High Voltage Longwall AFCs Using ATB Morley 11kV Flameproof MotorsThursday Aug 29th - 12:44
The majority of high production coal mining has previously been 3.3kV which gives rise to limits on power in order to restrict the operating currents and avoid high capacity electrical switchgear to provide the operating currents required. There has previously been a general reluctance from mines to use higher voltages underground but ATB Morley has driven flameproof motors into a new era by equipping what Peter Henderson (Xstrata) described as the “World’s most powerful AFC”.
Blakefield South is part of Xstrata Coal’s Bulga complex which produces approximately 10 million tonnes of semi soft coking and thermal coal per year primarily for export into Japan. The Blakefield South longwall is the first mine in the world to use 11,000V flameproof equipment. The ground-breaking Armoured Face Conveyor utilises 2 x 1600kW IMW115 motors designed and manufactured by ATB Morley. The 400m face has a maximum extraction height of 3.7m and a panel length of around 3.5km.
The benefits of installing ATB Morley’s high voltage motors include:
- Increased production rates by increasing the AFC power
- Facilitates the use of longer AFC and faces thus reducing roadway driveage
- Robust, reliable design drawing on ATB Morley’s wealth of experience and expertise
- Reduced cable sizes with respect to the power rating as a result of lower operating currents
- Removed the requirement for a transformer for the AFC motors
- Capability to upgrade the AFC to use 3 off 1600kW motors
- IEC certification and fully tested to satisfy the appropriate authorities
- Motors equipped with a large range of temperature and vibration sensors giving remote feedback to operators and advanced warning of any mechanical problems
- Highly automated longwall operation supported by the monitoring equipment reduces the need for personnel to be in the higher risk areas
The Blakefield South mine has paved the way for future operators to make the move to higher voltages and has proven that with thorough design and testing 11kV can be implemented underground both safely and cost effectively. This application has further endorsed ATB Morley’s reputation as a world leader in mining motor manufacture and innovation.