performance. Optimized dimensions and proportions ensure uniform distribution of materials within the housing 1, improving pyrolysis efficiency. Appropriate margins facilitate equipment inspection and maintenance by maintenance personnel, enhancing system safety.

[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0057] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0058] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0059] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0060] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A pyrolysis box for ammonium carbamate denitrification agent for preventing crystallization, characterized in that: include: A box body, wherein the box body has a pyrolysis chamber, and is provided with a feed pipe and an exhaust pipe connected to the pyrolysis chamber, wherein the feed pipe is used for the ammonium carbamate powder to enter the box body, and the exhaust pipe is used for exhausting carbon dioxide and ammonia generated by the pyrolysis of ammonium carbamate; A conveyor belt is arranged in the box body, and one end of the conveyor belt is arranged below the discharge pipe to receive the ammonium carbamate powder falling from the discharge pipe; A first heating component and a second heating component, the first heating component is arranged in the box and above the conveyor belt, the second heating component is arranged in the box and between the upper belt and the lower belt of the conveyor belt, the first heating component and the second heating component are both used to heat the ammonium carbamate powder transported on the conveyor belt to decompose the ammonium carbamate powder into carbon dioxide and ammonia.

2. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The first heating assembly includes a heating plate and an energy storage battery. The heating plate has a heating surface facing the conveyor belt. The heating surface is provided with a mounting hole for accommodating the energy storage battery. The energy storage battery is used to discharge to heat the heating surface.

3. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 2, characterized in that: The inner diameter of the mounting hole is 2 cm to 5 cm.

4. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 2, characterized in that: There are multiple heating plates, and the multiple heating plates are arranged at intervals along the conveying direction of the conveyor belt.

5. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The second heating assembly includes an electric heating rod and a heat dissipation sleeve. The axial direction of the electric heating rod is parallel to the conveying direction of the conveyor belt. The heat dissipation sleeve is mounted on the electric heating rod to dissipate the heat generated by the electric heating rod.

6. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 5, characterized in that: The distance between the heat dissipation sleeve and the upper belt and the lower belt of the conveyor belt is 0.1m to 0.15m.

7. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The pyrolysis temperature in the box is 180°C to 240°C.

8. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The discharge end of the discharge pipe extends into the pyrolysis chamber and has a flared portion, and the cross-sectional area of ​​the flared portion gradually increases along the discharge direction of the discharge pipe.

9. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The mass flux of the ammonium carbamate powder in the feed pipe is 0 to 500 kg·m2·s1; and / or the gas flow rate in the gas outlet pipe is 10 to 15 m·s1.

10. The ammonium carbamate denitrification agent pyrolysis box for preventing crystallization according to claim 1, characterized in that: The box is generally rectangular, the conveying direction of the conveyor belt is parallel to the length direction of the box, the ratio of the length: width: height of the conveyor belt is (5-6): (1-1.5): (1.2-1.5), the distance between the conveyor belt and the long side of the box is 0.5m-1.0m, the distance between the conveyor belt and the wide side of the box is 1m-2m, and the height of the box is 1.8m-2.5m.

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