CN104722386A - Air ring air speed distribution measurement and adjustment device and method of coal mill - Google Patents

Abstract

The invention relates to a device and method for measuring and adjusting wind speed distribution of an air ring of a coal mill, comprising a plurality of Pitot tubes corresponding to the air ring ports one-to-one, a plurality of pressure measuring devices and a plurality of Pitot tubes one-to-one corresponding to the Pitot tubes The connecting pipe, multiple deflectors located in the inlet air duct, and the adjustment rods corresponding to the deflectors one by one, the Pitot tube is equipped with a measuring head, a static pressure hole and a total pressure hole, and the measuring head is located below the air ring mouth, And facing the wind direction of the inlet of the air ring, the total pressure hole and the static pressure hole are connected to the pressure measuring device through the connecting pipe, the deflector is set on the adjustment rod, and the wall of the inlet air duct is provided with a plurality of pairs corresponding to the adjustment rod. The through hole, the adjusting rod is sleeved in the through hole, and both ends thereof protrude from the wall. The wind speed distribution of the wind ring is measured by the Pitot tube, and the wind speed distribution of the wind ring is adjusted by the deflector to prevent the raw coal from falling from the wind ring with low wind speed, so as to solve the problem of raw coal discharge by the coal mill, improve the utilization rate of raw coal, and reduce production costs.

Description

Measuring and adjusting device and method for wind speed distribution of wind ring of coal mill

technical field

The invention relates to the technical field of coal pulverizers, in particular to a device and method for measuring and adjusting wind speed distribution of an air ring of a coal pulverizer.

Background technique

At present, the primary air of the coal mill enters the grinding area of the coal mill from bottom to top through the air ring, and the pebble coal falls from top to the pebble coal header through the air ring. The main reason for the problem of raw coal is that the wind speed of the wind ring is not enough. Usually, the problem of a large amount of raw coal discharged by the coal mill is solved by increasing the wind speed of the wind ring as a whole by increasing the ventilation rate and reducing the circulation area of the wind ring. However, in actual operation, even if the calculated wind speed of the wind ring meets the theoretical requirements by increasing the ventilation rate, some coal mills still have the problem of discharging raw coal. Although the above two methods can calculate the average wind speed of the wind ring, they cannot reflect the distribution of the wind speed of the wind ring. When there is a large deviation in the wind speed distribution of the wind ring, the raw coal will fall from the wind ring with a low wind speed, resulting in waste of raw coal .

Contents of the invention

The object of the present invention is to provide a device and method for measuring and adjusting the wind speed distribution of the air ring of a coal mill, which can measure and adjust the distribution of the wind speed of the air ring, solve the problem of raw coal discharge by the coal mill, and improve the utilization rate of raw coal.

For realizing the purpose of the present invention, the technical scheme that takes is:

A device for measuring and adjusting wind speed distribution of an air ring of a coal mill. The air ring is provided with a plurality of air ring ports, and the air ring port is provided with an air inlet end. The coal mill includes stones located below the air ring and close to the air inlet end. The coal header, and the inlet air channel connected with the side wall of the gravel coal header, the air ring wind speed distribution measuring and adjusting device of the coal mill includes a plurality of pit tubes corresponding to the air ring ports one by one, and the pit tubes one by one. Corresponding multiple pressure measuring devices and multiple connecting pipes, multiple deflectors located in the inlet air duct, and adjustment rods corresponding to the deflectors one by one, the Pitot tube is equipped with measuring heads, static pressure holes and total pressure holes , the measuring head is located below the air ring mouth and is facing the wind direction of the air ring inlet. The total pressure hole and the static pressure hole are connected to the pressure measuring device through the connecting pipe. There are multiple pairs of through holes corresponding to the adjusting rods one by one, the adjusting rods are sleeved in the through holes, and both ends of the adjusting rods protrude from the wall.

