Konecranes explains the advantages
of its AGD grab unloader
The operations of modern bulk terminals need to be based on
sustainable environmental thinking and modern, reliable
equipment in order to provide excellent service to their
customers and achieve strong financial results.
Konecranes contributes to the effort with modern, reliable
bulk handling cranes that undergo continuous improvement.
New technologies and designs that improve environmental
performance are always being refined and incorporated, without
sacrificing production performance or operational reliability. On
the contrary: new developments support both objectives. A
simple and maintenance-friendly solution will often be the most
environmentally friendly solution.
 
THE PROOF IS WITH THE CUSTOMER
The Konecranes AGD grab unloader, used with satisfaction by
many bulk terminal operators in all the major global markets, is a
good example. Its unique four-rope drum system with electrical
drive synchronization has proved to be an extremely reliable
bulk crane drive system. The AGD’s simple mechanical
configuration employs standard components and is easy to
maintain. Normal maintenance routines are easily carried out in
the intervals between vessels.
The Advanced Grab Drive (AGD) system was developed by
Konecranes at the end of the 1990s. The first AGD grab
unloader was delivered in 1999 to the Port of Pori in Finland.
Today, 19 AGD grab unloaders are working around the globe and
three units are scheduled to be commissioned in 2011/12. All
AGD customers have reported a high rate of operational
reliability, and three of them have placed a repeat order for a
new unloader (Bristol Port and Port of Koper in Europe, Rio
Tinto in Australia).
An interesting part of the AGD story is that, during the last
ten years, almost every European power plant that has decided
to purchase a ship unloader has chosen the Konecranes AGD
grab unloader over continuous ship unloaders (CSUs) or other
grab unloader types. These customers include Endesa in Spain,
Vattenfall in Germany and Dong Energy in Denmark.
 
ACCEPTANCE IN JAPAN
The tide seems to be turning in the Far East as well. Traditional
CSU markets like Japan, Korea and Taiwan are showing interest
in AGD grab unloaders. In fact, the major Japanese steel
producer Nippon Steel has purchased one 80-tonne, 3,000tph
(tonnes per hour) AGD crane for its Yawata Works in South
Japan. The order was awarded to Konecranes after long and
thorough evaluation of the technology and quality, as well as
Konecranes’ ability to provide service in Japan.
What then is the key word that sways customers in favour of
the Konecranes AGD grab unloader? Reliability. The AGD’s
simple rope reeving and standard components make the crane
easy to maintain, which in turn results in high uptime. Other
grab unloader mechanisms are characterized by either
complicated rope systems or very large planetary gear boxes.
It is known that some CSUs require heavy maintenance in
order to provide satisfactory uptime. Only a very few
customers report availability better than 90% for their
CSUs. Users of AGD grab unloaders report
availability rates up to 99%.
The AGD grab unloader maximizes ecoefficiency
by reducing energy consumption
and emissions. It has the lowest power
consumption of any type of ship
unloader: 0.27kWh per unloaded
tonne of material, setting the
benchmark for ship unloaders.
The bucket-chain type CSU
consumes 50% more
electrical energy per unloaded
tonne than the AGD. The
screw-type CSU consumes three
times more per unloaded tonne than the
AGD.
 
DEALING WITH DUST AND SPILLAGE
Dust emissions and spillage are major
problems in ship unloading. A modern grab unloader can be
furnished with an efficient dust extraction system for dusty
cargoes, while dust suppression is usually sufficient for coal and
iron ore. The AGD control system provides new ways to handle
dusty materials. These include automatic discharge with or
without swing, and a special mode for grab lowering and opening
above the hopper. Spillage is eliminated by using the automatic
modes in grab discharge. Since all drivers make mistakes, even
experienced ones, the AGD control system mitigates driver
error by opening the grab in the same way every time.
The latest development is a new hopper and feeder system
for unloading woodchips. Renewable energy sources are
becoming more and more important in power generation, and
different types of biomass are being investigated.
Woodchips are perhaps the most difficult material
to handle in large volumes. The existing material handling systems
are definitely not up to the job.
The Konecranes solution is to use a box-type hopper with a special chain
feeder adopted from the pulp and paper industry.
The portal conveyors can be either belt conveyors or
screw conveyors, depending on the feed arrangement to
the shore conveyor lines. The system is very simple and
provides high capacity. Feed rates of up to 3,000m3/hour
are possible.
‘Accurate kinematics’ is the best way to describe the
overall performance of the AGD grab unloader. The
Konecranes design philosophy of designing and
producing key components in-house brings the
advantages of easy maintenance and quick recovery
times. The result is high performance and excellent
operational reliability.
 
TAKING RESPONSIBILITY
The ship unloader is the bulk terminal’s front-line production
machine. Bulk terminal operators want smooth and
uninterrupted operation from their ship unloaders and all their
other equipment: unexpected stops due to equipment failures
are intolerable. It happens, however, and then the question is:
who will get the operation running again, and how fast?
Konecranes wants to be known as the company that takes
complete responsibility for its cranes throughout their operating
life. With the AGD grab unloader Konecranes is able to do this:
its design is based on in-house components including the control
system, and it is supported by a global service network.