Underground » Detection and Prevention of Fires and Explosions
This report describes the work undertaken on a project - "An Investigation of Conveyor Belt Flammability Test Methods". The project, fully funded by Australian Coal Research Limited under the Australian Coal Association Research Program (ACARP), was undertaken by WorkCover NSW at Londonderry Occupational Safety Centre (LOSC).
Conveyor belts are extensively used to transport bulk solids in underground mines. The belts contain polymeric materials and can present a serious hazard in terms of rapid fire spread and generation of toxic, corrosive smoke. This can result in loss of life and property, and in extended production down-time. To minimise the fire damage, it is essential to use fire resistant belts as well as effective fire detection, control and suppression systems. In Australia, all conveyor belts for underground use are required to comply with fire resistance tests [1 - 3] and be rated as Fire Resistant Anti Static (FRAS).
In the last few years there have been incidents in Australia and the USA wherein approved belts have been involved in major underground fires. Such incidents have raised questions about the suitability of current standard fire tests to properly distinguish between belts that will and will not propagate a fire.
This report covers the following work conducted under the project :
* A critical review of the current methods of testing fire resistance of conveyor belts
* A survey of underground conveyor fires in Australia and current work practices in the mining industry
* Correlation of the large Gallery propane burner test [3] with two state of the art, bench-scale fire test methods - Cone Calorimetry [4 - 6] and Factory Mutual flammability apparatus [7].
* A risk management strategy for underground conveyor fires
* A simple quality control / check test for fire resistance of conveyor belts
A major part of the work has involved testing a range of conveyor belts in the Gallery, Cone Calorimeter and Factory Mutual tests, and studying the correlation between the three tests to investigate the potential of the Cone / FMRC type of test to replace the Gallery test.
Throughout this report, the above three tests are denoted as follows :
Large propane gallery test : Gallery test
Cone Calorimeter test : Cone test
Factory Mutual flammability apparatus test : FMRC test
The Gallery and Cone tests were performed at LOSC and the FMRC tests were conducted at Factory Mutual Research Corporation (FMRC), Boston, USA.