1
24-011
Analyzing the Effectiveness of Fire Suppression Systems to
Extinguish a Fire on Mobile Mine Equipment Used in the
Mining Industry
James H Rowland III
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Davood Bahrami
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Richard A Thomas
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Liming Yuan
National Institute for Occupational Safety and
Health, Pittsburgh, PA
ABSTRACT
To reduce the number of injuries resulting from fires on
mobile, diesel-powered mine equipment, it is crucial to
promptly suppress a fire once it is detected. The focus of
this research was to determine the effectiveness of fire sup-
pression agents. Large-scale tests were conducted using five
different fire suppression systems based on: dry chemical,
wet chemical, dual agent (dry and wet chemical), carbon
dioxide, and water mist. Suppression nozzles were placed
around the diesel engine where diesel fuel, engine motor
oil, and hydraulic circulating oil spray fires were ignited.
The results of this study can help mining companies and
manufacturers by providing scientifically based data on the
capabilities of the different fire suppression systems.
INTRODUCTION
Mineworkers often face a threat from mine equipment fires
that can occur both at surface mines and in underground
mine environments that can cause injuries or fatalities. The
effectiveness of the fire suppression system installed on
mine equipment can be limited by design quality, instal-
lation practices, and the type of fire suppressant employed.
There are not any scientifically based measures available to
help mine operators effectively prevent and suppress equip-
ment fires. Most of the reportable mine fires are equip-
ment fires caused by ignitions of combustible fluids such
as hydraulic fluid released from a hose rupture onto hot
engine surfaces. To reduce the number of equipment fires,
it is necessary to develop effective measures to limit or pre-
vent hot surface ignitions on mine equipment. To reduce
the number of fire-related injuries and fatalities, it is impor-
tant to improve the suppression techniques for the equip-
ment fires to protect the equipment operators. Although
some mine equipment include a fire suppression system,
the efficacy of the system is compromised by poor design,
ineffective installation, and fire damage to the system if not
activated in time [1].
Various fire suppressing agents can be used for a fire
suppression system such as dry chemical, wet chemical, car-
bon dioxide, water mist, and foam. Each fire suppressing
agent has a different degree of effectiveness, depending on
the type of fuel involved in the fire and fire conditions such
as location, amount of fuel available, and ventilation sur-
rounding the fire. The major fire-extinguishing mechanisms
include cooling, separation or removal of fuel, dilution of
oxygen, and breaking combustion chain reaction. Every fire
suppressing agent acts on one or more mechanisms. Dry
chemical fire suppressing agents generally consist of a chem-
ical powder mixture that is electrically non-conductive.
Dry chemical extinguishing systems are primarily suited
for surface fires but are not effective on deep-seated fires.
Wet chemical fire suppressing agents consist of a mixture of
24-011
Analyzing the Effectiveness of Fire Suppression Systems to
Extinguish a Fire on Mobile Mine Equipment Used in the
Mining Industry
James H Rowland III
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Davood Bahrami
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Richard A Thomas
National Institute for Occupational Safety and
Health, Pittsburgh, PA
Liming Yuan
National Institute for Occupational Safety and
Health, Pittsburgh, PA
ABSTRACT
To reduce the number of injuries resulting from fires on
mobile, diesel-powered mine equipment, it is crucial to
promptly suppress a fire once it is detected. The focus of
this research was to determine the effectiveness of fire sup-
pression agents. Large-scale tests were conducted using five
different fire suppression systems based on: dry chemical,
wet chemical, dual agent (dry and wet chemical), carbon
dioxide, and water mist. Suppression nozzles were placed
around the diesel engine where diesel fuel, engine motor
oil, and hydraulic circulating oil spray fires were ignited.
The results of this study can help mining companies and
manufacturers by providing scientifically based data on the
capabilities of the different fire suppression systems.
INTRODUCTION
Mineworkers often face a threat from mine equipment fires
that can occur both at surface mines and in underground
mine environments that can cause injuries or fatalities. The
effectiveness of the fire suppression system installed on
mine equipment can be limited by design quality, instal-
lation practices, and the type of fire suppressant employed.
There are not any scientifically based measures available to
help mine operators effectively prevent and suppress equip-
ment fires. Most of the reportable mine fires are equip-
ment fires caused by ignitions of combustible fluids such
as hydraulic fluid released from a hose rupture onto hot
engine surfaces. To reduce the number of equipment fires,
it is necessary to develop effective measures to limit or pre-
vent hot surface ignitions on mine equipment. To reduce
the number of fire-related injuries and fatalities, it is impor-
tant to improve the suppression techniques for the equip-
ment fires to protect the equipment operators. Although
some mine equipment include a fire suppression system,
the efficacy of the system is compromised by poor design,
ineffective installation, and fire damage to the system if not
activated in time [1].
Various fire suppressing agents can be used for a fire
suppression system such as dry chemical, wet chemical, car-
bon dioxide, water mist, and foam. Each fire suppressing
agent has a different degree of effectiveness, depending on
the type of fuel involved in the fire and fire conditions such
as location, amount of fuel available, and ventilation sur-
rounding the fire. The major fire-extinguishing mechanisms
include cooling, separation or removal of fuel, dilution of
oxygen, and breaking combustion chain reaction. Every fire
suppressing agent acts on one or more mechanisms. Dry
chemical fire suppressing agents generally consist of a chem-
ical powder mixture that is electrically non-conductive.
Dry chemical extinguishing systems are primarily suited
for surface fires but are not effective on deep-seated fires.
Wet chemical fire suppressing agents consist of a mixture of