Pulverized coal discharging device and coal mill

Abstract

The invention relates to the technical field of coal mills, in particular to a pulverized coal discharging device and a coal mill. The pulverized coal discharging device is used for discharging pulverized coal at a rotating part of a swing arm of the coal mill and comprises an air pipe, an air blowing unit and a pulverized coal collecting pipe, the air pipe is communicated with the shell of the rotating part; the air blowing unit is arranged on the air pipe, and the air blowing unit is configured to be capable of blowing air to the rotating part so that pulverized coal can be far away from the rotating part; the pulverized coal collecting pipe is arranged below the shell and is communicated with the lower part of the shell or is communicated with the lower part of the shell through the air pipe; according to the pulverized coal discharging device, coal accumulation at the swing arm of the coal mill can be reduced or avoided, and then the problem of coal leakage of the coal mill is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of coal mills, and in particular to a coal powder discharging device and a coal mill. Background Art

[0002] The raw coal of coal gasification is transported to the coal mill and ground into powder inside the coal mill; the hydraulic system applies extrusion force to the grinding roller and grinding disc through the swing arm of the coal mill to crush the coal blocks. During normal operation, the swing arm of the coal mill will move slightly around its axis; the swing arm of the coal mill has a shell to protect the swing arm and prevent coal leakage. If coal powder accumulates inside the shell at the swing arm, the coal powder will be squeezed under the movement of the swing arm; when the coal powder is compressed to a certain extent, this extrusion force will be transmitted to the shell at the swing arm of the coal mill, which may cause the flange bolts of the shell to break and cause coal leakage from the shell. Summary of the invention

[0003] In view of the above shortcomings of the prior art, an object of the present invention is to provide a coal powder discharging device and a coal mill which can reduce or avoid coal accumulation at the swing arm of the coal mill, and can reduce or avoid the occurrence of coal leakage problems.

[0004] In order to achieve the above-mentioned purpose and other related purposes, the present invention provides a pulverized coal discharge device, which is used for discharging pulverized coal at the rotating part of the swing arm of a coal mill. The pulverized coal discharge device comprises:

[0005] An air duct is connected to the housing of the rotating part;

[0006] an air blowing unit, disposed in the air duct, and configured to blow air toward the rotating part to keep the coal powder away from the rotating part;

[0007] The coal powder collecting pipe is arranged below the shell and is communicated with the lower part of the shell or is communicated with the lower part of the shell through the air duct.

[0008] In one embodiment of the present invention, a first gas inlet end is provided on the air duct, and the first gas is at least a gas that does not react with coal powder at room temperature.

[0009] In one embodiment of the present invention, the coal powder collecting pipe comprises

[0010] The tube body comprises a first end and a second end, wherein the first end is connected to the air duct or the lower part of the shell, and the second end is connected to the outside;

[0011] a first valve, disposed on the tube body and at a preset distance from the first end;

[0012] The second valve is disposed on the tube body and close to the second end.

[0013] In one embodiment of the present invention, a window is provided on the tube body at least between the first valve and the second valve.

[0014] In an embodiment of the present invention, the length of the coal powder collection pipe is greater than a preset length.

[0015] In one embodiment of the present invention, the air duct includes a first pipeline, and one end of the first pipeline connected to the shell is located on a side of the rotating portion away from the grinding disc of the coal mill.

[0016] In an embodiment of the present invention, the air duct includes a second pipeline, and one end of the second pipeline connected to the shell is located at the lower end of the shell.

[0017] In one embodiment of the present invention, the upper end of the coal powder collecting pipe is connected to the lower part of the second pipeline.

[0018] In one embodiment of the present invention, the direction of the second pipeline toward the shell is tangent to the rotating part and is inclined toward the grinding disc or grinding roller side of the coal mill, and the extension direction of the shell is consistent with the direction of the second pipeline.

[0019] To achieve the above-mentioned object and other related objects, the present invention provides a coal mill, comprising the coal powder discharge device according to any one of claims 1 to 9, as well as a frame, a grinding disc, a grinding roller, a swing arm and a casing;

[0020] The grinding roller cooperates with the grinding disc to grind coal; one end of the swing arm is connected to the grinding roller, and the other end is rotatably connected to the frame, and the swing arm is configured to drive the angle and gap of the grinding roller relative to the grinding disc;

[0021] The casing comprises a cavity, the grinding disc, the grinding roller and the swing arm are all accommodated in the cavity, and the shell is a part of the casing.

