Surface World June 2019 Surface World June 2019 | Page 80
PRODUCTS & PROCESSES
Reliable, leak-free pumping of hazardous
fluids with sealless mag-drive pumps
When fluids handling
applications involve
hazardous, flammable
or corrosive liquids
the need for robust
and reliable leak-free
pumps is crucial and
in these situations
DICKOW SCM Series
magnetically coupled
pumps are designed
and built to excel.
Available from UK
pump specialists
MICHAEL SMITH
ENGINEERS these self-
priming, horizontal,
side-channel pumps,
operate more economically
when pumping low
capacities at high heads
than standard centrifugal
pumps.
Suited to pumping clean liquids without
solids in the chemical and petrochemical
industries, Dickow SCM pumps can handle
capacities up to 37 m³/hr on fluid handling
systems with differential heads to 400 metres
and liquids at temperatures up to 180°C.
They have a maximum operating pressure of
40 Bar, although a high system pressure
option is available for applications with
pressures up to 110 Bar. They are also suited
to priming suction lines after filling.
The magnetic coupling and static
containment shell design of these pumps
results in a closed system which eliminates
the need for double acting mechanical seals,
external fluid reservoirs and any associated
control equipment. With around 90% of
pump failures caused by leaking mechanical
seals, the sealless design brings the benefits
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of reduced costs associated with unscheduled
repairs and maintenance caused by failing
mechanical seals and therefore reduces the
overall costs of ownership. when handling volatile liquids with low
viscosities, the pumps can be fitted with
additional SiC rings to avoid contact between
the rotating and stationary parts.
The single elements of the multipolar magnet
coupling elements are completely
encapsulated and not in contact with liquid
and are made from Cobalt-Samarium for
unlimited lifetime durability. Power is
transmitted to the hermetically sealed liquid
end by a bank of external magnets with the
inner and outer magnet rings locked together
by magnet forces which work as a
synchronous coupling. The pump drive shaft is carried in anti-friction
bearings which are rated for in excess of 3
years and grease-filled for life and protected
against challenging environmental conditions
by a radial seal ring. Options are also
available which feature an oil-lubricated
bearing bracket and close-couple design.
The internal sleeve bearings are positioned in
the pumped liquid with both the sleeves and
the thrust bearings made from pure Silicone
carbide which is highly resistant to corrosion
and wear. Standard material for the
stationary bearings is carbon, although
Silicon carbide is also available. These
features ensure long service intervals and
reduce the chance of premature failures.
To achieve low NPSH conditions, the impeller
on the suction side has an enlarged eye area
while the rotating star-shaped side channel
impellers are fitted in a chamber between the
suction and pressure disk and keyed to the
pump shaft in a floating position which
eliminates the risks associated with excessive
hydraulic loads.
The tight clearances between the rotating
impeller and the stationary disks ensure
superior self-priming capabilities along with
high efficiency and high differential pressures
to be achieved. Also, in applications where
prolonged dry-running can be a problem, or
When coupled with Ex-drive motors Dickow
SCM pumps can be used in hazardous area
Group II, Category 2 situations and are
suitable for sites which have increased safety
requirements.
Telephone: FREEPHONE: 0800 316 7891
Email: [email protected]
Visit: www.michael-smith-engineers.co.uk
read online: www.surfaceworld.com