product news
61
07.13
New slurry seal
introduced by Metso
Metso is launching a new slurry seal to meet
the increased sealing demands from its cus-
tomers. The seal offers a sealing solution
that minimises dilution of sealing water into
product, eliminates leakage to atmosphere,
increases life time of the seal by preventing
slurry from entering the seal chamber and al-
lows easy conversion from box packing solu-
tions to mechanical seal solutions.
According to Metso, the ESF design seals
satisfy the demand for advanced and reliable
sealing solutions on even the heaviest of slur-
ry applications.
The ESF seal is designed to fit into the stan-
dard Orion Series pump flushed gland and a
cartridge design makes it easy to install. In ad-
dition, retrofit installations are quick and easy
when converting a packed seal pump.
Metso, tel (+27 11) 961-4000,
website:
The South African division of Cummins is
powering an electric rope shovel at Debswa-
na’s Jwaneng diamond mine in Botswana.
Cummins South Africa’s GM for the proj-
ects division, Werner Bester, indicates that
the Bucyrus (now Cat) 495 rope shovel is
powered by a 2 MVA Cummins motivator – a
containerised diesel generator that is mount-
ed on a custom-built Martin trailer, which is
pulled by a Western Star 6900XD truck.
“The Cummins C2250-D5 generator is pow-
ered by a Cummins QSK 60 G4 engine, which
is coupled to a Stamford alternator that pro-
duces 2 000 kVA at 6 600 volts prime power.
The Cummins PCC 3201 generator controller
provides control and protection to the Cum-
mins engine and the generator,” he explains.
Cummins South Africa Project Manager
Jan Maritz notes that the Martin trailer has
heavy-duty axles and a jumping beam sus-
pension, which was specifically designed to
accommodate the rough road and challeng-
ing conditions in the pit. “The axles were also
positioned in such a way that the trailer has
a small turning radius to easily manoeuvre in-
side the open-pit mine.”
The rope shovel requires an electrical sup-
ply in order to tram from one point to the next,
and the motivator provides this power while
the shovel is being moved.
According to Bester, the motivator has
been designed with numerous protection
features to safeguard the equipment, as well
as the operating team. “A regeneration pre-
vention feature is built into the motivator, as
regenerative power occurs while the bucket
is being lowered,” he says. “High volumes of
this type of power can cause damage to the
alternator, and it is therefore monitored to en-
sure that vital equipment is protected.”
Bester highlights the fact that the fire pro-
tection system is a dual system, with FM 200
Cummins motivator powers Jwaneng shovel
gas in the switchgear section and dry powder
in the generator section. “Additional infrared
arc detection is installed within close proxim-
ity to the switch gear, which will dispense the
fire suppression agent as soon as a flash is
detected. What’s more, there are a number of
easy accessible fire extinguishers mounted
on the trailer too,” he continues.
The fire protection system continuously
monitors the earth resistance between the
components and, should a short circuit or
open circuit occur, Bester explains that it will
change the value of the neutral earth from the
one point to the next. “As soon as there is
a fluctuation picked up on the neutral earth,
it will open the supply breaker and shut the
machine down.”
Another safety feature of the Cummins mo-
tivator is the fact that it comes standard with
The Cummins motivator on site at Jwaneng.
an externally visible three colour alarm light-
ing system. This system alerts operators of
likely problems ranging from minor to major
faults, in addition to potential fire hazards.
Werner Bester, Cummins SA,
tel (+27 11) 321-8700
