A multi-stage coal crushing device for thermal power generation

Abstract

This utility model discloses a multi-stage coal crushing device for thermal power generation, relating to the field of thermal power generation technology. Specifically, it includes a coal crushing device housing. The inner cavity of the housing is sequentially equipped with a first partition, a second partition, and a third partition. These three partitions divide the inner cavity of the coal crushing device housing from the feed end to the discharge end into a first crushing chamber, a second crushing chamber, a third crushing chamber, and a coal powder collection chamber. A feeding hopper is located in the middle of the top of the first crushing chamber. This application features a pre-crushing function, utilizing the directional impact force between the falling coal and the pre-crushing needles to induce initial cracks or promote micro-cracks on the surface of the coal block, weakening the overall structural strength of the coal block and reducing the crushing load on core components such as the crushing rollers in the subsequent multi-stage crushing chambers. This significantly improves the efficiency of the step-by-step crushing of coal from large pieces to coal powder, reduces overall crushing energy consumption, and extends the service life of key crushing components.

Description

Technical Field

[0001] This utility model relates to the field of thermal power generation, specifically a multi-stage coal crushing device for thermal power generation. Background Technology

[0002] Thermal power generation is a method of generating electricity by converting the heat energy produced when combustible materials burn into electrical energy through a power generation device. When using coal for thermal power generation, crushing the coal into pulverized coal is a necessary process. The purpose of this process is to increase the contact area between the pulverized coal and air, thereby achieving more complete combustion, improving power generation efficiency, and reducing pollutant emissions.

[0003] In related technologies, multi-stage crushing equipment can be used to gradually crush coal into coal powder. However, most multi-stage crushing equipment is a single-line series process, that is, the output of the previous crushing structure is directly used as the input of the next stage. However, in the crushing process of each stage, coal powder that meets the requirements will be generated. This part of the coal powder flows between each stage in turn, which reduces the coal crushing efficiency. Moreover, the falling coal will impact the crushing structure and reduce the service life of the crushing structure. Based on this, this application proposes a multi-stage coal crushing equipment for thermal power generation. Utility Model Content

[0004] This application proposes a multi-stage coal crushing device for thermal power generation, which has the following advantages: it has a pre-crushing function, which utilizes the directional impact force between the falling coal and the pre-crushing needles to induce initial cracks or achieve micro-crack propagation on the surface of the coal block, weakening the overall structural strength of the coal block, improving the efficiency of the step-by-step crushing of coal from large blocks to coal powder, and reducing the impact force of coal on the crushing structure; it can timely screen out qualified coal powder that meets the particle size requirements and separate it from the crushing process in a timely manner, avoiding increased energy consumption and reduced efficiency due to over-crushing of qualified coal powder, thus solving the technical problems mentioned in the background art.

[0005] To achieve the above objectives, this application adopts the following technical solution: a multi-stage coal crushing device for thermal power generation, comprising a coal crushing device housing, wherein the inner cavity of the coal crushing device housing is sequentially provided with a first partition, a second partition, and a third partition, which divide the inner cavity of the coal crushing device housing from the feeding end to the discharging end into a first crushing chamber, a second crushing chamber, a third crushing chamber, and a coal powder collection chamber; a feeding hopper is provided in the middle of the top of the first crushing chamber, a pre-crushing needle assembly is provided at the top of the first crushing chamber, the pre-crushing needle assembly is located directly below the discharging end of the feeding hopper, a first crushing structure is provided at the bottom of the first crushing chamber, the first crushing structure includes a crushing plate, crushing plates are provided on both sides of the bottom of the first crushing chamber, the crushing plates are connected to the coal crushing device housing through a first telescopic structure, and a material guide interception plate is provided at the top of the crushing plate;

[0006] An air inlet plate is provided on one side of the second crushing chamber, and an air inlet one-way valve is provided at the air inlet end of the air inlet plate. The air inlet end of the air inlet one-way valve is located outside the coal crushing equipment box. An exhaust plate is provided on the other side of the second crushing chamber. A coal powder filter box is provided on the outside of the second crushing chamber. A collection box is provided at the discharge end of the coal powder filter box. An interception mesh plate is provided in the inner cavity of the coal powder filter box. The inner cavity of the coal powder filter box is divided into a power cavity and a temporary storage cavity by the interception mesh plate. An exhaust fan is provided in the power cavity. The air outlet end of the exhaust plate is located in the temporary storage cavity, and a first star-shaped discharge valve is provided at the bottom of the temporary storage cavity.

