The Innovation News article in the December issue looks at the lead Bucyrus (now Caterpillar) has in coal plows. One of the most recent installations was an automated plow longwall ordered by Lubelski Węgiel Bogdanka for its Bogdanka mine in Puchaczów – 29 km from Lublin in eastern Poland.
This was commissioned in March this year and within months of delivery, the new longwall had far exceeded the production target specified in the invitation to tender – and even set a new European record for plow faces as well as a new world production record for plow longwalls in mines using arches to support their entries.
This complete automated longwall plow system was required to achieve a daily output of 10,000 t. The system was delivered at the end of 2009 with installed power of two x 210/630 kW for the plow and two x 800 kW for the AFC. An impressive output of 13,000 t was achieved during commissioning in March.
On August 25, 2010 the longwall achieved a daily output record of 16,894 t. During only 10.5 hours of operation, the plow made over 300 passes along the 250-m panel, travelling a total distance of 76 km or a distance of 120 m/min on average.
The face advanced a total of 21.6 m with a cutting height of only 1.5 m – “an achievement impossible for any shearer in such seam heights,” Bucyrus says. “This is the result of huge advances in plow automation and technology especially over the past 10 years.
Advances in drive, control and transmission systems – with more powerful motors, stronger plow chain, faster plow, larger transverse push force, exact control of the plowing depth, and plow bit improvements – allow Bucyrus plows to be used for high volume production in any coal hardness. This is supported by greater installed power than any other manufacturer – up to 1,600 kW as used for the Gleithobel® plow system GH 1600 as installed in Bogdanka mine.
“The GH 1600 plow is designed for high productivity in very hard coal and is the system of choice for seams up to 2.3 m. Each of the 173 roof supports – with a support range 950 to 2,000 mm – is equipped with its own PMC®-R roof support control. Other units of the Bucyrus Programmable Mining Control family are used for overall face automation and visualisation as well as drive control.” The longwall is also equipped with a PF4/1032 face conveyor, a PF4/1132 entry conveyor, an SK 1111 crusher and an S147600 belt tail-piece.
Power supply and pump station were also supplied by Bucyrus. Bogdanka’s plow longwall is working in automatic mode, allowing a significant reduction of personnel required at the face during operation to control the plow or advance the shields. “An automated Bucyrus plow face doesn’t need operators on the face,” Bucyrus states. Incremental plowing is employed, which means that the plow cuts an exactly defined depth, regardless of coal hardness, seam structure and faults. This cutting depth is electronically preset using accurate stroke sensors and an advanced algorithm. Horizon control allows exact control of the plow angle, ensuring that the plow does not dig or climb unless required by the seam geology. This control allows plow operation accurately along the seam/floor boundary and to follow undulated seams.
Polish steam coal production declined by 11% in the first six months of 2010. Lubelski Węgiel Bogdanka is the only company to buck this trend. It is planning to increase its output to 11 Mt of clean coal by 2014.
Bogdanka is considering the purchase of another longwall system in 2011 for its new Stefanów panel.
It is estimated that some 30 to 35% – or 1,000 Mt – of Poland’s coal reserves are in thin seams. The industry abandoned plow technology in the 1990s because of its low productivity back then (caused by low power and the lack of any automation), but the success of Bucyrus’ latest plow systems is causing a renaissance. At Bogdanka alone, plow technology will increase recoverable reserves by some 100 Mt.
