Coal mill device for power generation of thermal power plant

Abstract

The application discloses a coal mill device for power generation of a thermal power plant, and relates to the field of coal mills, which comprises a coal mill body and a coal falling pipe for feeding coal to the coal mill body, a coal inlet pipe and a coal outlet pipe are installed on the top side of the coal mill body, and an air inlet pipe for conveying hot air is installed on one side of the coal mill body; the preheating and drying device is installed on the coal inlet pipe and the air inlet pipe. It should be noted that, in the embodiment of the application, when coal is fed, the hot air provided by the air inlet pipe makes the coal screen rotate to dry and screen the coal, thereby ensuring the safe use of the coal mill. When a fire breaks out, the switching box, the driving pipe, the rotating preheating hopper and the coal falling pipe and other parts can be actively closed, the carbon dioxide fire extinguisher is communicated with the switching air tank, automatic fire extinguishing is realized, the purpose of stopping the supply of hot air and coal to the coal mill is achieved, the fire extinguishing effect of the fire extinguisher is ensured, and the safety hazard is eliminated.

Description

Technical Field

[0001] This invention relates to the field of coal mill technology, and more particularly to a coal mill device for power generation in thermal power plants. Background Technology

[0002] Medium-speed coal mills are suitable for pulverizing medium-hardness materials such as bituminous coal and lean coal. They are widely used in pulverizing systems in industries such as power, metallurgy, building materials, and chemicals, especially in blast furnace pulverizing systems that require large quantities of bituminous coal. The motor drives the grinding disc to rotate via a reducer. Material falls from the feed inlet into the center of the grinding disc through the airlock feeder, while hot air enters the mill from the air inlet. As the grinding disc rotates, the material moves towards the edge under centrifugal force. Passing through the annular groove on the grinding disc, it is crushed by the grinding rollers. The crushed material is then carried up by the high-speed airflow of the air ring at the edge of the grinding disc. Large particles fall directly back onto the grinding disc for re-grinding. As the material in the airflow passes through the upper separator, the coarse powder falls from the conical hopper back onto the grinding disc for re-grinding under the action of the rotating rotor. Qualified fine powder exits the mill with the airflow and is collected by a dust collection device, becoming the final product.

[0003] However, during the actual operation of the coal mill, due to the uneven quality of the coal, large-sized coal lumps are mixed in. Furthermore, since the coal is not dried before grinding, and given its inherent structural characteristics, coal is highly absorbent, these large-diameter or damp coal lumps, when continuously entering the coal mill, can easily cause blockages, excessive wear, or even damage, resulting in poor output and severely impacting the normal power generation of the thermal power plant. In addition, during power generation, various unforeseen circumstances can cause the coal mill outlet temperature to become excessively high, leading to the entry of already ignited or beginning-of-ignition coal lumps into the mill, posing a significant risk of fire or even explosion. Summary of the Invention

[0004] The purpose of this invention is to provide a coal mill for power generation in thermal power plants, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A coal mill for power generation in a thermal power plant includes a coal mill body and a coal drop pipe for feeding coal into the coal mill body. A coal inlet pipe and a coal outlet pipe are installed on the top side of the coal mill body, and an air inlet pipe for conveying hot air is installed on one side of the coal mill body.

[0007] It also includes a preheating and drying device, which is installed on the coal inlet pipe and the air inlet pipe. The preheating and drying device is used to dry and screen the coal entering the coal inlet pipe. The preheating and drying device includes a transfer air box, which is connected to the air inlet pipe. A drive pipe is rotatably installed on the transfer air box. A rotating preheating hopper is rotatably installed on the top side of the coal inlet pipe. A coal screening plate is installed inside the rotating preheating hopper. A transfer pipe is rotatably installed on the coal screening plate. The drive pipe is rotatably installed on the transfer pipe. The drive pipe delivers hot air from the air inlet pipe to the coal screening plate through the transfer pipe. The coal screening plate is multi-holeed, and multiple air outlets are provided in the holes. Hot air is blown out through the multiple air outlets to dry the coal. An installation bracket is installed on the transfer pipe.

