Method for testing intensity of eddy current dust control flow field

Abstract

The invention relates to an eddy current dust control flow field intensity testing method. The method comprises the following steps: installing an experimental device, measuring ambient atmospheric pressure and temperature, adjusting frequency of a frequency converter, measuring dynamic pressure in an experimental pipeline, calculating air volume in front of and behind an eddy current dust control device, and calculating eddy current intensity. Different vortex intensities are obtained by changing the motor power supply frequency of the wind direction converter in the vortex dust control device and the air supply amount of the compressed air fan, so that the design and operation parameters of the vortex dust control device are optimized, and the dust control efficiency of the vortex dust control device is improved. According to the method, testing can be carried out under different air supply volume conditions by changing the air supply volume of the compressed air fan, the function relation between the vortex intensity and the power frequency of the vortex dust control device under different air supply volumes is established, and reference is provided for adaptability and flexibility of the vortex dust control device.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine dust control and relates to a method for testing the flow field strength of eddy current dust control. Background Art

[0002] Eddy current dust control is a dust control technology that uses the centrifugal force generated by the eddy current and the relative movement of the gas and solid phases to separate the particles in the dust-laden airflow. The eddy current dust control device is generally composed of a wind direction changer and a eddy current wind tube. The wind direction changer converts the incoming airflow into a radial airflow, and the eddy current wind tube converts the radial airflow into an axial airflow and forms a vortex in the eddy current wind tube. The eddy current dust control device has the advantages of simple structure, stable operation, high efficiency, and low energy consumption, and is widely used in industrial production and environmental protection fields.

[0003] The dust control efficiency of the eddy current dust control device is closely related to the eddy current intensity. The greater the eddy current intensity, the better the particle separation effect. The eddy current intensity refers to the ratio of the air volume difference before and after the eddy current dust control device to the air volume at the rear section, reflecting the degree of air flow change inside the eddy current dust control device. Therefore, testing and analyzing the eddy current intensity of the eddy current dust control device is of great significance for optimizing the design and operating parameters of the eddy current dust control device and improving the dust control efficiency of the eddy current dust control device. Summary of the invention

[0004] In view of this, the present invention solves the problem of testing the eddy current intensity and provides a method for testing the eddy current dust control flow field intensity.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A method for testing the strength of an eddy current dust control flow field comprises the following steps:

[0007] S1. Installation of experimental device: connect the compressed air fan, rectifier grid, experimental pipeline, eddy current dust control device and experimental pipeline in series in sequence, wherein the eddy current dust control device includes a wind direction converter and a eddy current wind tube; two frequency converters are respectively connected to the compressed air fan and the wind direction converter to realize frequency conversion control; two compensating micro-manometers are respectively connected to two sections of experimental pipelines;

[0008] S2. Measure the ambient atmospheric pressure and temperature: Use an empty box barometer to measure the atmospheric pressure at the experimental site, and the reading is B a ; Use a thermometer to measure the temperature in the environment, measure 3 times and take the average value

[0009] S3. Adjust the frequency of the frequency converter: turn on the compressed air fan and the wind direction converter, adjust the frequency of the wind direction converter, and change the radial and axial air volume of the eddy current dust control device;

[0010] S4. Measure the dynamic pressure in the experimental pipeline: After the airflow is stable, use a compensated micromanometer to measure the dynamic pressure in the two experimental pipelines before and after the eddy current dust control device. Measure each measuring point 3 times and take the arithmetic average p di As the dynamic pressure value at this point, the average dynamic pressure value of the cross section is calculated as follows:

[0011]

[0012] S5. Calculate the air volume Q before and after the eddy current dust control device 1 and Q 2 , calculate the air volume according to the following formula:

[0013]

[0014] Where: Pitot tube correction factor; p d , the average dynamic pressure at the measurement section, Pa; B a , atmospheric pressure, kPa; Ambient temperature, °C; Average static pressure, kPa; A, cross-sectional area of ​​the measuring point, m 2 ;

[0015] S6. Calculate the eddy current intensity according to the air volume Q before and after the eddy current dust control device. 1 and Q 2 , calculate the eddy current intensity of the eddy current dust control device

[0016] Furthermore, when measuring the dynamic pressure in the experimental pipeline, the cross-sectional measuring points are arranged in at least 4 evenly distributed radial directions on the cross section. In each radial direction, at least 5 measuring points are arranged outward from the center of the cross section, and the spacing between adjacent measuring points along the radial direction decreases.

