Effectiveness of gas fire suppression in drill hole by additives-containing water mist

The paper takes it as its purpose to present the experimental 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.