By setting a Pitot tube at the air inlet end of each air ring port, and measuring the pressure difference between the static pressure hole and the total pressure hole through a pressure gauge, the wind speed of the corresponding air ring port can be obtained, and measured according to each pressure The distribution of the wind speed of the wind ring can be obtained from the measurement results of the wind ring; then by setting multiple deflectors in the inlet air duct of the coal mill, and adjusting the angle between the deflectors and the flow direction of the primary air pipe in the inlet air duct through the adjustment rod, when When there is a relatively large deviation in the wind speed distribution of the air ring, adjust the deflectors at different positions according to the distribution of the partial speed of the air ring, so that the wind speed distribution of each air ring port of the air ring is uniform, and prevent the raw coal from being blown from the low wind speed. The air ring is dropped, so as to solve the problem of raw coal discharge by the coal mill, improve the utilization rate of raw coal, and reduce production costs. Moreover, the deflectors correspond to the adjustment rods one by one, and each deflector can be adjusted independently, making the adjustment of the wind speed distribution of the wind ring more flexible.

The technical scheme is further described below:

Further, the air ring wind speed distribution measuring and adjusting device of the coal mill also includes a mounting bracket, which is arranged on the inner wall of the gravel coal header, and a plurality of pitot tubes are fixed on the mounting bracket. Fix the Pitot tube on the air inlet side of the air ring through the installation bracket.

Furthermore, the air ring wind speed distribution measuring and adjusting device of the coal mill also includes multiple pairs of pressure measuring tubes and multiple connecting plugs. The multiple connecting plugs are evenly fixed on the inner wall, and the pressure measuring tubes pass through the stone through the connecting plugs. On the wall of the coal header, each pair of pressure measuring tubes corresponds to a Pitot tube. One end of the pressure measuring tube is connected to the connecting pipe, and the other end is connected to the pressure measuring device. Through the pressure measuring tube, the pressure signal of the connecting pipe is led out of the pebble coal header to make the measurement more convenient, and the airtightness of the pebble coal header is ensured by connecting the plug to make the measured data more accurate.

Further, the air ring wind speed distribution measuring and adjusting device of the coal mill also includes a bridge frame fixed on the inner wall, the bridge frame and a plurality of connecting plugs are located on the same installation plane, and the connecting pipes are accommodated on the bridge frame. Place the connecting pipe between the Pitot tube and the connecting plug on the bridge frame so that the connecting pipe in the gravel coal header is placed neatly.

Furthermore, there are three bridges evenly distributed on the inner wall, so that the placement of the connecting pipes is more orderly and reasonable.

Further, the outer diameter of the Pitot tube is not greater than 6mm. When the outer diameter of the Pitot tube is not greater than 6mm, it will not affect the wind speed distribution of the wind ring.

Further, the cross-section of the deflector is arc-shaped, and the plurality of deflectors are relatively parallel, and there is a distance between two adjacent deflectors. A plurality of deflectors are arranged relatively parallel to make the adjustment of the deflectors easier; and the deflectors are arc-shaped plates to reduce the resistance of the inlet air duct.

Further, the deflector is provided with a shaft hole matched with the adjustment rod, and the deflector is sheathed on the adjustment rod. The deflector turns with the rotation of the adjustment lever, making the adjustment of the deflector easier.

Further, an angle scale is provided at one end of the adjusting rod, and a handle is provided at the other end. The adjustment angle of the adjustment rod is controlled by the angle scale, so that the adjustment of the deflector is more precise and quick; and the adjustment of the adjustment rod is made easier by turning the adjustment rod by the handle.

The present invention also provides a method for measuring and adjusting the wind speed distribution of the wind ring of the coal mill, including a device for measuring and adjusting the wind speed distribution of the wind ring of the coal mill, including the following steps:

Start the coal mill, do not send coal to the coal mill, send air to the inlet air duct, measure the pressure difference of each pit tube, and calculate the measurement result of the wind speed distribution of the wind ring in the first state;

Send coal to the coal mill, measure the pressure difference of each pit tube, and calculate the measurement result of the wind speed distribution of the wind ring in the second state;

Calculate the wind speed deviation of the wind ring in the first state and the second state;

When the wind speed deviation of the wind ring exceeds ±5% to 10%, adjust the angle between the deflector and the axis of the inlet air duct.

