Coal blocking alarm device for medium-speed coal mill

Abstract

The application belongs to the technical field of coal mill safety equipment, and discloses a medium-speed coal mill coal blocking alarm device, which comprises a controller, an alarm lamp and a sensor, a signal interface and an assembling cavity are respectively arranged on the back of the controller, and an intermediate hole is arranged in the inside of the back of the controller. The gas is pressed into the elastic air bag through the cooperation of the rotating extrusion, the inflation effect after the inside of the elastic air bag is ventilated is utilized, the signal connector maintains good sealing after being sleeved, the air in the signal interface is extracted when the movable plug in the suction assembly is moved by the cooperation of the operation assembly, the signal connector is adsorbed and fixed after being sleeved with the sealing frame under the negative pressure, the stability after actual wiring installation is greatly improved, good plug-in stability can be maintained under external force pulling or vibration effect, the situation of relaxation and disconnection can be effectively avoided, the frequency of arranging artificial maintenance and troubleshooting can be reduced, the use effect is good, and the monitoring and alarm are stable and reliable.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mill safety equipment, specifically a coal blockage alarm device for a medium-speed coal mill. Background Technology

[0002] The medium-speed coal mill coal blockage alarm device is used to monitor and alert on coal blockage in medium-speed coal mills. The medium-speed coal mill is a key piece of equipment in a pulverized coal grinding system, used to grind coal into a fine powder for boiler combustion. However, due to factors such as coal properties and process parameters, coal blockage may occur during the operation of the medium-speed coal mill, leading to equipment failure and safety hazards.

[0003] Existing medium-speed coal mill blockage alarm devices typically employ multiple sets of sensors to detect blockages. During assembly, these wired sensors are connected via signal connectors inserted into the controller's signal input. However, after a period of use, the stability of these directly inserted connectors deteriorates due to external forces and vibrations, often resulting in them detaching. This affects the actual detection and alarm capabilities, necessitating regular maintenance and repair, increasing manpower and leading to unsatisfactory performance. Summary of the Invention

[0004] The purpose of this invention is to provide a coal blockage alarm device for a medium-speed coal mill to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a coal blockage alarm device for a medium-speed coal mill, comprising a controller, an alarm light, and a sensor. The back of the controller has a signal interface and an assembly cavity. An internal central hole is provided inside the back of the controller, with both ends of the central hole connected to the signal interface and the assembly cavity, respectively. A signal connector is movably fitted inside the signal interface. A cable is electrically connected between the signal connector and the sensor. An elastic airbag is fitted on the outer surface of the signal connector. An adjusting ring is threaded onto the end face of the signal connector. A suction assembly is provided inside the assembly cavity, and the suction assembly is connected to the central hole. An operating component is provided on the bottom surface of the suction assembly. A connecting component is provided at the front of the back of the controller. An installation component is fixedly installed on the side of the controller. A closing component is provided on the side of the installation component. Both ends of the connecting component are connected to the suction assembly and the closing component, respectively.

[0006] Preferably, the outer surface of the signal connector is provided with an installation ring groove, the elastic airbag is sleeved in the installation ring groove, a sealing frame is fixedly sleeved on the outer surface of the signal connector, a threaded groove and a through hole are respectively provided on the end face and the inside of the signal connector, the inner surface of the threaded groove is threadedly sleeved with the adjusting ring, and the two ends of the through hole are respectively connected to the threaded groove and the elastic airbag.

[0007] Preferably, the suction assembly includes a suction cylinder, a connecting plate, a movable plug, a pull rod, and a first spring. The suction cylinder is fixedly connected to the top surface of the inner surface of the assembly cavity and communicates with the intermediate hole. The pull rod is fixedly connected to the top surface of the connecting plate. The movable plug is fixedly connected to the top end of the pull rod and sleeved inside the suction cylinder. The upper end of the first spring is fixedly connected to the bottom surface of the movable plug, and the lower end of the first spring is fixedly connected to the top surface of the connecting plate.