[0022] In summary, the present invention is used for discharging coal powder at the rotating part of the swing arm of the coal mill through the setting of the coal powder discharging device, so as to reduce the problem of coal leakage from the casing caused by the accumulation of coal powder. The present invention is connected to the casing of the rotating part of the swing arm through the air duct, and through the cooperation of the blower unit, the wind force of the air duct can cover the rotating part of the swing arm and its surrounding area, thereby reducing the accumulation of coal powder at the rotating part and its casing; because the air duct can only blow away fine coal powder, it is impossible to blow away all coal powder particles, therefore, by setting a coal powder collection pipe below the casing, the coal powder collection pipe is connected to the lower part of the casing or is connected to the lower part of the casing through the air duct, the coal powder particles that cannot be blown away by the air duct at the rotating part of the casing can be released and collected, thereby avoiding the problem of coal powder particles gathering at the casing causing damage to the casing and causing coal powder leakage, and ensuring the normal use of the coal mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 It is a schematic diagram of the structure of the connection between the pulverized coal discharge device and the coal mill in an optional embodiment of the present invention, wherein the direction of arrow A is the direction of airflow, and the direction of arrow B is the direction of falling pulverized coal particles;

[0025] Figure 2 It is a structural schematic diagram of a further improved pulverized coal discharge device connected to a coal mill in an optional embodiment of the present invention;

[0026] Explanation of component numbers: air duct 10, first gas inlet end 101, blowing unit 11, first pipeline 12, second pipeline 13, coal powder collecting pipe 20, pipe body 21, first end 211, first valve 22, second valve 23, valve guide 24, window 25, casing 30, shell 31, swing arm 40, rotating part 41, grinding disc 50, grinding roller 60. DETAILED DESCRIPTION

[0027] The following is an explanation of the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the features in the following embodiments and the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific embodiments, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or according to the conditions recommended by the manufacturers.

[0028] See also Figure 1 to Figure 2. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical content disclosed by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be regarded as the scope of the implementation of the present invention without substantially changing the technical content.

[0029] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any methods, equipment and materials of the prior art similar or equivalent to the methods, equipment and materials described in the embodiments of the present invention can also be used to implement the present invention.

[0030] See also Figure 1-2 The present invention provides a pulverized coal discharge device for discharging pulverized coal at a rotating portion 41 of a coal mill swing arm 40, wherein the pulverized coal discharge device comprises an air duct 10, an air blast unit 11 and a pulverized coal collection pipe 20;

[0031] The air duct 10 is connected to the shell 31 of the rotating part 41; the blowing unit 11 is arranged on the air duct 10, and the blowing unit 11 is configured to blow air toward the rotating part 41 to keep the coal powder away from the rotating part 41; the coal powder collecting pipe 20 is arranged below the shell 31, and is connected to the lower part of the shell 31 or is connected to the lower part of the shell 31 through the air duct 10.

[0032] It should be noted that the air duct 10 is generally made of wear-resistant and high-temperature resistant materials to ensure durability in the working environment of the coal mill. The layout of the air duct 10 is based on the space limitations inside the coal mill and the characteristics of the coal powder flow to ensure that the air duct 10 can effectively cover the rotating part 41 of the swing arm 40 and blow away the coal powder; the blower unit 11 generally selects a high-efficiency blower or a self-sealing fan to provide sufficient wind force to blow away the coal powder; the blower unit 11 may include one or more fans and corresponding motor drive devices to ensure stable and controllable wind flow; the control of the blower unit 11 can be achieved through automation, for example, by automatically adjusting the wind force according to the working state of the coal mill and the coal powder concentration inside the shell 31, so as to achieve energy saving; if considering setting a wind speed sensor and a coal powder concentration sensor to monitor and adjust the blower unit 11 in real time, Working state; the upper part of the coal powder collecting pipe 20 or the shell 31 connected to the coal powder collecting pipe 20 or the air duct 10 connected to the coal powder collecting pipe 20 should have a sufficient inclination so that the coal powder can slide smoothly to the collection point by gravity; the material of the coal powder collecting pipe 20 should also be selected from wear-resistant and corrosion-resistant materials to adapt to the harsh environment inside the coal mill; it should be understood that the entire coal powder discharging device should be integrated with the control system of the coal mill to achieve linkage control. Specifically, when the coal mill starts working, the coal powder discharging device should start automatically; when the coal mill stops, the device should also stop working accordingly. An emergency stop button or switch can be set to quickly cut off the power supply of the device when necessary; and the coal powder collecting pipe 20 also needs regular maintenance and cleaning to avoid the problem that the coal powder collecting pipe 20 is filled with coal powder and continues to affect and damage the casing 30 and cause coal leakage.