[0007] Preferably, it also includes a coal conveyor belt, which is fixedly installed above the feeding hopper.

[0008] Preferably, the material guide interceptor plate has a two-section structure, including a vertical section and an inclined section. The vertical section and the inclined section are smoothly connected. The top of the vertical section is at the same height as the bottom of the feeding hopper. The bottom of the vertical section is located below the bottom of the pre-crushing needle assembly. The end of the inclined section away from the vertical section is connected to the top of the extrusion plate. Both the material guide interceptor plate and the extrusion plate are provided with wear-resistant plates on their inner sides.

[0009] Preferably, a first screen is provided at the bottom of the first partition, and the first crushing chamber and the second crushing chamber are connected through the first screen; a second star-shaped discharge valve is provided at the middle of the bottom of the second partition, and the discharge end of the second star-shaped discharge valve is located at the top of the third crushing chamber; a second screen is provided at the middle of the third partition, and the third crushing chamber and the coal powder collection chamber are connected through the second screen.

[0010] Preferably, the pre-crushing needle group has an inverted V-shaped structure, comprising a plurality of pre-crushing needles arranged at equal intervals.

[0011] Preferably, the air inlet end of the exhaust plate is provided with a filter screen that allows only the target coal powder to pass through, the exhaust plate and the air inlet plate form a guide groove, the first screen is located in the middle of the upper part of the guide groove, and a second crushing structure is provided in the middle of the bottom end of the guide groove.

[0012] Preferably, a receiving trough is provided at the bottom of the pulverized coal collection chamber.

[0013] Preferably, a third crushing structure is provided at the bottom end of the third crushing chamber.

[0014] Preferably, the power chamber is provided with a striking structure, which includes a hammer head for striking the intercepting mesh plate. The hammer head is connected to the coal powder filter box through a second telescopic structure.

[0015] This utility model has the following beneficial effects:

[0016] 1. It has a pre-crushing function, which uses the directional impact force between the coal and the pre-crushing needles when the coal falls to induce the initial cracks or achieve the propagation of micro-cracks on the surface of the coal block, weaken the overall structural strength of the coal block, reduce the crushing load of core components such as crushing rollers in the subsequent multi-stage crushing chamber, thereby significantly improving the step-by-step crushing efficiency of coal from large blocks to coal powder, reducing the overall crushing energy consumption and extending the service life of key crushing components, and reducing the impact force of coal on the first screen.

[0017] 2. It can promptly screen out qualified coal powder that meets the particle size requirements and separate it from the crushing process in a timely manner, avoiding increased energy consumption and reduced efficiency due to over-crushing of qualified coal powder.

[0018] 3. Under the negative pressure suction of the exhaust fan, the air inside the coal crushing equipment box flows in a directional manner, which can cool down the second crushing structure, reduce the probability of wear caused by high temperature, extend the service life of the second crushing structure, and effectively suppress dust from escaping to the outside of the equipment, significantly reduce the amount of dust leakage during operation, and improve the cleanliness of the working environment and operational safety. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of a multi-stage coal crushing device for thermal power generation proposed in this utility model;

[0020] Figure 2 for Figure 1 Internal diagram;

[0021] Figure 3 for Figure 1 Top view diagram;

[0022] Figure 4 for Figure 2 Enlarged diagram of A in the middle;

[0023] Figure 5 for Figure 2 Enlarged diagram of B in the middle;

[0024] Figure 6 for Figure 2 Enlarged diagram of C.

