Dust deposition layer formation and instability mechanism simulation experiment platform

Abstract

The invention belongs to the field of dust disaster prevention and control, and particularly relates to a dust deposition layer formation and instability mechanism simulation experiment platform. Comprising an air supply input mechanism, an air supply input mechanism, a powder supply input mechanism, a transparent air duct and various detection sensors. The air duct is formed by splicing a plurality of sections and can be freely combined according to an experiment requirement environment; input mechanisms are arranged at the two ends of the air duct, and air supply, air supply and powder supply are achieved from the two ends of the air duct and used for simulating deposition and movement conditions of dust under one-way air flow or air flow reversion; dust collecting pieces are arranged at different positions of the air duct, and the air duct is further connected with an image collecting device; multi-physical field coupling is realized through the organic glass air duct, and the dynamic evolution process of a dust deposition layer under the synergistic effect of an air flow field, a viscous force field and a gravity field can be accurately simulated; the method can be applied to dust deposition layer instability characteristic simulation research.

Description

Technical Field

[0001] The invention belongs to the field of environmental and safety science and technology, and relates to the field of dust disasters; specifically, it is a dust deposition layer formation and instability mechanism simulation experimental platform. Background Art

[0002] In recent years, with the acceleration of the industrialization process, the safety issues in the production process of the mining industry, as one of the important pillar industries of the national economy, have received increasing attention. Among them, dust disasters have become a major hidden danger to the safe production of the mining industry due to their strong suddenness and destructive power. Due to the limitations of the operation process and technology, dust accumulation in the pipeline is inevitable, and there are many corner-connected pipelines distributed in the mining pipeline network. The corner-connected pipelines themselves have poor stability and are very prone to wind reversal. As a result, some of the deposited dust forms dust under the action of gravity and wind flow. These dusts are broken and dispersed in the pipeline due to impact and other reasons, further forming dust clouds, which are very likely to cause explosions and other types of dust disasters, seriously threatening people’s lives and property safety. Therefore, building a similar platform for the formation of instability due to deposited dust is of great significance for the study and prevention of dust disasters.

[0003] At present, the simulation of the formation and instability of the deposited dust layer remains at the microscopic perspective, mostly relying on software simulation, lacking information on the transition to the macroscopic state, and there is little research on corner-connected pipe networks and wind flow reversal. At present, there is no dedicated experimental platform for simulating the formation and instability of dust deposits in air ducts, and some existing experimental platforms are mostly fully enclosed systems, and the experimental equipment can only achieve unidirectional wind flow, and cannot achieve wind flow reversal and specifically measure the thickness of the deposited dust layer in the air duct. Therefore, it is urgent to build an experimental platform to study the formation of the deposited dust layer in the air duct and the instability of the deposited layer under wind flow reversal. Summary of the invention

[0004] The present invention overcomes the shortcomings of the prior art and proposes a dust deposition layer formation and instability mechanism simulation experimental platform; the present invention is achieved through the following technical solutions: A dust deposition layer formation and instability mechanism simulation experimental platform, including a premixed gas cylinder, an air supply system, a powder supply system, a data acquisition terminal, an analysis terminal, a high-speed camera, a three-dimensional laser Doppler velocimeter, a dust collection sheet, an ignition device, a heater, a humidifier, a temperature sensor, a humidity sensor, a gas concentration sensor, a wind speed sensor, a dust concentration sensor, and an air duct; The air duct is made of transparent explosion-proof glass and is composed of multiple sections; The premixed gas cylinder is connected to different positions on the air duct through the gas delivery channel, and a valve is provided on the gas delivery channel; the powder supply system and the air supply system are connected to both ends of the air duct; the air supply system includes an axial flow variable frequency fan and an air duct valve, and the air supply system is located outside the powder supply system to simulate the deposition and movement of dust under unidirectional airflow or airflow reversal; Humidifiers, heaters, temperature sensors, humidity sensors, gas concentration sensors, wind speed sensors, dust concentration sensors and ignition devices are installed at both ends of the air duct; data collected by the temperature sensor, humidity sensor, wind speed sensor, gas concentration sensor and dust concentration sensor are transmitted to the analysis terminal for analysis and processing through the data acquisition terminal; The three-dimensional laser Doppler velocimeter and the high-speed camera are both connected to the air duct; Dust collecting sheets are arranged at different positions of the air duct.

