MECHANISED COAL
A visual diagram of the FAMAC
KWM system
performance longwall operations,” Cat explained.
“Advanced microcontroller technology with
increased computing power and enhanced
communication capabilities offers improved
functionality to control roof supports in a selfadvancing
longwall system. The new controller
also features enhanced serviceability.”
The company has also been busy refining its
three shearers – the EL1000, EL2000 and largest
EL3000 (with a 5,000 t/h cutting and loading
capacity) – after a detailed analysis of all recent
shearer installations.
Following this review, Cat shearers now feature
the PMC Evo-S control system with Ethernet
connectivity, a down-drive design and ranging
arms with longer service life, enhanced power
pack with easy access, refined modular haulage
system and electrical control box, and online
vibration monitoring with VibraGuard, the
company said.
“The future-proof design allows upgrades, such
as stronger cutting arms and haulage units, and
the addition of a coal sizer during rebuild,” it
added.
On recent shearer success stories, Cat
highlighted the performance of a new EL2000 that
has recently been put to the test mining a Utah,
USA, metallurgical coal seam riddled with faults
measuring 0.5-4 m in the thick seam. Coming with
a cutting range of 1.8-4.5 m, the shearer has
produced 1.2 Mt while achieving an average
mechanical availability of about 99% over the past
year, Cat says.
The latest addition to the Cat armoured face
conveyor offering, meanwhile, is the Cat PF HD
Line Pan, designed for heavy-duty longwall
applications with demanding conditions.
“With a bottom plate thickness of as much as
40 mm and deck plate thickness of as much as 70
mm, the new pan is the most robust and reliable
Cat line pan, lasting up to two times the life of
corresponding PF5 and PF6 pans,” the company
says.
Two conveyors equipped with PF HD line pans
are now operating at a Pennsylvania, USA, mine
with annual production of about 6 Mt of coal. The
mine anticipates extended wear life to optimise
uptime in its longwall panels with these new pans,
according to Cat.
Autonomous methane regulation
Methane-related incidents continue to plague the
industry, leading to temporary suspensions,
shutdowns and, at their very worst, explosions.
New tools to monitor and tackle rising methane
levels continue to be developed, with one such
technology coming from Poland-based FAMUR.
As Lukasz Herb (Senior Industrial IT Systems
Specialist) and Jerzy Krodkiewski (Project
Management Specialist in the Control Systems
Development Department of Longwall Systems) of
FAMUR explain, increasing cutting speeds while
operating in potentially hazardous conditions can
lead to more potentially dangerous methane being
released.
With many underground mines having methane
detection systems in place that record gas levels
and, when limits are exceeded, automatically shut
down operations, moderating the speed of a
shearer in line with methane levels is very
important when it comes to keeping up
production.
This is where FAMUR’s FAMAC KWM Methane
Emissions Control System comes in.
The system’s main task is to reduce the
downtime associated with power cuts caused by
methane-related safety shutdowns, Herb and
Krodkiewski say.
“The FAMAC KWM system is intended to
continuously determine the maximum permitted
speed of the cutting machine on the basis of
information about the current distribution of
methane concentration in the longwall, with
particular emphasis on the impact of the mining
process on the changing dynamics,” Herb and
Krodkieski told IM.
The core of the FAMAC KWM system is an
underground EH-O computer. This collects
aerological data from the coal mining area –
including the distribution of methane
concentration along the wall, absolute pressure,
and air flow velocity in the bottom gallery – and
data from the longwall shearer on the mining
process. The latter includes the location, speed,
load of the drives, etc.
Important information about events affecting
methane hazards in the area, as well as work
performed by the staff that cannot be registered
by the system’s sensors, is manually fed into the
computer.
Due to the unique nature of the data
aggregated by the system, it was necessary to
develop a special visual analysis tool to present
the change in the distribution of methane
concentration along the wall in correlation with
the mining process data, Herb and Krodkieski
said. This tool allows operators to analyse the
impact of the longwall shearer’s speed and
position on methane levels.
This is all integrated into the FAMAC KWM
system application for automatic analysis and
operating adjustments, according to Herb and
Krodkieski.
Preliminary tests of the FAMAC KWM system
were carried out between January 26 and March
20, 2019, for the configuration shown above.
These tests were conducted at a depth of 700 m in
a hard coal mine, in the Silesia region of Poland,
with a very high degree of methane hazards, they
say.
Integrated with the control system of a FAMUR
FS 400 longwall shearer, the test confirmed the
technical possibility of automatic adjustment of
the longwall shearer's cutting speed to reduce the
methane release in the longwall face, Herb and
Krodkieski said.
The two concluded on the tests: “It appears
that the methane emission control system should
be an integral part of any autonomous longwall
system operating under methane hazard
conditions. Such a solution allows for full
utilisation of production capacity by working at
the maximum possible speed under individual
conditions.”
Despite the positive results, Herb and
Krodkieski say efforts are underway to optimise
the algorithm for controlling the cutting speed and
the tools for processing the information already
recorded in order to obtain as much knowledge as
possible about the process itself.
The aim is to eventually offer the FAMAC KWM
system for integration on all longwall shearers
manufactured by FAMUR.
IM
86 International Mining | SEPTEMBER 2020