circuit between the working chamber of
the coupling and the heat exchanger.
The operating fluid is drawn from the
working chamber by a discharge pump
with no need for additional external
energy. Optimisation of this discharge
pump ensures maximum heat
management within the coupling oil
circuit.
With multi-motor drives TPKL fluid
couplings provide active load sharing,
which protects individual motors from
overload. A sequential start-up of the
motors is possible with fluid couplings
in the drive. This avoids simultaneous
current peaks and is beneficial for the
electric grid.
The TPKL fluid couplings are very
powerful. The power transmission
capacity ranges up to 4000 kW at
1500 rpm (Figure 4). As they are also
very compact in size, easy
transportation and underground
installation is ensured. The design of
the TPKL is optimised to provide a long
life and reliable operation. This
translates into maximum availability,
long maintenance and service intervals
with little downtime. In general the
TPKL is extremely robust. It is
insensitive to tough environmental
conditions, such as dust, dirt or
humidity. Therefore it is well suited for
use in underground mining.
Case study
DaTong Coal Mining Group Co. Ltd is
located in DaTong City, Shanxi Province,
China. It is one of the top three coal
groups in China, with a coal production
capacity of 152 million tpy. The coal
group operates a large number of coal
mines across the country.
The 1000
th
Voith TPKL coupling will
go to the DaTong Coal Mining Group in
China. In this specific case, a newmine
will receive four identical fluid
couplings. The fill-controlled couplings
will be used in a 6.4 MW belt conveyor
drive, driven by four 1600 kWmotors.
The 3160 m (10 367 ft) long underground
belt conveyor is designed for a
challenging workload, as it will
transport coal uphill at a 14˚ angle. The
planned capacity is 4000 tph.
The decision in favour of Voith fluid
couplings for the drive line
arrangement in the main belt conveyor
was based on the group’s previous
positive experiences with the
performance of hydrodynamic power
transmission. According to the mine’s
manager of the mechanical and
electrical department, DaTong Coal
Mining is very happy to use
fill-controlled couplings from Voith in
their new belt conveyors. He highlights
soft start characteristics, reliability and
aftersales service as key aspects to
guarantee safe production.
Conclusion
TPKL fluid couplings are not the only
type to be successfully used in
underground mining. Voith has been
supplying different types of fluid
coupling to underground mining
applications for over 40 yrs. For
example, in high‑power armoured face
conveyor (AFC) drives, many mines use
DTPKWL2 and CPC (chain protection
coupling) fluid couplings from Voith.
They have been specifically developed
for the tough working conditions in AFC
drives in underground mining. They are
robust and powerful but compact at the
same time. Torque limitation against
overload can be individually pre-set
according to customer needs to prevent
damage to motor, gearbox and chain.
Thanks to active cooling of the operating
fluid, CPCs can start up as many times
as necessary to break an overloaded
AFC free. Miners appreciate this feature
because they do not have to clear the
conveyor by hand.
Figure 3. Active cooling of the Voith TPKL fluid coupling by an integrated heat
exchanger system.
Figure 4. The TPKL fluid coupling
transmits up to 4000 kW.
40
|
World Coal
|
January 2016
