Precise positioning anti-blocking coal mill primary air flow measuring device

Abstract

The present application relates to primary air flow measurement technical field, and disclose a kind of accurate positioning anti-blocking type coal mill primary air flow measuring device, including sealing mounting plate and the differential pressure transmitter being arranged in the top surface of sealing mounting plate, the top surface of differential pressure transmitter is provided with display instrument.The present application relies on wind channel itself airflow power to realize full-automatic back-blowing cleaning operation, without additional power equipment, can be completed by the reciprocating stretching and resetting of elastic air bag, with the directional flow guiding effect of multiple groups of one-way valve, alternate pipe back-blowing and filter screen self-cleaning operation, on the one hand, the dust and sundries accumulated in the inner wall of full-pressure tapping pipe, static pressure tapping pipe and various support pipelines can be removed in time, to avoid pipe blockage affecting the accuracy of pressure measurement, on the other hand, the surface of filter screen can be independently blown off dirt, continuously maintain the permeability of filter screen, ensure the effect of air intake filtration, effectively reduce equipment failure frequency, ensure that the device can be long-term continuous stable operation.

Description

Technical Field

[0001] This invention relates to the field of primary air flow measurement technology, and in particular to a precise positioning anti-clogging coal mill primary air flow measurement device. Background Technology

[0002] The precise positioning and anti-clogging coal mill primary air flow measurement device is a multi-point array differential pressure flow measurement device designed for the harsh operating conditions of primary air (including pulverized coal, high humidity, and high dust) in coal mills of thermal power plants. It solves the three major pain points of traditional single-point measurement: inaccuracy, easy clogging of pressure taps, and easy wear of probes. It achieves long-term maintenance-free, high-precision, anti-clogging and wear-resistant online monitoring of primary air flow.

[0003] In the actual operation of primary air flow measurement devices in coal mills of thermal power plants, existing equipment generally uses a cleaning rod installed inside the pressure tapping pipe to deal with ash accumulation and blockage. However, this type of traditional self-cleaning mechanism relies solely on the pulsation of airflow in the duct or equipment vibration to passively shake the cleaning rod, removing dust adhering to the pressure tapping hole and the inner wall of the pipe through simple shaking. Its cleaning path is short and the sweeping range is limited, making it impossible to achieve comprehensive and continuous scraping of key areas such as pressure tapping holes, pipe corners, and convergence dead corners. Especially under low load and low wind speed operating conditions, the airflow driving force is insufficient, and the shaking amplitude of the cleaning rod is weakened, making it difficult to effectively remove highly sticky wet powder or hardened ash. Under high load and high dust concentration operating conditions, a large amount of coal dust that rushes in instantaneously will quickly cover the pressure tapping channel. Passive shaking alone cannot clear the blockage in time, which can easily cause blockage of the pressure tapping hole and accumulation in the pipe, ultimately leading to distortion of the differential pressure signal and inaccurate airflow measurement, affecting the safe and stable operation of the coal mill and boiler system.

[0004] Therefore, it is necessary to design a precise positioning anti-clogging coal mill primary air flow measurement device to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a precise positioning anti-clogging coal mill primary air flow measurement device.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A precise positioning anti-clogging coal mill primary air flow measurement device includes a sealed mounting plate and a differential pressure transmitter mounted on the top surface of the sealed mounting plate. A display instrument is mounted on the top surface of the differential pressure transmitter. A measuring structure adapted to the differential pressure transmitter is mounted on the bottom surface of the sealed mounting plate. A support plate is fixedly mounted on the side of the sealed mounting plate. A support base is fixedly mounted on the top surface of the support plate. A protective shell is fixedly mounted on the top surface of the support base. An elastic airbag is fixedly mounted on the inner bottom surface of the protective shell. A drive plate is fixedly mounted on the top surface of the elastic airbag. A drive screw for driving the drive plate is passed through the inner bottom surface of the protective shell. A drive assembly for driving the drive screw is located on the inner side of the support base. A guide assembly for connecting the drive screw and the drive plate is located on the inner wall of the protective shell. A communication mechanism is provided between the elastic airbag and the measuring structure. The drive assembly includes a transmission cone roller fixedly installed at the bottom end of the drive screw, a shaft is provided through the bottom surface of the support plate, and a drive cone roller is fixedly installed at the top end of the shaft. The guiding assembly includes a guide plate fixedly installed on the inner wall of the protective shell. Two U-shaped guide grooves are symmetrically opened on the side of the guide plate. Two semi-guide blocks that are screwed to the drive screw are symmetrically slidably installed on the outer wall of the drive plate.

