Fires and explosions pose a constant threat to the safety of underground miners and to the productive capacity of mines. They result in loss of life and property damage on a scale unmatched in other industrial sectors, head of fire division for I-CAT ANDRO GIBHARD tells SASCHA SOLOMONS.
“Underground fires are particularly dangerous due to the confined nature of excavations and the quantity of smoke and noxious fumes produced in relation to the limited quantity of fresh air present in underground mining sections,” starts Gibhard.
He illustrates that safety for fires and explosions in underground mines is based on the general principles of preventing fire and explosion. Normally, this involves using fire safety techniques, such as preventing smoking, as well as providing built-in fire protection measures to prevent fires from growing, such as portable extinguishers or early fire detection systems, which are critical for the protection of both life and property.
Poor maintenance and bad operator practice are some of the biggest contributors to fires in underground mines, he continues. “In some cases, the fire suppression system installation itself is deemed erroneously to be the cause of a fire, as suppression hoses can allegedly chafe against fuel or hydraulic lines, thus causing them to rupture and spray fuel on hot engine surfaces.”
Gibhard notes that because people cannot always access a safe area when there is a fire incident, it is paramount that mines do everything in their power to prevent fires and make sure they implement effective technologies to detect and suppress fires as quickly as possible.
He comments that I-CAT’s range of products is specially designed to mitigate special fire risk applications by early detection and effective suppression of fires.
The I-CAT systems do not rely on electricity to detect or suppress a fire. Because the system is mechanical, it proves to be less prone to false activations and more effective when having to detect fires in harsh underground mining conditions.
Gibhard points out that each I-CAT product line has its own regulations and specifications that it needs to adhere to and is continuously tested and verified against recognised international approval bodies and design standards.
“Many of the systems available on the market are purchased from overseas companies in the US or Europe. This not only makes the systems expensive, but also makes it very difficult to adjust to South African and African conditions. Our locally manufactured T-Rotor Technology systems is an internationally patented technology providing atomised non-conductive mist at the low pressure of 4 bar.”
The system utilises water more efficiently by enlarging the surface reaction area of the volume of water. This means that a lot less water is used to extinguish or control a fire than what is normally needed. The surface reaction area of 1 litre of water can be enlarged to as much as 120 m2.
“Together with our nozzle technology it has been proven to be a very effective solution for the mitigation of various special fire risk applications, especially in underground mining,” he adds.
Understanding the underground environment
Gibhard explains that all the fire systems in the I-CAT range are designed to detect and suppress fires in the most economical and effective way while maintaining an environmental friendly status.
“By conducting on-going life fire testing in risk specific areas, I-CAT strives to remain at the cutting edge of technology and by always improving on current systems we aim never to become complacent or stagnant in the market,” he comments.
In any underground mining environment, fresh oxygen is introduced constantly as it is imperative to maintain human living conditions. Unfortunately, this also counteracts any fire suppression system that is designed to remove or reduce oxygen content.
“I-CAT’s systems are designed to suppress fires while maintaining liveable conditions for humans in the vicinity. The atomised mist shields operators and bystanders from harmful and potentially lethal heat radiation while also scrubbing smoke. By cooling the incident area’s hot surfaces or ignition point it drastically prevents the chance of re-ignition of fires,” Gibhard concludes.