[0008] It also includes an active fire extinguishing device, which is installed on the coal outlet pipe and is used to extinguish fires in the coal outlet pipe. The active fire extinguishing device includes a transfer box, a mounting bracket installed on the top side of the transfer box, and a carbon dioxide fire extinguisher installed on the bottom side of the transfer box. The carbon dioxide fire extinguisher is used to extinguish fires in the coal outlet pipe. An automatic sealing frame is rotatably installed inside the transfer box. The automatic sealing frame is used to automatically close the transfer box and drive the carbon dioxide fire extinguisher to open and extinguish fires in the coal outlet pipe.

[0009] It also includes an automatic sealing device, which is connected to the active fire extinguishing device. The automatic sealing device is used to seal the rotating preheating hopper. The automatic sealing device includes two sealing covers, which rotate to close, thus sealing the coal drop pipe and the rotating preheating hopper.

[0010] Furthermore, in a preferred embodiment of the present invention, the preheating and drying device further includes two pulleys, which are respectively sleeved on the rotating preheating bucket and the drive tube, and a transmission belt is sleeved on the two pulleys;

[0011] The drive tube rotates, which in turn drives the rotating preheating bucket to rotate via the transmission belt. This is used to uniformly receive coal and to dry and screen the coal.

[0012] Furthermore, in a preferred embodiment of the present invention, a plurality of blowing blades are installed equidistantly in a ring on the drive tube, and all of the plurality of blowing blades are located inside the transfer box.

[0013] Furthermore, in a preferred embodiment of the present invention, the active fire extinguishing device further includes a lifting frame, which is movably installed in the transfer box, and the automatic sealing frame rotates to push the lifting frame to move;

[0014] The carbon dioxide fire extinguisher is equipped with a squeeze handle, and the lifting frame is equipped with a push frame. The movement of the lifting frame causes the push frame to squeeze the squeeze handle, thereby driving the carbon dioxide fire extinguisher to extinguish the fire.

[0015] Furthermore, in a preferred embodiment of the present invention, a support shaft is installed inside the transfer box, and a sealing seat for sealing the air inlet pipe is sleeved on the support shaft;

[0016] A drive groove is provided on one side of the sealing seat, and a sliding shaft is rotatably mounted on the lifting frame. The sliding shaft is slidably installed in the drive groove. The movement of the lifting frame drives the sealing seat to rotate and seal the air inlet pipe through the sliding shaft.

[0017] Furthermore, in a preferred embodiment of the present invention, a sealing seat is installed on the lifting frame, and the lifting frame moves upward to close the drive tube through the sealing seat.

[0018] Furthermore, in a preferred embodiment of the present invention, the automatic sealing frame is provided with a return groove, and an installation shaft is rotatably installed in the return groove. The two ends of the installation shaft are respectively installed on the inner walls of the two sides of the adapter box.

[0019] A return torsion spring is installed on the inner wall of the return groove, and the other end of the return torsion spring is installed on the mounting shaft. The return torsion spring is used to drive the automatic sealing frame to reset.

[0020] The adapter box is equipped with a locking frame, which is inserted into the automatic sealing frame.

[0021] Furthermore, in a preferred embodiment of the present invention, the automatic sealing device further includes a mounting base, which is mounted on the mounting bracket;

[0022] Both of the two closed covers are equipped with rotating rods, and both rotating rods are rotatably mounted on the top side of the mounting base.

[0023] Furthermore, in a preferred embodiment of the present invention, both of the rotating rods are provided with torsion grooves, and two torsion shafts are installed on the top side of the mounting base, with the two torsion shafts rotatably installed in the two torsion grooves respectively;

[0024] A torsion spring is mounted on the torsion shaft, and the other end of the torsion spring is mounted on the inner wall of the torsion groove. The torsion spring is used to drive the rotating rod to reset.

[0025] Furthermore, in a preferred embodiment of the present invention, a pressing pusher is installed on the lifting frame, and two wedge-shaped pressing plates are installed on the top side of the pressing pusher. One side of each of the two rotating rods is arc-shaped. When the lifting frame moves upward, it drives the two pressing plates to press the two rotating rods, and drives the two closing cover plates to close the rotating preheating hopper and the coal drop pipe.

[0026] Each of the two closed cover plates has an adapter groove on one side that is close to each other, and the two closed cover plates are fitted onto the adapter pipe through the two adapter grooves.

