Modern Mining December 2015

MATERIALS HANDLING

 A linear heat detection cable, which is used for very long distances – common with con- veyor belt systems – and responds to a rise in heat that is above the alarm threshold.  The 40-40 IR3, which uses three different infrared light wavelengths to detect an open flame.  The TEC247, a fire control panel that manages all of the detection devices, the alarms and the suppression equipment valves.  The TEC057-1, an interface unit that allows for multiple suppression systems or cylinders to be connected to a single fire control panel. Over and above this, van Niekerk recom- mends other industry-leading technologies for cost-effective conveyor belt fire-suppression: “The I-Cat Firetrace self-activating fire- detection and suppression system is a prime example. This technology can automatically detect fire and effectively suppress it in a mat- ter of seconds before it becomes a problem.” The Firetrace system boasts polymer tub- ing that will rupture when exposed to a flame. The specialised Firetrace detection tubing reportedly combines leak resistance, flexibility, durability and precise temperature sensitiv- ity, allowing it to react quickly when the heat from a fire is present. It connects to a custom- engineered valve and a Firetrace cylinder that contains the best fire suppression agent for a particular hazard. “These low-pressure systems cause no ther- mal shock, have long operational life, allow for on-site refilling of the systems, are electrically non-conductive and use sustainable, clean technology, and can even be used with other external fire detection systems,” explains van Niekerk. The I-Cat T-Rotor Technology systems are another example of innovative technology – providing localised protection, hand-held extinguishers, fast response back-packs and vehicle protection systems. They comprise extinguishers that use a combination of water

electrical failure or overheating of the conveyor belt motors. He offers the following outline of common causes of fire on conveyor belt systems:  Friction due to a belt losing traction and slip- ping on the drive roller, or due to a misaligned belt slipping off the jam rollers and jamming. This can generate sufficient heat to ignite the belt itself or the product it is transporting.  Cutting or welding activities generate hot moltenmetal particles that can ignite the belt.  Accumulatedwaste below the belt due to lack of regular housekeeping.  Overheated materials from ovens, kilns or dryers that have not been sufficiently cooled before being placed on the conveyor belt.  Undetected electrical malfunctioning of con- veyor belt motors. To ensure early fire detection in conveyor belt environments, ASP Fire recommends the installation of a variety of Technoswitch fire detection technologies, which are especially suited to long-distance and moving environ- ments. These include:  The 246-1 Ember Detector, which recognises a smoldering ember on a moving conveyor belt before it bursts into flames.

The Backpack water mist system being used on a fuel spill fire. The environmen- tally friendly system rapidly extinguishes 250 litres of burning fuel using 12 litres of water. According to ASP Fire, this has the same knock out power as a 500 litre trailer-mounted system.

feature

30  MODERN MINING  December 2015