primary drive pulley and another
1100 kW drive on the tail pulley. The
tail end drive would be controlled by
reference to a load cell beneath its snub
pulley and a control loop that maintains
a tension set point.
The author and his team nominated
an extensive horizontal curve in the
conveyor, so this arrangement of drives
should be adopted to minimise the
number of transfer points, minimise
belt tension and gain control over
acceleration and braking situations, to
ease operation of the curved section of
conveyor.
Making it work
It is one thing to have minimised the
structural steel, the number of idlers,
the belt carcass strength, the number of
transfer points and to optimise the
geometry; it is another to make it work
in the field.
For the best results, the designer also
needs to consider a few other important
points:
n
n
Real world coordinates refer to
a sphere, slightly smaller than
the Earth. As a result of that,
mathematical calculations over
long distances do not refer to the
actual physical distance from the
head to tail pulley. Depending on
the elevation above sea level, the
distance will be wrong by several
metres. Make sure the design
allows the conveyor to be built. The
consequences of this mistake are
not insurmountable in a straight
conveyor, but a curved one can be
very expensive to correct after the
event.
n
n
Building adjustment into a
structure increases assembly time
onsite, increases the potential for
misalignment and commissioning
issues and allows people to play
with it post commissioning,
leading to an increase in potential
operational issues. Try to maximise
the decree of modularisation to
avoid this tendency.
n
n
Support structures deflect under
load. Aligning them when the
conveyor is empty means they will
be misaligned when it is loaded.
This is particularly true of beams,
gantries and conventional idler
tables. This deformation when
the idler is most heavily loaded
can have an enormous impact on
idler roll life. The idler support
structure shown in this example
minimises this tendency by having
every idler supported directly by
a leg.
n
n
Long conveyors can experience
transient behavioural issues when
subject to sudden braking events.
In this instance, the operational
issues associated with this event
can be offset by distributed brakes
and a method for locking the
take-up position during braking.
Getting these things right has very
little impact on the cost of the
conveyor (it is a question of doing
the analysis and implementing
whatever the flywheeling, braking
and take-up operation is that gives
the best result). The cost is all in
fixing it afterwards, when the
analysis is not done completely
and competently to begin with.
Tel: +1-630-971-0150
Email:
SOLVING ISSUES
ALONG THE BELT LINE
At Flexco, we take your system’s
productivity as seriously as you do.
That’s why we offer comprehensive solutions to your belt conveyor
issues. From conveyor belt splicing, belt cleaning systems, and
belt tracking, to impact beds and maintenance tools – we can help
you maximize your uptime, keep your output high, and help your
employees work safer.
MECHANICAL BELT SPLICING
BELT CONVEYOR MAINTENANCE
CONVEYOR BELT CLEANING SYSTEMS
