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February 2008
Click to View Electrically Heated Pump (Adobe PDF file)
Electrically heated ROTAN pumps for Asphalt and
Bitumen.
Temperature sensor
The pump is equipped with a temperature sensor Type K DIN EN 60584 Class
2, with a 10 ft twin core cable. The green core is the positive pole and
the white core is the negative pole.
This temperature sensor, which is placed in the rear cover, is connected
to an operating device which will prevent the motor from starting up until
the pump medium is liquid enough to be pumped.
If the distance to this operating device is more than 3 m, the temperature
sensor can be connected to a temperature transmitter, or the wire can
be elongated with a Type K cable (NiCr-Ni).
Electrical Cartridge heaters
The voltage for the heaters used in the electrically heated ROTAN pumps
is 230V single phase.
If the pump is equipped with more than one cartridge heater, the cables
from the heaters can be joined together in a junction box, and a single
cable from there can be connected to the operating device, for instance
a temperature control box.
Heating time
The heating time for HD and GP pumps, equipped with electrical cartridge
heaters, from 68°F to 302°F is about four hours. This is when
the pump is insulated. When the pump is not insulated, the heating time
will extend about 50% or more. The heating time will vary depending on
the ambient temperature and air.
It is highly recommended to insulate the front cover, the pump casing,
and the rear cover against the pump casing with 50 mm windtight insulation.
The bearing bracket (item CQ) should not be insulated, because this will
cause the ball bearing (item CU) to be too warm.
Stuffing Box
The stuffing box packing with Desmi/Rotan material code 825, used in ROTAN
pumps for Asphalt and Bitumen, is made of discontinuous aramidic yarns
with a graphite based compound impregnation.
The temperature range is between -148°F to +750°F. For rotating
pumps the pressure rating is up to 725 bar, and the speed limit is 15
m/s. The chemical resistance is pH 2 - 12.
Mechanical shaftseal
When the pump is equipped with a mechanical shaft seal, the temperature
sensor has to be installed near it. This prevents the pump from starting
up until the pump medium is liquid enough to secure the dynamic parts
in the shaft seal.
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