[0017] Furthermore, under the condition that the air supply volume of the compressed air fan is constant, the air volume at the axial air outlet and the radial air outlet of the eddy current dust control device is changed by changing the motor power frequency of the wind direction converter in the eddy current dust control device, and the eddy current intensity ε under different power supply frequencies is calculated. The change law of the eddy current intensity ε under different power supply frequencies f is analyzed, and thus the functional relationship between the eddy current intensity ε and the power supply frequency f of the eddy current dust control device is established.

[0018] Furthermore, by changing the air supply volume of the compressed air fan, tests are performed under different air supply volume conditions, so as to establish a functional relationship between the eddy current intensity ε and the power supply frequency f of the eddy current dust control device under different air supply volumes.

[0019] The beneficial effects of the present invention are:

[0020] 1. The present invention provides a method for testing the eddy current dust control flow field strength. The method can accurately measure and analyze the eddy current strength of the eddy current dust control device, is simple to operate, is not affected by airflow, and has high reliability and stability.

[0021] 2. The testing method of the present invention can adjust the frequency of the inverter according to different working conditions and requirements, change the radial and axial air volume of the eddy current dust control device, thereby obtaining different eddy current intensities, and then optimize the design and operating parameters of the eddy current dust control device, and improve the dust control efficiency of the eddy current dust control device.

[0022] 3. The testing method of the present invention can be tested under different air supply volume conditions by changing the air supply volume of the compressed air fan, and a functional relationship between the eddy current intensity and the power supply frequency of the eddy current dust control device under different air supply volumes can be established, thereby providing a reference for the adaptability and flexibility of the eddy current dust control device.

[0023] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 Schematic diagram of the experimental device for testing the eddy current dust control flow field strength in the present invention.

[0026] Figure numerals: 1- compressed air fan; 2- rectifier grid; 3- experimental pipeline; 4- wind direction converter; 5- vortex air cylinder. DETAILED DESCRIPTION

[0027] The following describes 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 illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] A method for testing the strength of an eddy current dust control flow field comprises the following steps:

[0031] S1. Experimental device installation: please refer to Figure 1 , the compressed air fan 1, the rectifier grid 2, the experimental pipeline 3, the eddy current dust control device, and the experimental pipeline 3 are connected in series in sequence, and the eddy current dust control device includes a wind direction converter 4 and a eddy current wind tube 5; two frequency converters are respectively connected to the compressed air fan 1 and the wind direction converter 4 to realize frequency conversion control; two compensation micro-manometers are respectively connected to two sections of the experimental pipeline 3;

[0032] S2. Measure the ambient atmospheric pressure and temperature: Use an empty box barometer to measure the atmospheric pressure at the experimental site, and the reading is B a ; Use a thermometer to measure the temperature in the environment, measure 3 times and take the average value

[0033] S3, adjusting the frequency of the frequency converter: turning on the compressed air fan 1 and the wind direction converter 4, adjusting the frequency of the wind direction converter 4, and changing the radial and axial air volume of the eddy current dust control device;

[0034] S4. Measure the dynamic pressure in the experimental pipe 3: After the wind flow is stable, use a compensated micromanometer to measure the dynamic pressure in the two sections of the experimental pipe 3 before and after the vortex dust control device. Measure each measuring point 3 times and take the arithmetic average p di As the dynamic pressure value of the point, when measuring the dynamic pressure in the experimental pipeline 3, the arrangement of the cross-sectional measuring points is to take at least 4 evenly distributed radial directions on the cross section, and in each radial direction, at least 5 measuring points are arranged from the center of the cross section to the outside, and the distance between adjacent measuring points along the radial direction decreases.

[0035] The average dynamic pressure of the cross section is calculated as follows:

[0036]

[0037] S5. Calculate the air volume Q before and after the eddy current dust control device 1 and Q 2 , calculate the air volume according to the following formula:

[0038]

[0039] Where: Pitot tube correction factor; p d , the average dynamic pressure at the measurement section, Pa; B a , atmospheric pressure, kPa; Ambient temperature, °C; Average static pressure, kPa; A, cross-sectional area of ​​the measuring point, m 2 ;

[0040] S6. Calculate the eddy current intensity according to the air volume Q before and after the eddy current dust control device. 1 and Q 2 , calculate the eddy current intensity of the eddy current dust control device

[0041] The testing process is divided into two cases:

[0042] 1. Under the condition that the air supply volume of the compressed air fan 1 is constant, the air volume at the axial air outlet and the radial air outlet of the eddy current dust control device is changed by changing the motor power supply frequency of the wind direction converter 4 in the eddy current dust control device, and the eddy current intensity ε under different power supply frequencies is calculated. The change law of the eddy current intensity ε under different power supply frequencies f is analyzed, so as to establish the functional relationship between the eddy current intensity ε and the power supply frequency f of the eddy current dust control device.