[0033] In this case, the pulverized coal discharge device is provided to discharge pulverized coal at the rotating part 41 of the swing arm 40 of the coal mill, so as to reduce the coal leakage problem of the casing 30 caused by the accumulation of pulverized coal. Specifically, the air duct 10 is connected with the casing 31 of the rotating part 41 of the swing arm 40, and the wind force of the air duct 10 can cover the rotating part 41 of the swing arm 40 and the surrounding area through the cooperation of the blast unit 11, thereby reducing the accumulation of pulverized coal at the rotating part 41 and its casing 31; because the air duct 10 can only It is impossible to blow away all the coal powder particles by blowing away the fine coal powder. Therefore, by arranging a coal powder collecting pipe 20 under the shell 31, the coal powder collecting pipe 20 is connected to the lower part of the shell 31 or is connected to the lower part of the shell 31 through the air duct 10. The coal powder particles at the shell 31 of the rotating part 41 that cannot be blown away by the air duct 10 can be released and collected, thereby avoiding the problem of coal powder particles gathering at the shell 31 causing damage to the shell 31 and causing coal powder leakage, thereby ensuring the normal use of the coal mill.

[0034] As an optional embodiment of the present case, the end of the air duct 10 away from the rotating part 41 is a first gas inlet end 101, and the first gas is at least a gas that does not react with coal powder at room temperature, such as nitrogen, carbon dioxide, inert gas, etc., which hardly react with any substance under room temperature conditions, including coal powder; thereby ensuring that when the coal powder at the rotating part 41 of the coal mill swing arm 40 is cleaned by airflow, gas components that may cause chemical reactions or safety problems will not be introduced, and there is no need to worry about equipment damage or safety hazards caused by the interaction between the gas and the coal powder.

[0035] In this case, since a gas that does not react with coal powder at room temperature, such as nitrogen, is used to blow air through the air duct 10, a small amount of coal powder and coal blocks still fall into the shell 31 during operation; in order to avoid coal accumulation in the shell 31, a coal powder collection pipe 20 is designed at the low point of the gas blown into the air duct 10 entering the shell 31, and the coal powder in the shell 31 is regularly collected and discharged; because the gas medium blown out of the air duct 10 is at least mostly nitrogen and has a certain pressure, if the coal powder in the coal powder collection pipe 20 is discharged during the operation of the coal mill, it is easy to cause nitrogen asphyxiation accidents to the surrounding personnel and coal powder to be blown into the atmosphere to cause environmental pollution accidents. Therefore, the coal mill needs to be shut down before the coal powder in the coal powder collection pipe 20 can be discharged. The coal mill generally runs for a few days, and the coal powder collection pipe 20 will be full of coal powder, which needs to be shut down for post-processing, which seriously affects the long-term stable operation of the coal mill. In view of the above-mentioned problems, in this case, the coal powder collection pipe 20 is further improved.

[0036] In this case, in order to solve the problem that the coal pulverizer must be shut down and the coal pulverizing cycle is affected when the coal powder in the shell 31, the second pipeline 13 and the coal powder collecting pipe 20 is discharged, the coal powder collecting pipe 20 is extended from the original 400mm to 2000mm to increase the coal powder collection amount; a first valve 22 is added to the upper part of the coal powder collecting pipe 20, a second valve 23 is added to the bottom, a valve guide 24 is set at the lower part of the first valve 22, and a window 25 is set at the lower part of the guide valve, which is made of resin glass; during normal operation, , the first valve 22 is opened and the second valve 23 is closed, and the coal powder threaded into the rotating part 41 is collected in the coal powder collection pipe 20 and located on the upper part of the second valve 23. When the coal mill has been running for a preset number of days or it is observed from the window 25 that the coal powder is full, the first valve 22 is closed, and then the valve guide 24 is opened to release the pressure. After the pressure release is completed, the second valve 23 is opened to discharge the collected coal powder into a cart for unified treatment; after the discharge is completed, the second valve 23 and the valve guide 24 are closed, and the first valve 22 is opened to continue collecting the coal powder.