Compared with the prior art, the present invention has the following beneficial effects:

In the present invention, a Pitot tube is arranged at the air inlet end of each air ring port, and the pressure difference between the static pressure hole and the total pressure hole is measured by a pressure measuring device, thereby obtaining the wind speed of the corresponding air ring port, and according to each The distribution of wind speed in the air ring can be obtained from the measurement results of the pressure measuring device; then a plurality of deflectors are installed in the inlet air duct of the coal mill, and the angle between the deflectors and the flow direction of the primary air pipe in the inlet air duct is adjusted by the adjusting rod , when there is a relatively large deviation in the wind speed distribution of the air ring, adjust the deflectors at different positions according to the distribution of the partial speed of the air ring, so that the wind speed distribution of each air ring port of the air ring is evenly distributed, and the raw coal is prevented from falling The low air ring falls, so as to solve the problem of raw coal discharge by the coal mill, improve the utilization rate of raw coal, and reduce production costs.

Description of drawings

Fig. 1 is the structure diagram of the air ring wind speed distribution measuring and adjusting device of the coal mill of the embodiment of the present invention;

Fig. 2 is the A direction view of Fig. 1;

Fig. 3 is the B-B sectional view of Fig. 1;

Fig. 4 is a schematic structural diagram of a Pitot trusteeship embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a deflector according to an embodiment of the present invention.

Explanation of reference signs:

10. Air ring, 110. Air ring mouth, 111. Air inlet end, 20. Stone coal header, 210. Connecting plug, 220. Inner wall, 30. Inlet air duct, 310. Wall surface, 320. Through hole, 40 . Pitot tube, 410. Connecting pipe, 420. Measuring head, 430. Static pressure hole, 440. Total pressure hole, 50. Deflector, 510. Shaft hole, 60. Adjusting rod, 70. Mounting bracket, 80. Pressure Measuring tube, 910. Angle scale, 920. Handle.

Detailed ways

Embodiments of the present invention are described in detail below in conjunction with accompanying drawings:

As shown in Figures 1 to 4, an air ring wind speed distribution measuring and adjusting device for a coal mill, the air ring 10 is provided with a plurality of air ring ports 110, the air ring port 110 is provided with an air inlet end 111, the coal mill Including the gravel coal header 20 located below the wind ring 10 and close to the air inlet end 111, and the inlet air duct 30 communicating with the side wall of the gravel coal header 20, the air ring wind speed distribution measurement and adjustment device of the coal mill includes A plurality of Pitot tubes 40 one-to-one corresponding to the air ring port 110, a plurality of pressure measuring devices (not marked in the drawings) and a plurality of connecting pipes 410 corresponding to the Pitot tubes 40 one-to-one, and a plurality of pipes located in the inlet air duct 30 A deflector 50, and the adjusting rod 60 corresponding to the deflector 50 one by one, the Pitot tube 40 is provided with a measuring head 420, a static pressure hole 430 and a total pressure hole 440, and the measuring head 420 is located under the air ring mouth 110, And facing the wind direction of the inlet of the wind ring 10, the total pressure hole 440 and the static pressure hole 430 are connected to the pressure measuring device through the connecting pipe 410, and the deflector 50 is arranged on the adjustment rod 60, and partly extends into the gravel coal header 20 The wall surface 310 of the inlet air duct 30 is provided with a plurality of pairs of through holes 320 corresponding to the adjusting rods 60 one by one.