[0007] As a preferred embodiment of the present invention, the measuring structure includes a main support pipe fixedly installed on the bottom surface of a sealed mounting plate and connected to one side interface of a differential pressure transmitter. Four branch pipes are symmetrically arranged through the outer wall of the main support pipe. A total pressure tapping pipe is arranged through the end of each branch pipe away from the main support pipe. A static pressure tapping pipe connected to the other side interface of the differential pressure transmitter is fixedly installed on the bottom surface of the sealed mounting plate.

[0008] As a preferred embodiment of the present invention, a cleaning rod for cleaning dust inside the full pressure tapping tube is provided on the inner side of the full pressure tapping tube.

[0009] As a preferred embodiment of the present invention, the communication mechanism includes an air intake tube that passes through one side of the outer wall of the elastic airbag, and a backflush tube that passes through the other side of the outer wall of the elastic airbag. The end of the backflush tube that is away from the elastic airbag is connected to the top of the full pressure tapping tube and the static pressure tapping tube, respectively.

[0010] As a preferred embodiment of the present invention, a filter screen is provided at the suction end of the suction pipe, a cleaning pipe for connecting the two is installed between the suction pipe and the backflush pipe, and a one-way valve is installed on the inner wall of the suction pipe, the backflush pipe and the cleaning pipe.

[0011] As a preferred embodiment of the present invention, the drive assembly further includes a guide rod fixedly installed on the inner bottom surface of the support base and located between the drive cone roller and the transmission cone roller. An adjusting screw is provided through the inner bottom surface of the support base and located on the side of the guide rod. An adjusting disc is fitted on the outer wall of the adjusting screw and the guide rod. A transmission wheel is fitted on the outer wall of the adjusting disc. A blade is fixedly installed at the bottom end of the shaft. A cover covering half of the blade is fixedly installed on the bottom surface of the support plate through a bracket.

[0012] In a preferred embodiment of the present invention, the driving cone roller and the transmission cone roller are arranged opposite to each other, and the outer wall of the transmission wheel is in contact with the outer walls of the driving cone roller and the transmission cone roller.

[0013] As a preferred embodiment of the present invention, a hexagonal nut is fixedly installed at one end of the adjusting screw located on the outside of the support base.

[0014] As a preferred embodiment of the present invention, the guide assembly further includes a slider fixedly installed on the side of the semi-guide block, and the slider is slidably connected to the inner wall of the U-shaped guide groove. A magnetic sheet is fixedly installed on the side of the slider, and a magnetic sheet is fixedly installed at each of the two corner positions on the outer side of the inner wall of the U-shaped guide groove.

[0015] As a preferred embodiment of the present invention, the magnetic poles of the first magnetic sheet are opposite to those of the upper magnetic sheet, and are the same as those of the lower magnetic sheet.

