综掘工作面气室降尘技术研究

Research on dust reduction technology of air chamber in fully mechanized mining face

针对掘进巷道中的粉尘控制问题,传统的长压短抽通风降尘技术存在粉尘扩散区域大、风幕降尘技术存在射流孔易堵塞等弊端。以巴拉素煤矿综掘工作面为工程研究背景,建立了掘进作业过程中的粉尘运动数学模型,得出降低综掘工作面粉尘浓度的关键因素是控制掘进巷道风流场扰动范围及减小粉尘颗粒运动时间。以上述关键因素为依据,在风幕降尘的基础上开发了气室降尘技术,通过在正压风筒末端加装风袖,与风幕共同作用将粉尘封闭在气室区域内,再由负压风机抽出,以提高降尘效率。采用Fluent软件对长压短抽通风降尘、风幕降尘和气室降尘进行模拟对比分析,并优化了气室降尘技术参数。模拟结果表明:采用气室降尘技术时,综掘工作面人体呼吸带位置的粉尘浓度为350 mg/m^(3),较采用长压短抽通风降尘时的600 mg/m^(3)和风幕降尘时的480 mg/m^(3)大幅降低;气室降尘最优技术参数为正压风筒出风口距综掘工作面14 m、负压风筒末端直径0.6 m。在巴拉素煤矿2号煤2号回风大巷综掘工作面进行现场试验,结果表明采用气室降尘时,掘进巷道最低粉尘浓度为118 mg/m^(3),低于采用长压短抽通风降尘时的184 mg/m^(3)和风幕降尘时的156 mg/m^(3),且降尘效率较长压短抽通风降尘平均提高54.8%。

In response to the dust control problem in excavation roadways,the traditional long pressure short suction ventilation dust reduction technology has problems such as large dust diffusion areas and easy blockage of jet holes in the air curtain dust reduction technology.Taking the Balasu Coal Mine fully mechanized mining face as the engineering research background,a mathematical model of dust movement during the excavation process is established.It is found that the key factors to reduce the dust concentration in the fully mechanized mining face are to control the disturbance range of the wind flow field in the excavation roadway and reduce the movement time of dust particles.Based on the above key factors,an air chamber dust reduction technology has been developed on the basis of air curtain dust reduction.By installing air sleeves at the end of the positive pressure air duct and working together with the air curtain,the dust is enclosed in the air chamber area.The dust is extracted by a negative pressure fan to improve dust reduction efficiency.Fluent software is used to simulate and compare the dust reduction of long pressure short suction ventilation,air curtain,and air chamber.The technical parameters of air chamber dust reduction are optimized.The simulation results show that when using the air chamber dust reduction technology,the dust concentration at the breathing zone of the human body in the fully mechanized mining face is 350 mg/m^(3).It is significantly lower than the 600 mg/m^(3) when using long pressure and short suction ventilation for dust reduction and the 480 mg/m^(3) when using air curtain dust reduction.The optimal technical parameters for air chamber dust reduction are a positive pressure air duct 14 meters away from the excavation face and a negative pressure air duct end diameter of 0.6 meters.On site experiments are conducted on the fully mechanized mining face of the second coal seam and second return air roadway in Balasu Coal Mine.The results showed that when using air chamber dust reduction,the minimum dust concentration in the excavation roadway is 118 mg/m^(3).It is better than the 184 mg/m^(3) when using long pressure short suction ventilation and 156 mg/m^(3) when using air curtain dust reduction.The dust reduction efficiency is also improved by an average of 54.8%compared to long pressure short suction ventilation for dust reduction.