[0037] As an optional embodiment of the present case, the pulverized coal collection pipe 20 includes a pipe body 21, a first valve 22, a first valve 22, a second valve 23, a valve guide 24 or a pressure relief valve;

[0038] The tube body 21 includes a first end 211 and a second end, the first end 211 is connected to the air duct 10 or the lower part of the shell 31, and the second end is connected to the outside; the first valve 22 is arranged on the tube body 21 and has a preset distance from the first end 211; the second valve 23 is arranged on the tube body 21 and is close to the second end; a valve guide 24 or a pressure relief valve is arranged on the tube body 21 between the first valve 22 and the second valve 23.

[0039] It should be noted that the tube body 21 includes a first end 211 and a second end, the first end 211 is connected to the air duct 10 or the lower part of the shell 31 to ensure that the coal powder that cannot be blown off can be effectively collected; the second end is connected to the outside world and is used to discharge the collected coal powder to a safe area; the first valve 22 is arranged on the tube body 21 and has a preset distance from the first end 211. The preset distance needs to ensure that the coal powder can be stored in a short time, so that there is enough time to clean the coal powder in the coal powder collection pipe 20; the first valve 22 remains closed when the coal mill is operating normally to prevent the coal powder from being directly discharged after entering the coal powder collection pipe 20, causing environmental pollution. The second valve 23 is arranged on the pipe body 21 and is close to the second end. This valve is mainly used to control the timing of coal powder discharge and the exhaust volume to ensure that the discharge operation is performed only under appropriate conditions, and to close the first valve 22 when discharging coal powder to prevent overflow from the shell 31 from blowing coal powder into the surrounding environment and affecting the safety of surrounding personnel; the valve drain 24 refers to the process in which a drain device is arranged before and after the valve in an industrial pipeline system to flush and clean the inside of the valve with a fluid, usually water, steam or gas. This process is mainly used to remove impurities, sediments or residual media inside the valve to ensure the normal operation of the valve and extend its service life. At the same time, it can also relieve pressure on the pipeline. In this case, the valve drain 24 can be used to clean the first valve 22 and / or the second valve 23 and the coal powder collection pipe 20 to avoid blockage, and it can also be used for pressure relief; the pressure relief valve is arranged on the pipe body 21 and is located at the first valve 22. Between the first valve 22 and the second valve 23, the main function of the pressure relief valve is to automatically open when the internal pressure of the system is too high, releasing part of the gas to reduce the pressure, and preventing equipment damage or safety accidents caused by excessive pressure; at the same time, when the first valve 22 is closed and the second valve 23 is opened to prepare for discharging coal powder, due to the insufficient air pressure in the pipe body 21 above the second valve 23, the coal powder in the pipe body 21 may not be easy to fall under the action of gravity. Therefore, by opening the pressure relief valve, the coal powder in the pipe body 21 can be smoothly dropped and collected, thereby improving the convenience of use; through these improvement measures, the coal powder collection pipe 20 can not only effectively collect and discharge coal powder, but also ensure the safe operation of the entire system, and can clean up the coal powder without stopping the machine. Moreover, by reasonably controlling the opening and closing sequence of the valves, the risk of nitrogen leakage can be reduced, and at the same time, the coal powder can be avoided from being directly blown into the atmosphere to cause environmental pollution, thereby improving the safety and environmental protection performance of the coal mill, and helping to achieve its long-term stable operation.

[0040] As an optional embodiment of the present case, a window 25 is provided on the pipe body 21 between at least the first valve 22 and the second valve 23 for observing the situation inside the coal powder collection pipe 20. The design of this window 25 enables the operator to monitor the collection status of the coal powder in real time and determine whether discharge treatment is required. Through the window 25, the height and density of the coal powder and whether there are any abnormal substances mixed in can be clearly seen, so that timely decisions can be made.

[0041] As an optional embodiment of the present case, the length of the coal powder collection pipe 20 is greater than the preset length; because a longer pipe can ensure that the coal powder has enough space to settle and flow during the transportation process, thereby reducing the risk of blockage. Secondly, by increasing the length of the pipe, gravity can be used to more effectively guide the coal powder to move to the collection end, thereby improving the collection efficiency. In addition, a longer pipe can also provide a larger surface area, which is conducive to the separation of gas and coal powder, and further improves the emission effect. It should be understood that in actual applications, this preset length is determined based on the working environment of the pulverizer, the properties of the coal powder and the required collection efficiency. Through precise calculation and optimized design, it can be ensured that the coal powder collection pipe 20 not only meets the functional requirements, but also adapts to the specific conditions on site; for example, the coal powder collection pipe 20 with an original preset length X of only 400 mm is improved to a length Y. For example, the length Y can be set to a range of 1000 mm-2000 mm, thereby increasing the amount of coal powder and extending the coal powder cleaning cycle.

