Dealing with open fire in an underground coal mine by ventilation control techniques
N Sahay, A Sinha, B Haribabu†, PK Roychoudhary
Open fire in coal mines is one of the most serious threats to miners, as well
as to the mine. Open fire can often be effectively dealt with by prompt local
action, otherwise it very quickly becomes uncontrollable. In one incident,
none of the available open fire control technologies, viz., water deluge and
sprinkler systems, high-expansion foam, high-pressure high-stability
nitrogen foam, water misting, and ventilation and pressure control
techniques, were effective for saving the mine without sealing from
surface, since the fuel-rich environment prohibited underground access due
to the methane explosion hazard.
The authors have developed a methodology for dealing with advancedstage
open fires underground by the application of a modified ventilation
control technique. It is based primarily on a better understanding of the
behaviour of open fires, proper diagnosis of the problem, application of
judicious ventilation control techniques, and selection of suitable fire
indices for assessing the status of an open fire. This methodology was used
to successfully control an open fire in Surakachhar 3 and 4 incline mine
Surakachhar, central India. The fire area was sealed underground and
production subsequently resumed in record time. The paper discusses the
behaviour of open fires, particulars of the mine, diagnosis of the problem,
experimentation methods, and the results obtained.
Keywords: spontaneous combustion, high-pressure hig-stability nitrogen foam, water
misting technology, ventilation and pressure control techniques, oxygenrich
and fuel-rich fire.