Lignite pulverizing system

Abstract

The present application provides a kind of lignite powder system, comprising: hot blast stove, settling tube, coal mill and dust collector, the side of hot blast stove is fixedly connected with combustor, the feed inlet of hot blast stove is connected with pneumatic feeding device, fire wall is arranged in the furnace cavity near the air outlet of hot blast stove, and the gap for airflow passing between fire wall and furnace cavity is left;The air inlet of settling tube is connected with the air outlet of hot blast stove, and baffle is arranged in the settling tube near the air outlet of settling tube, and the gap for airflow passing between baffle and the inner wall of settling tube is left;The coal mill is connected with the settling tube, and the air inlet of coal mill is connected with the air inlet of settling tube, and the air inlet of settling tube is connected with the air inlet of coal mill, and filter plate is connected on air inlet channel;The dust collector is connected with the coal mill, and the dust collector is connected with finished product bin.The present application solves the problem that hot flue gas carrying spark enters coal mill and easily causes deflagration, so that lignite powder system can be long-term, stable, efficient and safe production.

Description

Technical Field

[0001] This invention relates to the field of lignite pulverization technology, and more particularly to a lignite pulverization system. Background Technology

[0002] Lignite, as a type of coal with a low degree of coalification, generally has the characteristics of high volatile matter, high ash content, high moisture content, and low calorific value. Due to its high reactivity, lignite is prone to spontaneous combustion and deflagration during the pulverization, transportation, and storage of lignite, posing many challenges to safe production. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention provide a lignite pulverizing system that can prevent safety problems such as spontaneous combustion and deflagration of lignite during pulverization, transportation, and storage.

[0004] This invention provides a lignite pulverizing system, comprising: a hot blast stove, a settling cylinder, a coal mill, and a dust collector. The hot blast stove has a furnace cavity and a feed inlet and an air outlet connecting to the furnace cavity. A burner is fixedly connected to one side of the hot blast stove, located at the feed inlet. The feed inlet is connected to a pneumatic feeding device via a feed pipe. A fire baffle is installed inside the furnace cavity near the air outlet, with a gap between the fire baffle and the furnace cavity for airflow. The settling cylinder... The settling cylinder has an air inlet and an air outlet. The air inlet of the settling cylinder is connected to the air outlet of the hot air furnace. A baffle is installed inside the settling cylinder near the air outlet, and a gap is left between the baffle and the inner wall of the settling cylinder for airflow. The coal mill has an air inlet, a feed inlet, and a discharge outlet. The air inlet of the coal mill is connected to the air outlet of the settling cylinder. The dust collector has a feed inlet and a discharge outlet. The feed inlet of the dust collector is connected to the discharge outlet of the coal mill, and the discharge outlet of the dust collector is connected to the finished product silo.

[0005] In some embodiments, an air intake channel is connected between the air outlet of the settling cylinder and the air inlet of the coal mill. A filter plate is connected to the air intake channel near the air inlet of the coal mill. The filter plate has several filter holes to prevent particulate matter in the flue gas from entering the coal mill.

[0006] In some embodiments, the fire baffle includes a main fire baffle and an auxiliary fire baffle. The main fire baffle is fixedly connected to the air outlet of the furnace cavity near the hot blast stove. The upper and lower ends of the main fire baffle are respectively left with gaps between them and the inner wall of the hot blast stove to allow airflow. The auxiliary fire baffle is located between the main fire baffle and the burner and is closer to the main fire baffle. There are two auxiliary fire baffles, which are respectively fixedly connected to the upper and lower ends of the inner wall of the hot blast stove. The vertical distance between the two auxiliary fire baffles is less than the width of the main fire baffle. The main fire baffle and the auxiliary fire baffle form an S-shaped baffle structure.

[0007] In some embodiments, the hot air furnace has a cold air inlet connected to a cold air blower, and a cold air valve is provided at the cold air inlet. There are two cold air inlets, which are respectively located on the upper and lower sides of the air outlet of the hot air furnace.

