scholarly journals Research on the Deformation Characteristics and Support Technology of a Bottom Gas Extraction Roadway under Repeated Interference

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Rongkun Pan ◽  
Zhihui Ma ◽  
Minggao Yu ◽  
Shuaidong Wu
Keyword(s):  
Coal Mine ◽  
Maximum Shear Stress ◽  
Mechanical Analysis ◽  
Gas Extraction ◽  
Deformation Characteristics ◽  
Maximum Displacement ◽  
Multiple Disturbances ◽  
Mining Disturbance ◽  
Mining Face

Taking Pingbao Coal Mine as the engineering background, the stress distribution, surrounding rock displacement, and plastic zone distribution characteristics of a bottom gas extraction roadway are simulated by FLAC3D under multiple disturbances. The mining disturbance due to the overlying coal seam is obtained: the deformation of the roof subsidence and lower rib closure of the bottom gas extraction roadway are larger than the floor heave and upper rib closure, respectively. According to the mechanical analysis of the bottom gas extraction roadway, the equations for calculating the displacement at each point on the surface of the bottom gas extraction roadway and the methods for calculating the maximum displacement, the maximum normal stress, and the maximum shear stress are obtained to reasonably explain the deformation of the bottom gas extraction roadway under multiple disturbances. Then, the bolt-mesh-anchor and ladder beam support mode are designed. After onsite observation of the bottom gas extraction roadway of the 12030 coal mining face of the Pingbao Coal Mine, it is concluded that the deformation characteristics of the bottom gas extraction roadway basically conform to the abovementioned equations and that the support is effective. This paper can provide a reference for the optimization of bottom gas extraction roadway positioning, the determination of support parameters, and the deformation prediction around a bottom gas extraction roadway under similar conditions.

Study on Mine Pressure Behavior of Roadway in Highly Irregular Working Face in Daizhuang Coal Mine

2012 ◽  
Vol 256-259 ◽  
pp. 1443-1446
Author(s):  
Xing Lin Wen ◽  
Lin Hai Gao ◽  
Chuan Lei Li ◽  
Meng Meng Dong
Keyword(s):  
Coal Mine ◽  
Surrounding Rock ◽  
Mine Pressure ◽  
Mining Engineering ◽  
Deformation Characteristics ◽  
Working Face ◽  
Production Safety ◽  
Support Force ◽  
Mining Face ◽  
Important Significance

The irregular face mechanized mining is one of the difficult problems in the field of mining engineering. In this thesis, the roadways of 4324 extremely irregular face in DaiZhuang Mine were taken as research object. Through on-site mine pressure observation, the deformation characteristics of the surrounding rock and support force was analyzed. Next the mine pressure appeared rule of the roadways was study. This study benefited that the production of 4324 mining face went on wheels, at the same time, it had important significance to production safety of irregular working face with similar conditions.

scholarly journals Experimental Study on the Cement-Based Materials Used in Coal Mine Gas Extraction for Hole Sealing

ACS Omega ◽  
2021 ◽  
Author(s):  
Jianhua Fu ◽  
Dengke Wang ◽  
Xuelong Li ◽  
Zhiming Wang ◽  
Zhengjie Shang ◽  
...  
Keyword(s):  
Experimental Study ◽  
Coal Mine ◽  
Gas Extraction ◽  
Coal Mine Gas ◽  
Cement Based Materials ◽  
Mine Gas ◽  
Materials Used

Determination of iodide based on dynamic gas extraction and colorimetric detection by paper modified with silver triangular nanoplates

2019 ◽  
Vol 145 ◽  
pp. 729-736 ◽  
Author(s):  
Marina O. Gorbunova ◽  
Anastasiya A. Baulina ◽  
Margarita S. Kulyaginova ◽  
Vladimir V. Apyari ◽  
Aleksei A. Furletov ◽  
...  
Keyword(s):  
Colorimetric Detection ◽  
Gas Extraction

scholarly journals Deformation Characteristics of the Surrounding Rock of a Six-Lane Multiarch Tunnel under Different Excavation Conditions

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lina Luo ◽  
Gang Lei ◽  
Haibo Hu
Keyword(s):  
Three Dimensional ◽  
Class Ii ◽  
Surrounding Rock ◽  
Displacement Rate ◽  
Construction Technology ◽  
Deformation Characteristics ◽  
Highway Traffic ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Secondary Lining

Highway tunnel plays an increasingly prominent role in the development of high-grade highway traffic in mountainous countries or regions. Therefore, it is necessary to explore the deformation characteristics of the surrounding rock of a six-lane multiarch tunnel under different excavation conditions. Using the three-dimensional indoor model test and finite element analysis, this paper studies the dynamic mechanical behavior of a six-lane construction, reveals the whole process of the surrounding rock deformation process of class II surrounding rock under different excavation conditions, and puts forward the best construction and excavation method. The results show that the maximum displacement rate of excavation scheme III is the largest, and the maximum displacement rate of excavation scheme I is basically the same as that of excavation scheme II. Therefore, in terms of controlling the displacement rate of the surrounding rock, the effect of excavation scheme I is basically the same as that of excavation scheme II, while that of excavation scheme III is poor. In terms of construction technology, scheme II is simpler than scheme I and can ensure the integrity of the secondary lining. Therefore, in class II surrounding rock of the supporting project, it is recommended to adopt scheme II for construction.