[0025] In the diagram: 1. Coal crushing equipment housing; 2. Coal conveyor belt; 3. Feeding hopper; 4. Feed gate; 51. First partition; 52. First screen; 53. Crushing plate; 54. First telescopic structure; 55. Material guide and interception plate; 56. Pre-crushing needle assembly; 61. Second partition; 62. Air inlet plate; 63. First servo motor; 64. Crushing roller; 65. Second star-shaped discharge valve; 66. Air inlet check valve; 67. Coal powder filter box; 68. Exhaust fan; 69. Interception screen plate; 610. First star-shaped discharge valve; 611. Temporary storage chamber; 612. Second telescopic structure; 613. Collection box; 614. Hammer head; 615. Exhaust plate; 71. Third partition; 72. Second screen; 73. Inclined frame; 74. Second servo motor; 75. Grinding plate; 76. Grinding trough; 8. Receiving trough. Detailed Implementation

[0026] The technical solution of this utility model will be clearly and completely described below with reference to preferred embodiments. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] like Figures 1 to 6 As shown, a multi-stage coal crushing device for thermal power generation includes a coal crushing device housing 1, a coal conveyor belt 2, and a feeding hopper 3. The feeding hopper 3 is fixedly installed at the top of the coal crushing device housing 1, and the coal conveyor belt 2 is fixedly installed above the feeding hopper 3. In embodiment 1, the coal conveyor belt 2 is a common mining transmission belt, which can input the large pieces of coal that need to be crushed toward the top of the feeding hopper 3. The large pieces of coal will be poured into the coal crushing device housing 1 along the funnel-shaped feeding hopper 3 for crushing and grinding.

[0028] The inner cavity of the coal crushing equipment housing 1 is sequentially equipped with a first partition 51, a second partition 61, and a third partition 71. These three partitions divide the inner cavity of the coal crushing equipment housing 1 from the feed end to the discharge end into a first crushing chamber, a second crushing chamber, a third crushing chamber, and a coal powder collection chamber. In embodiment 2, the first partition 51, the second partition 61, and the third partition 71 are made of stainless steel metal plates, and these three partitions are connected to the coal crushing equipment housing 1 by welding. Furthermore, all three partitions are detachably connected to the coal crushing equipment housing 1, facilitating disassembly, cleaning, and replacement.

[0029] The first partition 51 has a first screen 52 at its bottom, and the first crushing chamber and the second crushing chamber are connected through the first screen 52. A feeding hopper 3 is located in the middle of the top of the first crushing chamber, and a pre-crushing needle assembly 56 is located at the top of the first crushing chamber. The pre-crushing needle assembly 56 is positioned directly below the discharge end of the feeding hopper 3 and includes several equidistant pre-crushing needles. In use, coal blocks discharged from the feeding hopper 3 fall onto the pre-crushing needles under gravity. The sharp tips of the pre-crushing needles convert the gravitational potential energy of the falling coal blocks into concentrated local stress. This concentrated stress easily causes cracks or direct crushing on the surface of the coal blocks, thus achieving pre-crushing of the coal blocks and improving crushing efficiency. Furthermore, the pre-crushing needle assembly 56 has an inverted V-shaped structure, which guides the coal blocks to slide down along the inclined portion of the pre-crushing needle assembly 56, reducing the impact force of the coal blocks on the first screen 52. The mesh diameter of the first screen 52 can be set according to requirements and is not limited here.

[0030] A first crushing structure is provided at the bottom of the first crushing chamber. The first crushing structure includes a crushing plate 53. Crushing plates 53 are provided on both sides of the bottom of the first crushing chamber. The crushing plates 53 are connected to the coal crushing equipment box 1 through a first telescopic structure 54. By extending and retracting the first telescopic structure 54, the position of the crushing plate 53 connected to it can be changed. The cooperation of the two crushing plates 53 can realize the crushing of coal blocks. The crushed coal blocks can enter the second crushing chamber for further crushing through the first screen 52. The first telescopic structure 54 is existing technology and can realize the stable extension and retraction of the crushing plate 53 in a straight line and precisely control its displacement position. The first telescopic structure 54 can be a hydraulic telescopic rod.

[0031] A material guide and interceptor plate 55 is provided on the top of the crushing plate 53. The material guide and interceptor plate 55 has a two-section structure, including a vertical section and an inclined section. The vertical section and the inclined section are smoothly connected. The top of the vertical section is at the same height as the bottom of the feeding hopper 3. The bottom of the vertical section is located below the bottom of the pre-crushing needle group 56. The end of the inclined section away from the vertical section is connected to the top of the crushing plate 53. By setting the material guide and interceptor plate 55, the material guide and interceptor plate 55 can restrict the falling coal blocks and prevent the coal blocks from falling between the crushing plate 53 and the first telescopic structure 54.

