Parr Instrument A3040HC - Manual

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A3040HC Compact Magnetic Drive
Operating Instruction Manual
441M
Description
The A3040HC compact magnetic stirrer consists of a
lower rotor assembly with an inner set of magnets
and an outer coupling assembly with a second set of
magnets. Typically a 1/17 HP variable speed motor is
used with the A3040HC. This assembly is intended
for low viscosity applications and has a torque rating
of 2.5 in-lbs (28.2 Ncm).
The A3040HC magnetic stirrer can be used with both
the standard stirrer shaft and impeller(s) or with a
gas entrainment stirrer arrangement. It is designed
to stir at speeds up to approximately 1700 rpm.
Maximum stirrer speeds are dependent upon the
viscosity of the vessel contents and the resultant
load on the motor.
This magnetic stirrer requires minimal maintenance;
however, it is important to protect these magnetic
stirrers from the heat in the reactor vessel. To pre-
vent overheating each magnetic drive includes a
cooling sleeve. The cooling sleeve is held in place
on the housing with a snap ring and seals against
the housing with two O-rings. A steady flow of cold
water through this sleeve during all vessel operation
at temperatures above 80 °C is required. Excessive
heating without use of the cooling water will also
damage the O-rings in the cooling sleeve.
Shaft Removal and Installation
To remove the stirrer shaft hold the A3077HC outer
housing of the compact magnetic drive assembly,
and unscrew the stirrer shaft in a counter-clockwise
rotation. To install a replacement or alternate shaft,
hold the outer housing of the compact magnetic
drive firmly and screw in the new shaft.
Caution!
It is important to hold the housing securely
when installing any of the stirrer shafts so
that the threads are fully engaged.
Magnetic Drive Maintenance
The thrust washers and bushings in this magnetic
stirrer are self lubricating and do not require service
during normal operation.
It is advisable to periodically inspect the internal
portion of this drive to monitor the wear on both the
thrust washers and bushings as well as any debris
build-up that may occur from solvents in the reac-
tor system. This can be done without removing the
entire drive from the vessel head.
To inspect the internal rotor area:
Loosen the (4) set screws located around the outer
housing. Lift the A3077HC outer housing assem-
bly off of the magnetic drive. Unscrew the end cap
(A3076HC) out of the magnetic drive. This will expose
the 1137HCHA PTFE O-ring as well as the lower rotor,
thrust washers, and bushings.
Check for any evidence of leakage past the O-ring
seal. If vapors from the reaction have produced
solid deposits around the rotor housing these will
need to be removed to maintain free movement of
the inner rotor assembly.
To remove the A3035HC internal rotor assembly,
push upward using the internal stirrer shaft. Hold
the internal rotor and unscrew the stirrer shaft from
the rotor.
The two thrust washers are positioned on the top
and bottom sides of the internal rotor. The lower two
bushings are located in the 2721HC housing. The
upper (3rd) bushing is located in the bottom of the
end cap. These components require periodic replace-
ment, typically once or twice a year depending upon
usage. Over time the bushings will wear leaving
small flakes of material in the housing. It will be
evident with visual inspection of these thrust wash-
ers and bushings when replacement is required. The
1132HC upper and lower thrust washers, as well as
the three 1133HC bushings, are all manufactured of
carbon-filled PTFE and are easily replaced.