[0016] The present invention has the following beneficial effects: 1. In this invention, fully automatic backflushing cleaning is achieved by relying on the airflow power of the duct itself, without the need for additional power equipment. Through the reciprocating stretching and resetting of the elastic airbag, combined with the directional flow guidance of multiple sets of one-way valves, the pipeline backflushing and filter self-cleaning operations are alternately completed. On the one hand, it can promptly remove dust and debris accumulated on the inner walls of the full pressure tapping pipe, static pressure tapping pipe, and various support pipes, avoiding pipeline blockage that affects pressure tapping accuracy. On the other hand, it can autonomously blow away dirt attached to the filter screen surface, continuously maintaining the filter screen's permeability and ensuring the air intake filtration effect. At the same time, an adjustable conical roller transmission structure is set up. According to different airflow speeds and different dust accumulation conditions in the duct, the operator can adjust the meshing position of the screw fine-tuning transmission wheel, change the transmission ratio of the two sets of conical rollers, and precisely control the running speed of the drive screw, thereby adjusting the cyclic working frequency of the elastic airbag and achieving flexible adaptation of the backflushing cleaning frequency. 2. In this invention, a multi-point pressure sampling method using the equal-area grid method of the duct cross-section is adopted, which can comprehensively collect airflow pressure data at different points in the duct. The differential pressure transmitter completes signal aggregation and pressure equalization processing, and the Bernoulli equation is used to accurately calculate airflow velocity and air volume parameters, effectively avoiding data deviation caused by single-point measurement. At the same time, the internal structure layout of the equipment is optimized, and the drive structure such as the blades is set behind the pressure sampling pipeline, which will not block the pressure sampling channel or interfere with the air pressure sampling process. From the structural level, the stability of the pressure sampling operation is guaranteed, allowing the device to output accurate primary air volume flow rate and mass flow rate data that are consistent with the actual working conditions for a long time. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention; Figure 2 This is a schematic diagram of the bottom structure of the sealing mounting plate of a precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention; Figure 3 This is a schematic diagram of the support plate structure of a precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention; Figure 4 This is a schematic diagram of the inner structure of the protective shell of a precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention; Figure 5 This is a schematic diagram of the overall partial cross-sectional structure of the support plate of the precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention; Figure 6 for Figure 5 Enlarged structural diagram at point A in the middle; Figure 7 This is an exploded view of the guide plate and semi-guide block of a precise positioning anti-clogging coal mill primary air flow measurement device proposed in this invention.

[0018] In the diagram: 1. Sealing mounting plate; 2. Differential pressure transmitter; 21. Display instrument; 22. Support main pipe; 23. Branch pipe; 24. Total pressure tapping pipe; 25. Static pressure tapping pipe; 26. Cleaning rod; 3. Support plate; 31. Support base; 32. Protective shell; 4. Elastic airbag; 41. Drive plate; 42. Drive screw; 5. Drive assembly; 51. Transmission cone roller; 52. Shaft; 53. Blade; 54. Drive cone roller; 55. Guide rod; 56. Adjusting screw; 57. Adjusting disc; 58. Transmission wheel; 6. Guide assembly; 61. Guide plate; 62. U-shaped guide groove; 63. Semi-guide block; 64. Slider; 65. Magnetic sheet one; 66. Magnetic sheet two; 7. Suction tube; 71. Backflush tube; 72. Cleaning tube. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example 1: This example discloses a precise positioning anti-clogging coal mill primary air flow measurement device, referring to... Figure 1-7 The device includes a sealing mounting plate 1 and a differential pressure transmitter 2 disposed on the top surface of the sealing mounting plate 1. A display instrument 21 is disposed on the top surface of the differential pressure transmitter 2. A measuring structure adapted to the differential pressure transmitter 2 is disposed on the bottom surface of the sealing mounting plate 1. The measuring structure includes a support main pipe 22 fixedly installed on the bottom surface of the sealing mounting plate 1 and connected to one side interface of the differential pressure transmitter 2. Four branch pipes 23 are symmetrically arranged through the outer wall of the support main pipe 22. A total pressure tapping pipe 24 is arranged through the end of the branch pipe 23 away from the support main pipe 22. A static pressure tapping pipe 25 connected to the other side interface of the differential pressure transmitter 2 is fixedly installed on the bottom surface of the sealing mounting plate 1. A cleaning rod 26 for cleaning the dust inside the total pressure tapping pipe 24 is disposed on the inner side of the total pressure tapping pipe 24. A support plate 3 is fixedly installed on the side of the sealing mounting plate 1. A support base 31 is fixedly installed on the top surface of the support plate 3. A protective shell 32 is fixedly installed on the top surface of the support base 31. An elastic airbag 4 is fixedly installed on the inner bottom surface of the protective shell 32. A drive plate 41 is fixedly installed on the top surface of the elastic airbag 4. A drive screw 42 for driving the drive plate 41 is provided through the inner bottom surface of the protective shell 32. A drive assembly 5 for driving the drive screw 42 is provided on the inner side of the support base 31. A guide assembly 6 for connecting the drive screw 42 and the drive plate 41 is provided on the inner wall of the protective shell 32. A communication mechanism is provided between the elastic airbag 4 and the measuring structure.