[0008] Preferably, the operating component includes a threaded rod, a rotating plate, a fixed sleeve, and a stepped cavity. The fixed sleeve is fixedly connected to the bottom surface of the connecting plate, the stepped cavity is opened at the bottom of the fixed sleeve, the rotating plate is rotatably sleeved inside the stepped cavity, the bottom surface of the rotating plate is fixedly connected to the threaded rod, and a threaded hole is opened inside the back of the controller, and the threaded rod is threadedly sleeved in the threaded hole.

[0009] Preferably, the mounting assembly includes a mounting bracket and mounting bolts, the mounting bracket being fixedly connected to the side of the controller, and the mounting bolts being sleeved on the end face of the mounting bracket.

[0010] Preferably, the sealing assembly includes a horizontal plate, a sleeve, a sealing cover, a movable rod, and a second spring. The horizontal plate is fixedly connected to the side of the mounting bracket, the sleeve is fixedly connected to the side of the horizontal plate, the sealing cover is fitted over the outside of the mounting bolt, one end of the movable rod is fixedly connected to the sealing cover, and the other end of the movable rod is fixedly connected to the second spring. One end of the movable rod is fitted inside the sleeve, the second spring is located inside the sleeve, and the other end of the second spring is fixed inside the sleeve.

[0011] Preferably, the connecting component includes a connecting frame, a suction tube, and an outlet tube. The two ends of the suction tube are fixedly connected to the connecting frame and the suction cylinder, respectively, and the two ends of the outlet tube are fixedly connected to the connecting frame and the sleeve, respectively.

[0012] Preferably, the alarm light is fixedly installed on the top of the controller, and the alarm light corresponds one-to-one with the sensor, with a total of three sensors.

[0013] The beneficial effects of this invention are as follows:

[0014] 1. This invention utilizes an adjusting ring in conjunction with an elastic airbag. After the signal connector is fitted, gas is forced into the elastic airbag through rotational compression. The expansion effect of the airbag after ventilation ensures a good seal for the signal connector after fitting. Furthermore, when the operating component pulls the movable plug in the suction component, air is extracted from the signal interface. Under negative pressure, the sealing frame adheres and fixes the signal connector after fitting, greatly improving the stability after actual wiring and installation. It maintains good connection stability under external force or vibration, effectively preventing loosening and detachment. This reduces the frequency of manual inspection and troubleshooting, resulting in good performance and stable and reliable monitoring and alarm.

[0015] 2. This invention utilizes the suction assembly again to extract internal gas from the signal interface. During the suction process, the lower cavity of the suction cylinder is compressed, and the gas in its lower space is compressed and input into the sealing assembly through the connecting assembly. The increased air pressure in the sealing assembly enables the movable rod to move the sealing cover, thereby sealing the mounting bolts. This effectively isolates the outer end of the metal mounting bolts from the external environment, preventing corrosion and damage to the mounting bolts due to moisture and oxidation. This improves the synchronous protection after the mounting bolts are installed, thereby enhancing the actual installation stability, preventing the controller from becoming loose, and extending the installation service life. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the present invention;

[0017] Figure 2 This is a schematic diagram of the back of the present invention;

[0018] Figure 3 This is a schematic diagram showing the connection between the sensor and the signal connector of the present invention;

[0019] Figure 4 This is a schematic diagram of the back of the controller of the present invention;

[0020] Figure 5 This is a cross-sectional schematic diagram of the signal connector of the present invention;

[0021] Figure 6 This is a schematic diagram of the signal connector structure of the present invention;

[0022] Figure 7 This is a schematic diagram showing the connection between the operating component and the suction component of the present invention;

[0023] Figure 8 This is an exploded view of the suction assembly of the present invention;

[0024] Figure 9 This is an exploded view of the operating components of the present invention;

[0025] Figure 10 This is an exploded view of the mounting component and the sealing component of the present invention;

[0026] Figure 11 This is a schematic diagram of the connecting component of the present invention.