[0005] Furthermore, it also includes an electrostatic dust removal device, which is installed on both sides of the air duct and located on the inner side of the air supply system.

[0006] Furthermore, the humidifiers and heaters at both ends of the air duct are arranged relative to each other.

[0007] Furthermore, the powder supply system is mainly composed of a micro screw feeder and a control box, and the control box controls the start and stop of the screw feeder and adjusts the speed of dust supply.

[0008] Furthermore, the dust collecting pieces are made of detachable transparent glass plates, which are respectively installed in the middle of each section of the air duct, and a dust collecting piece is arranged on the upper, lower, left and right walls of each section of the air duct.

[0009] Furthermore, the air ducts are divided into two groups, each group of air ducts has a bending angle at both ends, the two ends of the two groups of air ducts converge together and are connected to each other, and two movable partitions are respectively arranged at the convergence point; a plurality of movable partitions are also arranged in sequence in the middle of each group of air ducts.

[0010] Furthermore, a connecting air duct is connected between the two groups of air ducts; the two groups of air ducts are connected through the connecting air duct, and a partition is also provided at the connecting point.

[0011] Furthermore, an ignition device is arranged in the middle of the air duct and the connecting air duct, and dust collecting sheets are arranged on both sides of the middle of the air duct and in the middle of the connecting air duct.

[0012] Furthermore, the high-speed camera and the three-dimensional laser Doppler velocimeter are both connected to a movable base.

[0013] The beneficial effects of the present invention compared with the prior art are as follows: The present invention includes multiple units such as gas and dust supply, environmental control, data collection and visual observation. The experimental platform realizes multi-physical field coupling through organic glass wind ducts, and can accurately simulate the dynamic evolution process of dust deposition layer under the synergistic effect of wind flow field-viscous force field-gravity field. The system can monitor the formation, instability, fracture, loosening, impact and secondary dust of dust deposition layer in real time, especially can accurately capture the deposition characteristics and movement laws of dust layer under wind flow reversal conditions, and provide an important experimental platform and theoretical support for the research of dust disaster prevention and control technology; it can be used to study the formation of deposited dust layer and the instability of dust after wind flow reversal. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the dust deposition layer formation and instability mechanism simulation experimental platform described in Example 1; Figure 2 This is a schematic diagram of the structure of the experimental platform for simulating the formation and instability mechanism of the dust deposition layer under the corner-connected air duct in Example 2.

[0015] 1. Premixed gas cylinder; 2. Axial frequency conversion fan; 3. Air duct valve; 4. Electrostatic dust removal device; 5. Screw feeder; 6. Control box; 7. Data acquisition terminal; 8. Analysis terminal; 9. High-speed camera; 10. Three-dimensional laser Doppler velocimeter; 11. Dust collection sheet; 12. Ignition device; 13. Heater; 14. Valve; 15. Humidifier; 16. Temperature sensor; 17. Humidity sensor; 18. Gas concentration sensor; 19. Wind speed sensor; 20. Dust concentration sensor; 21. Air duct; 22. Partition; 23. Connecting air duct 23. DETAILED DESCRIPTION

[0016] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail in conjunction with the embodiments and the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The technical solutions of the present invention are described in detail below in conjunction with the embodiments and the accompanying drawings, but the scope of protection is not limited thereto.

[0017] Example 1 See also Figure 1The present embodiment proposes a dust deposition layer formation and instability mechanism simulation experimental platform; it includes a premixed gas cylinder 1, an air supply system, an electrostatic dust removal device 4, a powder supply system, a data acquisition terminal 7, an analysis terminal 8, a high-speed camera 9, a three-dimensional laser Doppler velocimeter 10, a dust collection sheet 11, an ignition device 12, a heater 13, a valve 14, a humidifier 15, a temperature sensor 16, a humidity sensor 17, a gas concentration sensor 18, a wind speed sensor 19, a dust concentration sensor 20, and an air duct 21, wherein the data acquisition terminal 7 and the analysis terminal 8 are connected to each sensor.

[0018] The premixed gas cylinder 1 mainly contains premixed gas. Premixed gas cylinders 1 with different concentrations can be equipped according to specific experimental requirements. The premixed gas cylinder 1 is connected to the front and rear positions of the air duct 21 through two gas delivery channels. A valve 14 is provided on the gas delivery channel. The position where the gas enters the air duct 21 and the concentration of the gas in the pipeline can be controlled by adjusting the valve 14 on the gas delivery channel.

