在瓦斯抽放钻孔的钻进过程中,由于钻头、钻杆与周围煤壁的摩擦升温,会发生瓦斯火灾。为了预防与控制煤矿瓦斯燃烧火灾,采用细水雾灭火技术和自制的钻孔瓦斯火试验系统,在0.4MPa、0.6MPa和0.8MPa下,选择5种配方的含添加剂细水雾,对瓦斯抽放钻孔火灾进行了灭火有效性研究,主要考察了施加细水雾前后瓦斯火焰温度、燃烧强度和灭火时间的变化。结果表明,在清水中添加化学添加剂后,使细水雾熄灭瓦斯火的有效性大大提高,在0.4MPa下,清水细水雾不能熄灭的钻孔瓦斯火灾,使用添加剂2、3、4、5后,可以在32.4.70.3s的时间内熄灭。升高压力,细水雾对瓦斯火的熄灭有效性提高,当压力为0.6—0.8MPa时,含添加剂5的细水雾熄灭瓦斯火的时间比清水细水雾缩短76.1%-88.6%。在实际应用中,使用低压细水雾灭火系统,并选择合适的灭火添加剂配方,可有效防治钻孔瓦斯火灾。
The paper takes it as its purpose to present the experimen- ted investigation and results of our method for coal gas fire prevention and control with 5 kinds of additives into the water mist to extinguish the gas fire in the drilling hole. The water mist technology and the fire suppression facility developed by us has undergone test under the water pressure of 0.4 MPa, 0,6 MPa and 0.8 MPa, respectively. The focus of our study has been mainly experimented on the variations of the flame temperature, combustion rate and extinguishment time before and after the activation of the water mist. The results of our experiments show that the additives-containing water mist contributes greatly to the improvement of the extinguishing effectiveness. Under water pressure of 0.4 MPa, the water mist containing additives indexed by 2, 3, 4 and 5 help to extinguish the gas fire in the time range of 32.4- 70.3 s. The actual potential for further improvement can be made to display with the increase of water pressure. For example, the water mist containing the additive indexed by 5 can help to shorten the extinguishment time by 76%-78% with the pressure of 0.8 MPa as compared to that with the pressure of 0.4 MPa.