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December 2015
MODERN MINING
29
MATERIALS HANDLING
feature
T
his is the view of Michael van
Niekerk from ASP Fire, who goes
on to add: “Conveyor belt sys-
tems and supporting structures
are normally of non-combustible
construction; however, any large fire may
damage or cause the collapse of the structural
elements. The principal fire load includes the
material being conveyed, the mechanical com-
ponents of the system, and the belt itself.”
He says there is a misconception that con-
veyors are not easily ignitable, which can often
prevent mines from taking the necessary pre-
cautions to ensure that there is sufficient fire
protection in place: “Once a conveyor fire
starts, it will grow rapidly and become very dif-
ficult to control in a very short period of time.”
He points out that belts contain polymeric
materials, which present a serious risk in terms
of rapid fire spread and the generation of toxic,
corrosive smoke – making these fires lethal and
incredibly difficult to control.
In June 2015, for example, a fire that burned
a multi-story conveyor belt at a Lake Elsinore
aggregate mining and crushing business in the
USA caused an estimated US$13 million in
Fire protection essential
for conveyor belt systems
Belt conveyor systems are used exten-
sively in the mining industry – they
provide an ideal solution to transport
manageable sized material from one
processing point to another. Using
such a system reduces the reliance
on manpower and reliability is maxi-
mised. However, a key protection area
that has to be considered is how to
best handle the issue of conveyor belt
system fires.
An underground conveyor
tail pulley fire with water
mist system in action.The
water mist fire suppression
systems available from ASP
Fire force water through
micro nozzles at a very high
pressure to create a water
vapour mist. Fire extin-
guishing occurs due to a
combination of the cooling
effect of the water mist and
the displacement of oxygen
caused by the expansion
of the water mist as it is
vaporised.
damage and took firefighters more than two
hours to contain. “When you consider the
overall loss caused by a conveyor belt fire,
you can’t just think about the possible loss of
lives, injured staff and the loss of expensive
equipment, but you also have to consider the
excessive loss of revenue that will be incurred
by the downtime required to fix or rebuild the
conveyor belt,” says van Niekerk.
“As such, the essential ethos behind any
quality conveyor belt fire protection needs to
revolve around the preservation of the con-
veyor belt system itself. Hence, the need for
early detection and the quick and successful
extinguishing of any fire, while simultaneously
cooling the affected structure, remains key.
“It is important to note that every conveyor
belt system is unique and, as such, an individ-
ual assessment has to be made for each system
in order to adequately and accurately deter-
mine where the fire risks lie for that particular
system design.”
He notes that – in his experience – the
most common causes of conveyor belt fires are
static heat build-up from friction caused by
belt movement, moving fire on the belt itself,