[0008] In some embodiments, a baffle is fixedly connected to the bottom of the settling cylinder, and a gap is left between the upper end of the baffle and the inner wall of the settling cylinder for airflow to pass through. The horizontal projections of the air inlet and outlet of the settling cylinder on the baffle are both located in the middle of the baffle, so as to form a baffle structure inside the settling cylinder.

[0009] In some embodiments, the gas source for the pneumatic feeding device is nitrogen, which is stored in a nitrogen tank.

[0010] In some embodiments, the finished product silo has a feed inlet, an air inlet, and a discharge outlet. The feed inlet of the finished product silo is connected to the discharge outlet of the dust collector, and the air inlet of the finished product silo is connected to a nitrogen tank through a pipeline to transport pulverized coal to a designated location by pneumatic conveying.

[0011] In some embodiments, the burner is a swirl backflow burner, which includes a return cap with a plurality of holes on its end face, one of which is located at the center of the end face of the return cap, and the remaining holes are evenly arranged around the central hole.

[0012] In some embodiments, the swirl reverse-jet burner includes an outer air duct, an inner air duct, a swirl tube, a return cap, a primary air duct, and an air box. The inner air duct has a feed inlet and an air outlet, located at opposite ends of the inner air duct. The swirl tube is fixedly connected to the feed inlet of the inner air duct and contains swirl blades. The outer air duct is fitted around the outer side of the inner air duct, with an annular gap between the outer and inner air ducts for the passage of secondary air. The primary air duct runs horizontally... The vortex tube extends into the inner air duct, and the return cap is located inside the inner air duct and fixedly connected to the end of the primary air duct. The walls of the vortex tube and the outer air duct are respectively provided with air inlets. The air box has an air inlet, a first air outlet and a second air outlet. The air inlet of the air box is connected to the blower. The air inlet of the vortex tube and the first air outlet of the air box are connected through an inner secondary air duct. The air inlet of the outer air duct and the second air outlet of the air box are connected through an outer secondary air duct.

[0013] In some embodiments, the filter plate is made of stainless steel. Attached Figure Description

[0014] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings. in: Figure 1 This is a schematic diagram of the lignite pulverizing system according to an embodiment of the present invention; Figure 2 for Figure 1 A schematic diagram of the burner structure in the diagram; Figure 3 for Figure 1 A schematic diagram of the arrangement of the orifices in the return cap; Figure label: 1. Pneumatic feeding device; 2. Primary air duct; 3. Burner; 4. Return cap; 401. Orifice; 5. Hot blast stove; 6. Fire baffle; 601. Auxiliary fire baffle; 602. Main fire baffle; 7. Cold air valve; 8. Settling cylinder; 9. Baffle; 10. Filter plate; 11. Coal mill; 12. Dust collector; 13. Finished product silo; 301. Swirl tube; 302. Pre-combustion chamber; 303. External air duct; 304. Internal air duct; 305. Igniter; 306. Internal secondary air duct; 307. External secondary air duct; 308. Air box; 309. Blower. Detailed Implementation

[0015] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0016] The lignite pulverizing system of the present invention is described below with reference to the accompanying drawings.

[0017] like Figure 1-3 As shown in the figure, this embodiment of the invention proposes a lignite pulverizing system, including: a hot blast stove 5, a settling cylinder 8, a coal mill 11, and a dust collector 12. The hot blast stove 5 has a furnace cavity and a feed inlet and an air outlet connecting the furnace cavity. A burner 3 is fixedly connected to one side of the hot blast stove 5, and the burner 3 is located at the feed inlet of the hot blast stove 5. The feed inlet of the hot blast stove 5 is connected to a pneumatic feeding device 1 through a feed pipe. A fire baffle 6 is provided in the furnace cavity near the air outlet of the hot blast stove 5, and a gap is left between the fire baffle 6 and the furnace cavity for airflow. The settling cylinder 8 The settling cylinder 8 has an air inlet and an air outlet. The air inlet of the settling cylinder 8 is connected to the air outlet of the hot air furnace 5. A baffle 9 is provided inside the settling cylinder 8 near the air outlet. A gap is left between the baffle 9 and the inner wall of the settling cylinder 8 for airflow. The coal mill 11 has an air inlet, a feed inlet and a discharge outlet. The air inlet of the coal mill 11 is connected to the air outlet of the settling cylinder 8. The dust collector 12 has a feed inlet and a discharge outlet. The feed inlet of the dust collector 12 is connected to the discharge outlet of the coal mill 11. The discharge outlet of the dust collector 12 is connected to the finished product silo 13.

