Effects of air volume ratio parameters on air curtain dust suppression in a rock tunnel’s fully-mechanized working face

2018 ◽  
Vol 29 (2) ◽  
pp. 230-244 ◽  
Author(s):  
Hao Wang ◽  
Wen Nie ◽  
Weimin Cheng ◽  
Qiang Liu ◽  
Hu Jin
Keyword(s):  
Volume Ratio ◽  
Dust Suppression ◽  
Air Curtain ◽  
Air Volume ◽  
Working Face

Experimental study of the effects of air volume ratios on the air curtain dust cleaning in fully mechanized working face

2021 ◽  
Vol 293 ◽  
pp. 126109
Author(s):  
Hao Wang ◽  
Weimin Cheng ◽  
Zhanyou Sa ◽  
Jie Liu ◽  
Ran Zhang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Air Curtain ◽  
Air Volume ◽  
Working Face

scholarly journals CFD-Based Determination of the Optimal Blowing and Suction Air Volume Ratio of Dual-Radial Swirl Shielding Ventilation in a Fully Mechanized Excavation Face

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kuan Wu ◽  
Shiliang Shi ◽  
Yijie Shi ◽  
Yong Chen
Keyword(s):  
Ventilation System ◽  
Volume Ratio ◽  
Simulation Method ◽  
Dust Concentration ◽  
Dust Control ◽  
Underground Mines ◽  
Physical And Mental Health ◽  
Control Effect ◽  
Air Curtain ◽  
Air Volume

Dust is one of the main pollutants in coal mines, which seriously affects the physical and mental health of workers, as well as the safe production in underground mines. Dual-radial swirl shielding ventilation is a new ventilation method for a fully mechanized excavation face and can effectively reduce the dust concentration in the underground. The dust control effect of dual-radial swirl shielding ventilation is mainly affected by the thickness and integrity of the shielding air curtain, as well as the disturbance of the flow field near the air curtain. By changing the blowing and suction air volume ratio of the air duct, the strength of the radial air curtain can be improved, and the dust control effect of the dual-radial swirl shielding ventilation system can be effectively improved. In order to determine the optimal operating parameters of the dual-radial swirl shielding ventilation system, a numerical simulation method was used to conduct an in-depth study on the blowing and suction air volume ratio of the system. The results showed that when the blowing and suction air volume ratio of the air duct was 1.5, the radial air curtain had the highest strength. Under this condition, the dust concentration at the driver’s position of the roadheader was the lowest, and the dual-radial swirl shielding ventilation system can achieve an ideal dust control effect.

scholarly journals Influence of the strip-shaped air-out slits’ width in the fully mechanized working face under wallattached swirling ventilation condition

2019 ◽  
Vol 81 ◽  
pp. 01016 ◽  
Author(s):  
Yongjun Li ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Han Han ◽  
Xuanhao Tan ◽  
...  
Keyword(s):  
Control Effect ◽  
Control Block ◽  
Air Curtain ◽  
Ventilation Condition ◽  
Air Volume ◽  
Working Face ◽  
Airflow Field ◽  
Fluent Software ◽  
Dust Diffusion ◽  
Bag Precipitator

For the purpose of mastering the influence of the strip-shaped air-out slits’ width in the fully mechanized working face under wallattached swirling ventilation condition, By using fluent software, numerical simulation of airflow field and dust diffusion in fully mechanized working face under different strip-shaped air-out slits’ width conditions was carried out. The results show that the wall-attached swirling ventilation can effectively control the dust diffusion in the fully mechanized working face, improve the dust collecting effect of the bag precipitator fan, and reduce the particle mass concentration at the driver and the rear of the tunnel; Increasing the air volume of the strip-shaped airout slits can improve the control effect of the swirling air curtain on the dust, appropriate air volume can make the swirling air curtain control the dusty airflow and push it to the end of the heading surface to control, block and propel the dust; When the width of the strip-shaped air-out slits is 0.06 m, the dust collecting effect of the exhaust air cylinder on the dust and the effect of the wall-attached swirling on the plugging of the dust are best.