scholarly journals APPLICATION OF MATHEMATICAL PLANNING OF THE EXPERIMENT IN THE CHOOSING THE OPTIMUM CONDITIONS OF THE VAPOR-PHASE GAS-CHROMATOGRAPHIC DETERMINATION OF FORMALDEHYDE IN THE URINE

2018 ◽  
Vol 97 (10) ◽  
pp. 985-989 ◽  
Author(s):  
Аnton N. Alekseenko ◽  
O. M. Zhurba
Keyword(s):  
Mathematical Model ◽  
Vapor Phase ◽  
Statistical Processing ◽  
Analytical Signal ◽  
Heating Time ◽  
Gas Extraction ◽  
Optimal Conditions ◽  
Steep Ascent ◽  
The Mathematical Model

Introduction. There was substantiated a method for the determination of formaldehyde by vapor-phase gas chromatography by the use of derivatizing reagent o-(2,3,4,5,6-pentafluorbenzyl)hydroxylamine. Material and methods. Formaldehyde in urine was derivatized to o-pentafluorobenzyloxime and recovered to the vapor phase by heating the urine sample with o-(2,3,4,5,6-pentafluorbenzyl)hydroxylamine in a sealed vial. Gas-chromatographic analysis of the vapor-air phase was performed in a mode of the temperature gradient on a capillary column HP-5 with a flame ionization detector. Identification of the analyte in the form of the derivative-o- pentafluorobenzyloxime of formaldehyde was carried out according to the absolute retention time, which was established by comparing the chromatograms of model formaldehyde mixtures in the urine of different concentrations. Results. The optimal conditions for gas extraction are selected using mathematical experimental planning. The most important factors of gas extraction in the vapor-phase analysis are the temperature and time of the establishment of the interphase equilibrium with heating. From the experimentally obtained curves of the analytical signal on the temperature and the heating time, the zero level and the interval of variation of these factors are chosen. A matrix for planning a 2-factor experiment was constructed. The coefficients of the mathematical model are determined. There was carried out statistical processing of the experimental data, which was reduced to the estimation of the reproducibility of the optimization parameter and to the evaluation of the significance of the coefficient of the mathematical model. The adequacy of the mathematical model was evaluated, its interpretation was carried out. Discussion. The peak area of the analyte increases with the elevating the temperature and heating time, due to an increase in the analyte concentration in the vapor phase. Moreover, the heating time makes a greater contribution to the formation of the analytical signal than the temperature. The step of motion along the gradient was calculated and the experiments of steep ascent were carried out. Conclusion. According to the results of the steep ascent experiments, the optimal conditions for the gas extraction of formaldehyde in the form of a derivative were chosen.

scholarly journals Characteristics of New Permanent Magnetic Eddy Current Drive System of the Scraper Conveyor

2021 ◽  
Author(s):  
shuang wang ◽  
Yongcun GUO ◽  
Deyong LI
Keyword(s):  
Eddy Current ◽  
Coal Mine ◽  
Mining Area ◽  
Current Drive ◽  
Drive System ◽  
Model Accuracy ◽  
Working Face ◽  
Scraper Conveyor ◽  
Mining Face ◽  
Motion Characteristics

Abstract This study provides a new permanent magnetic eddy current drive system to solve the ener-gy-saving drive problem of the scraper conveyor working under bad conditions, including overload startup, severe abrasion and pollution. Considering the practical conveying conditions of the scraper chain on a fully mechanised coal mining face, this study creates a mathematical model for the new permanent magnetic eddy current drive system of the scraper conveyor based on its characteristics and indicates the motion characteristics of the scraper chain driven by two wheels. This study verifies the model accuracy with a pre-startup technology depending on the scraper conveyor on the No. 12318 working face of the 8th coal mine in the West No. 1 mining area of the Pansan Coal Mine of the Huainan Mining Group. According to the results, the motion acceleration of the scraper chain based on the new permanent magnetic eddy current drive is lower than that of the scraper chain with a hydraulic coupler under the same running condition and load during startup and acceleration and declines by approximately 14.7%. Consequently, this can decline the startup impact due to the serious abrasion and frequent overload of the scraper chain working under bad conditions.

Applications of Carbon Dioxide Cannon Blasting on the Problem of Triangular Flap Top in Coal Mine Handling Mechanized Mining Face

2012 ◽  
Vol 256-259 ◽  
pp. 71-74
Author(s):  
Yan Bo Zhang ◽  
Er Qiang Li ◽  
Jia Wei Liu ◽  
Xin Jia Leng ◽  
Wen Guo Li
Keyword(s):  
Carbon Dioxide ◽  
Coal Mine ◽  
Effective Solution ◽  
Large Area ◽  
Triangular Flap ◽  
Production Safety ◽  
Mining Face

As mining process in the Mechanized mining face, making it easy come with flap top[1] along the the upward and downward entries. In this paper, through the use of carbon dioxide cannon, we do pre-split blasting experiment on triangular flap top in mechanized mining face, exploring an effective solution to a large area of goaf flap top suddenly breaking down, with the hurricane caused damage and fan-out of toxic and harmful gases, to achieve the purpose of production safety.

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