[0018] This invention, through the installation of a fire baffle 6, a settling cylinder 8, and a baffle 9, forces the hot flue gas to bend, drastically reducing the amount of high-temperature sparks emitted from the outlet of the settling cylinder 8. This solves the problem of deflagration easily caused by sparks carried by hot flue gas entering the coal mill 11, enabling the lignite pulverizing system to operate long-term, stably, efficiently, and safely. The baffle 9 causes the high-temperature sparks carried by the hot flue gas to settle after impacting the baffle 9.

[0019] It should be noted that, Figure 1 The arrows inside the medium-heat blast furnace 5 and the settling cylinder 8 indicate the flue gas trajectory.

[0020] Furthermore, the settling cylinder 8 is set vertically, with dimensions of Φ2.3m×6m.

[0021] Furthermore, the dust collector 12 also has an exhaust port for discharging flue gas. The exhaust port is connected to an exhaust pipe, and a gas treatment device is connected to the exhaust pipe to ensure that the flue gas meets emission requirements. The hot blast stove 5 also has a flue gas recirculation inlet, which is located near the air outlet of the hot blast stove 5. The exhaust pipe is connected to a branch pipe, which is connected to the flue gas recirculation inlet, allowing for the recirculation of flue gas. The branch pipe is connected to a flow control valve, which can adjust the temperature and oxygen content of the flue gas before it enters the coal mill 11.

[0022] Furthermore, the pneumatic feeding device 1, the hot air furnace 5, and the finished product silo 13 are each equipped with temperature measuring points. The air inlet of the coal mill 11 is equipped with temperature, pressure, CO concentration, oxygen content, and flow rate measuring points. The dust collector 12 is equipped with temperature, pressure, CO concentration, and oxygen content measuring points. This ensures that the temperature at the outlet of the coal mill 11 and the dust collector 12 is maintained at 65-75℃. The oxygen content can be adjusted by the flow rate of the circulating flue gas, maintaining an oxygen content ≤11%, a CO concentration ≤100ppm, and a temperature in the finished product silo 13 ≤50℃.

[0023] In some embodiments, such as Figure 1 As shown, an air inlet channel is connected between the air outlet of the settling cylinder 8 and the air inlet of the coal mill 11. A filter plate 10 is connected to the air inlet channel near the air inlet of the coal mill 11. The filter plate 10 has several filter holes to prevent particulate matter in the flue gas from entering the coal mill 11.

[0024] As the last physical barrier before the flue gas enters the coal mill 11, the filter plate 10 can finally and directly intercept any very few residual particles or high-temperature hot masses that may penetrate the mixing duct.

[0025] In some embodiments, such as Figure 1As shown, the fire baffle 6 includes a main fire baffle 602 and an auxiliary fire baffle 601. The main fire baffle 602 is fixedly connected to the air outlet of the furnace cavity near the hot blast stove 5. Gaps for airflow are left between the upper and lower ends of the main fire baffle 602 and the inner wall of the hot blast stove 5. The auxiliary fire baffle 601 is located between the main fire baffle 602 and the burner 3, and is closer to the main fire baffle 602. Two auxiliary fire baffles 601 are provided and fixedly connected to the upper part of the inner wall of the hot blast stove 5. At the lower ends, the vertical distance between the two auxiliary fire walls 601 is smaller than the width of the main fire wall 602. In the horizontal direction, the auxiliary fire walls 601 completely block the gap between the upper and lower ends of the main fire wall 602 and the inner wall of the hot air furnace 5. The main fire wall 602 and the auxiliary fire walls 601 form an S-shaped baffle structure, which allows the flue gas to flow along the S-shaped baffle structure. This can physically block the direct penetration path of sparks generated by combustion, and at the same time effectively isolate high-temperature radiant heat.