[0019] The air duct 21 used in the experiment is made of transparent explosion-proof plexiglass. The overall shape is rectangular, with a height of 200mm, a width of 300mm, and a length of 6m. It is divided into four sections, and the lengths of each section are 2m, 1m, 1m, and 2m respectively. The adjacent sections are connected by flanges. The transparent plexiglass used in the air duct can clearly observe the experimental process.

[0020] The powder supply system is mainly composed of a micro screw feeder 5 and a control box 6, which are used as dust sources to provide dust to the experimental equipment. Single or mixed types of dust can be added according to the required dust type. The control box 6 controls the start and stop of the screw feeder 5 and adjusts the speed of dust supply. The screw feeder 5 is used to transport dust and ensure uniform supply of dust. Powder supply systems are set at both ends of the air duct 21, and powder supply can be achieved from both ends of the air duct 21.

[0021] The air supply system is mainly composed of an axial-flow variable-frequency fan 2 and an air duct valve 3, which can simulate wind flows of different sizes and control wind speeds. Air supply systems are provided at both ends of the air duct 21, which can not only simulate the deposition and movement of dust under unidirectional wind flow, but also simulate wind flow reversal by opening the air supply system on the other side, so as to study the instability law of dust under wind flow reversal. The electrostatic dust removal device 4 is installed on both sides of the air duct 21 and is located on the inner side of the air supply system. While preventing dust, it can also purify gas and recover useful dust particles, reducing pollution to the environment and improving the utilization rate of experimental materials.

[0022] A humidifier 15, a heater 13, a temperature sensor 16, a humidity sensor 17, a gas concentration sensor 18, a wind speed sensor 19, a dust concentration sensor 20 and an ignition device 12 are provided at both ends of the air duct 21, and are all located on the inner side of the air supply system; wherein the ignition device 12 is symmetrically arranged on both sides of the air duct 21, and is mainly used to provide a controllable ignition source to simulate explosions that may occur under certain special circumstances, such as detecting the explosion limit of a gas-dust mixture system, so as to realize the observation and research of the explosion characteristics of the dust-gas mixture system.

[0023] The humidifiers 15 and the heater 13 at both ends of the air duct 21 are relatively arranged, that is, the humidifiers 15 and the heaters 13 at each end are respectively located on both sides of the air duct 21; since humidity and temperature are important factors affecting dust deposition in some actual workplaces, the temperature and humidity in the pipeline can be controlled according to the required experimental conditions to achieve better experimental results; at the same time, by studying the deposition of dust under different humidity and temperature, a reference basis can be provided for preventing disasters caused by wind flow reversal.

[0024] Specifically, there are two humidity sensors 17, which are respectively arranged on both sides of the air duct 21. Since humidity has an important influence on the deposition and instability of dust, this device is mainly used to detect the humidity in the air duct 21 during the experiment; there are two temperature sensors 16, which are respectively located on both sides of the air duct 21. They are mainly used to detect the temperature in the air duct 21 during the experiment. Temperature is also an important factor affecting the formation and explosion of explosive dust clouds under wind countercurrent. The formation of explosive dust clouds can be further analyzed by collecting and analyzing temperature data during the experiment.

[0025] There are two wind speed sensors 19, located on both sides of the air duct 21, and are used to measure the wind speed data in the air duct 21. Wind speed is an important factor affecting the formation and stability of the dust layer. Wind speed plays a key role in the deposition, resuspension and transportation stages. By collecting wind speed data, the relationship between the formation of the dust layer and the wind speed can be analyzed, which provides a basis for subsequent research on dust suppression measures and prevention of dust disasters caused by wind flow reversal.

[0026] The gas concentration sensor 18 is located on both sides of the air duct 21. In a specific industrial and mining environment, there may be gas release and leakage. The gas concentration will affect the dust limit. Studying the dust concentration under different gas concentrations is of great significance for preventing dust disasters.