[0027] The beneficial effects of the coal mill equipment for power generation in thermal power plants proposed in this invention are:

[0028] In this invention, by setting up a preheating and drying device, hot air provided by the air inlet pipe can blow and heat the coal through the coal screening plate when the coal is falling, so that the coal can be further dried before entering the coal mill body. Large pieces of coal can be screened by the selection of the coal screening plate, avoiding the problem of coal caking or moisture causing blockage or even damage to the coal mill body.

[0029] Furthermore, in this invention, by setting up an active fire extinguishing device, if a fire occurs at the coal outlet pipe, the transfer box, drive pipe, etc., can be actively sealed, and the carbon dioxide fire extinguisher can be connected to the transfer air box. While achieving automatic fire extinguishing, the supply of hot air to the coal mill can be stopped, ensuring the fire extinguishing effect of the fire extinguisher and thus ensuring the safe use of the coal mill.

[0030] Furthermore, in this invention, by setting up an automatic sealing device, in the event of a fire, the rotating rod rotates to drive two sealing covers to seal the rotating preheating hopper and the coal drop pipe, thereby preventing coal from falling during fire extinguishing, further ensuring the fire extinguishing effect, and effectively preventing the further spread of danger. Attached Figure Description

[0031] Figure 1 A three-dimensional structural schematic diagram of a coal mill equipment for power generation in a thermal power plant, provided in an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram illustrating the structural connection between the transfer air box and the transfer box of a coal mill equipment used for power generation in a thermal power plant, as provided in an embodiment of the present invention.

[0033] Figure 3 A partial structural diagram of the connection between the pulley and the transmission belt of a coal mill used for power generation in a thermal power plant, provided in an embodiment of the present invention;

[0034] Figure 4This is a partial structural diagram of the connection between the rotating preheating bucket and the coal screening plate of a coal mill for power generation in a thermal power plant, provided in an embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram illustrating the connection between a transfer box and a carbon dioxide fire extinguisher in a coal mill used for power generation in a thermal power plant, as provided in an embodiment of the present invention.

[0036] Figure 6 A coal mill device for power generation in a thermal power plant is provided as an embodiment of the present invention. Figure 5 A schematic diagram of the structure of part A;

[0037] Figure 7 This is a schematic diagram of the internal structure of a transfer box for a coal mill used in a thermal power plant, provided by an embodiment of the present invention.

[0038] Figure 8 This is a partial cross-sectional view of the connection between the transfer box and the automatic sealing frame of a coal mill equipment used for power generation in a thermal power plant, as provided in an embodiment of the present invention.

[0039] Figure 9 This is a partial structural diagram of the connection between the closed cover plate and the extrusion pusher of a coal mill equipment used for power generation in a thermal power plant, provided in an embodiment of the present invention.

[0040] Figure 10 This is a partial structural diagram illustrating the connection between the enclosed cover plate and the mounting base of a coal mill used for power generation in a thermal power plant, as provided in an embodiment of the present invention.

[0041] Figure 11 This is a schematic diagram of the connection between the closed cover plate and the rotating rod of a coal mill equipment used for power generation in a thermal power plant, provided in an embodiment of the present invention.

[0042] In the diagram: 1- Coal mill body; 2- Coal inlet pipe; 3- Coal outlet pipe; 4- Air inlet pipe; 5- Coal drop pipe; 6- Preheating and drying device; 601- Transfer air box; 602- Rotary preheating hopper; 603- Coal screen plate; 604- Transfer pipe; 605- Mounting bracket; 606- Drive pipe; 607- Pulley; 608- Drive belt; 609- Blowing blades; 610- Air outlet; 7- Active fire extinguishing device; 701- Transfer box; 702- Carbon dioxide fire extinguisher; 703- Squeezing handle; 704- Automatic sealing Frame; 705-Locking frame; 706-Lifting frame; 707-Push frame; 708-Sealing seat; 709-Drive slide groove; 710-Sliding shaft; 711-Sealing seat; 712-Mounting shaft; 713-Return groove; 714-Return torsion spring; 715-Support shaft; 8-Automatic sealing device; 801-Sealing cover plate; 802-Mounting base; 803-Extrusion push frame; 804-Extrusion plate; 805-Torsion groove; 806-Torsion shaft; 807-Torsion spring; 808-Adaptor groove; 809-Rotating rod. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0044] Please refer to the attached instruction manual. Figure 1-11 The present invention provides a coal mill equipment for power generation in a thermal power plant, which includes a coal mill body 1 and a coal drop pipe 5 for feeding coal to the coal mill body 1. A coal inlet pipe 2 and a coal outlet pipe 3 are installed on the top side of the coal mill body 1, and an air inlet pipe 4 for conveying hot air is installed on one side of the coal mill body 1.