[0021] The implementation principle of this embodiment is as follows: In actual use, the staff first fixes the entire device to the preset installation position in the air duct with the sealing mounting plate 1, ensuring that the measuring structure matched on the bottom surface of the sealing mounting plate 1 is completely placed inside the air duct. After the device is positioned and sealed, the differential pressure transmitter 2 can be started to enter the normal measurement working state. During the measurement process, multiple sets of total pressure taps 24, evenly distributed using an equal-area grid method across the primary air duct cross-section, along with corresponding static pressure taps 25, can simultaneously collect total pressure data on the windward side and static pressure data on the leeward side of the airflow within the duct. This allows for the accurate acquisition of differential pressure signals at various monitoring points within the duct. The differential pressure signals collected from each point are uniformly transmitted to the differential pressure transmitter 2, which performs signal aggregation and equalization processing to obtain a standard differential pressure signal that accurately reflects the average velocity of the airflow inside the duct. Subsequently, the system uses Bernoulli's equation to calculate this differential pressure signal, accurately estimating the average velocity of the airflow inside the duct. Then, by matching the actual cross-sectional area of ​​the duct with the gas density parameters under the on-site conditions, the system calculates the volumetric flow rate and mass flow rate data corresponding to the primary airflow, thus completing the accurate measurement and statistics of the airflow. Under normal operating conditions, the airflow inside the duct can autonomously drive the built-in drive component 5, which, in conjunction with the guide component 6, completes the directional reciprocating motion of the drive plate 41, reciprocatingly stretching the elastic airbag 4. During the stretching process, through the transmission effect of the connecting mechanism, the main support pipe 22, branch pipe 23, total pressure tapping pipe 24, and static pressure tapping pipe 25 of the equipment are simultaneously backflushed and cleaned, promptly removing dust, debris, and other attachments accumulated inside the pipes, effectively avoiding pipe blockage problems, ensuring the smooth flow of each pipe, keeping the pressure tapping and transmission process stable, and continuously ensuring the stability and accuracy of the air volume measurement data of the device.

[0022] Example 2: Based on Example 1, this example discloses a precise positioning anti-clogging coal mill primary air flow measurement device, such as... Figure 2 and Figure 3 As shown, the connecting mechanism includes an air intake pipe 7 that passes through one side of the outer wall of the elastic airbag 4, and a backflush pipe 71 that passes through the other side of the outer wall of the elastic airbag 4. The end of the backflush pipe 71 away from the elastic airbag 4 is connected to the top of the full pressure tapping pipe 24 and the static pressure tapping pipe 25, respectively. A filter screen is provided at the air intake end of the air intake pipe 7. A cleaning pipe 72 for connecting the two is installed between the air intake pipe 7 and the backflush pipe 71. One-way valves are installed on the inner walls of the air intake pipe 7, the backflush pipe 71 and the cleaning pipe 72.

