- Author
- Litton, C. D. | Lazzara, C. P. | Perzak, F. J.
- Title
- Fire Detection for Conveyor Belt Entries.
- Coporate
- Bureau of Mines, Pittsburgh, PA
- Report
- RI 9380, 1991, 27 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- belt conveyors | fire detection | coal mines | fire prevention
- Identifiers
- mine haulage; safety appliances
- Abstract
- The U. S. Bureau of Mines report de4tails the results of a series of large-scale experiments where small coal fires were used to ignite the conveyor belt at air velocities ranging from 0.76 to 6.1 m/s. In the tests, electrical strip heaters imbedded within a pile of coal were used to heat the coal to apoint of flaming ignition. The flaming coal subsequently ignited the conveyor belt located approximately 5 to 10 cm above the coal pile. During the tests, temperature, CO, and smoke levels were continuously measured in order to determine both alarm time and level as the fire intenbsity progressed through the stages of smoldering coal, flaming coal, and flaming coal plus flaming belt. Analysis of the data leads to certain conditions of air velocity and sensor alarm levels that are required for early detection of conveyor belt entry fires. Two nomographs are presented, which define sensor alarm levels and sensor spacings as a function of belt entry cross-sectional area and belt entry air velocity.