[0032] Both the material guide interceptor plate 55 and the crushing plate 53 have wear-resistant plates on their inner sides. The material of the wear-resistant plates can be set according to requirements and is not limited here. The wear-resistant plates are detachably connected to the material guide interceptor plate 55 or the crushing plate 53. In use, the wear-resistant plates can directly resist the friction and impact of coal blocks, reducing the wear of the material guide interceptor plate 55 and the crushing plate 53. When the wear-resistant plates are worn due to long-term use, they only need to be removed from the material guide interceptor plate 55 or the crushing plate 53 and replaced with new wear-resistant plates to restore the complete protection and crushing function of the first crushing structure. There is no need to replace the entire material guide interceptor plate 55 and the crushing plate 53, which greatly extends the service life of the core components and reduces maintenance costs.

[0033] An air inlet plate 62 is provided on one side of the second crushing chamber. An air inlet one-way valve 66 is provided at the air inlet end of the air inlet plate 62. The air inlet end of the air inlet one-way valve 66 is located outside the coal crushing equipment box 1. The air outlet end of the air inlet plate 62 is located inside the second crushing chamber, and air outlet holes are evenly arranged at the air outlet end of the air inlet plate 62. An exhaust plate 615 is provided on the other side of the second crushing chamber. The air inlet end of the exhaust plate 615 is located inside the second crushing chamber. Air inlet holes are evenly arranged at the air inlet end of the exhaust plate 615, and a filter screen is provided at the air inlet end of the exhaust plate 615 for only the target coal powder to pass through. The mesh size of the filter screen can be set according to the requirements and is not limited here.

[0034] A pulverized coal filter box 67 is installed on the outside of the second crushing chamber. An intercepting mesh plate 69 is installed inside the pulverized coal filter box 67. The intercepting mesh plate 69 is used to intercept pulverized coal, so that the pulverized coal is separated from the air. The inner cavity of the pulverized coal filter box 67 is divided into a power chamber and a temporary storage chamber 611 by the intercepting mesh plate 69. An exhaust fan 68 is installed in the power chamber. The air inlet of the exhaust fan 68 is located in the power chamber, and the air outlet of the exhaust fan 68 is located outside the pulverized coal filter box 67. The air outlet of the exhaust plate 615 is located in the temporary storage chamber 611.

[0035] When this application is in use, if the inlet one-way valve 66 is connected to the outlet of an ion blower or other blower in the prior art, the blower can blow air into the inner cavity of the inlet plate 62 through the inlet one-way valve 66. The air in the inner cavity of the inlet plate 62 is discharged into the second crushing chamber through the outlet hole. When the exhaust fan 68 is working, the air and target coal powder in the second crushing chamber enter the inner cavity of the exhaust plate 615 through the inlet hole. The coal powder-containing air in the exhaust plate 615 enters the temporary storage chamber 611 through the outlet of the exhaust plate 615. The synergistic effect of the exhaust fan 68 and the blower causes the air to flow in a directional manner in the second crushing chamber. During this process, qualified coal powder that meets the particle size requirements can be screened out in real time and separated from the crushing process in a timely manner. This avoids the increase in energy consumption and the reduction in efficiency due to over-crushing of qualified coal powder, thereby significantly improving the economy and efficiency of the overall coal crushing process. Furthermore, the intercepting mesh plate 69 can separate the coal dust from the air. The coal dust is left in the temporary storage chamber 611, while the air is discharged through the exhaust fan 68.

[0036] Furthermore, in practical applications, a bin vibrator can be installed at the air inlet of the exhaust plate 615. The vibrator model can be set according to requirements and is not limited here. The vibration generated when the bin vibrator is powered on can also cause the air inlet of the exhaust plate 615 and the filter screen to vibrate. Through the vibration, the coal powder particles attached to the air inlet and the surface of the filter screen are loosened and detached, thereby effectively reducing the probability of blockage at the air inlet of the exhaust plate 615 and the filter screen due to coal powder accumulation, ensuring the continuous unobstructed airflow channel and the stable coal powder screening efficiency.

