Mine fire detection has come a long way in the past 30 years with the development and application of sensors/systems and the research into fire, ventilation and modelling. Since these developments, times have changed and there is now new demand for better fire detection, largely due to expanding regulations.

National Institute for Occupational Safety and Health (NIOSH) research physicist Dave Litton explained at the fire detection technology workshop, held by the US Centres for Disease Control and Prevention’s (CDC) and NIOSH, how the future direction of fire detection runs hand in hand with the needs of customers.

“Regulatory bodies need good sensors, good standards and good science and engineering to effectively implement and enforce fire safety codes and regulations," Litton said.

“Mine operators need good sensors, good standards and good science and engineering in order to comply with codes and regulations, to protect their employees and to protect their (and the nation’s) valuable resources,” he said.

“Mine workers need to know they are protected by good sensors that are based upon sound data and good scientific and engineering principals.

“Mine equipment manufacturers need good data and good science and engineering in order to design, build and market good sensors that will satisfy the needs of regulatory bodies, mine operators and mine workers.”

In response to these needs, Litton said the US underground coal industry had chosen two parallel paths. To develop, design and evaluate improved smoke sensors and to develop, design and evaluate multi-sensor systems using neural networks.

One smoke sensor option being developed is the optical/ionization sensor. This sensor combines optical scattering and ionization chamber smoke measurements in the one sensor. By using ratio of Ion to optical response it reduces false alarms due to diesel and dust.

There are currently 10 prototypes being tested and evaluated and similar devices are being evaluated as continuous particle monitors.

Look out for International Longwall News report on multiple fire sensors in the next few weeks.