Safety and Standards in Conveyor Belt Fire Prevention
Conveyor belt fires pose a significant risk due to their rapid spread potential. While the belt itself can burn, it's the belt's length and movement that exacerbate the danger, allowing fires to quickly traverse large facility distances. Typically, fires start from friction-induced heat at pulleys or from materials inadvertently loaded onto the belt.
To mitigate these risks, best practices include:
- Regular belt inspections
- Clearing combustible accumulations
- Addressing potential fire sources of fire such as seized rollers, overheated bearings, or belt misalignment
In environments with heightened risks—like underground coal mining—strict regulations often mandate self-extinguishing belting to replace less stringent flame-retardant options.
It's important to note that all conveyor belts can burn if exposed to sufficient heat and airflow. Governmental regulatory bodies use standardized laboratory tests to categorize the burning characteristics of different conveyor belts. A "self-extinguishing" belt, in general terms, refers to one that does not propagate a fire once the ignition source is removed in a controlled laboratory setting.
Fire-safety standards for conveyor belting are similar among major coal mining countries, including Australia, Canada, China, Germany, India, Indonesia, Poland, Russia, and South Africa. For example, Germany implemented strict requirements over 30 years ago.
Various international regulatory and advisory organizations, such as the British Standards Institution (BSI), Conveyor Manufacturers Equipment Association (CEMA), Deutsches Institut für Normung (DIN), European Standards (EN), and the International Organization for Standardization (ISO), provide guidance on conveyor belt safety.
Tests conducted in these countries typically include:
- Drum Friction Test (DIN 22100 and others): Measures surface temperature to ensure it remains below 325 degrees Celsius (617° F) after a specified time and tension.
- Surface Resistance Test (ISO 284/EN20284/DIN 20284): Ensures the belting is conductive enough to prevent electrostatic charge build-up.
- High-Energy Propane Burner Test (EN12881): Determines if flames self-extinguish within a specified time after ignition.
- Laboratory Scale Gallery Test (DIN22100 and 22118): Ensures flames self-extinguish and leave a defined undamaged length after ignition.
In the United States, outside of underground coal mines, the regulatory standard for conveyor belts is primarily determined by the Bunsen Burner Test (CFR Part 30 Section 18.65). This test involves exposing a small piece of belt (approximately 150 by 12 millimeters or 6 by 1⁄2 inches) to a Bunsen burner flame for one minute. After removing the flame, airflow is applied for three minutes, and the duration of any flames or afterglow is recorded. To meet the standard, the average of four samples must not burn for more than one minute or exhibit afterglow for more than three minutes.
Historically, Europe and the US differed in belt safety regulations until stricter measures aligned practices globally. For underground coal mines in the US, the Belt Evaluation Laboratory Test (BELT) ensures belts resist flames for extended periods, reflecting updated safety norms.
Other Safety Considerations for Conveyor Belts
Additional standards may apply globally, varying by region or industry. Some countries impose stricter requirements concerning belt toxicity, hygiene, or surface roughness. Detailed specifications can be found in standards established by organizations such as DIN, EN, ISO, BSI, CEMA, and others. It is crucial for conveyor belting to be compatible with the materials it transports, ensuring safety and compliance with applicable standards.