[0042] like Figure 1 As shown, as an optional embodiment of the present case, the air duct 10 includes a first pipeline 12, and one end of the first pipeline 12 connected to the shell 31 is located on the side of the rotating part 41 away from the grinding disc 50 of the coal mill; the air duct 10 includes a second pipeline 13, and one end of the second pipeline 13 connected to the shell 31 is located at the lower end of the shell 31.

[0043] It should be noted that sealing gas and purge gas are added to the rotating part 41 and the shell 31 of the coal mill. In this case, the first pipeline 12 blows out sealing gas, and the second pipeline 13 blows out purge gas. At least the sealing gas is nitrogen with a pressure of 9kPa to 15kPa and a flow rate of 0.32kg / s to 0.8kg / s, which is continuously transported to the rotating shaft of the swing arm 40 for sealing, thereby reducing the wear of the seal of the swing arm 40 by the pulverized coal. The purge gas of the shell 31 is nitrogen with a pressure of 9kPa to 25kPa and a flow rate of 2.6kg / s to 4.0kg / s, thereby preventing coal powder or small coal blocks from falling into the shell 31. In addition, through the reasonable control of the gas pressure and flow rate, it is possible to avoid the purpose of blowing away the coal powder being too small and the waste of resources being too large. Specifically, the first pipeline 12 helps to more effectively utilize the airflow to blow the coal powder away from the rotating part 41 to prevent the coal powder from accumulating in the key operating area. Secondly, by introducing gas from the side away from the grinding disc 50, the direct interference with the coal grinding process can be reduced to ensure the coal grinding efficiency. The connection point of the second pipeline 13 is located at the lower end of the shell 31 in order to directly clean the coal powder that may be deposited at the bottom of the shell 31. Due to the effect of gravity, the coal powder tends to gather at the lowest point. Therefore, the introduction of airflow from below can directly impact these deposits, promote their movement and discharge, help keep the inside of the shell 31 clean, and reduce the safety hazards caused by coal powder accumulation.

[0044] As an optional embodiment of the present case, the upper end of the coal powder collecting pipe 20 is connected to the lower part of the second pipeline 13, thereby optimizing the coal powder collection and discharge process; even if the coal powder of the blowing pipe 10 is cleaned, a small amount of coal powder and coal blocks still fall on the shell 31 and enter the second pipeline 13 along the shell 31. Therefore, in order to avoid coal accumulation in the shell 31 and the second pipeline 13, the present case connects the upper end of the coal powder collecting pipe 20 with the lower part of the second pipeline 13, so that the coal powder collecting pipe 20 and the second pipeline 13 can share the structure. The second pipeline 13 provides guidance for the coal powder collection pipe 20 to collect coal powder, thereby saving the material usage of the coal powder collection pipe 20 and improving the structural compactness of the system.

[0045] As an optional embodiment of the present case, the direction of the second pipeline 13 toward the shell 31 is tangent to the rotating part 41 and is inclined toward the grinding disc 50 or grinding roller 60 of the coal mill, and the extension direction of the shell 31 is consistent with the direction of the second pipeline 13.

[0046] It should be noted that the design of the second pipeline 13 being tangent to the rotating part 41 helps to reduce the direct impact of the airflow on the rotating part 41, and can ensure that the airflow is smoother when entering the shell 31; the shell 31 is also inclined along the tangential direction at the rotating part 41, which is more conducive to the second pipeline 13 to clean the coal powder in the shell 31, improve the cleaning effect, and reduce the risk of blockage.

[0047] As an optional embodiment of the present case, the diameter of the main pipe of the air duct 10 can be selected within the size range of 150㎜-250㎜, for example, 200㎜ in diameter; the diameter of the first pipeline 12 can be selected within the size range of 30-60㎜, for example, 40㎜ in diameter; the diameter of the second pipeline 13 can be selected within the size range of 50㎜-70㎜, for example, 65㎜ in diameter; the diameter of the coal powder collection pipe 20 can be selected within the size range of 100㎜-150㎜, for example, 125㎜ in diameter.