By setting the Pitot tube 40 at the air inlet end 111 of each air ring port 110, and measuring the pressure difference between the static pressure hole 430 and the total pressure hole 440 through a pressure measuring device, the wind speed of the corresponding air ring port 110 is obtained, And according to the measurement results of each pressure measuring device, the distribution of the wind speed of the wind ring 10 is obtained; then a plurality of deflectors 50 are set at the inlet air duct 30 of the coal mill, and the adjustment rod 60 is used to adjust the deflectors 50 and the inlet The angle of the flow direction of the primary air duct in the air duct 30, when there is a relatively large deviation in the wind speed distribution of the air ring 10, adjust the deflectors 50 at different positions according to the distribution of the speed of the air ring 10, so that the air ring 10 The wind speed distribution of each air ring port 110 is uniform, preventing raw coal from falling from the air ring 10 with low wind speed, thereby solving the problem of raw coal discharge by the coal mill, improving the utilization rate of raw coal, and reducing production costs. Moreover, the deflectors 50 correspond to the adjusting rods 60 one by one, and each deflector 50 can be adjusted independently, so that the adjustment of the wind speed distribution of the wind ring is more flexible.

In this embodiment, as shown in FIG. 3 and FIG. 4 , the measuring head 420 is facing the flow direction of the airflow at the air inlet end 111 of the air ring mouth 110 , so that the measured data is more accurate. And the connecting pipe 410 is a high-temperature-resistant rubber hose, at least ensure that the connecting pipe 410 can withstand a high temperature of about 300°C, and require that the outer diameter of the pipe tube 40 is not greater than 6mm, so as to avoid affecting the wind speed distribution of the wind ring 10 .

As shown in Figure 3, the air ring wind speed distribution measuring and adjusting device of the coal mill also includes a mounting bracket 70, the mounting bracket 70 is arranged on the inner wall 220 of the gravel coal header 20, and a plurality of pit tubes 40 are all fixed on the mounting bracket 70 superior. The Pitot tube 40 is fixed on the wind inlet end 111 side of the wind ring 10 through the installation bracket 70 .

In this embodiment, the mounting bracket 70 is composed of round pipes, and in order to avoid affecting the wind speed distribution of the wind ring 10 , the diameter of the round pipes is not greater than 6 mm.

As shown in Figure 3, the air ring wind speed distribution measuring and adjusting device of the coal mill also includes multiple pairs of pressure measuring tubes 80 and multiple connecting plugs 210, the multiple connecting plugs 210 are evenly fixed on the inner wall 220, and the pressure measuring tubes 80 runs through the wall 310 of the gravel coal header 20 through the connecting plug 210, and each connecting plug 210 is provided with multiple pairs of pressure measuring tubes 80, each pair of pressure measuring tubes 80 corresponds to a Pitot tube 40, and the pressure measuring tubes 80 One end is connected to the connecting pipe 410, and the other end is connected to the pressure measuring device. Through the pressure measuring tube 80, the connecting pipe 410 is led out of the pebble coal header 20 to make the measurement more convenient, and the airtightness of the pebble coal header 20 is ensured through the connecting plug 210, so that the measured data is more accurate.

The air ring wind speed distribution measuring and adjusting device of the coal mill also includes a bridge frame (not marked in the drawings) fixed on the inner wall 220, and the bridge frame and multiple connecting plugs 210 are located on the same installation plane. Place the connecting pipe 410 between the pit tube 40 and the connecting plug 210 on the bridge frame, so that the connecting pipe 410 in the gravel coal header 20 is neatly placed.

In this embodiment, the inner wall 220 is evenly distributed with three bridges along the circumferential direction, so that the placement of the connecting pipe 410 is more orderly and reasonable.

As shown in FIG. 1 and FIG. 2 , the cross-section of the deflector 50 is arc-shaped, and a plurality of deflectors 50 are arranged relatively in parallel, and there is a distance between two adjacent deflectors 50 . A plurality of deflectors 50 are arranged relatively parallel to make the adjustment of the deflectors 50 easier; and the deflectors 50 are arc-shaped plates to reduce the resistance of the inlet air duct 30 .

In this embodiment, the air ring wind speed distribution measurement and adjustment device of the coal mill is provided with four deflectors 50, and the air ring wind speed distribution measurement and adjustment device of the coal mill can also be based on the inlet air duct 30 and the wind ring 10. More than two deflectors 50 are set in different sizes; the deflectors 50 can also be arranged in other shapes according to actual needs.