[0045] It also includes a preheating and drying device 6, which is installed on the coal inlet pipe 2 and the air inlet pipe 4. The preheating and drying device 6 is used to dry and screen the coal entering the coal inlet pipe 2. The preheating and drying device 6 includes a transfer air box 601, which is connected to the air inlet pipe 4. A drive pipe 606 is rotatably installed on the transfer air box 601. A rotating preheating bucket 602 is rotatably installed on the top side of the coal inlet pipe 2. A coal screening plate 603 is installed inside the rotating preheating bucket 602. A transfer pipe 604 is rotatably installed on the coal screening plate 603. The drive pipe 606 is rotatably installed on the transfer pipe 604. The drive pipe 606 delivers the hot air from the air inlet pipe 4 to the coal screening plate 603 through the transfer pipe 604. The coal screening plate 603 is multi-hole, and multiple air outlets 610 are provided in the holes. The hot air is blown out through the multiple air outlets 610 to dry the coal. An installation bracket 605 is installed on the transfer pipe 604.

[0046] It should be noted that, in this embodiment of the invention, during coal conveying, the coal first falls onto the coal screen plate 603 through the coal drop pipe 5. Hot air is then blown into the transfer air box 601, and then into the coal mill body 1 through the air inlet pipe 4. This air blows multiple blowing blades 609 to rotate, which in turn drives the drive pipe 606 to rotate. The rotation of the drive pipe 606 drives one pulley 607 to rotate. The pulley 607 rotates through the transmission belt 608, which in turn drives the rotating preheating hopper 602 to rotate. The rotation of the rotating preheating hopper 602 drives the coal screen plate 603 to rotate, ensuring that the coal falling from the coal drop pipe 5 is evenly spread on the coal screen plate. Furthermore, the rotation of the coal screening plate 603 enables active screening of coal, allowing coal to fall into the coal inlet pipe 2 through the rotating preheating hopper 602. The hot air in the transfer air box 601 is transported to the transfer pipe 604 through the drive pipe 606, and then input into the coal screening plate 603 through the transfer pipe 604. It is also blown out through multiple air outlets 610, which can both heat the coal screening plate 603 and blow air onto the coal, so that the coal can be further dried before entering the coal mill body 1, and large pieces of coal can be screened to avoid the problem of blockage or even damage to the coal mill body 1 due to coal caking or moisture.

[0047] Further, please refer to the appendix to the instruction manual. Figure 5-8 The coal mill equipment for power generation in a thermal power plant provided by this embodiment of the invention also includes an active fire extinguishing device 7, which is installed on the coal outlet pipe 3 and is used to extinguish fires in the coal outlet pipe 3. Specifically, the active fire extinguishing device 7 includes a transfer box 701, a mounting bracket 605 installed on the top side of the transfer box 701, and a carbon dioxide fire extinguisher 702 installed on the bottom side of the transfer box 701. The carbon dioxide fire extinguisher 702 is used to extinguish fires in the coal outlet pipe 3. An automatic sealing frame 704 is rotatably installed inside the transfer box 701. The automatic sealing frame 704 is used to automatically close the transfer box 701 and drive the carbon dioxide fire extinguisher 702 to open and extinguish fires in the coal outlet pipe 3. It should be noted that in this embodiment of the invention, when the coal outlet pipe 3 catches fire, the automatic sealing frame 704 automatically resets, seals the transfer box 701, and connects the carbon dioxide fire extinguisher 702 with the transfer air box 601 to actively extinguish the fire, thereby effectively avoiding a greater danger caused by the fire.