Numerical Simulation Study on Air-Flow Migration Law about Vortex Air Curtain of Plane Wall Fan Drum

2012 ◽  
Vol 241-244 ◽  
pp. 1285-1292
Author(s):  
Gang Zhou ◽  
Sen Cao ◽  
De Ming Wang ◽  
Wei Min Cheng ◽  
Wen Nie
Keyword(s):  
Numerical Simulation ◽  
Control System ◽  
Simple Algorithm ◽  
Plane Wall ◽  
Dust Control ◽  
High Concentration ◽  
Air Curtain ◽  
Working Face ◽  
Simulation Results ◽  
Migration Law

Vortex air curtain of plane wall fan drum can control the diffusion of air stripping dust effectively. In order to solve the high-concentration dust problem in fully mechanized excavation face, formation mechanism of vortex air curtain was analyzed. According to fluid mechanical control equations of gas phase flow, mathematical model was established to solve air migration law of vortex air curtain in fully mechanized excavation face. By using Simple algorithm based on collocated grid and fluent software, numerical simulation of air spatial migration law of closed-end dust control in fully mechanized excavation face was carried out. The simulation results show that vortex air curtain dust control system can form dust control fan drum along driving head to the front of the roadheader driver. According to the simulation results and actual conditions of working face field, vortex air curtain suction dust control system consisted of plane wall fan drum and exhausted dust purification device in fully mechanized excavation face was designed, and after it was applied in fully mechanized excavation face, the dust concentration decreased effectively in the working face field.

Experimental Research on the Stability of Airflow in Diagonal Network during Fire

2013 ◽  
Vol 807-809 ◽  
pp. 2345-2350
Author(s):  
Wen Cai Wang ◽  
Bo Zhang ◽  
Wen Bin Wei ◽  
Yu Hong Jiang ◽  
Ya Chen Li ◽  
...  
Keyword(s):  
Wind Direction ◽  
Experimental Simulation ◽  
Diagonal Branch ◽  
Mine Fire ◽  
Tunnel Fire ◽  
Air Volume ◽  
Working Face ◽  
Air Supply ◽  
The Stability ◽  
Angle Connection

In order to study the influence of tunnel fire on the airflow stability in diagonal network of single diagonal network ventilation, according to the principle of similitude air supply system of 4101 working face of Huhewusu was taken for research object. In a proportion of 1:20, simulation device for angle connection roadway was established. By means of this simulation device and the method of experimental simulation, change law of the air volume and wind direction of diagonal branch in single diagonal network was studied. The results showed that in a particular period of mine fire, air volume decreased in fire roadway and windage increased; air volume in diagonal branch decreased and with the process of fire the wind direction would change. After the change of wind direction, with the changing of fire scale the reverse air volume would show the same changing process.

scholarly journals Researches on the numerical simulation of the dust pollution characteristics and the optimal dust suppression wind-speed on fully mechanised caving face

2021 ◽  
pp. 014459872110558
Author(s):  
Jinming Mo ◽  
Wei Ma
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Wind Velocity ◽  
Mass Concentration ◽  
Dust Control ◽  
Dust Pollution ◽  
Dust Suppression ◽  
Working Face ◽  
Dust Mass ◽  
Wind Velocities

Dust removal by ventilation is a commonly used dust control strategy. This study analyses the characteristics of airflow transport and dust pollution on a fully mechanised top-coal caving face at different inlet wind velocities by using a numerical simulation experiment, and the best wind velocity for dust suppression is obtained. When the inlet wind velocity fluctuates in the range of 0.5 to 3.0 m/s, the overall dust mass concentration on the working face initially increases and then remains stable, but in the range of 2.5 to 3.0 m/s, the changes in the overall dust mass concentration and dust mass concentration of the respiratory zone on the working face are not significant. The dust pollution in the respiratory zone produced by the hydraulic support lowering pillar and moving frame on the working face is quantitatively analysed at different inlet wind velocities of 2.5 to 3.0 m/s to determine the optimum wind velocity for dust suppression on the working face. The optimum wind speed for dust suppression is 2.6 m/s. This study lays a foundation for the ventilation design and dust control in the early stage of a mine and for the establishment of a clean and green production mine.