[0027] In the diagram: 1. Controller; 2. Alarm light; 3. Signal interface; 4. Assembly cavity; 5. Central hole; 6. Signal connector; 7. Sealing frame; 8. Cable; 9. Sensor; 10. Threaded groove; 11. Elastic airbag; 12. Through hole; 13. Adjusting ring; 14. Mounting ring groove; 15. Threaded hole; 16. Suction assembly; 161. Suction cylinder; 162. Connecting plate; 163. Movable plug; 164. Pull rod; 165. No. 1 17. Spring; 171. Operating assembly; 172. Threaded rod; 173. Rotating plate; 174. Fixed sleeve; 175. Stepped cavity; 18. Connecting assembly; 181. Connecting frame; 182. Suction pipe; 183. Exit pipe; 19. Mounting assembly; 191. Mounting bracket; 192. Mounting bolt; 20. Sealing assembly; 201. Horizontal plate; 202. Sleeve; 203. Sealing cover; 204. Movable rod; 205. No. 2 spring. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] like Figures 1 to 11 As shown, this embodiment of the invention provides a coal blockage alarm device for a medium-speed coal mill, including a controller 1, an alarm light 2, and a sensor 9. The back of the controller 1 is provided with a signal interface 3 and an assembly cavity 4. The back of the controller 1 is provided with a central hole 5. The two ends of the central hole 5 are connected to the signal interface 3 and the assembly cavity 4, respectively. A signal connector 6 is movably sleeved inside the signal interface 3. A cable 8 is electrically connected between the signal connector 6 and the sensor 9. An elastic airbag 11 is sleeved on the outer surface of the signal connector 6. An adjusting ring 13 is threaded onto the end face of the signal connector 6. A suction component 16 is provided inside the assembly cavity 4. The suction component 16 is connected to the central hole 5. An operating component 17 is provided on the bottom surface of the suction component 16. A connecting component 18 is provided at the front of the back of the controller 1. An installation component 19 is fixedly installed on the side of the controller 1. A closing component 20 is provided on the side of the installation component 19. The two ends of the connecting component 18 are connected to the suction component 16 and the closing component 20, respectively.

[0030] First embodiment: 1. Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 As shown, when wiring sensor 9, the corresponding signal connector 6 is inserted along the signal interface 3 on the back of controller 1 to complete the electrical connection. The adjusting ring 13 on the end face of the signal connector 6 is rotated so that the adjusting ring 13 is spirally inserted and squeezes the internal air, so that the air is squeezed into the elastic airbag 11 through the through hole 12, causing the elastic airbag 11 to inflate and completely seal the end of the signal interface 3. The threaded rod 171 in the operating assembly 17 is rotated downward so that the threaded rod 171 moves spirally downward along the threaded hole 15. As the threaded rod 171 moves spirally downward, it drives the fixed sleeve 173 to move downward, so that the movable plug 163 in the suction assembly 16 moves downward inside the suction cylinder 161. As the movable plug 163 moves downward, it sucks the air in the signal interface 3 through the middle hole 5, so that the signal interface 3 has a negative pressure, so that the inner and outer end faces of the signal connector 6 have a pressure difference. Under the negative pressure, the signal connector 6 and the sealing frame 7 are adsorbed and fixed at the end face of the signal interface 3.

[0031] First, by using the adjusting ring 13 in conjunction with the elastic airbag 11, after the signal connector 6 is fitted, gas is forced into the elastic airbag 11 under rotational compression. The expansion effect of the elastic airbag 11 after air is introduced inside ensures that the signal connector 6 maintains a good seal after being fitted. Then, when the operating component 17 pulls the movable plug 163 in the suction component 16, the air in the signal interface 3 is extracted. Under negative pressure, the sealing frame 7 achieves adsorption and fixation of the signal connector 6 after fitting, which greatly improves the stability after actual wiring installation. It can maintain good insertion stability under external force or vibration, effectively avoiding loosening and detachment. It can reduce the frequency of manual inspection and troubleshooting, and has good performance and stable and reliable monitoring and alarm.

[0032] Second embodiment: 1. Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11As shown, during installation, after the controller 1 is positioned in the installation position and the threaded connection of the mounting bolt 192 is completed, and after the negative pressure adsorption fixation is completed, when the movable plug 163 inside the suction cylinder 161 moves down, the air in the lower space of the movable plug 163 is simultaneously squeezed into the connecting component 18 through the suction pipe 182, and the squeezed gas is squeezed into the sealing component 20 through the outlet pipe 183. As the gas in the sleeve 202 is continuously filled, the internal air pressure increases, and the air pressure pushes the movable rod 204 to move laterally, so that the sealing cover 203 is sleeved on the outside of the mounting bolt 192 and completes the seal.

