- Author
- Perzak, F. J. | Litton, C. D. | Mura, K. E. | Lazzara, C. P.
- Title
- Hazards of Conveyor Belt Fires. Report of Investigations.
- Coporate
- Pittsburgh Research Center, Pittisburgh, PA
- Report
- RI 9570, May 1995, 33 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- belt conveyors | heat transmission | flammability | smoke detection | carbon monoxide | flame spread | heat release | fire growth | air flow | air velocity | fire hazards | air temperature | ventilation | sensors
- Identifiers
- belt flammability; belt fires; carbon monoxide detection; heat flow
- Abstract
- This report descirbes a U.S. Bureau of Mines' study on the hazards of large-scale conveyor belt fires as a function of both air velocity and distance from belt surface to gallery roof. The fire hazards considered were smoke obscuration, toxic effects of carbon monoxide (CO), and elevated air temperatures downstream of the fire. All of these hazards scale with the ratio of fire intensity to ventilation airflow. These hazards were all found to be greater at the lower belt-to-roof distance, owing to the greater fire intensities that resulted. The hazards of smoke obscuration and elevated CO levels were greater at lower air velocities. Smoke obscuration was found to be the earliest hazard, reaching critical levels before the stage of belt flame spread. Critical levels ofCO and donwstream air temperatures were not reached until the later stages of flame spread. Fire growth rates during rapid flame spread were much greter than the fire growth rates measured during the early stages of belt burning. Data were analyzed to determine the early-warning capability of fire sensors. Smoke sensors provided the earliest warning, followed closely by CO sensors. Thermal sensors did not exhibit any early warning capability.