Advanced Photonics Australia’s Director Ubaldo Torre is proud to announce the completion of commissioning of a conveyor fire detection system for MCG (part of the Harmony Gold group) conveyor fire detection system situated in the highlands of Papua New Guinea.

The unique challenge for this project was commissioning the system whilst not being on site due to the COVID19 travel restrictions.  Our experienced staff took direct control of the DTS system via a secure communication link, with the remote commissioning completed successfully from Australia to PNG with the cooperation of site staff. The contract provided a fully redundant fibre optic cable DTS based fire detection system for the crushing processing plant and overland conveyor (5.4 km length).  The system provides full area coverage from the crushing plant down to the refinery via the overland conveyor. A particular challenge for this project is the route of the overland conveyor (tubular belt design), twisting up the mountain side with frequent 90° curved bends.  

Our Solution

Our solution includes dual DTS units, one at each of the conveyor system including redundant detection channels, plus redundant fibre optic cabling to provide a total conveyor fire detection system. In addition to fire detection, this design will provide early warning of abnormal heat build-up to minimise the potential serious consequences of equipment overheating, which could endanger personnel, damage the mine and equipment. In summary, the Hidden Valley mine identified the need for conveyor fire detection which provides:

• Conveyor fire detection coverage;
• Interface not only to the fire alarm system, but fully integrated with their existing site DCS control system for
  • Early warning of abnormal heat build-up
  • Exact localization of the abnormal heat or fire within a metre;
  • Fire event management (i.e. evacuation, fire-fighting activities)
  • Full history of the fire initiation point, its movement/spread, temperatures reached, with date/time stamping for the eventual reporting & investigation
  • Automatic activation of conveyor deluge systems at critical areas of the plant;
• A maintenance free fire detection system requiring no calibration;
• A 24x7 fire detection and temperature monitoring system that increases safety for the protection of people and fixed assets.

The DTS Key Components

The cable is the sensor

Distributed Temperature Sensing (DTS) technology using a linear heat detector laser source through a single fibre optic core measuring 4 mm in diameter.  It has been successfully tested and deployed in both surface and underground mines. The ruggedized fibre optic based system has the capacity to detect heat build-up quickly and localize the source to within 0.5 metres. This precision is unaffected by wind and other environmental effects, because not only convective, but also conductive and radiant (infrared) heat is detected by the cable. The fibre optic cable is:

• Accredited for fire detection use (flame resistance 750°C for 2 hours, IEC 60331).
• Doesn’t propagate the flame along the cable (IEC60332-3).
• Can be installed in harsh environments (stainless steel cable sheath with high crush resistance).
• Is immune to EMI (electromagnetic interference).
• Requires no maintenance, after it is installed.
• The sensor, no other cabling or field interface devices required.

The DTS system’s capabilities include:

• 24x7 remote temperature monitoring of the entire length, for total coverage.
• Provides not only the temperature but the actual location of the fire.
• It provides early warning of abnormal heat before a flame occurs.
• Interfaces to fire alarm panels & existing site HMI/SCADA systems.
• Safety Integrity Level SIL2 (IEC61508) for high reliability when asked to alarm.
• Available in 19” rack or IP66 external stainless steel enclosures.

If you would like to know more, please contact Ubaldo (Aldo) Torre - +61 480 268 855; email enquiries@apapl.com.au.