[0033] First, the internal gas of the signal interface 3 is drawn in again by the suction assembly 16. During the suction process, the lower cavity of the suction cylinder 161 is compressed, and the gas in its lower space is compressed and input into the sealing assembly 20 through the connecting assembly 18. The increased air pressure in the sealing assembly 20 causes the movable rod 204 to move the sealing cover 203, thereby sealing the mounting bolt 192. This effectively isolates the outer end of the metal mounting bolt 192 from the external environment, preventing corrosion and damage to the mounting bolt 192 due to moisture and oxidation. This improves the synchronous protection after the mounting bolt 192 is installed and connected, thereby improving the actual installation stability, preventing the controller 1 from becoming loose, and extending the service life of the installation.

[0034] The signal connector 6 has an installation ring groove 14 on its outer surface, and the elastic airbag 11 is sleeved in the installation ring groove 14. The outer surface of the signal connector 6 is fixedly sleeved with a sealing frame 7. The end face and the inside of the signal connector 6 are respectively provided with a threaded groove 10 and a through hole 12. The inner surface of the threaded groove 10 is threadedly sleeved with the adjusting ring 13, and the two ends of the through hole 12 are respectively connected to the threaded groove 10 and the elastic airbag 11.

[0035] The mounting groove 14 is used for local fixation with the elastic airbag 11, maintaining the connection stability of the elastic airbag 11, while allowing the outer surface of the elastic airbag 11 to expand and deform. The through hole 12 facilitates the introduction of compressed air into the elastic airbag 11 to achieve expansion.

[0036] The suction assembly 16 includes a suction cylinder 161, a connecting plate 162, a movable plug 163, a pull rod 164, and a first spring 165. The suction cylinder 161 is fixedly connected to the top surface of the inner surface of the assembly cavity 4 and communicates with the intermediate hole 5. The pull rod 164 is fixedly connected to the top surface of the connecting plate 162. The movable plug 163 is fixedly connected to the top end of the pull rod 164 and sleeved inside the suction cylinder 161. The upper end of the first spring 165 is fixedly connected to the bottom surface of the movable plug 163, and the lower end of the first spring 165 is fixedly connected to the top surface of the connecting plate 162.

[0037] The suction component 16 enables suction from multiple signal interfaces 3, achieving adsorption and fixation under negative pressure. The elasticity of the first spring 165 facilitates the upward movement and reset of the movable plug 163.

[0038] The operating component 17 includes a threaded rod 171, a rotating plate 172, a fixed sleeve 173, and a stepped cavity 174. The fixed sleeve 173 is fixedly connected to the bottom surface of the connecting plate 162. The stepped cavity 174 is opened at the bottom of the fixed sleeve 173. The rotating plate 172 is rotatably sleeved inside the stepped cavity 174. The bottom surface of the rotating plate 172 is fixedly connected to the threaded rod 171. A threaded hole 15 is opened inside the back of the controller 1, and the threaded rod 171 is threadedly sleeved in the threaded hole 15.

[0039] The operating component 17 is used to pull the connecting plate 162 in the suction component 16 to realize the movement control of the movable plug 163. It cooperates with the threaded hole 15 and the threaded rod 171 to maintain the self-locking stability after rotation adjustment. The stepped cavity 174 is adapted to the bottom sleeve of the threaded rod 171 and the rotation sleeve of the rotating plate 172 to ensure that when the threaded rod 171 rotates down, it only pulls the connecting plate 162 to move up and down.

[0040] The mounting assembly 19 includes a mounting bracket 191 and mounting bolts 192. The mounting bracket 191 is fixedly connected to the side of the controller 1, and the mounting bolts 192 are sleeved on the end face of the mounting bracket 191.

[0041] Mounting component 19 is used to assemble and fix the alarm controller 1, maintaining a stable installation.