[0048] More specifically, in this embodiment of the invention, an automatic sealing device 8 is also included. The automatic sealing device 8 is connected to the active fire extinguishing device 7 and is used to seal the rotating preheating hopper 602. The automatic sealing device 8 includes two sealing covers 801, which rotate to close, sealing the coal drop pipe 5 and the rotating preheating hopper 602. It should be noted that in this embodiment of the invention, in the event of a fire, the two sealing covers 801 seal the rotating preheating hopper 602 and the coal drop pipe 5, thereby preventing coal from falling during fire extinguishing, further ensuring the fire extinguishing effect, and effectively preventing the further spread of danger.

[0049] Further, please refer to the appendix to the instruction manual. Figure 2-5 The coal mill equipment for power generation in a thermal power plant provided by this embodiment of the invention includes a preheating and drying device 6, which further includes two pulleys 607. The two pulleys 607 are respectively sleeved on the rotating preheating bucket 602 and the drive pipe 606. A transmission belt 608 is sleeved on the two pulleys 607. The rotation of the drive pipe 606 drives the rotating preheating bucket 602 to rotate through the transmission belt 608, so as to uniformly receive coal and dry and screen the coal. It should be noted that, in this embodiment of the invention, when hot air is supplied to the coal mill body 1, the drive pipe 606 rotates, which drives a pulley 607 to rotate. The pulley 607 rotates through the transmission belt 608, which in turn drives the rotating preheating hopper 602 to rotate. The rotation of the rotating preheating hopper 602 drives the coal screening plate 603 to rotate, so that the coal falling from the coal drop pipe 5 can be evenly spread on the coal screening plate 603. Furthermore, the rotation of the coal screening plate 603 achieves active screening of the coal, allowing the coal to fall into the coal inlet pipe 2 through the rotating preheating hopper 602.

[0050] Please continue to refer to the instruction manual appendix. Figure 2-5 More specifically, in this embodiment of the invention, a plurality of blowing blades 609 are equidistantly mounted in a ring on the drive pipe 606, and all the blowing blades 609 are located inside the transfer air box 601. It should be noted that, in this embodiment of the invention, when air enters through the air inlet pipe 4, the hot air first blows into the transfer air box 601, and blows the plurality of blowing blades 609 to rotate, thereby blowing the drive pipe 606 to rotate, providing power for the rotating preheating hopper 602.

[0051] Further, please refer to the appendix to the instruction manual. Figure 5-8 The present invention provides a coal mill equipment for power generation in a thermal power plant. The active fire extinguishing device 7 also includes a lifting frame 706, which is movably installed in the transfer box 701. The automatic sealing frame 704 rotates to push the lifting frame 706 to move.

[0052] In addition, a squeeze handle 703 is installed on the carbon dioxide fire extinguisher 702, and a push frame 707 is installed on the lifting frame 706. The movement of the lifting frame 706 causes the push frame 707 to squeeze the squeeze handle 703, thereby driving the carbon dioxide fire extinguisher 702 to extinguish the fire. It should be noted that, in this embodiment of the invention, when a fire breaks out at the coal outlet pipe 3, the lifting frame 706 moves upward, and the push frame 707 squeezes the squeeze handle 703, causing the carbon dioxide fire extinguisher 702 to open and extinguish the fire in the coal outlet pipe 3 and inside the coal mill body 1.

[0053] More specifically, in this embodiment of the invention, a support shaft 715 is installed inside the transfer air box 601, and a sealing seat 708 for sealing the air inlet pipe 4 is sleeved on the support shaft 715; a drive groove 709 is provided on one side of the sealing seat 708, and a sliding shaft 710 is rotatably installed on the lifting frame 706. The sliding shaft 710 is slidably installed in the drive groove 709. The movement of the lifting frame 706 drives the sealing seat 708 to rotate and seal the air inlet pipe 4 through the sliding shaft 710. It should be noted that, in this embodiment of the invention, during the upward movement of the lifting frame 706, the sealing seat 708 is rotated through the sliding shaft 710, so that the sealing seat 708 can seal the transfer air box 601, thereby automatically stopping the supply of hot air to the coal mill body 1.