[0026] Furthermore, the horizontal distance between the main firewall 602 and the auxiliary firewall 601 is 0.45m.

[0027] Furthermore, the auxiliary fire barrier 601 is made of refractory bricks and refractory mortar.

[0028] In some embodiments, such as Figure 1 As shown, the hot blast stove 5 has a cold air inlet connected to a cold air fan. A cold air valve 7 is installed at the cold air inlet. There are two cold air inlets, located above and below the outlet of the hot blast stove 5. This facilitates forced mixing and temperature homogenization of hot and cold air within the settling tank 8. By adjusting the cold air valve 7, the flue gas temperature can be regulated, thereby controlling the temperature of the flue gas entering the coal mill 11. Furthermore, it can significantly reduce the dust concentration in the flue gas and decrease spark deposits.

[0029] In some embodiments, such as Figure 1 As shown, the baffle 9 is fixedly connected to the bottom of the settling cylinder 8. A gap is left between the upper end of the baffle 9 and the inner wall of the settling cylinder 8 for airflow to pass through. The horizontal projections of the air inlet and outlet of the settling cylinder 8 on the baffle 9 are both located in the middle of the baffle 9, so that a baffle structure is formed inside the settling cylinder 8.

[0030] When the hot flue gas enters the settling cylinder 8, it is forced to turn upward to the top of the settling cylinder 8, then turns downward and flows into the coal mill 11 through the horizontally set air inlet channel.

[0031] In some embodiments, the pneumatic feeding device 1 uses nitrogen as its gas source, which is stored in a nitrogen tank. Using inert nitrogen as the medium for coal powder fluidization, conveying, and injection replaces traditional compressed air (containing approximately 21% oxygen), fundamentally eliminating the risk of lignite coal powder explosion. This maximizes the inerting of coal powder storage and conveying, elevating the safety level of the entire coal powder system from "relying on monitoring and prevention" to an intrinsically safe level of "eliminating oxidizers from the medium." This not only solves the risk of spontaneous combustion during conveying but also significantly reduces the possibility of explosions inside storage equipment such as the finished product silo 13, coal powder tower, and pipelines, thus improving safety.

[0032] Furthermore, the nitrogen concentration is greater than or equal to 85%. Furthermore, the nitrogen tank's inlet is connected in parallel to multiple nitrogen generators via pipelines, forming a stable and reliable nitrogen supply network with redundancy for equipment failures. The pipeline diameter must be designed to be consistent or calculated to meet the maximum flow requirements, ensuring stable pressure after parallel connection.

[0033] In some embodiments, such as Figure 1 As shown, the finished product silo 13 has a feed inlet, an air inlet and a discharge outlet. The feed inlet of the finished product silo 13 is connected to the discharge outlet of the dust collector 12. The air inlet of the finished product silo 13 is connected to a nitrogen tank through a pipeline to transport pulverized coal to a designated location (such as a boiler system) by pneumatic conveying.

[0034] Furthermore, a small gas storage tank is installed near the pulverized coal tower of the boiler system and connected to a nitrogen tank. The small gas storage tank is connected to the injection pipeline of the pulverized coal tower to realize full nitrogenization of the bottom fluidization, anti-clogging and injection in front of the furnace of the pulverized coal tower.

[0035] In some embodiments, such as Figure 1 , Figure 3 As shown, the burner 3 is a swirl reverse jet burner. The burner 3 includes a return cap 4. The end face of the return cap 4 is provided with a plurality of holes 401. One hole 401 is located at the center of the end face of the return cap 4, and the remaining holes 401 are evenly arranged around the central hole 401.

