CONVEYOR FIRES: CAUSES AND PREVENTION Part 2

The global leader in conveyor accessories, Martin Engineering, is dedicated to conveyor safety by educating the bulk handling industry on the hazards of conveyor fires. This is Part 2 of a two-part series.

Significant amounts of dust can collect on the walls of the loading zone chute.  If a foreign metal object is accidentally introduced into the enclosed area, a spark can potentially create an explosion.  Additionally, common maintenance within the chute such as removal of the wear liner using a cutting torch often requires confined space entry by workers.  If the inside of the chute is not adequately cleaned, this task could pose a serious hazard.

Think like an inspector

When examining conveyor equipment, one should approach the task with the same critical mindset as an inspector from OSHA, MSHA or the local fire department.  Safety professionals recommend a holistic view of the system and the combustibility of the material.  When making a conveyor fire risk assessment, also consider:

• Spillage levels and cleaning schedules.
• The conveyor’s proximity to workstations.
• How the conveyor design (enclosures, narrow walkways, etc.) could create a hazard for employees.
• Safe storage of flammable liquids.
• Compliant signage.

Considerations for conveyor fire prevention

Often, the potential return on investment (ROI) for prevention equipment isn’t recognized until managers are inspecting burnt rubble and negotiating with insurance adjusters.  However, safety-minded operators understand that the same equipment they would implement for increased efficiency such as belt cleaners and impact cradles, can also help prevent fires.

• Impact cradles and support cradles help reduce fugitive material by providing a flat, stable belt surface that facilitates effective sealing.
• Transfer chute design is a critical element of fugitive material control, with sufficient settling zones and confinement. New raised chute designs also allow for external wear liners that eliminate the need for confined space entry or torch removal.  When paired with improved skirt seal designs, fugitive spillage and dust emissions are drastically reduced.
• Modern belt trackers detect mis-tracking and correct the belt path immediately using troughed idlers or gripping return idlers.
• A heavy-duty belt cleaner system featuring modern primary and secondary cleaners with an effective tensioner increases the volume of discharge and limits the amount of carryback and fugitive dust. Along with limiting spillage, tail pulley health is improved and there is less fouling of rolling components.

Conclusion

Operators should regularly contain airborne dust at transfer points and remove accumulation.  Damaged rollers must be replaced promptly.  Conveyor belt alignment is also an essential prerequisite to belt safety.  Consider using flame-resistant grease and other lubricants.  Fire detection and suppression systems must be tested in accordance to regulatory standards.  Experience has shown that clean conveyor systems and ongoing maintenance form the best defense against fire.

References

[1] Rowland III, J.H. and Smith, A.C. “Flammability of wider conveyor belts using large-scale fire tests”. National Institute for Occupational Safety and Health (NIOSH), Pittsburgh, PA. 2010. https://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/fowcbu.pdf

[2] Fernández, Marta; Rodriguez, Ángel. “Early Detection and Fighting of Fires in Conveyor Belt.” Edaffic. Publications Office of the European Union, EUR 25364. Luxembourg, 2013. https://publications.europa.eu/en/publication-detail/-/publication/2684b552-3658-446e-aa0f-030ff7b98e6c/language-en  Where does this reference appear in the original text?