Cat plowing ahead in China

CATERPILLAR will deliver an automated longwall plow system to the Chinese Gasification Co of the Lvliang Dongyi Group in the first quarter of 2013 which will go to work in the Xinyan mine in Shanxi province.

Lou Caruana

The system marks the eleventh plow system from DBT/Bucyrus/Caterpillar destined for Chinese mines.

The system will mine a metallurgical coal seam with a height of 1-1.2m and the face length will be 240m.

The Cat GH800 plow will be paired with a Cat armored face conveyor using PF3 line pans and the Cat PMC-R roof support control system will manage roof support advance.

Automation enhances safety, as there is no need for an operator to be at the coal face during operation.

In China, automated plow longwall faces from Caterpillar’s predecessors DBT and Bucyrus hold all of the production records for seams less than 2m thickness.

Tiefa Coal Mining Group, with a 50% share in the joint venture project with Dongyi, owns four such systems already and has publicly indicated that the plow systems enable it to profitably mine thin seam reserves that otherwise would be uneconomic.

Advancements in drive, control and transmission systems – with more powerful motors, a stronger plow chain, increased plow speeds, higher advancing force provided by the roof supports, precise control of the cutting depth, and plow bit design improvements – all combine to allow Cat plows to be used for any coal hardness and with high efficiency extraction in low and medium seam heights.

The gliding plow guide is welded to the face side of the armored face conveyor. Plow chains up to 42 mm can be used, allowing power installations up to 2 x 800 kW.

On older-style systems, the cutting depth was typically controlled by adjusting the shield advancing ram pressure. As a result, cutting depths varied with coal hardness. A modern Cat plow system can cut a precisely defined depth, regardless of coal hardness and seam structure.

Cat plows offer a horizon control system and incremental plowing that allow the plow angle to change to follow the seam and to easily traverse geological faults. They also offer overload protection and load sharing to maximise efficiency.