In February, 2014, the Polish coal mining company Lubelski Węgiel Bogdanka S.A. purchased its fourth complete Cat® Plow Longwall system. All four longwalls center on the Cat GH1600 Plow System, the same model that Bogdanka used to set plow-equipped longwall production records in 2012. The automated plow system achieved almost 25 000 tonnes daily production from a single face, and the new system is expected to average 10 000 tonnes production per day in the thin seam, which has maximum thickness of 1.7 meters. The mine production target for 2015, when the new longwall is fully operational, is 11.5 million tonnes per year.
The company commissioned its first Cat longwall system at the mine near Lublin in eastern Poland, in March 2010. Now, only four years later, Bogdanka has purchased a fourth system.
"Coal plows are simple, durable machines that achieve high production through a combination of precise control and high installed power, making them the machine of choice in seams lower than 1.8 meters," said Michael Myszkowski, product support manager for Cat plow systems. "Bogdanka's experience shows how productive our automated plow systems can be in the right hands, and they obviously have confidence that the new system will deliver great results just as their other Cat longwall systems have."
The GH1600 Plow System, with 2 x 800 kW installed power, is designed for high productivity even in very hard coal seams. The Cat plow longwalls installed at Bogdanka work in automatic mode, which means that fewer people are needed on the face to control the plow and to advance the shields during operation. An automated Cat plow face does not require a human operator on the face—unlike shearer operations.
The new longwall system includes 180 Cat roof supports for the 318-meter face and Cat PMC-R roof support control. Other components are the Cat AFCPF4 face conveyor with PF4 pans and Cat CST drives for the conveyor and plow.
All four drives in the system work with a Cat variable frequency drive, Cat VFD-A800/W800. The new Cat variable frequency drive for longwall systems is designed to work in conjunction with the CST gearboxes to deliver variable speed of the armored face conveyor, very accurate load sharing between gearboxes, and better efficiency when operating in weak power networks. The advanced technology medium-voltage drive controls torque and speed to optimize longwall productivity, reduces wear and breakage of armored face conveyor and plow components and makes most efficient use of electrical power.
A key to Bogdanka's success in mining thin seams is incremental plowing. The new Cat system, as well as the previous three, can cut to a precisely defined depth, set as a function of coal hardness, regardless of seam structure or faults. The cutting depth is electronically preset using accurate stroke sensors and an advanced software algorithm. Horizon control provides precise control of the plow angle, ensuring that the plow does not dig or climb unless required to do so by the seam geology. This allows the system to follow the seam-floor boundary accurately, as well as enabling it to follow undulating seams.
Its fourth Cat plow longwall system positions Bogdanka to continue to economically mine thin seams far into the future.