Advanced thermal imaging cameras are being used as a frontline defence against fires on any mining conveyor belt transporting warm materials or in instances where a risk of fires poses a danger to people or process equipment.

Although infrared thermal imaging cameras are not new in military and law enforcement circles, the adaptation of the cameras to meet industrial applications is quite unique.

Thermal image showing hotspots among material on a moving conveyor belt
Thermal image showing hotspots among material on a moving conveyor belt

Ruggedized versions from specialist manufacturer, Land, have been designed to work in grueling industrial applications using non-military type technology that circumvents the need for expensive export licenses. These are required on traditional thermal imaging camera to prevent the technology from ending up in radical military hands.

Introduced locally by process specialists, Protea Automation, the new range of cameras can operate in dirty, dusty and hot applications found in mining and industrial sites and are designed to operate reliably with little need for maintenance over extended periods of time in harsh conditions.

Automated solution

According to product manager Gavin Westley, the cameras are used to detect hotspots that are above the desired temperature of materials being transported. With parameters stored on-board the camera as well as on the Arc Land Imaging Processing Software (LIPS), the detection of a hotspot will trigger an alarm and set in motion a sequence of measures to prevent fire and avoid damage to the belt.

In the event of the Scada or control system being unavailable for whatever reason the on-board intelligence of the camera acts as a fail safe system and still triggers an alarm that will allow appropriate action to be taken.

“Management of warm materials on conveyors is a hot topic following a recent fire which destroyed an entire incline conveyor system at a lime manufacturing plant in the Northern Cape which caused several of millions Rands damage to the plant and led to considerable loss of production,” says Westley.

Preventative measures

The thermal imaging cameras can work reliably in hot, dusty and dirty environments
The thermal imaging cameras can work reliably in hot, dusty and dirty environments

“Following the catastrophe we were called in to design and install a system to prevent a recurrence of this type of event and have subsequently installed Land Arc Thermal cameras as well as scanners to identify hotspots, as well as identify trends which show when the temperature of clinker from the rotary kilns is rising above the normal range. With the equipment and procedures in place the plant is now able to significantly reduce costly belt repairs, reduce downtime and prevent dangerous situations from occurring in future.”

Westley explains that many materials that are transported on rubber conveyors contain hot inclusions that can damage the belt or cause material fires. As a result processing plants usually make use of traditional temperature measurement methods to try detecting hot materials, but in many instances these are unable to detect small hotspots on the moving conveyor.

The addition of Land thermal cameras allows users to monitor the entire conveyor width simultaneously at ranges from -20 to 1000°C continuously. The real live imaging and software automatically detects temperature variations and can trigger a number of responses via onboard I/O s that can trigger sprinklers, alarms, strobes or stop the belt or feeders, whichever is appropriate.

Images may also be transmitted to a controller for further action, while simultaneously recording alarm conditions for review at a later stage.

About the camera

The Land Arc range of cameras are general purpose radiometric thermal imaging cameras which are designed to be rugged enough for industrial applications while being small enough to fit into confined areas. The cameras are able to provide detailed high resolution thermal images with high temperature accuracies and are supplied with viewer software as standard and have direct connection to a range of I/O modules through standard industrial Ethernet. A choice of enclosures allows the cameras to be used in a wide variety of applications.

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