[0054] More specifically, in this embodiment of the invention, a sealing seat 711 is installed on the lifting frame 706, and the lifting frame 706 moves upward to seal the drive pipe 606 through the sealing seat 711. It should be noted that, in this embodiment of the invention, when the lifting frame 706 moves upward, it drives the sealing seat 711 to seal the drive pipe 606, blocking hot air from blowing towards the coal screening plate 603.

[0055] Please continue to refer to the instruction manual appendix. Figure 5-8 More specifically, in this embodiment of the invention, the automatic sealing frame 704 is provided with a return groove 713, and an installation shaft 712 is rotatably installed in the return groove 713. The two ends of the installation shaft 712 are respectively installed on the inner walls of the two sides of the adapter box 701. A return torsion spring 714 is installed on the inner wall of the return groove 713, and the other end of the return torsion spring 714 is installed on the installation shaft 712. The return torsion spring 714 is used to drive the automatic sealing frame 704 to reset.

[0056] Furthermore, a locking frame 705 is installed inside the adapter box 701, and the locking frame 705 is inserted into the automatic sealing frame 704. It should be noted that, in this embodiment of the invention, in the event of a fire, the locking frame 705 is quickly melted. At this time, under the restoring force of the return torsion spring 714, the automatic sealing frame 704 is reset, thereby achieving the purpose of automatically sealing the adapter box 701.

[0057] Please refer to the instruction manual attached. Figure 9-11More specifically, in this embodiment of the invention, the automatic sealing device 8 further includes a mounting base 802, which is mounted on a mounting bracket 605; each of the two sealing cover plates 801 is equipped with a rotating rod 809, and both rotating rods 809 are rotatably mounted on the top side of the mounting base 802. It should be noted that, in this embodiment of the invention, when the two rotating rods 809 are pressed by the two pressing plates 804, the two rotating rods 809 rotate, causing the two sealing cover plates 801 to seal the rotating preheating hopper 602 and the coal drop pipe 5.

[0058] More specifically, in this embodiment of the invention, each of the two rotating rods 809 has a torsion groove 805, and two torsion shafts 806 are mounted on the top side of the mounting base 802. The two torsion shafts 806 are rotatably mounted in the two torsion grooves 805 respectively. In addition, a torsion spring 807 is mounted on the torsion shaft 806, and the other end of the torsion spring 807 is mounted on the inner wall of the torsion groove 805. The torsion spring 807 is used to drive the rotating rod 809 to reset. It should be noted that in this embodiment of the invention, when the rotating rod 809 is compressed and drives the closing cover 801 to rotate, the rotating rod 809 rotates on the torsion shaft 806 and drives the torsion spring 807 to be stressed. Therefore, when the rotating rod 809 is no longer compressed, the restoring force of the torsion spring 807 helps the closing cover 801 to reset.

[0059] Please continue to refer to the instruction manual appendix. Figure 9-11 More specifically, in this embodiment of the invention, a pressing pusher 803 is installed on the lifting frame 706, and two wedge-shaped pressing plates 804 are installed on the top side of the pressing pusher 803. One side of the two rotating rods 809 is arc-shaped. When the lifting frame 706 moves upward, it drives the two pressing plates 804 to press the two rotating rods 809, and drives the two closing cover plates 801 to close the rotating preheating hopper 602 and the coal drop pipe 5.

[0060] Furthermore, each of the two closed cover plates 801 has an adapter groove 808 on one side close to the other, and the two closed cover plates 801 are fitted onto the transfer pipe 604 through the two adapter grooves 808. It should be noted that, in this embodiment of the invention, when the lifting frame 706 moves upward, the pressing push frame 803 drives the two pressing plates 804 to rotate, so that the two pressing plates 804 press the two rotating rods 809. The two rotating rods 809 rotate on the two torsion shafts 806 respectively, and drive the torsion spring 807 to be stressed. The rotation of the two rotating rods 809 drives the two closed cover plates 801 to close the rotating preheating hopper 602 and the coal drop pipe 5, so as to stop coal from falling during fire extinguishing, further ensuring the fire extinguishing effect, and effectively preventing the further expansion of danger.