[0042] The sealing component 20 includes a horizontal plate 201, a sleeve 202, a sealing cover 203, a movable rod 204, and a second spring 205. The horizontal plate 201 is fixedly connected to the side of the mounting bracket 191, the sleeve 202 is fixedly connected to the side of the horizontal plate 201, the sealing cover 203 is sleeved on the outside of the mounting bolt 192, one end of the movable rod 204 is fixedly connected to the sealing cover 203, and the other end of the movable rod 204 is fixedly connected to the second spring 205. One end of the movable rod 204 is sleeved inside the sleeve 202, and the second spring 205 is located inside the sleeve 202. The other end of the second spring 205 is fixed inside the sleeve 202. The connecting component 18 includes a connecting frame 181, a suction pipe 182, and an outlet pipe 183. The two ends of the suction pipe 182 are fixedly connected to the connecting frame 181 and the suction cylinder 161, respectively, and the two ends of the outlet pipe 183 are fixedly connected to the connecting frame 181 and the sleeve 202, respectively.

[0043] The sealing component 20 guides the compressed air in the adsorption and fixing operation into the sealing component 20 through the connecting component 18, and pushes the movable rod 204 to move laterally in the sleeve 202, thereby achieving the protection and isolation of the front end of the mounting bolt 192 by the sealing cover 203, avoiding oxidation and corrosion from oxygen and moisture in the ambient air, improving the service life and structural stability of the mounting components, and thus improving the installation life of the alarm device.

[0044] The alarm light 2 is fixedly installed on the top of the controller 1. The alarm light 2 corresponds one-to-one with the sensor 9. There are three sensors 9.

[0045] Sensor 9 consists of a pressure sensor, a temperature sensor, and a vibration sensor, all of which are existing components. It is used to comprehensively monitor coal blockage and issue an alarm. The pressure sensor is a TE Connectivity3051S piezoelectric sensor, the temperature sensor is a Fluke 80PK-22 thermocouple sensor, and the vibration sensor is a Hansford Sensors HS-100 vibration sensor.

