Preplanning for conveyor belt fires
Vol. 27 No. 3
Conveyor belts are found in a wide variety of industries. They move everything from chemicals, coal, minerals, grain to luggage and warehouse goods. The belts are usually combustible (many fire retardant belts will still burn). The goods they carry may or may not add an additional fuel load. This article intends to address conveyors at industrial facilities. Conveyor belts in underground mines are specifically beyond the scope of the article. Industrial sites that may have belt conveyors include power plants, paper mills, grain elevators, glass plants, cement plants, rock quarries, warehouses, and airports.
According to www.wikipedia.org, the world’s longest conveyor system is 61 miles. They can run overland in remote areas, run underneath industrial buildings and also be well over 100 feet above grade. Therefore access is a key issue.
Conveyor belt fires can be caused by friction from misaligned belts, overheated motors, burning material on the belts, smoking, hot work, and even arson. If the belt breaks and is not shut down, the resulting pile can burn like an equivalent size pile of tires according to the text Industrial Firefighting for Municipal Firefighters. This can in turn mean that water alone might be ineffective and a water additive might be needed for extinguishment. Fire can be intense enough to cause the collapse of their support structure. This means that the structure might not be safe as an attack platform and that apparatus should be positioned outside a potential collapse zone. The best source of images of conveyor fires for training and discussion is an internet search of “conveyor belt fire” images. This will give you an idea of what to expect.
Some conveyors are protected by sprinkler or water spray systems but many are not. High expansion foam systems might be found protecting below grade conveyors. Linear fire detection systems are relatively common. The need for such systems depends on the importance of the conveyor, the combustibility of the belt and contents, and the difficulty of manual fire fighting. Details can be found in NFPA standards (specifically those on power plants) and the standards of various industrial insurance companies. It is essential to know what kind of fixed fire protection is available.
As stated above, access can be the number one issue that governs response tactics. Conveyors can easily be beyond the reach of ground level water streams and even beyond the reach of aerial apparatus. If they are enclosed, they may be inaccessible by water streams regardless of height. This should be evaluated before the incident. Long overland conveyors can be in remote areas without water supplies. Some facilities have modified large off-road vehicles as large water tenders. Large diameter hose relays and tanker shuttles are other options.
Conveyors can also be in tunnels below ground or below buildings. The text Industrial Firefighting for Municipal Firefighters recommends treating these areas as basement fires. There can be very little room for firefighters to maneuver. It might also be appropriate to modify tactics for road tunnel fires; depending on the diameter and length of the tunnel. Road tunnel fires are very common in some parts of the world and techniques and equipment to deal with them already exist. Referring to power plant coal conveyors, NFPA 850 states that conveyors that are below grade or enclosed are extremely hazardous to maintenance or fire-fighting personnel in the event of a fire. Automatic water spray or sprinkler systems should be provided for these conveyors even though they might not be critical to plant operations.
Another hazard, especially in confined areas, is that combustible dust from the material being carried (such as coal) can be kicked up and result in a dust explosion. Of course, the threat of carrying burning material from one location to another must also be planned for and managed. Finally, conveyors in cold climates may have a deicing system installed that should be reviewed.
Conveyor belts at industrial plants are common and pose more hazards than might at first be apparent. This article outlines some considerations when preparing for incidents involving them.
Feel free to contact this author at email@example.com. John Frank is with XL GAPS, a leading loss prevention services provider and a member of the XL Group of companies. XL Insurance is the global brand used by XL Group plc’s insurance companies and underwriting divisions offering property, casualty, professional and specialty insurance products throughout the world. More information about XL Insurance is available at www.xlinsurance.com. XL Group plc, through its subsidiaries, is a global insurance and reinsurance company providing property, casualty, and specialty products to industrial, commercial, and professional firms, insurance companies and other enterprises on a worldwide basis. More information about XL Group plc is available at www.xlgroup.com.