scholarly journals Control of gas concentration distribution in a semiconductor process chamber using CT-TDLAS measurement

AIP Advances ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 025034
Author(s):  
Daisuke Hayashi ◽  
Yuhei Sakaguchi ◽  
Masakazu Minami
Keyword(s):  
Concentration Distribution ◽  
Gas Concentration ◽  
Semiconductor Process

Gas Concentration Distribution Law in the Roadway after Coal and Gas Outburst

2015 ◽  
Vol 713-715 ◽  
pp. 314-318
Author(s):  
Chun Li Yang ◽  
Yi Liang Zhao ◽  
Xiang Chun Li ◽  
Yang Yang Meng ◽  
Fei Fei Zhu
Keyword(s):  
Concentration Distribution ◽  
Correlation Coefficients ◽  
Coal And Gas Outburst ◽  
Gas Emission ◽  
Distribution Law ◽  
Gas Concentration ◽  
Research Results ◽  
Gas Outburst ◽  
Whole Process ◽  
Secondary Disasters

Gas emission happens after coal and gas outburst, and it could cause secondary disasters in the roadway. Therefore it is necessary to research gas concentration distribution law in the roadway after coal and gas outburst, and theoretical basis for avoiding the occurrence of secondary disasters could be provided. Based on the above, Fluent is used to simulate gas concentration distribution law in the roadway during outburst. The research results show that gas velocity of the initial stage is larger in the whole process of gas outburst and gas emission impacts opposite walls in the form of jet in the roadway intersection. The flow changes direction and moves along the main airway and return airway. It produces countercurrent along the main airway. Because the pressure in the main airway is high, gas migration velocity becomes zero after a certain distance and is "back" to return airway. The higher the outburst velocity is, the longer the flow length is. Gas concentration variation with two kinds of different outburst intensities and position are regressed and it shows that correlation coefficients of power function are the highest. The research results have a certain theoretical value to prevent the occurrence of secondary disasters after coal and gas outburst.

Experimental measurement of gas concentration distribution in an impinging entrained-flow gasifier

2008 ◽  
Vol 89 (11) ◽  
pp. 1060-1068 ◽  
Author(s):  
Miaoren Niu ◽  
Zhuoyong Yan ◽  
Qinghua Guo ◽  
Qinfeng Liang ◽  
Guangsuo Yu ◽  
...  
Keyword(s):  
Experimental Measurement ◽  
Concentration Distribution ◽  
Gas Concentration ◽  
Entrained Flow ◽  
Entrained Flow Gasifier

A method for the measurement of gas concentration distribution in the adsorptive bed

1999 ◽  
Vol 54 (23) ◽  
pp. 5755-5760 ◽  
Author(s):  
Wang Zhixiang ◽  
Mo Fenzhu ◽  
Shi Yiqiang ◽  
Zhou Ming ◽  
Yu Guocong
Keyword(s):  
Concentration Distribution ◽  
Gas Concentration

Numerical Simulation of Diffusion of UDMH in Confined Space

2013 ◽  
Vol 295-298 ◽  
pp. 586-589
Author(s):  
Jia Zhao Chen ◽  
Chao Ning ◽  
Yu Xiang Zhang
Keyword(s):  
Numerical Simulation ◽  
Concentration Distribution ◽  
Geometric Model ◽  
Polluted Area ◽  
Confined Space ◽  
Gas Concentration ◽  
Diffusion Pattern ◽  
Toxic Gas ◽  
3D Geometric Model ◽  
And Diffusion

In order to study the diffusion pattern of Unsymmetrical Dimethyl Hydrazine (UDMH) in a confined space, a 3D geometric model of cylindrical space with a column obstacle in the center was built and diffusion of UDMH in the space was simulated by using FLUENT. The gas concentration distribution in the space was gained at different moments, and the polluted area with concentration above 0.5ppm was focused on. The simulation result suggests that the toxic gas is mainly concentrated in an area about 1m above the bottom of the space, and ventilation can effectively reduce the hazard time and continuous expansion of polluted area.

Remote sensing of hydrogen gas concentration distribution by Raman lidar

2012 ◽  
Author(s):  
Ippei Asahi ◽  
Sachiyo Sugimoto ◽  
Hideki Ninomiya ◽  
Tetsuo Fukuchi ◽  
Tatsuo Shiina
Keyword(s):  
Remote Sensing ◽  
Concentration Distribution ◽  
Hydrogen Gas ◽  
Raman Lidar ◽  
Gas Concentration

scholarly journals Disastrous Mechanism and Concentration Distribution of Gas Migration in Fully Mechanized Caving Stope in Wuyang Coal Mine

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Li Chong ◽  
He Sifeng ◽  
Xu Zhijun
Keyword(s):  
Coal Mine ◽  
Concentration Distribution ◽  
Spontaneous Combustion ◽  
Concentration Field ◽  
Gas Migration ◽  
Coal Spontaneous Combustion ◽  
Gas Drainage ◽  
Gas Concentration ◽  
Research Results ◽  
Working Face

The overrunning disaster of harmful gas tends to occur in the working face in thick coal seam with high gas concentration, as the fully mechanized caving stope has the characteristics of high mining intensity, high remnant coal, and high gas content. Therefore, the disastrous mechanism and concentration distribution of gas migration in fully mechanized caving stope are the theoretical basis for gas control scheme. Based on the 7607 working face in Wuyang coal mine, the gas emission quantity in working face is comprehensively analyzed by field measurement in this paper. The gas leakage field, oxygen concentration field, and gas concentration field in 7607 working face are simulated by establishing the equal proportional numerical model. Due to the increase of air leakage in working face caused by the high alley pumping drainage, the risk of coal spontaneous combustion is also analyzed, when gas extraction in goaf is carried out. The research results show that the gas drainage technology in high drainage roadway has a remarkable effect on the gas overrunning phenomenon. The gas concentration near the upper corner of the working surface has been reduced from 0.7%-1% to 0.5%. At the same time, it is necessary to pay attention to the risk of coal spontaneous combustion in the goaf for gas drainage in the high drainage roadway. The width of the oxidation zone in the goaf is about 25 m deeper than that before the drainage. Research results provide the references for gas control technology and coal spontaneous combustion prevention in similar working faces.

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