Transcript Narrator - Sandvik Training Portal

Narrator: This presentation explains
the basic functions of how the
Sandvik VSI Autogenous crusher
works. This is a rock on rock
(autogenous) crusher, whereby no
wear parts are used to crush the
rock.
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Sandvik Mining and Construction
Narrator: Look at the image showing
the main parts and basic function of a
VSI crusher. A VSI is typically a third
stage crusher (maixmum feed size is
55mm) and crushes rock by the
impact of rock agianst rock. The VSI
works by accelerating rocks using
centrifugal force, to a very high
speed and then impacting them into
each other within the crushing
chamber. Click on the link opposite
to see the basic functions of the
Sandvik VSI crusher.
Click
Sandvik Mining and Construction
Narrator: Crushing is achieved by
feeding the rocks, via gravity feed
from either a conveyor or feeder.
From the moment of entry into the
feed hopper, rock ledges are formed
within the crusher, which protect
the crusher and guides the flow of
material through the crusher and
onto the discharge conveyor. Click
on the link to see the flow of
material through the crusher.
Narrator: The high speed rotating
rotor is the heart of the crusher.
This rotor acts as a rock lined
centrifugal pump. Click on the links
below to see a sectioned view of the
rotor in action.
Click here to see rotor
without feed
Click here to see rotor with
feed
Sandvik Mining and Construction
Narrator: The rocks are accelerated
by centrifugal force to typically 53
metres per second - that’s 190
kilometers an hour or around 118
miles an hour.
Sandvik Mining and Construction
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Sandvik Mining and Construction
Narrator: The chamber inside the VSI
is cleverly designed so that it always
keeps a layer of rock on its surface.
Therefore the rocks that have been
accelerated from the rotor are
impacted into other rocks within the
crushing chamber – this protects the
machine parts from wear. The highly
energized rocks within the crushing
chamber, impact and move in a
helical path around the crushing
chamber in the same direction of the
rotor. This gives multiple breakage
by impact, attrition and cleavage.
Click on the link to see the rock
acceleration and movement in the
crushing chamber.
Click
Sandvik Mining and Construction
Narrator: A Sandvik VSI also has what
is called Bi-Flow system. The Bi-Flow
rocks pass through adjustable gates
within the feed hopper and are
directed to fall into the crushing
chamber, but in the opposite
direction of the rotor fed material.
Here they combine with rocks that
are being accelerated out of the
rotor. Bi-Flow can increase the
crushers capacity by around 20%,
without reducing crusher efficiency.
Material in Bi-Flow is indepedant
from the rotor (and motor power)
and therefore requires no energy
input and causes no increased wear
to the rotor wear parts.