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.

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.

Coal-Dust Motion Law and Control Technology of the Feeder

2011 ◽  
Vol 204-210 ◽  
pp. 928-931
Author(s):  
De Ji Jing ◽  
Shao Cheng Ge ◽  
Jian Liu
Keyword(s):  
Numerical Simulation ◽  
Coal Dust ◽  
Measurement Data ◽  
Dust Control ◽  
Positive Pressure ◽  
Dust Collector ◽  
Coal Preparation ◽  
Dust Pollution ◽  
Control Plan ◽  
Air Volume

The aim of this paper is mainly to study the main coal-dust pollution sources in the coal preparation plants of Ping Shuo Branch of China National Coal Group. Through the combination of many measurement data with numerical simulation of gas-solid two-phase flow, dust precipitation mechanisms have been gained for the feeder in Ping Shuo Coal Preparation Plant. Dust pollution of the feeder is caused by the positive pressure of the induced feeding wind-flow and the bad seal itself. Firstly, the durable flexible seal material is used to seal up the feeder. Secondly, the seal guide-chute with the dust collector is installed on the belt. Finally, the air volume and the pressure of the dust collector are determined by means of numerical simulation, and the reasonability of the plan is explained from the angle of the dust control mechanism. The main technical parameters of the dust control plan, such as the seal guide-chute length, and the air volume and the pressure of the dust collector, are determined through the numerical simulation. The simulation result and the actual result verify the above dust control plans. The study methods and results provide a guide for the dust control in a certain similar business.

scholarly journals Study on Dust Control Technology in Artillery Working Face

2021 ◽  
Author(s):  
Changfu Zou
Keyword(s):  
Wind Speed ◽  
High Efficiency ◽  
Diffusion Path ◽  
Dust Control ◽  
Prevention Measures ◽  
Working Face ◽  
Reduction Efficiency ◽  
Reduction Effect ◽  
Mining Work ◽  
Dust Reduction

Aiming at the serious problem of dust pollution in blasting work, the dust generation law and dust-bearing air flow time and space evolution law of blasting working face is analyzed and studied, and the optimal dust-exhausting wind speed of blasting work was 1.5 m/s. Combining with the dust production characteristics and wind speed conditions of the 107 blasting face in Dongling Coal Mine, Chongqing, Comprehensive dust prevention measures such as high-efficiency water cannon mud, high-pressure spray dust reduction, and dust concentration over-limit spray dust reduction are adopted to control the dust from the source and cut off the dust diffusion path, and the total dust reduction efficiency reached 94.8%, the respirable dust reduction efficiency reached 92%, and a good dust reduction effect has been achieved, which provides a basic basis for the control of dust in the blast mining work.

Numerical simulation of wind characteristics at bridge site considering thermal effects

2017 ◽  
Vol 21 (9) ◽  
pp. 1313-1326 ◽  
Author(s):  
Mingjin Zhang ◽  
Yongle Li ◽  
Bin Wang ◽  
Sen Ren
Keyword(s):  
Numerical Simulation ◽  
Wind Velocity ◽  
Wind Field ◽  
Thermal Effects ◽  
Surface Wind ◽  
Horizontal Wind ◽  
Bridge Site ◽  
Western Sichuan ◽  
Wind Velocities ◽  
Wind Characteristics

In order to study the variation of wind field characteristics under the influence of thermal effects at a bridge site in a deep-cutting gorge with high-altitude and temperature difference, the simulation of natural convection was realized by adding momentum source terms in FLUENT. And the correctness of the simulation results was verified. Then, choosing Dadu River Bridge located at a deep-cutting gorge in western Sichuan as an engineering background, combined with the variation of temperature tested at the bridge site, the numerical simulation of the wind field characteristics at the bridge site was carried out under the influence of the thermal effects. The influences of different thermal factors on the surface wind characteristics of bridge site area were discussed. The wind characteristics at the bridge site under the combined action of different wind velocities and thermal effects were analyzed. As shown in the results, the maximum vertical wind velocity caused by the thermal effects at the height of main girder is 3.0 m/s, and the maximum horizontal wind velocity is 6.4 m/s. When the upcoming wind velocity is greater than 5.0 m/s, the thermal effects have been significantly reduced, and the wind field at the bridge site is mainly influenced by the upcoming wind velocity, wind direction, and local terrain. Under the influence of thermal, the surface temperature distribution at the bridge site is significantly uneven, which are obviously different from the case of not considering the thermal effects.

Investigation on dust dispersion during support movement in a fully mechanized mining face and the technology with support frame enclosure dust control

2021 ◽  
pp. 095440892110311
Author(s):  
Jinming Mo ◽  
Wei Ma ◽  
Dandan Li ◽  
Sheji Zhang
Keyword(s):  
Wind Speed ◽  
Field Application ◽  
Dust Concentration ◽  
Dust Control ◽  
Average Wind Speed ◽  
Dust Source ◽  
Air Inlet ◽  
Support Frame ◽  
Site Field ◽  
Mining Face

