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Chemical Technology • January 2016
PETROCHEMICALS
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Another partial flow between the rotor and the can absorbs
the heat and flows back through the rear bearing and the
hollow shaft. Logically, the pump section and the rotor space
have to be connected. This design is out of the question for
fluids with high temperatures or fluids containing particles
which must not enter the rotor space. So the two spaces
are separated from each other in the corresponding design
variant.
For fluids with a low boiling point, such as ammonia
or light hydrocarbons, another variant with the code HP
is available. With these fluids a few degrees difference in
temperature can cause vaporisation. This variant has been
specifically designed to maintain the pressure in the rotor
space at the same high level as the pressure produced by
the main hydraulic system. An integrated auxiliary hydrau-
lic system circulates the coolant and lubricant in the rotor
space. This securely prevents vaporisation of the fluid in the
rotor space and mechanical seals.
The fourth variant of the new type series is based on
the same design. The HS variant has been developed for
solids-laden fluids. “Generally, the can is relatively thin
between the rotor and stator in order to keep energy losses
to aminimum,” explains Dr Kastrup. “When handling solids-
laden fluids, solid particles can wear through the sheet
metal and enter the stator space.” The HS variant covers
applications with ferritic particles in the fluid, which would
accumulate in the magnetic field of the motor and result in
wear at the motor. Other applications this model caters for
are fluids which form deposits or polymerise quickly. KSB
has developed a special sealing concept and cooling liquid
flow paths which make the fluid passage reliable as well as
energy-optimised.
PUMPS & V VES
Ecochem HP variant has an integrated auxiliary hydraulic system that circu-
lates the coolant and lubricant in the rotor space.