[0027] There are two dust concentration sensors, which are respectively arranged on both sides of the air duct 21. They are mainly used to detect the dust concentration in the air duct 21. In the actual working environment, the formation of dust accumulation layer and the reversal of wind flow may produce explosive dust cloud in the experimental air duct. Therefore, studying the dust concentration under different wind speed, temperature and humidity environments is of great significance for preventing accidents. Fixed sensors or movable sensors can be used for data collection according to different experimental conditions.

[0028] The data collected by the temperature sensor 16, the humidity sensor 17, the wind speed sensor 19, the gas concentration sensor 18, and the dust concentration sensor 20 are all transmitted through the data collection terminal 7 to the analysis terminal 8 (such as a computer) for analysis and processing.

[0029] The dust collecting sheet 11 adopts a detachable transparent glass plate, which is respectively installed in the middle position of the four sections of the air duct 21. Four dust collecting sheets 11 are set in each section of the air duct 21, and a total of 16 are set; a dust collecting sheet 11 is arranged on the upper, lower, left and right walls of each section of the air duct 21, which is mainly used to measure the dust accumulation on the inner wall of the air duct at different positions away from the dust source under different experimental conditions, and the dust instability at different positions after the wind flow reversal occurs. The detachable device is used to facilitate experimental observation and research. To ensure the accuracy of the experiment, the dust collecting sheet 11 must be flush with the inner wall of the air duct 21, and the inner wall of the air duct must be flat. Based on the principle of micro-weighing, the dust thickness of the samples collected by the dust collecting sheet 11 is measured; if the dust used in the experiment is mixed dust, the deposition and instability laws of different types of dust can be further compared and analyzed.

[0030] The three-dimensional laser Doppler velocimeter 10 and the high-speed camera 9 are located in the middle of the entire air duct 21, and are used to measure the parameters such as the migration speed, particle size and fluid flow rate of dust particles under different experimental conditions. The high-speed camera 9 can also record the changes in dust movement at the moment of wind flow reversal or the moment of changing experimental conditions. The three-dimensional laser Doppler velocimeter 10 and the high-speed camera 9 in this device can be fixedly installed or removably installed according to specific experimental requirements to optimize the overall equipment.

[0031] Example 2 See also Figure 2 This embodiment proposes a dust deposition layer formation and instability mechanism simulation experimental platform; it is an experimental device that simulates the corner-connected air duct, which can further study the deposition and migration laws of dust under the corner-connected air duct.

[0032] The structure is the same as that of Example 1: it also includes a premixed gas cylinder 1, an air supply system, an electrostatic dust removal device 4, a powder supply system, a data acquisition terminal 7, an analysis terminal 8, a high-speed camera 9, a three-dimensional laser Doppler velocimeter 10, a dust collection sheet 11, an ignition device 12, a heater 13, a valve 14, a humidifier 15, a temperature sensor 16, a humidity sensor 17, a gas concentration sensor 18, a wind speed sensor 19, a dust concentration sensor 20, and an air duct 21, wherein the data acquisition terminal 7 and the analysis terminal 8 are connected to each sensor.

[0033] Different from Example 1: the structure of the air duct 21 is different. In this embodiment, the air duct 21 can be freely assembled, and different types of experimental air ducts 21 can be designed according to specific experimental requirements; specifically, in this embodiment, the air duct 21 is divided into two groups, and the two ends of each group of air ducts 21 have bending angles. The two ends of the two groups of air ducts 21 converge together and are connected to each other, and two movable partitions 22 are respectively set at the convergence; a plurality of movable partitions 22 are also sequentially set in the middle of each group of air ducts 21; by increasing or reducing the number of partitions 22 or moving the position of the partitions 22, the size, length and other structures of the detection space of the air duct 21 can be adjusted; since the air duct 21 is a splicing structure, it can also be freely assembled according to experimental needs. In this embodiment, a connecting air duct 23 is connected between the two groups of air ducts 21; the two groups of air ducts 21 are connected by the connecting air duct 23, and a partition 22 is also set at the connecting point, so that the two groups of air ducts 21 can be connected or disconnected.