[0037] The discharge end of the pulverized coal filter box 67 is equipped with a collection box 613, and the bottom of the temporary storage chamber 611 is equipped with a first star-shaped discharge valve 610. Through the setting of the first star-shaped discharge valve 610, the pulverized coal temporarily stored in the temporary storage chamber 611 can be discharged into the collection box 613.

[0038] The power chamber is equipped with a striking structure, which includes a hammer 614 that strikes the intercepting mesh plate 69. The hammer 614 is connected to the coal powder filter box 67 through a second telescopic structure 612. The extension and retraction of the second telescopic structure 612 can change the position of the hammer 614 connected to it. The hammer 614 can strike the intercepting mesh plate 69, and the intercepting mesh plate 69 vibrates when struck. This vibration causes the coal powder particles attached to the surface of the mesh to fall off, thereby effectively reducing the probability of the intercepting mesh plate 69 being blocked due to coal powder accumulation and ensuring the continuous unobstructed flow of the screening channel.

[0039] The exhaust plate 615 and the air inlet plate 62 form a guide groove. The first screen 52 is located in the middle of the upper part of the guide groove. A second crushing structure is set in the middle of the bottom of the guide groove. The crushed coal pieces will slide down along the guide groove after being squeezed. The second crushing structure can further crush the coal pieces.

[0040] In Example 3, the second crushing structure is a roller crushing structure, including two relatively parallel crushing rollers 64 movably connected to the coal crushing equipment box 1 and two first servo motors 63 connected to the coal crushing equipment box 1. The crushing rollers 64 are driven to rotate by the first servo motors 63, and under the drive of the first servo motors 63, the two crushing rollers 64 rotate in opposite directions towards the middle. The rotating crushing rollers 64 generate relative extrusion force, which can compress small pieces of coal into smaller fine coal slag, thereby realizing the secondary crushing of coal and forming coal slag.

[0041] A second star-shaped discharge valve 65 is provided at the middle of the bottom of the second partition plate 61. The discharge end of the second star-shaped discharge valve 65 is located at the top of the third crushing chamber. When the second star-shaped discharge valve 65 is working, it can discharge the secondary crushed coal slag into the third crushing chamber. In addition, during the secondary crushing process, the directional air flow in the second crushing chamber can cool down the crushing roller 64 and reduce the probability of wear of the crushing roller 64 due to high temperature.

[0042] The bottom of the third crushing chamber is provided with a third crushing structure. In embodiment 4, the third crushing structure uses grinding to crush coal slag into coal powder. The third crushing structure includes a grinding groove 76, which is a concave metal iron groove. A grinding plate 75 is rotatably connected to the inner side of the grinding groove 76. The grinding plate 75 is made of a heavy solid metal iron block. The grinding plate 75 is driven to rotate by a second servo motor 74. The second servo motor 74 is connected to the coal crushing equipment box 1. An inclined frame 73 is provided at the top of the third crushing chamber. The inclined frame 73 can guide the falling coal to slide to both sides and prevent it from accumulating on the second servo motor 74 and obstructing the motor's operation. After the second servo motor 74 is connected to the power supply and started, it can drive the lower grinding plate 75 to rotate. The grinding plate 75 rotates inside the grinding groove 76. Through the effect of rotation, extrusion and grinding, the crushed coal slag is ground into fine coal powder again.

[0043] A second screen 72 is provided in the middle of the third partition 71. The second screen 72 is connected to the middle of the bottom of the grinding tank 76. The third crushing chamber and the coal powder collection chamber are connected through the second screen 72. The coal powder can be screened using the second screen 72. Qualified coal powder falls into the coal powder collection chamber, while unqualified coal powder is further crushed through the third crushing structure.