[0023] The implementation principle of this embodiment is as follows: During the stretching process of the elastic airbag 4 by the drive plate 41, the one-way valve inside the suction pipe 7 restricts the airflow from the outside to the inside of the elastic airbag 4. Outside air can then flow into the elastic airbag 4 through the suction pipe 7, where it passes through a filter screen to remove impurities. After the stretching force disappears, the elastic airbag 4 returns to its original position due to its elastic structure. At this time, the one-way valve inside the backflush pipe 71 controls the airflow from the inside of the elastic airbag 4 to the support main pipe 22 and the static pressure tapping pipe 25. The stored gas is then transported to the corresponding pipeline structure through the backflush pipe 71. The high-speed jet of air can purge the impurities attached to the inner walls of the main support pipe 22, branch pipe 23, total pressure tapping pipe 24, and static pressure tapping pipe 25. At the same time, the one-way valve inside the cleaning pipe 72 directs the airflow from the backflush pipe 71 toward the suction pipe 7. Some of the airflow inside the backflush pipe 71 will be diverted into the suction pipe 7 and sprayed outward, thereby purging the dirt accumulated on the filter screen surface and maintaining the cleanliness of the filter screen surface.

[0024] Example 3: Based on Example 1, this example discloses a precise positioning anti-clogging coal mill primary air flow measurement device, such as... Figure 5 and Figure 6 As shown, the drive assembly 5 includes a transmission cone roller 51 fixedly installed at the bottom end of the drive screw 42. A shaft 52 is provided through the bottom surface of the support plate 3. A drive cone roller 54 is fixedly installed at the top end of the shaft 52. The drive cone roller 54 and the transmission cone roller 51 are arranged opposite to each other. The drive assembly 5 also includes a guide rod 55 fixedly installed on the inner bottom surface of the support base 31 and located between the drive cone roller 54 and the transmission cone roller 51. An adjusting screw 56 is provided through the inner bottom surface of the support base 31 and located at the side of the guide rod 55. A hexagonal nut is fixedly installed at one end of the adjusting screw 56 located on the outside of the support base 31. An adjusting disc 57 is fitted on the outer wall of the adjusting screw 56 and the guide rod 55. A transmission wheel 58 is fitted on the outer wall of the adjusting disc 57. The outer wall of the transmission wheel 58 is in contact with the outer walls of the drive cone roller 54 and the transmission cone roller 51. A blade 53 is fixedly installed at the bottom end of the shaft 52. A cover covering half of the blade 53 is fixedly installed on the bottom surface of the support plate 3 through a bracket.

[0025] The implementation principle of this embodiment is as follows: During actual installation, the blade 53 is placed inside the duct and positioned behind the main support pipe 22 and the static pressure tapping pipe 25 in the direction of airflow. This layout does not obstruct the pressure tapping channels of the total pressure tapping pipe 24 and the static pressure tapping pipe 25, thus avoiding interference from the blade 53 structure on the wind pressure acquisition operation and ensuring the normal and stable operation of routine measurement. During operation, the airflow inside the duct acts on the surface of the blade 53, causing it to rotate. The baffle covers half of the blade 53, and the airflow acts on the other half of the blade 53, ensuring that the blade 53 can rotate normally. The rotating blade 53 can synchronously drive the connected shaft 52 and the drive cone roller 54 to rotate together. The rotating drive cone roller 54 drives the drive cone roller 51 to rotate synchronously through the transmission wheel 58, thereby providing a stable power source for the rotation of the drive screw 42. Because the drive cone roller 54 and the transmission cone roller 51 are arranged symmetrically, the operator can rotate the adjusting screw 56 to drive the adjusting plate 57 and the transmission wheel 58 to slide directionally along the guide rod 55. This allows for fine adjustment of the meshing position of the transmission wheel 58 between the drive cone roller 54 and the transmission cone roller 51, changing the meshing transmission relationship between the two sets of cone rollers. This adjusts the transmission ratio between the drive cone roller 54 and the transmission cone roller 51, enabling precise control of the rotation speed of the drive screw 42. After the rotation speed of the drive screw 42 changes, the stretching and resetting cycle frequency of the elastic airbag 4 can be directly adjusted, ultimately completing the adjustment and adaptation of the equipment's backflushing cleaning frequency. This allows the equipment's backflushing cleaning rhythm to match different duct conditions and dust accumulation situations.

