Effects of water mist on open fire - a model study

Outbreak of open fire in coal mines is one of the major causes of disaster involving loss of life, hindrance in coal production and loss of machinery involved in coal winning operations. Until recently, no substantive work has been carried out in India to prevent such untoward incidents. To understand the complex phenomenon of open fires and its preventive techniques, a mine fire model gallery has been designed and constructed at the Central Mining Research Institute, Dhanbad, India. The gallery is equipped with state-of-the-art instrumentation systems to monitor the important fire parameters. Three fire suppression techniques - liquid nitrogen, high-pressure high-stability (HPHS) nitrogen foam, and water mist - were tried in three sets of experiments. This paper addresses the important design features of the gallery, experimental details, and the effects of the application of water mist on open fires. An international literature review regarding the application of water mist technology is also outlined. Experiments showed that water mist has the potential to reduce the intensity of fire, lower the products of combustion (POC) and reduce suspended particulate matter (SPM). Water mist technology is able to control open fires in underground coal mines.