[0046] Working principle and usage procedure: When wiring sensor 9, insert the corresponding signal connector 6 along the signal interface 3 on the back of controller 1 to complete the electrical connection. Rotate the adjusting ring 13 on the end face of signal connector 6 so that the adjusting ring 13 spirals in and compresses the internal air, causing the air to be forced into the elastic airbag 11 through the through hole 12. This causes the elastic airbag 11 to inflate and completely seal the end of the signal interface 3. Rotate the threaded rod 171 in the operating assembly 17 downward so that the threaded rod 171 spirals down along the threaded hole 15. As the threaded rod 171 spirals down, it drives the fixed sleeve 173 to move downward, causing the movable plug 163 in the suction assembly 16 to move downward inside the suction cylinder 161. As the movable plug 163 moves downward, it draws air from the signal interface 3 through the middle hole 5. The air creates a negative pressure in the signal interface 3, resulting in a pressure difference between the inner and outer end faces of the signal connector 6. Under this negative pressure, the signal connector 6, together with the sealing frame 7, is adsorbed and fixed at the end face of the signal interface 3. During installation, after the controller 1 is placed in the installation position and the threaded connection of the mounting bolt 192 is completed, and after the above-mentioned negative pressure adsorption and fixation is completed, when the movable plug 163 inside the suction cylinder 161 moves down, the air in the lower space of the movable plug 163 is simultaneously squeezed into the connecting component 18 through the suction pipe 182, and the squeezed gas is squeezed into the sealing component 20 through the outlet pipe 183. As the gas in the sleeve 202 is continuously filled, the internal air pressure increases, and the air pressure pushes the movable rod 204 to move laterally, so that the sealing cover 203 is sleeved on the outside of the mounting bolt 192 and completes the seal.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A coal blockage alarm device for a medium-speed coal mill, comprising a controller (1), an alarm light (2), and a sensor (9), characterized in that: The controller (1) has a signal interface (3) and an assembly cavity (4) on its back side. The controller (1) has a central hole (5) inside its back side. The two ends of the central hole (5) are connected to the signal interface (3) and the assembly cavity (4) respectively. The signal interface (3) has a signal connector (6) movably sleeved inside. The signal connector (6) is electrically connected to the sensor (9) by a cable (8). The outer surface of the signal connector (6) is fitted with an elastic airbag (11). The end face of the signal connector (6) is threaded with an adjusting ring (13). The assembly cavity (4) has a suction assembly (16) inside. The suction assembly (16) includes a suction cylinder (161), a connecting plate (162), and a movable plug (163). The assembly consists of a pull rod (164) and a first spring (165). The suction cylinder (161) is fixedly connected to the top surface of the inner surface of the assembly cavity (4) and communicates with the intermediate hole (5). The pull rod (164) is fixedly connected to the top surface of the connecting plate (162). The movable plug (163) is fixedly connected to the top end of the pull rod (164) and sleeved inside the suction cylinder (161). The upper end of the first spring (165) is fixedly connected to the bottom surface of the movable plug (163), and the lower end of the first spring (165) is fixedly connected to the top surface of the connecting plate (162). The bottom surface of the suction assembly (16) is provided with an operating component (17). The operating component (17) includes a threaded rod (171), a rotating plate (172), and a fixed sleeve (173). 3) and stepped cavity (174), the fixed sleeve (173) is fixedly connected to the bottom surface of the connecting plate (162), the stepped cavity (174) is opened at the bottom of the fixed sleeve (173), the rotating plate (172) is rotatably sleeved inside the stepped cavity (174), the bottom surface of the rotating plate (172) is fixedly connected to the threaded rod (171), the back of the controller (1) is provided with a threaded hole (15), the threaded rod (171) is threadedly sleeved in the threaded hole (15), the front of the back of the controller (1) is provided with a connecting component (18), the connecting component (18) includes a connecting frame (181), a suction pipe (182) and an outlet pipe (183), the side of the controller (1) is fixedly installed with an installation assembly. The mounting assembly (19) includes a mounting bracket (191) and mounting bolts (192). The mounting bracket (191) is fixedly connected to the side of the controller (1), and the mounting bolts (192) are sleeved on the end face of the mounting bracket (191). The side of the mounting assembly (19) is provided with a sealing assembly (20). The sealing assembly (20) includes a horizontal plate (201), a sleeve (202), a sealing cover (203), a movable rod (204), and a second spring (205). The horizontal plate (201) is fixedly connected to the side of the mounting bracket (191), the sleeve (202) is fixedly connected to the side of the horizontal plate (201), and the sealing cover (203) is sleeved on the outside of the mounting bolts (192).One end of the movable rod (204) is fixedly connected to the sealing cover (203), and the other end of the movable rod (204) is fixedly connected to the second spring (205). One end of the movable rod (204) is sleeved inside the sleeve (202), and the second spring (205) is located inside the sleeve (202). The other end of the second spring (205) is fixed inside the sleeve (202). The two ends of the connecting component (18) are respectively connected to the suction component (16) and the sealing component (20).

2. The coal blockage alarm device for a medium-speed coal mill according to claim 1, characterized in that: The outer surface of the signal connector (6) is provided with an installation ring groove (14), the elastic airbag (11) is sleeved in the installation ring groove (14), the outer surface of the signal connector (6) is fixedly sleeved with a sealing frame (7), the end face and the inside of the signal connector (6) are respectively provided with a threaded groove (10) and a through hole (12), the inner surface of the threaded groove (10) is threadedly sleeved with the adjusting ring (13), and the two ends of the through hole (12) are respectively connected to the threaded groove (10) and the elastic airbag (11).

3. The coal blockage alarm device for a medium-speed coal mill according to claim 1, characterized in that: The two ends of the suction tube (182) are fixedly connected to the connecting frame (181) and the suction cylinder (161), respectively.

4. The coal blockage alarm device for a medium-speed coal mill according to claim 1, characterized in that: The two ends of the outlet pipe (183) are fixedly connected to the connecting frame (181) and the sleeve (202), respectively.

5. The coal blockage alarm device for a medium-speed coal mill according to claim 1, characterized in that: The alarm light (2) is fixedly installed on the top of the controller (1), and the alarm light (2) corresponds one-to-one with the sensor (9).

6. The coal blockage alarm device for a medium-speed coal mill according to claim 5, characterized in that: The number of sensors (9) is three.

7. The coal blockage alarm device for a medium-speed coal mill according to claim 1, characterized in that: The sensor (9) includes a pressure sensor, a temperature sensor and a vibration sensor.

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