Theoretical and practical research on relationship between blast air condition and hearth activity in large blast furnace

2020 ◽  
Vol 117 (1) ◽  
pp. 113 ◽  
Author(s):  
Bing Dai ◽  
Hong-ming Long ◽  
Yi-long Ji ◽  
Jia-ting Rao ◽  
Yun-cai Liu
Keyword(s):  
Blast Furnace ◽  
Kinetic Energy ◽  
Raw Materials ◽  
Volume Ratio ◽  
Operation Condition ◽  
Extensive Experience ◽  
Air Volume ◽  
Blast Furnace Production ◽  
Air Speed

From the results calculated by theoretical derivations, it was found that the characteristics of tuyere raceway determined by the operation condition for blast air played a critical effect on the heart activity. The speed and kinetic energy of blast air should be proportional to the volume of blast furnace (BF), and the comprehensive optimization of air volume and tuyere which should vary with the quality of raw materials was essential. The calculation methods of air volume ratio and coefficient for different BFs were put forward. Moreover, the details on hearth activity recovery of a 4747 m3 blast furnace in China were elaborated. Based on the extensive experience in blast furnace production, the various phenomena used to judge air speed and kinetic energy whether reasonable were discussed. In summary, hearth activity was closely related to the characteristics of BF raceway and reasonable air speed and kinetic energy could effectively improve the activity.

scholarly journals Research and Application on the Key Parameters of the Long Compression and Short Pumping Ventilation Dust Removal System

2018 ◽  
Vol 237 ◽  
pp. 01015
Author(s):  
Zhang She-ji ◽  
MA Wei ◽  
MO Jin-ming
Keyword(s):  
Process Parameters ◽  
Dust Removal ◽  
Confined Space ◽  
Technological Parameters ◽  
Field Verification ◽  
System A ◽  
Air Jet ◽  
Air Volume ◽  
Working Face ◽  
Removal System

For the question of circulation wind emerged in the process of using long compression and short pumping ventilation dust removal system, a new model of air volume matching was proposed, and the empirical formula of the key process parameters such as axial and radial air volume, axial and radial air out distance were derived according to the relevant theories of air jet in the confined space. Then the 20106 return roadway of fully mechanized working face in Wang Jia Ling coal mine was selected to conduct field verification tests. The result showed that the new air volume catching model had good adaptability, and the key process parameters obtained by theoretical calculation and field test were basically identical. Under the condition of optimum technological parameters, the total dust and respiratory dust concentration of the driver’s place can be reduced 91.98% and 89.53% respectively.

scholarly journals Wave energy absorption by a floating air bag

2016 ◽  
Vol 812 ◽  
pp. 294-320 ◽  
Author(s):  
A. Kurniawan ◽  
J. R. Chaplin ◽  
D. M. Greaves ◽  
M. Hann
Keyword(s):  
Dynamic Response ◽  
Energy Absorption ◽  
Wave Energy ◽  
Volume Ratio ◽  
Phase Control ◽  
Small Scale ◽  
Air Volume ◽  
Air Bag ◽  
The Waves ◽  
Shape And Size

A floating air bag, ballasted in water, expands and contracts as it heaves under wave action. Connecting the bag to a secondary volume via a turbine transforms the bag into a device capable of generating useful energy from the waves. Small-scale measurements of the device reveal some interesting properties, which are successfully predicted numerically. Owing to its compressibility, the device can have a heave resonance period longer than that of a rigid device of the same shape and size, without any phase control. Furthermore, varying the amount of air in the bag is found to change its shape and hence its dynamic response, while varying the turbine damping or the air volume ratio changes the dynamic response without changing the shape.

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