[0036] The orifices 401 on the end face of the recirculation cap 4 can actively intervene in the micro-combustion dynamics environment. Through these orifices 401, the airflow field, temperature field and fuel mixing state inside the recirculation zone can be precisely changed, thereby optimizing the flame shape, making combustion more uniform and complete, avoiding the formation of local high-temperature points, and directly solving the core pain point of the burner 3 being "easy to overheat".

[0037] Furthermore, there are a total of 5 holes 401, with four holes 401 evenly arranged around the central hole 401. The diameter of each hole 401 is 6-10mm.

[0038] In some embodiments, such as Figure 2 As shown, the swirl reverse-jet burner includes an outer air duct 303, an inner air duct 304, a swirl tube 301, a return cap 4, a primary air duct 2, and an air box 308. The inner air duct 304 has a feed inlet and an air outlet, which are located at opposite ends of the inner air duct 304. The swirl tube 301 is fixedly connected to the feed inlet of the inner air duct 304 and has swirl blades inside. The outer air duct 303 is fitted over the inner air duct 304, and an annular gap is left between the outer air duct 303 and the inner air duct 304 for the passage of secondary air. The primary air duct 2 runs horizontally through the inner air duct 304. The vortex tube 301 extends into the inner air duct 304. The return cap 4 is located inside the inner air duct 304 and is fixedly connected to the end of the primary air duct 2. The cylinder wall of the vortex tube 301 and the cylinder wall of the outer air duct 303 are respectively provided with air inlets. The air box 308 has an air inlet, a first air outlet and a second air outlet. The air inlet of the air box 308 is connected to the blower 309. The air inlet of the vortex tube 301 and the first air outlet of the air box 308 are connected through the inner secondary air duct 306. The air inlet of the outer air duct 303 and the second air outlet of the air box 308 are connected through the outer secondary air duct 307.

[0039] The ignition principle of the swirl-reverse-injection burner is as follows: Pulverized coal gas flows backward through the primary air duct 2 and is injected backward through the return cap 4. A small portion of the pulverized coal gas is ejected outward from the orifice 401 of the return cap 4, forming the initial flame. The majority of the pulverized coal gas flows back and diffuses into the pre-combustion chamber 302, where it meets the rotating secondary air injected into the inner air duct 304, forming the main flame. After exiting the pre-combustion chamber 302, the inner and outer secondary air mix, ultimately forming a stable combustion flame. The main flame spirals forward with the airflow, forming a recirculation zone. The recirculation zone is characterized by high temperature, low oxygen, and low velocity. The recirculation zone transmits the high-temperature hot flue gas from the burner 3 outlet to the pre-combustion chamber 302 as a stable heat source for ignition, which helps stabilize the combustion of pulverized coal, ultimately forming a stable combustion flame.

[0040] Furthermore, control valves are connected to the internal secondary air duct 306 and the external secondary air duct 307 respectively.

[0041] It should be noted that the swirl reverse jet burner also includes an igniter 305. The structure and installation position of the igniter 305 are conventional. For example, the igniter 305 can be in the form of a fuel ignition gun, passing through the swirl tube 301 horizontally and extending into the inner air duct 304. This will not be elaborated here.

[0042] The swirl reverse-jet burner of this invention can achieve precise temperature control of the hot blast stove 5 according to the changes in the quality of the raw coal, thus solving the problem of coal powder deflagration caused by high temperature.

[0043] In some embodiments, the filter plate 10 is made of high-temperature resistant stainless steel.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0048] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0049] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A lignite pulverizing system, characterized in that, include: A hot blast stove has a furnace cavity and a feed inlet and an air outlet connecting the furnace cavity. A burner is fixedly connected to one side of the hot blast stove, and the burner is located at the feed inlet of the hot blast stove. The feed inlet of the hot blast stove is connected to a pneumatic feeding device through a feed pipe. A fire baffle is provided inside the furnace cavity near the air outlet of the hot blast stove, and a gap is left between the fire baffle and the furnace cavity for airflow to pass through. A settling cylinder has an air inlet and an air outlet. The air inlet of the settling cylinder is connected to the air outlet of the hot air furnace. A baffle is provided inside the settling cylinder near the air outlet. A gap is left between the baffle and the inner wall of the settling cylinder for airflow to pass through. A coal mill, the coal mill having an air inlet, a feed inlet and a discharge outlet, the air inlet of the coal mill being connected to the air outlet of the settling cylinder; A dust collector having an inlet and an outlet, wherein the inlet of the dust collector is connected to the outlet of the coal mill, and the outlet of the dust collector is connected to the finished product silo.