As shown in FIG. 5 , the deflector 50 is provided with a shaft hole 510 matched with the adjusting rod 60 , and the deflector 50 is sheathed on the adjusting rod 60 . The deflector 50 rotates with the rotation of the adjusting lever 60, which makes the adjustment of the deflector 50 easier.

As shown in FIGS. 2 and 5 , an angle scale 910 is provided at one end of the adjusting rod 60 , and a handle 920 is provided at the other end. The adjustment angle of the adjustment rod 60 is controlled by the angle scale 910 to make the adjustment of the deflector 50 more precise and quick; and the adjustment rod 60 is turned by the handle 920 to make the adjustment of the adjustment rod 60 easier.

The air ring wind speed distribution measuring and adjusting device of the coal mill also includes a locking device (not marked in the drawings) fixed on the outer wall of the inlet air duct 30 , and the locking device is provided with a fixing groove matching the outer circumference of the adjusting rod 60 . After the adjustment of the adjustment rods 60 is completed, each adjustment rod 60 is locked by the locking device to prevent movement during work and ensure the stability of the air ring wind speed distribution measurement and adjustment device of the coal mill.

The present invention also provides a method for measuring and adjusting the wind speed distribution of the wind ring of the coal mill, including a device for measuring and adjusting the wind speed distribution of the wind ring of the coal mill, including the following steps:

Start the coal mill, do not send coal to the coal mill, send air to the inlet air duct 30, measure the pressure difference of each pit tube 40, and calculate the wind speed distribution measurement result of the wind ring 10 in the first state;

Send coal to the coal mill, measure the pressure difference of each pit tube 40, and calculate the wind speed distribution measurement result of the wind ring 10 in the second state;

Calculate the wind speed deviation of the wind ring 10 in the first state and the second state;

When the wind speed deviation of the wind ring 10 exceeds ±5%-10%, adjust the angle between the guide plate 50 and the axis of the inlet air duct 30 .

In the actual application process of the present invention, in order to prevent the pit tube 40 from being blocked by the fine coal powder falling from the wind ring 10, the measurement of the wind speed distribution of the wind ring 10 needs to be carried out within one week after the coal pulverizer is started for the first time. When using the air ring wind speed distribution measurement and adjustment device of the coal mill of the present invention to measure, in order to ensure the accuracy of the data, it is necessary to perform cold measurement and hot measurement. When performing cold measurement, start the coal mill and turn off the coal feeding machine, and open the hot and cold air door of the coal mill to ventilate the coal mill, and by measuring the pressure difference of each pit tube 40, calculate the wind speed distribution of the air ring 10 of the coal mill in the cold state; when measuring in the hot state, Start the coal mill and coal feeder, and measure the pressure difference of each pit tube 40 under the condition of normal operation of the coal mill, and calculate the wind speed distribution of the air ring 10 of the coal mill in a hot state. Finally, according to the measurement results of the wind speed distribution of the wind ring 10 in the hot state and the cold state, the deviation of the wind speed of the wind ring 10 is calculated. When the wind speed deviation exceeds ±5% to ±10%, the wind speed distribution of the wind ring 10 needs to be adjusted. .

In the present invention, a Pitot tube 40 is arranged at the air inlet end 111 of each air ring port 110, and the pressure difference between the static pressure hole 430 and the total pressure hole 440 is measured by a pressure measuring device, thereby obtaining the corresponding air ring port 110 Wind speed, and according to the measurement results of each pressure measuring device, the distribution of the wind speed of the wind ring 10 is obtained; then a plurality of deflectors 50 are set at the inlet air duct 30 of the coal mill, and the deflectors 50 are adjusted by the adjustment rod 60 When there is a relatively large deviation in the wind speed distribution of the air ring 10 relative to the flow direction of the primary air duct in the inlet air duct 30, the deflectors 50 at different positions are adjusted according to the distribution of the speed of the air ring 10 so that The wind speed distribution of each wind ring port 110 of the wind ring 10 is uniform, preventing raw coal from falling from the wind ring 10 with low wind speed, thereby solving the problem of raw coal discharge by the coal mill, improving the utilization rate of raw coal, and reducing production costs.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (10)

