scholarly journals Experimental Investigation on Atomization and Dustfall Characteristics of Combined Nozzles for Shearer External Spray in Fully Mechanized Coal Mining Face

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Qian Wang ◽  
Ruixin Song ◽  
Junpeng Wang ◽  
Cuicui Xu ◽  
Gang Zhou ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Coal Mining ◽  
High Efficiency ◽  
Field Application ◽  
Respirable Dust ◽  
Optimal Parameters ◽  
Angle Change ◽  
Phase Doppler Interferometry ◽  
Mining Face

To explore the dustfall effect of combined nozzles used in a fully mechanized mining face, Phase Doppler Interferometry (PDI) system was used to test 6 types of high-efficiency atomizer under 8 MPa. A new nozzle group of nozzles 2#, 3#, and 5# is selected by atomization experiment. The atomization experiment and field application test of the preferred nozzle are performed. The experiment and field application results show that, with the spray pressure of 8 MPa, when the distance in the nozzle group is 200 mm and the angle change is 10 degrees, the atomization effect is the best. Under the optimal parameters, the average dustfall rates of the entire and respirable dust are 81.82% and 79.96%, respectively, which are 23.49% and 20.75% higher than those of the traditional shearer.

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%.

The Adaptation Analysis of the Fully Mechanized Coal Mining Face of Huopu Mine’s Third Soft Coal Seam

2014 ◽  
Vol 1049-1050 ◽  
pp. 335-338 ◽  
Author(s):  
Fa Quan Liu ◽  
Xue Wen Geng ◽  
Yong Che ◽  
Xiang Cui
Keyword(s):  
Coal Seam ◽  
Coal Mining ◽  
Geological Condition ◽  
Soft Coal ◽  
Working Face ◽  
Mining Face ◽  
Soft Coal Seam ◽  
Working Resistance

To get the maximum coal in front of the working face of the 17# coal seam, we installed a longer beam which is 1.2m in length in the leading end of the original working face supports ZF3000/17/28, and know that working face supports’ setting load and working resistance are lower .We changed the original supports with shield supports ZY3800/15/33 that are adaptable in the geological condition and got the favorable affection.

scholarly journals Numerical and in-situ investigation on the ground behavior of the end roof in fully mechanized caving face

2021 ◽  
Vol 303 ◽  
pp. 01028
Author(s):  
Chuanwei Zang ◽  
Miao Chen ◽  
Yang Chen ◽  
Xuean Zhuang ◽  
Chenming Zhai ◽  
...  
Keyword(s):  
Coal Mining ◽  
Concentration Factor ◽  
High Efficiency ◽  
Vertical Displacement ◽  
High Yield ◽  
Support Pressure ◽  
Roof Structure ◽  
In Situ Investigation ◽  
And Migration ◽  
Seam Mining

Fully mechanized top coal caving is a major high-yield and high-efficiency coal mining method for thick seam mining. At present, it is affected by the further popularization and application of fully mechanized caving mining because the recovery rate is limited. The research on the technology of fully mechanized top coal caving and transitional coal mining is crucial. This paper aims at the top coal recovery with the top coal of the fully mechanized caving face and the transitional frame at both ends of the working face. With the top roof structure model of the fully mechanized caving face, the numerical simulation and field measurement is used to compare the end coal caving. With caving coal or not, the destruction and migration rules of the top coal in the fully mechanized caving face are obtained. The study found that at the end of the transport trough, the maximum concentration factor of the support pressure in the coal is 2.35, and the maximum vertical displacement is 9.2cm. And at the end of the return air trough, the support pressure concentration factor is 3.53, and the maximum vertical displacement of the roof is 102cm. The above research reveals the law of the occurrence of the pressure and the movement of the top coal when caving the coal at the end, while ensuring the safe production and efficient mining of the coal mine.

scholarly journals Проблемы при использовании травителя KOH-IPA для текстурирования кремниевых пластин

2020 ◽  
Vol 90 (10) ◽  
pp. 1758
Author(s):  
Н.А. Чучвага ◽  
Н.М. Кислякова ◽  
Н.С. Токмолдин ◽  
Б.А. Ракыметов ◽  
А.С. Серикканов
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Main Type ◽  
Single Crystal Silicon ◽  
Silicon Wafers ◽  
Optimal Parameters ◽  
Crystal Silicon ◽  
High Efficiency Solar Cells ◽  
Wet Chemical ◽  
Manufacturing Techniques

The wet chemical treatment of monocrystalline silicon wafers, said method comprising texturing, represents one of the fundamental steps of manufacturing techniques of high-efficiency solar cells. As part of this work, methods for texturing single-crystal silicon wafers for solar cells were studied.As a result of studies, the optimal parameters of texturing technology for the studied samples were determined. The main type of etchant for texturing processes, which is a solution of KOH with isopropanol, is also determined.

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