2. The lignite pulverizing system according to claim 1, characterized in that, An air intake channel is connected between the air outlet of the settling cylinder and the air inlet of the coal mill. A filter plate is connected to the air intake channel near the air inlet of the coal mill. The filter plate has several filter holes to prevent particulate matter in the flue gas from entering the coal mill.

3. The lignite pulverizing system according to claim 1, characterized in that, The fire baffle includes a main fire baffle and an auxiliary fire baffle. The main fire baffle is fixedly connected to the air outlet of the furnace cavity near the hot blast stove. The upper and lower ends of the main fire baffle are respectively left with gaps between them and the inner wall of the hot blast stove to allow airflow. The auxiliary fire baffle is located between the main fire baffle and the burner and is closer to the main fire baffle. There are two auxiliary fire baffles, which are respectively fixedly connected to the upper and lower ends of the inner wall of the hot blast stove. The vertical distance between the two auxiliary fire baffles is less than the width of the main fire baffle. The main fire baffle and the auxiliary fire baffle form an S-shaped baffle structure.

4. The lignite pulverizing system according to claim 1, characterized in that, The hot air furnace has a cold air inlet, which is connected to a cold air fan. A cold air valve is provided at the cold air inlet. There are two cold air inlets, which are respectively located on the upper and lower sides of the air outlet of the hot air furnace.

5. The lignite pulverizing system according to claim 1, characterized in that, The baffle is fixedly connected to the bottom of the settling cylinder. A gap is left between the upper end of the baffle and the inner wall of the settling cylinder for airflow. The horizontal projections of the air inlet and outlet of the settling cylinder on the baffle are both located in the middle of the baffle, so as to form a baffle structure inside the settling cylinder.

6. The lignite pulverizing system according to claim 1, characterized in that, The pneumatic feeding device uses nitrogen as its gas source, and the nitrogen is stored in a nitrogen tank.

7. The lignite pulverizing system according to claim 6, characterized in that, The finished product silo has a feed inlet, an air inlet, and a discharge outlet. The feed inlet of the finished product silo is connected to the discharge outlet of the dust collector. The air inlet of the finished product silo is connected to a nitrogen tank through a pipeline to transport pulverized coal to a designated location by pneumatic conveying.

8. The lignite pulverizing system according to claim 1, characterized in that, The burner is a swirl reverse-jet burner, which includes a return cap. The end face of the return cap has multiple holes, one of which is located at the center of the end face of the return cap, and the remaining holes are evenly arranged around the central hole.

9. The lignite pulverizing system according to claim 8, characterized in that, The swirl reverse-jet burner includes an outer air duct, an inner air duct, a swirl tube, a return cap, a primary air duct, and an air box. The inner air duct has a feed inlet and an air outlet, located at opposite ends. The swirl tube is fixedly connected to the feed inlet of the inner air duct and contains swirl blades. The outer air duct is fitted around the outer side of the inner air duct, with an annular gap between them for secondary air to pass through. The primary air duct runs horizontally through the inner air duct. The vortex tube extends into the inner air duct. The return cap is located inside the inner air duct and is fixedly connected to the end of the primary air duct. The walls of the vortex tube and the outer air duct are respectively provided with air inlets. The air box has an air inlet, a first air outlet, and a second air outlet. The air inlet of the air box is connected to a blower. The air inlet of the vortex tube and the first air outlet of the air box are connected through an inner secondary air duct. The air inlet of the outer air duct and the second air outlet of the air box are connected through an outer secondary air duct.

10. The lignite pulverizing system according to claim 2, characterized in that, The filter plate is made of stainless steel.

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