[0044] A receiving trough 8 is provided at the bottom of the coal powder collection chamber. The receiving trough 8 is used to collect coal powder. The upper part of the receiving trough 8 is opposite to the lower end of the second screen 72. A material removal door 4 is fixedly opened at the bottom of the outer wall of the coal crushing equipment box 1. The material removal door 4 facilitates the cleaning and collection of coal powder accumulated in the receiving trough 8. The interior of the material removal door 4 is opposite to the receiving trough 8.

[0045] All electrical components involved in this application are existing technologies. Those skilled in the art can select appropriate models of electrical components according to their needs. No restrictions or elaborations are made here. Those skilled in the art understand their connection methods. With the help of those skilled in the art, all electrical components in this application and their compatible power supplies are connected by wires. According to the actual situation, appropriate controllers are selected to meet control requirements. For specific connections and control sequences, please refer to the description below. The electrical connections between each electrical component are completed in the order of their operation. The detailed connection methods are well-known technologies in the art. The following mainly introduces the working principle and process, and will not describe the electrical control.

[0046] In summary: Before using this multi-stage coal crushing equipment for thermal power generation, the air inlet check valve 66 can be connected to the air outlet of an existing blower. When this application is used, the coal conveyor belt 2 can be used to feed the large pieces of coal that need to be crushed toward the top of the feeding hopper 3. The large pieces of coal will be poured into the inside of the coal crushing equipment box 1 along the funnel-shaped feeding hopper 3 for crushing and grinding preparation.

[0047] Large pieces of coal discharged from the feeding hopper 3 fall onto the pre-crushing needle group 56. Under the action of impact, the surface of the coal is opened to produce cracks or is directly crushed, thereby achieving pre-crushing of large pieces of coal and improving coal crushing efficiency.

[0048] The pre-crushed coal falls onto the first screen 52 under gravity. The controller of this application controls the first telescopic structure 54 to work. The first telescopic structure 54 drives the extrusion plate 53 connected to it to move. When the two extrusion plates 53 squeeze and close together in the middle, they can squeeze large pieces of coal into smaller pieces of crushed coal, thus achieving the initial crushing of coal.

[0049] After initial crushing, the pulverized coal passes through the first screen 52 and falls into the second crushing chamber, where it is further crushed by the second crushing structure to form coal slag. During the secondary crushing process, the blower can blow air into the inner cavity of the air inlet plate 62 through the air inlet one-way valve 66. The air in the inner cavity of the air inlet plate 62 is discharged into the second crushing chamber through the air outlet. The exhaust fan 68 is powered on, and under the negative pressure suction of the exhaust fan 68, the air and target coal powder in the second crushing chamber enter the inner cavity of the exhaust plate 615 through the air inlet. The coal powder-containing air in the exhaust plate 615 enters the temporary storage chamber 611 through the air outlet of the exhaust plate 615. The synergistic action of the exhaust fan 68 and the blower causes the air to flow in a specific direction in the second crushing chamber, and the intercepting mesh plate 69 separates the coal powder from the air. The coal powder is left in the temporary storage chamber 611, and the air is discharged through the exhaust fan 68.

[0050] The coal slag enters the third crushing chamber through the second star-shaped discharge valve 65. The third crushing structure crushes the coal slag. Under the action of the third crushing structure, the coal slag is crushed into coal powder. The coal powder with qualified size enters the coal powder collection chamber through the second screen 72 and is stored through the receiving trough 8.

[0051] This application utilizes a multi-stage process of first crushing large pieces of coal, then extruding them into smaller pieces, and finally grinding them into fine coal powder. The coal powder produced by this multi-stage crushing process is more uniform in size and burns more completely, thus reducing carbon monoxide production while generating high heat energy.