[0061] In summary, the working principle of the coal mill equipment for power generation in a thermal power plant provided by the embodiments of the present invention is as follows:

[0062] When the coal mill body 1 is running, coal falls onto the coal screen plate 603 through the coal drop pipe 5. Hot air is blown into the transfer air box 601, and then into the coal mill body 1 through the air inlet pipe 4, causing multiple blowing blades 609 to rotate. This, in turn, causes the drive pipe 606 to rotate. The rotation of the drive pipe 606 drives one pulley 607 to rotate. The pulley 607 rotates through the transmission belt 608, which in turn drives the rotating preheating hopper 602 to rotate. The rotation of the rotating preheating hopper 602 drives the coal screen plate 603 to rotate, so that the coal falling from the coal drop pipe 5 can be evenly spread on the coal screen plate 603. Furthermore, the rotation of the coal screening plate 603 enables active screening of coal, allowing coal to fall into the coal inlet pipe 2 through the rotating preheating hopper 602. The hot air in the transfer air box 601 is transported to the transfer pipe 604 through the drive pipe 606, and then input into the coal screening plate 603 through the transfer pipe 604. It is also blown out through multiple air outlets 610, which can both heat the coal screening plate 603 and blow air onto the coal, so that the coal can be further dried before entering the coal mill body 1, and large pieces of coal are screened to avoid the problem of blockage or even damage to the coal mill body 1 due to coal caking or moisture.

[0063] If a fire occurs at the coal outlet pipe 3 while the coal mill body 1 is running, causing the locking frame 705 to melt quickly, the return force of the return torsion spring 714 helps the automatic sealing frame 704 to reset, sealing the transfer box 701 and connecting the carbon dioxide fire extinguisher 702 to the transfer air box 601. Simultaneously, as the automatic sealing frame 704 rotates, it pushes the lifting frame 706 upwards. The lifting frame 706, through the push frame 707, presses against the pressure handle 703, allowing the carbon dioxide fire extinguisher to... 702 is opened to extinguish the fire in the coal outlet pipe 3 and inside the coal mill body 1. In addition, during the upward movement of the lifting frame 706, the sliding shaft 710 drives the sealing seat 708 to rotate, so that the sealing seat 708 can close the transfer air box 601 and stop supplying hot air to the coal mill body 1. At the same time, when the lifting frame 706 moves upward, it drives the sealing seat 711 to close the drive pipe 606 and stop supplying hot air to the coal screen plate 603, ensuring that the carbon dioxide fire extinguisher 702 can extinguish the fire normally.

[0064] Furthermore, when the lifting frame 706 moves upward, the pressing push frame 803 drives the two pressing plates 804 to rotate, causing the two pressing plates 804 to press the two rotating rods 809. The two rotating rods 809 rotate on the two torsion shafts 806 respectively, and drive the torsion spring 807 to be stressed. The rotation of the two rotating rods 809 drives the two sealing cover plates 801 to seal the rotating preheating hopper 602 and the coal drop pipe 5, so as to stop coal from falling during fire extinguishing, further ensuring the fire extinguishing effect, and effectively preventing the further expansion of danger.

[0065] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A coal mill for power generation in a thermal power plant, characterized in that, It includes a coal mill body and a coal drop pipe for feeding coal to the coal mill body. A coal inlet pipe and a coal outlet pipe are installed on the top side of the coal mill body, and an air inlet pipe for conveying hot air is installed on one side of the coal mill body. It also includes a preheating and drying device, which is installed on the coal inlet pipe and the air inlet pipe. The preheating and drying device is used to dry and screen the coal entering the coal inlet pipe. The preheating and drying device includes a transfer air box connected to the air inlet pipe. A drive pipe is rotatably mounted on the transfer air box. A rotating preheating hopper is rotatably mounted on the top side of the coal inlet pipe. A coal screening plate is installed inside the rotating preheating hopper. A transfer pipe is rotatably mounted on the coal screening plate. The drive pipe is rotatably mounted on the transfer pipe. The drive pipe delivers hot air from the air inlet pipe to the coal screening plate through the transfer pipe. The coal screening plate is multi-holeed, and multiple air outlets are provided in the holes. Hot air is blown out through the multiple air outlets to dry the coal. An installation bracket is installed on the transfer pipe. It also includes an active fire extinguishing device, which is installed on the coal outlet pipe and is used to extinguish fires in the coal outlet pipe. The active fire extinguishing device includes a transfer box, a mounting bracket installed on the top side of the transfer box, and a carbon dioxide fire extinguisher installed on the bottom side of the transfer box. The carbon dioxide fire extinguisher is used to extinguish fires in the coal outlet pipe. An automatic sealing frame is rotatably installed inside the transfer box. The automatic sealing frame is used to automatically close the transfer box and drive the carbon dioxide fire extinguisher to open and extinguish fires in the coal outlet pipe. It also includes an automatic sealing device, which is connected to the active fire extinguishing device. The automatic sealing device is used to seal the rotating preheating hopper. The automatic sealing device includes two sealing covers, which rotate to close, thus sealing the coal drop pipe and the rotating preheating hopper.

