Cradle to grave
Derive benefits from
banana screens
A completed Kwatani banana screen
ready for despatch to a customer.
While multi-slope screens — also
known as ‘banana’ screens — are
commonly used in various screening
applications, they need to be carefully
designed with the specific purpose in
mind. This is according to Kwatani
CEO, Kim Schoepflin.
At the top of these screens is usually
a first slope with a deck angle of at
least 35 degrees — allowing material
velocities of over three metres per
second — curving down to end at
about 10 degrees. This original layout,
however, is not always ideal for many
operations today.
According to Schoepflin, the company
aims to understand exactly what the
application is, so that they can align
the number of slopes as well as change
the angles of each slope to achieve
better efficiencies. “In this way, we
have been very successful placing
these designs in diamond and coal
applications, mainly in dense media
circuits, as well as for diamond
scrubber plants for degritting,” says
Schoepflin.
According to Kenny Mayhew-
Ridgers, chief operating officer at
Kwatani, failure to adapt the design
appropriately to the application can
lead to a number of challenges.
“Material velocity is exponentially linked
to the wear rate of the panels, and this high
panel wear will lead to frequent and costly
maintenance,” says Mayhew-Ridgers.
Another design strategy to reduce
panel wear is to create a more
continuous curvature profile along
the screen, with a higher number of
slopes making for a gradual change of
direction of material. This is based on
the simple principle that the greater the
change of direction, the more the panel
will wear.
OCTOBER 2018 MINING MIRROR
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