1. An air ring wind speed distribution measuring and adjusting device of a coal mill, the air ring is provided with a plurality of air ring ports, the air ring ports are provided with an air inlet end, and the coal mill includes a The gravel coal header at the air inlet end and the inlet air duct communicating with the side wall of the gravel coal header are characterized in that they include a plurality of pit tubes corresponding to the air ring openings one by one, and are connected to the Pitot tubes one-to-one corresponding to a plurality of pressure measuring devices and a plurality of connecting pipes, a plurality of deflectors located in the inlet air duct, and adjustment rods corresponding to the one-to-one adjustment rods of the deflectors, the Pitot tube is provided with A measuring head, a static pressure hole and a total pressure hole, the measuring head is located below the air ring mouth and facing the wind direction of the air ring inlet, the total pressure hole and the static pressure hole are connected to each other through the connecting pipe The pressure measuring device is connected, the deflector is arranged on the adjustment rod, the wall surface of the inlet air duct is provided with a plurality of pairs of through holes corresponding to the adjustment rod, and the adjustment rod is sleeved on the The inside of the through hole and both ends thereof protrude from the wall. 2. The air ring wind speed distribution measuring and adjusting device of the coal mill according to claim 1, further comprising a mounting bracket, the mounting bracket is arranged on the inner wall of the gravel coal header, and a plurality of The Pitot tubes are all fixed on the mounting bracket. 3. The air ring wind speed distribution measuring and adjusting device of the coal mill according to claim 2, further comprising multiple pairs of pressure measuring tubes and a plurality of connection plugs, and a plurality of connection plugs are uniformly fixed on the The inner wall, the pressure measuring tube penetrates through the wall of the gravel coal header through the connecting plug, a pair of the pressure measuring tubes corresponds to one Pitot tube, one end of the pressure measuring tube is connected to the The connecting pipe is connected, and the other end is connected with the pressure measuring device. 4. The device for measuring and adjusting the wind speed distribution of the wind ring of the coal mill according to claim 3, further comprising a bridge fixed on the inner wall, the bridge and a plurality of connecting plugs are located at the same On the installation plane, the connecting pipe is accommodated on the bridge frame. 5 . The device for measuring and adjusting wind speed distribution of the air ring of a coal mill according to claim 4 , wherein three bridges are evenly distributed on the inner wall. 6 . 6. The device for measuring and adjusting the wind speed distribution of the air ring of the coal mill according to any one of claims 1 to 5, characterized in that the outer diameter of the Pitot tube is not greater than 6mm. 7. The device for measuring and adjusting the wind speed distribution of the air ring of a coal mill according to claim 1, wherein the cross section of the deflector is arc-shaped, and a plurality of the deflectors are arranged relatively parallel to each other. There is a space between two adjacent deflectors. 8. The device for measuring and adjusting wind speed distribution of the air ring of a coal mill according to claim 1, wherein the deflector is provided with a shaft hole matched with the adjusting rod, and the deflector is sleeved on the adjustment rod. 9. The device for measuring and adjusting wind speed distribution of an air ring of a coal mill according to claim 7 or 8, wherein an angle scale is provided at one end of the adjusting rod, and a handle is provided at the other end. 10. A method for measuring and adjusting wind speed distribution of the wind ring of a coal mill, comprising the wind speed distribution measuring and adjusting device of the wind ring of a coal mill as claimed in any one of claims 1 to 9, characterized in that it comprises the following step: Start the coal mill, do not send coal to the coal mill, send air to the inlet air duct, measure the pressure difference of each pit tube, and calculate the measurement result of the wind speed distribution of the wind ring in the first state; Send coal to the coal mill, measure the pressure difference of each pit tube, and calculate the measurement result of the wind speed distribution of the wind ring in the second state; Calculate the wind speed deviation of the wind ring in the first state and the second state; When the wind speed deviation of the wind ring exceeds ±5% to 10%, adjust the angle between the deflector and the axis of the inlet air duct.