PUMPS
externally while their pumps are operating.
Internally, this repeated popping creates
shockwaves that can result in considerable
physical damage. Over time, cavitation can
destroy impellers and pump housing, result in
seal and bearing failure, impact flow and pressure
rates, and consume significantly more power.”
GIW adds: “Naturally, the best way to fix a
cavitating pump is to avoid cavitation altogether.
As far as general maintenance is concerned, it’s
important to ensure your pipe and filters are free
of blockages and that your pump is operating at
its most efficient point on its pump curve.
However, the most effective form of prevention is
to select the right pump from the start. Find a
centrifugal pump that operates far below the
required critical suction pressure or net positive
suction head (NPSH). It’s also important that
your system’s flow in and out of the pump
doesn’t exceed the pump’s capabilities. By
selecting a pump that’s an ideal fit for your
pressure, flow, and overall application, cavitation
should never be a concern.”
Atlas Copco on versatility
A recent article by Wim Moors, Vice-President for
Pumps at Atlas Copco Power Technique raised
the point that when building a pump portfolio,
it’s essential to choose equipment that is
versatile, productive, safe and trouble-free.
“When users have to choose a pump, they
usually opt for larger sizes on the basis that they
can cover a multitude of jobs, but bigger is not
always better and by choosing this option,
energy efficiency is often sacrificed. Buyers can
avoid this by considering new types of
technology, rather than simply replicating orders
they have always placed in the past.
Developments in technology are helping to
reduce fuel usage and operating costs. In recent
years, newer types of pump have been introduced
that are specifically designed to reduce fuel
consumption at times of low load and cope with
fluctuating application demands without running
up high-fuel costs or risking burnout.”
Smaller and lighter pumps are now being
developed, as well as those that are easier to
move and transport both on and between work
sites. Consequently, buyers should take time to
ensure they select a pump that is suitable for
use on multiple sites where the pumps could
potentially be working, and that the pump has
built-in features that enhance movement and
safety. “Many larger pumps have integrated
trailer options, as well as integrated lifting
beams and/or forklift slots. It’s important to find
out what options the manufacturer has added to
aid the safe movement of the pump from site to
site, or within the working location where it is
needed.”
He adds: “Those who work with pumps know
that no two jobs are ever the same, so it makes
sense to choose a pump that is suitable for
multiple applications. It should also be a priority
to look closely at the design of the pump’s
components and how they work together. So
users should consider pumps that come with a
range of accessories to enhance performance for
changing applications; performance that covers
multiple applications and offers different options;
and a modular design that enables upgrades or
changes to the existing pump, without the need
to replace it with a completely new one.”
Pumps in mining need to perform reliably in
extreme environments so it’s important that the
selected pump has been thoroughly tested and is
capable of withstanding tough and changeable
working conditions from the moment it is turned
on. “In addition, pumps shouldn’t get clogged
up. If a pump becomes clogged, then it will
reduce the flow of water being pumped. When
clogging occurs, it affects performance, and if
allowed to continue for an extended period of
time, the pump could ultimately burn out. It’s not
very often that users are pumping perfectly clean
water, so some elements of clogging are a hazard
of the task. To protect against problems, leading
manufacturers are continually looking at the
positioning of parts and specifically, at the inlet
holes and passing areas. Before choosing a
pump, users should ask what steps the
manufacturer has taken to avoid clogging and so
guarantee consistent performance.”