[0034] The converging points of the two ends of the two groups of air ducts 21 are respectively connected to the premixed gas cylinder 1, the air supply system, the electrostatic dust removal device 4, and the powder supply system; the two ends of each group of air ducts 21 are provided with a humidifier 15, a temperature sensor 16, a humidity sensor 17, a gas concentration sensor 18, a wind speed sensor 19, a dust concentration sensor 20, and a heater 13; an ignition device 12 is provided in the middle of the air duct 21 and the connecting air duct 23, and dust collection sheets 11 are provided on both sides of the middle of the air duct 21 and in the middle of the connecting air duct 23; the data collected by the temperature sensor 16, the humidity sensor 17, the wind speed sensor 19, and the gas concentration sensor 18 are all transmitted to the analysis terminal 8 (such as a computer) for analysis and processing through the data acquisition terminal.

[0035] The high-speed camera 9 and the three-dimensional laser Doppler velocimeter 10 are both connected to a movable base and move on the air duct 21 to take pictures.

[0036] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the present invention, which should be regarded as belonging to the present invention and the scope of patent protection determined by the submitted claims.

Claims

1. A dust deposition layer formation and instability mechanism simulation experimental platform, characterized in that: It includes a premixed gas cylinder (1), an air supply system, a powder supply system, a data acquisition terminal (7), an analysis terminal (8), a high-speed camera (9), a three-dimensional laser Doppler velocimeter (10), a dust collection sheet (11), an ignition device (12), a heater (13), a humidifier (15), a temperature sensor (16), a humidity sensor (17), a gas concentration sensor (18), a wind speed sensor (19), a dust concentration sensor (20), and an air duct (21); The air duct (21) is made of transparent explosion-proof glass, and the air duct (21) is composed of multiple sections spliced ​​together; The premixed gas cylinder (1) is connected to different positions on the air duct (21) through a gas delivery channel, and a valve (14) is provided on the gas delivery channel; a powder supply system and an air supply system are connected to both ends of the air duct (21); the air supply system is located outside the powder supply system and is used to simulate the deposition and movement of dust under unidirectional airflow or airflow reversal; A humidifier (15), a heater (13), a temperature sensor (16), a humidity sensor (17), a gas concentration sensor (18), a wind speed sensor (19), a dust concentration sensor (20) and an ignition device (12) are provided at both ends of the air duct (21); data collected by the temperature sensor (16), the humidity sensor (17), the wind speed sensor (19), the gas concentration sensor (18) and the dust concentration sensor (20) are transmitted to the analysis terminal (8) through the data collection terminal (7) for analysis and processing; The three-dimensional laser Doppler velocimeter (10) and the high-speed camera (9) are both connected to the air duct (21); Dust collecting sheets (11) are arranged at different positions of the air duct (21).

2. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 is characterized in that: It also includes an electrostatic dust removal device (4), which is installed on both sides of the air duct (21) and located inside the air supply system.

3. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 is characterized in that: The humidifier (15) and the heater (13) at both ends of the air duct (21) are arranged relative to each other.

4. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 is characterized in that: The powder supply system is mainly composed of a micro screw feeder (5) and a control box (6). The control box (6) controls the start and stop of the screw feeder (5) and adjusts the speed of dust supply.

5. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 is characterized in that: The dust collecting pieces (11) are made of detachable transparent glass plates and are respectively installed in the middle of each section of the air duct (21). A dust collecting piece (11) is arranged on the upper, lower, left and right walls of each section of the air duct (21).

6. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 is characterized in that: The air ducts (21) are divided into two groups. Both ends of each group of air ducts (21) have a bending angle. The two ends of the two groups of air ducts (21) converge together and are interconnected. Two movable partitions (22) are respectively arranged at the convergence point. A plurality of movable partitions (22) are also sequentially arranged in the middle of each group of air ducts (21).

7. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 6 is characterized in that: A connecting air duct (23) is connected between the two groups of air ducts (21); the two groups of air ducts (21) are connected via the connecting air duct (23), and a partition plate (22) is also provided at the connecting point.

8. The dust deposition layer formation and instability mechanism simulation experimental platform according to claim 7 is characterized in that: An ignition device (12) is disposed in the middle of the air duct (21) and the connecting air duct (23), and dust collection sheets (11) are disposed on both sides of the middle of the air duct (21) and in the middle of the connecting air duct (23).

9. A dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 or 6, characterized in that: The high-speed camera (9) and the three-dimensional laser Doppler velocimeter (10) are both connected to a movable base.

10. A dust deposition layer formation and instability mechanism simulation experimental platform according to claim 1 or 6, characterized in that: The air supply system comprises an axial-flow variable-frequency fan (2) and an air duct valve (3).

Images