The presence of coal dust explosions in coal mining are significant safety hazards.This study mainly explores the flame propagation of coal dust combustion so as to provide a theoretical basis for the prevention and c...The presence of coal dust explosions in coal mining are significant safety hazards.This study mainly explores the flame propagation of coal dust combustion so as to provide a theoretical basis for the prevention and control of coal dust explosions.In the experiment,a dust cloud ignition device was used to experimentally explore the influence of the coal dust concentration on the flame propagation of the coal dust,and high-speed photography was used to record the coal dust flame propagation process.The results show that the flame propagates vertically along the wall of the vertical glass tube,emits a bright yellow light during the propagation process,and forms a mushroom cloud-shaped flame at the upper end of the vertical glass tube.When the concentration of coal dust is 250 g/m^(3),its burning time is much less than those of 500 g/m^(3)and 750 g/m^(3).When the concentrations are 250 g/m^(3),500 g/m^(3)and 750 g/m^(3),respectively,the corresponding maximum propagation velocities of the flame front reach 1.51 m/s,2.00 m/s and 1.61 m/s at 100 ms,353 ms and 310 ms,respectively.The time for the flame front velocity to reach the maximum and the maximum velocity of flame propagation first increase and then decrease with the rising of concentration.展开更多
基金National Natural Science Foundation of China(No.11802272)Key Research and Development(R&D)Projects of Shanxi Province(No.201903D121028)+1 种基金Natural Science Foundation of Shanxi Province(No.201901D211228)National Defense Key Laboratory Foundation of Science and Technology on Combustion and Explosive Laboratory(Nos.6142603200509,6142603180408)。
文摘The presence of coal dust explosions in coal mining are significant safety hazards.This study mainly explores the flame propagation of coal dust combustion so as to provide a theoretical basis for the prevention and control of coal dust explosions.In the experiment,a dust cloud ignition device was used to experimentally explore the influence of the coal dust concentration on the flame propagation of the coal dust,and high-speed photography was used to record the coal dust flame propagation process.The results show that the flame propagates vertically along the wall of the vertical glass tube,emits a bright yellow light during the propagation process,and forms a mushroom cloud-shaped flame at the upper end of the vertical glass tube.When the concentration of coal dust is 250 g/m^(3),its burning time is much less than those of 500 g/m^(3)and 750 g/m^(3).When the concentrations are 250 g/m^(3),500 g/m^(3)and 750 g/m^(3),respectively,the corresponding maximum propagation velocities of the flame front reach 1.51 m/s,2.00 m/s and 1.61 m/s at 100 ms,353 ms and 310 ms,respectively.The time for the flame front velocity to reach the maximum and the maximum velocity of flame propagation first increase and then decrease with the rising of concentration.