[0052] All standard parts used in this utility model can be purchased from the market, and irregularly shaped parts can be customized according to the description and drawings. The specific connection methods of each structure adopt conventional technical means such as bolt connection in the existing technology. The machinery, parts and equipment adopt conventional models in the existing technology. The materials and specifications of each component can be selected according to the requirements and are not limited here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art. Although the embodiments of this utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this utility model. This utility model will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A multi-stage coal crushing device for thermal power generation, comprising a coal crushing device housing (1), characterized in that: The inner cavity of the coal crushing equipment box (1) is provided with a first partition (51), a second partition (61) and a third partition (71) in sequence. These three partitions divide the inner cavity of the coal crushing equipment box (1) from the feeding end to the discharging end into a first crushing chamber, a second crushing chamber, a third crushing chamber and a coal powder collection chamber in sequence. A feeding hopper (3) is provided in the middle of the top of the first crushing chamber. A pre-crushing needle group (56) is provided at the top of the first crushing chamber. The pre-crushing needle group (56) is located directly below the discharging end of the feeding hopper (3). A first crushing structure is provided at the bottom of the first crushing chamber. The first crushing structure includes a crushing plate (53). Crushing plates (53) are provided on both sides of the bottom of the first crushing chamber. The crushing plates (53) are connected to the coal crushing equipment box (1) through a first telescopic structure (54). A material guide intercepting plate (55) is provided at the top of the crushing plate (53). An air inlet plate (62) is provided on one side of the second crushing chamber. An air inlet one-way valve (66) is provided at the air inlet end of the air inlet plate (62). The air inlet end of the air inlet one-way valve (66) is located outside the coal crushing equipment box (1). An exhaust plate (615) is provided on the other side of the second crushing chamber. A coal powder filter box (67) is provided on the outside of the second crushing chamber. A collection box (613) is provided at the discharge end of the coal powder filter box (67). An interception mesh plate (69) is provided in the inner cavity of the coal powder filter box (67). The inner cavity of the coal powder filter box (67) is divided into a power chamber and a temporary storage chamber (611) by the interception mesh plate (69). An exhaust fan (68) is provided in the power chamber. The air outlet end of the exhaust plate (615) is located in the temporary storage chamber (611). A first star-shaped discharge valve (610) is provided at the bottom of the temporary storage chamber (611).

2. The multi-stage coal crushing equipment for thermal power generation according to claim 1, characterized in that: It also includes a coal conveyor belt (2), which is fixedly installed above the feeding hopper (3).

3. The multi-stage coal crushing equipment for thermal power generation according to claim 1, characterized in that: The material guide interceptor plate (55) has a two-section structure, including a vertical section and an inclined section. The vertical section and the inclined section are smoothly connected. The top of the vertical section is at the same height as the bottom of the feeding hopper (3). The bottom of the vertical section is located below the bottom of the pre-crushing needle group (56). The end of the inclined section away from the vertical section is connected to the top of the extrusion plate (53). Both the material guide interceptor plate (55) and the extrusion plate (53) are provided with wear-resistant plates on their inner sides.

4. The multi-stage coal crushing equipment for thermal power generation according to claim 1, characterized in that: The bottom of the first partition (51) is provided with a first screen (52), and the first crushing chamber and the second crushing chamber are connected through the first screen (52); the middle of the bottom of the second partition (61) is provided with a second star-shaped discharge valve (65), and the discharge end of the second star-shaped discharge valve (65) is located at the top of the third crushing chamber; the middle of the third partition (71) is provided with a second screen (72), and the third crushing chamber and the coal powder collection chamber are connected through the second screen (72).

5. A multi-stage coal crushing device for thermal power generation according to claim 1, characterized in that: The pre-crushing needle group (56) has an inverted V-shaped structure and includes several pre-crushing needles arranged at equal intervals.

6. A multi-stage coal crushing device for thermal power generation according to claim 4, characterized in that: The air inlet end of the exhaust plate (615) is provided with a filter screen that allows only the target coal powder to pass through. The exhaust plate (615) and the air inlet plate (62) form a guide groove. The first screen (52) is located in the middle of the upper part of the guide groove. A second crushing structure is provided in the middle of the bottom end of the guide groove.

7. A multi-stage coal crushing device for thermal power generation according to claim 1, characterized in that: A receiving trough (8) is provided at the bottom of the pulverized coal collection chamber.

8. A multi-stage coal crushing device for thermal power generation according to claim 1, characterized in that: The bottom end of the third crushing chamber is provided with a third crushing structure.

9. A multi-stage coal crushing device for thermal power generation according to claim 1, characterized in that: The power chamber is provided with a striking structure, which includes a hammer (614) for striking the interception mesh plate (69). The hammer (614) is connected to the coal powder filter box (67) through a second telescopic structure (612).

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