[0043] 2. By changing the air supply volume of the compressed air fan 1, tests were conducted under different air supply volume conditions to establish the functional relationship between the eddy current intensity ε and the power frequency f of the eddy current dust control device under different air supply volumes. Under 13 air volume conditions of the compressed air fan, that is, when the power frequency of the compressed air fan 1 is set to 50Hz, 40Hz, and 30Hz respectively, the power frequency of the wind direction converter 4 is adjusted to 50Hz, 45Hz, 40Hz, 35Hz, and 30Hz respectively, and the air volume Q before and after the eddy current dust control device under different frequency combinations is measured. 1 and Q 2 , according to Q 1 and Q 2 The eddy current intensity ε under different power supply frequencies is calculated, the changing law of the eddy current intensity under different power supply frequencies is analyzed, and the function of the eddy current intensity ε under different power supply frequencies of the compressed air blower 1 and the frequency f of the eddy current dust control device is established.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for testing the strength of eddy current dust control flow field, characterized in that: The steps include: S1. Installation of experimental device: connect the compressed air fan, rectifier grid, experimental pipeline, eddy current dust control device and experimental pipeline in series in sequence, wherein the eddy current dust control device includes a wind direction converter and a eddy current wind tube; two frequency converters are respectively connected to the compressed air fan and the wind direction converter to realize frequency conversion control; two compensating micro-manometers are respectively connected to two sections of experimental pipelines; S2. Measure the ambient atmospheric pressure and temperature: Use an empty box barometer to measure the atmospheric pressure at the experimental site, and the reading is B a ; Use a thermometer to measure the temperature in the environment and take the average value of the measurement three times S3. Adjust the frequency of the frequency converter: turn on the compressed air fan and the wind direction converter, adjust the frequency of the wind direction converter, and change the radial and axial air volume of the eddy current dust control device; S4. Measure the dynamic pressure in the experimental pipeline: After the airflow is stable, use a compensated micromanometer to measure the dynamic pressure in the two experimental pipelines before and after the eddy current dust control device. Measure each measuring point 3 times and take the arithmetic average p di As the dynamic pressure value at this point, the average dynamic pressure value of the cross section is calculated as follows: S5. Calculate the air volume Q1 and Q2 before and after the eddy current dust control device. Calculate the air volume according to the following formula: Where: Pitot tube correction factor; p d , the average dynamic pressure at the measurement section, Pa; B a , atmospheric pressure, kPa; Ambient temperature, °C; Average static pressure, kPa; A, cross-sectional area of ​​the measuring point, m 2 ; S6. Calculate the eddy current intensity. Calculate the eddy current intensity of the eddy current dust control device based on the air volume Q1 and Q2 before and after the eddy current dust control device.

2. The eddy current dust control flow field strength testing method according to claim 1, characterized in that: When measuring the dynamic pressure in the experimental pipeline, the arrangement of the cross-sectional measuring points is to take at least 4 evenly distributed radial directions on the cross section. In each radial direction, at least 5 measuring points are arranged from the center of the cross section outward, and the distance between adjacent measuring points along the radial direction decreases.

3. The eddy current dust control flow field strength testing method according to claim 1, characterized in that: Under the condition of a certain air supply volume from the compressed air blower, the air volume at the axial and radial outlets of the eddy current dust control device is changed by changing the motor power frequency of the wind direction converter in the eddy current dust control device. The eddy current intensity ε under different power supply frequencies is calculated, and the variation law of the eddy current intensity ε under different power supply frequencies f is analyzed, so as to establish a functional relationship between the eddy current intensity ε and the power supply frequency f of the eddy current dust control device.

4. The eddy current dust control flow field strength testing method according to claim 3 is characterized in that: By changing the air supply volume of the compressed air fan, tests are carried out under different air supply volume conditions to establish a functional relationship between the eddy current intensity ε and the power supply frequency f of the eddy current dust control device under different air supply volumes.

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