2. The coal mill equipment for power generation in a thermal power plant according to claim 1, characterized in that, The preheating and drying device also includes two pulleys, which are respectively sleeved on the rotating preheating bucket and the drive tube, and a transmission belt is sleeved on the two pulleys; The drive tube rotates, which in turn drives the rotating preheating bucket to rotate via the transmission belt. This is used to uniformly receive coal and to dry and screen the coal.

3. The coal mill equipment for power generation in a thermal power plant according to claim 1, characterized in that, Multiple blowing blades are installed in a ring at equal intervals on the drive tube, and all of the blowing blades are located inside the transfer box.

4. The coal mill equipment for power generation in a thermal power plant according to claim 1, characterized in that, The active fire extinguishing device also includes a lifting frame, which is movably installed in the transfer box, and the automatic sealing frame rotates to push the lifting frame to move; The carbon dioxide fire extinguisher is equipped with a squeeze handle, and the lifting frame is equipped with a push frame. The movement of the lifting frame causes the push frame to squeeze the squeeze handle, thereby driving the carbon dioxide fire extinguisher to extinguish the fire.

5. A coal mill for power generation in a thermal power plant according to claim 4, characterized in that, The transfer box is equipped with a support shaft, and a sealing seat for sealing the air inlet pipe is sleeved on the support shaft. A drive groove is provided on one side of the sealing seat, and a sliding shaft is rotatably mounted on the lifting frame. The sliding shaft is slidably installed in the drive groove. The movement of the lifting frame drives the sealing seat to rotate and seal the air inlet pipe through the sliding shaft.

6. A coal mill for power generation in a thermal power plant according to claim 5, characterized in that, A sealing seat is installed on the lifting frame, and the lifting frame moves upward to seal the drive tube through the sealing seat.

7. A coal mill for power generation in a thermal power plant according to claim 6, characterized in that, The automatic sealing frame is provided with a return groove, and an installation shaft is rotatably installed in the return groove. The two ends of the installation shaft are respectively installed on the inner walls of the two sides of the adapter box. A return torsion spring is installed on the inner wall of the return groove, and the other end of the return torsion spring is installed on the mounting shaft. The return torsion spring is used to drive the automatic sealing frame to reset. The adapter box is equipped with a locking frame, which is inserted into the automatic sealing frame.

8. A coal mill for power generation in a thermal power plant according to claim 7, characterized in that, The automatic sealing device also includes a mounting base, which is mounted on the mounting bracket; Both of the two closed covers are equipped with rotating rods, and both rotating rods are rotatably mounted on the top side of the mounting base.

9. A coal mill for power generation in a thermal power plant according to claim 8, characterized in that, Both of the rotating rods are provided with torsion grooves, and two torsion shafts are installed on the top side of the mounting base. The two torsion shafts are rotatably installed in the two torsion grooves respectively. A torsion spring is mounted on the torsion shaft, and the other end of the torsion spring is mounted on the inner wall of the torsion groove. The torsion spring is used to drive the rotating rod to reset.

10. A coal mill for power generation in a thermal power plant according to claim 9, characterized in that, The lifting frame is equipped with a pressing pusher, and two wedge-shaped pressing plates are installed on the top side of the pressing pusher. One side of each of the two rotating rods is arc-shaped. When the lifting frame moves upward, it drives the two pressing plates to press the two rotating rods, and drives the two closing cover plates to close the rotating preheating hopper and the coal drop pipe. Each of the two closed cover plates has an adapter groove on one side that is close to each other, and the two closed cover plates are fitted onto the adapter pipe through the two adapter grooves.

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