[0026] Example 4: Based on Example 1, this example discloses a precise positioning anti-clogging coal mill primary air flow measurement device, such as... Figure 5-7 As shown, the guide assembly 6 includes a guide plate 61 fixedly installed on the inner wall of the protective shell 32. Two U-shaped guide grooves 62 are symmetrically opened on the side of the guide plate 61. Two semi-guide blocks 63 that are screwed to the drive screw 42 are symmetrically slidably installed on the outer wall of the drive plate 41. The guide assembly 6 also includes a slider 64 fixedly installed on the side of the semi-guide block 63. The slider 64 is slidably connected to the inner wall of the U-shaped guide groove 62. A magnetic sheet 65 is fixedly installed on the side of the slider 64. A magnetic sheet 66 is fixedly installed at the two corner positions on the outer side of the inner wall of the U-shaped guide groove 62. The magnetic poles of the magnetic sheet 65 are opposite to those of the upper magnetic sheet 66 and the same as those of the lower magnetic sheet 66.

[0027] The implementation principle of this embodiment is as follows: During equipment operation, when the drive screw 42 rotates, the two semi-guide blocks 63 in the initial state of the device remain closed and fitted. After closing, the semi-guide blocks 63 and the drive screw 42 form a stable screw connection structure. The rotating drive screw 42 can rely on the thread engagement relationship to drive the two semi-guide blocks 63 and the drive plate 41 connected to them to move upward synchronously, thereby smoothly stretching the elastic airbag 4 and reserving air pressure for subsequent backflushing operations. When the slider 64 mounted on the side of the semi-guide block 63 moves to the top position of the U-shaped guide groove 62 along with the overall structure, the magnetic sheet 65 mounted on the side of the slider 64 will be directly opposite to the magnetic sheet 66 at the top of the inner wall of the U-shaped guide groove 62. The magnetic poles of the opposite end faces of the two sets of magnetic sheets are opposite. Relying on the magnetic force of the attraction of opposite magnetic poles, the two semi-guide blocks 63 will separate to both sides to complete the separation action. The thread engagement relationship between the semi-guide block 63 and the drive screw 42 will be released. At this time, under the combined action of its own gravity and the elastic reset force of the elastic airbag 4, the drive plate 41, the two semi-guide blocks 63 and the slider 64 will slide down and reset along the groove track of the U-shaped guide groove 62. When the slider 64 falls back to the bottom of the U-shaped guide groove 62, the magnetic piece 65 at the slider 64 will be directly opposite the magnetic piece 66 at the bottom of the U-shaped guide groove 62. The magnetic poles of the opposite ends of the two sets of magnetic pieces are the same. Under the magnetic force of the repulsion of like magnetic poles, the two semi-guide blocks 63 will close together again and re-form a threaded connection with the drive screw 42. At the moment the screwing is completed, the running drive screw 42 can drive the two semi-guide blocks 63 and the drive plate 41 to slide upward again. The slider 64 is in the vertical groove of the U-shaped guide groove 62, and the semi-guide blocks 63 can maintain a stable closed state without separation. This cycle repeats to achieve the continuous and stable stretching and resetting cycle of the elastic airbag 4, ensuring the uninterrupted and orderly operation of the back-blowing cleaning structure of the device.

[0028] 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 precise positioning anti-clogging coal mill primary air flow measurement device, comprising a sealed mounting plate (1) and a differential pressure transmitter (2) disposed on the top surface of the sealed mounting plate (1), wherein a display instrument (21) is disposed on the top surface of the differential pressure transmitter (2), and a measuring structure adapted to the differential pressure transmitter (2) is disposed on the bottom surface of the sealed mounting plate (1), characterized in that, A support plate (3) is fixedly installed on the side of the sealing mounting plate (1). A support base (31) is fixedly installed on the top surface of the support plate (3). A protective shell (32) is fixedly installed on the top surface of the support base (31). An elastic airbag (4) is fixedly installed on the inner bottom surface of the protective shell (32). A drive plate (41) is fixedly installed on the top surface of the elastic airbag (4). A drive screw (42) for driving the drive plate (41) is provided through the inner bottom surface of the protective shell (32). A drive assembly (5) for driving the drive screw (42) is provided on the inner side of the support base (31). A guide assembly (6) for connecting the drive screw (42) and the drive plate (41) is provided on the inner wall of the protective shell (32). A communication mechanism is provided between the elastic airbag (4) and the measuring structure. The drive assembly (5) includes a transmission cone roller (51) fixedly installed at the bottom end of the drive screw (42), a shaft (52) is provided through the bottom surface of the support plate (3), and a drive cone roller (54) is fixedly installed at the top end of the shaft (52). The guide assembly (6) includes a guide plate (61) fixedly installed on the inner wall of the protective shell (32). Two U-shaped guide grooves (62) are symmetrically opened on the side of the guide plate (61). Two semi-guide blocks (63) that are screwed to the drive screw (42) are symmetrically slidably installed on the outer wall of the drive plate (41).

2. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 1, characterized in that, The measuring structure includes a support main pipe (22) fixedly installed on the bottom surface of the sealing mounting plate (1) and connected to one side interface of the differential pressure transmitter (2). Four branch pipes (23) are symmetrically arranged through the outer wall of the support main pipe (22). A total pressure tapping pipe (24) is arranged through the end of the branch pipe (23) away from the support main pipe (22). A static pressure tapping pipe (25) connected to the other side interface of the differential pressure transmitter (2) is fixedly installed on the bottom surface of the sealing mounting plate (1).

3. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 2, characterized in that, The inner side of the total pressure tapping tube (24) is provided with a cleaning rod (26) for cleaning the dust inside the total pressure tapping tube (24).

4. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 2, characterized in that, The communication mechanism includes an air intake tube (7) that passes through one side of the outer wall of the elastic airbag (4), and a backflush tube (71) that passes through the other side of the outer wall of the elastic airbag (4). The end of the backflush tube (71) away from the elastic airbag (4) is connected to the top of the full pressure tapping tube (24) and the static pressure tapping tube (25), respectively.

5. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 4, characterized in that, The suction end of the suction pipe (7) is provided with a filter screen. A cleaning pipe (72) for connecting the suction pipe (7) and the backflush pipe (71) is installed between the suction pipe (7) and the backflush pipe (71). One-way valves are installed on the inner walls of the suction pipe (7), the backflush pipe (71) and the cleaning pipe (72).

6. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 1, characterized in that, The drive assembly (5) further includes a guide rod (55) fixedly installed on the inner bottom surface of the support base (31) and located between the drive cone roller (54) and the transmission cone roller (51). An adjusting screw (56) located on the side of the guide rod (55) is provided through the inner bottom surface of the support base (31). An adjusting disc (57) is fitted on the outer wall of the adjusting screw (56) and the guide rod (55). A transmission wheel (58) is fitted on the outer wall of the adjusting disc (57). A blade (53) is fixedly installed at the bottom end of the shaft (52). A cover covering half of the blade (53) is fixedly installed on the bottom surface of the support plate (3) through a bracket.

7. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 6, characterized in that, The driving cone roller (54) and the transmission cone roller (51) are arranged opposite to each other, and the outer wall of the transmission wheel (58) is in contact with the outer walls of the driving cone roller (54) and the transmission cone roller (51).

8. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 6, characterized in that, The adjusting screw (56) is fixedly installed with a hexagonal nut at one end located outside the support base (31).

9. The precise positioning anti-clogging coal mill primary air flow measurement device according to claim 1, characterized in that, The guide assembly (6) also includes a slider (64) fixedly installed on the side of the semi-guide block (63), and the slider (64) is slidably connected to the inner wall of the U-shaped guide groove (62). A magnetic sheet (65) is fixedly installed on the side of the slider (64), and a magnetic sheet (66) is fixedly installed at the two corners of the outer side of the inner wall of the U-shaped guide groove (62).

10. A precise positioning anti-clogging coal mill primary air flow measurement device according to claim 9, characterized in that, The magnetic poles of the first magnetic piece (65) are opposite to those of the second upper magnetic piece (66), and are the same as those of the second lower magnetic piece (66).

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