A fully mechanized mining face is characterized by serious dust pollution and dust is a major cause of pneumoconiosis that haunts numerous miners. For a fully mechanized face having large mining heights, the main dust source in the pavement area is produced by the moving support frame. To reduce the amount of dust during support's movement, the distribution and dissipation of dust in this process were studied by combining numerical simulations with underground measurements. The results showed that with an increase of the distance from the air inlet, the wind speed of the sidewalk in the fully mechanized face first increased, then decreased, and finally increased again. At the position of the coal cutter, the highest wind speed was 1.78 m/s and the average wind speed of the roadway was about 0.8 m/s. The dust concentration at the dust source was >1000 mg/m3. An area with a high dust concentration and having a length of 15 m was formed on the rooftop, together with a 50 m long dust belt with a dust concentration of 300 to 450 mg/m3 in the pavement area of 10 m from the dust source. Beyond the 45 m radius from the dust source, the dust concentration was stable at about 250 mg/m3. Based on the dust production characteristics of the support frame, an enclosed dust-guiding device was designed and structure-optimized. Based on the on-site field application test results, it was found that the device has a satisfactory dust-guiding effect during support movement and the dust suppression rate near the dust source reached 94.8%.

scholarly journals Profiling Dust Mass Concentration in Northwest China Using a Joint Lidar and Sun-photometer Setting

2021 ◽  
Vol 13 (6) ◽  
pp. 1099
Author(s):  
Tianhe Wang ◽  
Ying Han ◽  
Wenli Hua ◽  
Jingyi Tang ◽  
Jianping Huang ◽  
...  
Keyword(s):  
Mass Concentration ◽  
Field Experiments ◽  
Negative Relationship ◽  
Northwest China ◽  
Dust Particles ◽  
Mass Loading ◽  
Average Mass ◽  
Dust Mass ◽  
Dust Loading ◽  
Sun Photometer

The satellite-based estimation of the dust mass concentration (DMC) is essential for accurately evaluating the global biogeochemical cycle of the dust aerosols. As for the uncertainties in estimating DMC caused by mixing dust and pollutants and assuming a fixed value for the mass extinction efficiency (MEE), a classic lidar-photometer method is employed to identify and separate the dust from pollutants, obtain the dust MEE, and evaluate the effect of the above uncertainties, during five dust field experiments in Northwest China. Our results show that this method is effective for continental aerosol mixtures consisting of dust and pollutants. It is also seen that the dust loading mainly occurred in the free troposphere (< 6 km), with the average mass loading of 905 ± 635 µg m−2 trapped in the planetary boundary layer. The dust MEE ranges from 0.30 to 0.60 m2 g−1 and has a significantly negative relationship with the size of dust particles. With the assumption of the dust MEE of 0.37 (0.60) m2 g−1, the DMC is shown to be overestimated (underestimated) by 20–40% (15–30%). In other words, our results suggest that the change of MEE with the size of dust particles should be considered in the estimation of DMC.

scholarly journals Numerical Simulation and Engineering Application of Coalbed Water Injection

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Yijie Shi ◽  
Pengfei Wang ◽  
Ronghua Liu ◽  
Xuanhao Tan ◽  
Wen Zhang
Keyword(s):  
Numerical Simulation ◽  
Process Parameters ◽  
Water Injection ◽  
Engineering Application ◽  
Working Environment ◽  
Engineering Practice ◽  
Characteristic Parameters ◽  
Injection Process ◽  
Working Face ◽  
Dust Reduction

Coalbed water injection is the most basic and effective dust-proof technology in the coal mining face. To understand the influence of coalbed water injection process parameters and coalbed characteristic parameters on coal wetting radius, this paper uses Fluent computational fluid dynamics software to systematically study the seepage process of coalbed water injection under different process parameters and coalbed characteristic parameters, calculation results of which are applied to engineering practice. The results show that the numerical simulation can help to predict the wetness range of coalbed water injection, and the results can provide guidance for the onsite design of coalbed water injection process parameters. The effect of dust reduction applied to onsite coalbed water injection is significant, with the average dust reduction rates during coal cutting and support moving being 67.85% and 46.07%, respectively, which effectively reduces the dust concentration on the working face and improves the working environment.

Numerical Simulation on the Temperature Characteristics of Indirect Air Cooling System

2015 ◽  
Vol 741 ◽  
pp. 536-540
Author(s):  
Xiao Zhi Qiu ◽  
Yan Ming Zhao ◽  
Bao Hua Huang ◽  
Wei Xu
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Cooling System ◽  
System Change ◽  
Temperature Characteristic ◽  
Air Cooling ◽  
Ansys Software ◽  
System A ◽  
Air Cooling System ◽  
Simulation Results

Based on the analysis of indirect air cooling system, a numerical simulation model of indirect air cooling system was constructed by ANSYS software. According to the different wind speed condition, the temperature characteristic of indirect air cooling system was analyzed. The simulation results show that with the increase of wind speed, the ventilation and heat release of the indirect air cooling system change greatly. It provides a theoretical basis for the design of the wind-proof device of indirect air cooling system.

Numerical simulation of ventilation and dust suppression system for open-type TBM tunneling work area

2016 ◽  
Vol 56 ◽  
pp. 70-78 ◽  
Author(s):  
Yimin Xia ◽  
Duan Yang ◽  
Chenghuan Hu ◽  
Caizhang Wu ◽  
Jialin Han
Keyword(s):  
Numerical Simulation ◽  
Dust Suppression ◽  
Open Type ◽  
Work Area ◽  
Suppression System
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