[0048] The present invention also provides a coal mill, comprising the above-mentioned coal powder discharge device, as well as a frame, a casing 30, a swing arm 40, a grinding disc 50 and a grinding roller 60;

[0049] The grinding roller 60 cooperates with the grinding disc 50 to grind coal; one end of the swing arm 40 is connected to the grinding roller 60, and the other end is rotatably connected to the frame, and the swing arm 40 is configured to drive the angle and gap of the grinding roller 60 relative to the grinding disc 50; the casing 30 includes a cavity, and the grinding disc 50, the grinding roller 60 and the swing arm 40 are all accommodated in the cavity, and the shell 31 is a part of the casing 30.

[0050] It should be noted that the coal mill is a device used to crush coal and grind it into fine powder, and is widely used in thermal power plants, metallurgy, building materials and other industries; the frame is the supporting structure of the coal mill, which is used to install and fix the main working parts such as the grinding disc 50, the grinding roller 60, and the swing arm 40, and has sufficient strength and rigidity to withstand the huge force and vibration generated during the coal grinding process; the grinding disc 50 is one of the core components of the coal mill, and is usually made of wear-resistant materials; the grinding disc 50 is used in conjunction with the grinding roller 60 to crush the coal and grind it into fine powder through relative movement; the grinding roller 60 is also a key component of the coal mill, and the grinding roller 60 is tightly connected to the grinding disc 50. The grinding roller 60 is a close fit and crushes the coal by applying pressure and friction. The material and shape of the grinding roller 60 are designed according to actual requirements to ensure its wear resistance and crushing effect. The swing arm 40 is an important component connecting the grinding roller 60 and the frame, which allows the grinding roller 60 to swing within a certain range to adjust the gap and angle with the grinding disc 50, thereby helping to optimize the coal grinding process and improve the crushing efficiency and product quality. The casing 30 is the external structure of the coal mill, which surrounds the entire coal grinding area to form a closed space. The casing 30 not only protects the internal components, but also guides the flow direction of the coal powder to prevent dust leakage.

[0051] In summary, the present invention effectively overcomes some practical problems in the prior art and thus has high utilization value and use significance.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A pulverized coal discharge device, characterized in that: Used for discharging coal powder at the rotating part of the swing arm of the coal mill, the coal powder discharging device comprises: An air duct is connected to the housing of the rotating part; an air blowing unit, disposed in the air duct, and configured to blow air toward the rotating part to keep the coal powder away from the rotating part; The coal powder collecting pipe is arranged below the shell and is communicated with the lower part of the shell or is communicated with the lower part of the shell through the air duct.

2. The pulverized coal discharge device according to claim 1, characterized in that: The air duct is provided with a first gas inlet end, and the first gas is at least a gas that does not react with coal powder at room temperature.

3. The pulverized coal discharge device according to claim 2, characterized in that: The pulverized coal collection pipe comprises: The tube body comprises a first end and a second end, wherein the first end is connected to the air duct or the lower part of the shell, and the second end is connected to the outside; a first valve, disposed on the tube body and at a preset distance from the first end; The second valve is disposed on the tube body and close to the second end.

4. The pulverized coal discharge device according to claim 3, characterized in that: A viewing window is provided on the pipe body at least between the first valve and the second valve.

5. The pulverized coal discharge device according to claim 1, characterized in that: The length of the coal powder collecting pipe is greater than a preset length.

6. The pulverized coal discharge device according to claim 1, characterized in that: The air duct comprises a first pipeline, one end of which is connected to the shell and is located at a side of the rotating part away from the grinding disc of the coal mill.

7. The pulverized coal discharge device according to claim 6, characterized in that: The air duct includes a second pipeline, and one end of the second pipeline communicating with the shell is located at the lower end of the shell.

8. The pulverized coal discharge device according to claim 7, characterized in that: The upper end of the coal powder collecting pipe is communicated with the lower part of the second pipeline.

9. The pulverized coal discharge device according to claim 7, characterized in that: The direction of the second pipeline toward the shell is tangent to the rotating part and is inclined toward the grinding disc or grinding roller side of the coal mill, and the extension direction of the shell is consistent with the direction of the second pipeline.

10. A coal mill, characterized in that: The device comprises the pulverized coal discharge device as claimed in any one of claims 1 to 9, as well as a frame, a grinding disc, a grinding roller, a swing arm and a casing; The grinding roller cooperates with the grinding disc to grind coal; one end of the swing arm is connected to the grinding roller, and the other end is rotatably connected to the frame, and the swing arm is configured to drive the angle and gap of the grinding roller relative to the grinding disc; The casing comprises a cavity, the grinding disc, the grinding roller and the swing arm are all accommodated in the cavity, and the shell is a part of the casing.

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