Correct Use; Useful Facts - IKA LABORTECHNIK RW 28 basic Instrucciones De Manejo

Additional hazards to the user may occur if inflammable materials
are used during the stirring operation or, if glass equipment is used,
the energy transmitted from the stirring device results in glass bre-
akage.
Make certain that the unit is set at the lowest speed before com-
missioning; otherwise, the unit will begin running at the speed last
set.
The unit will automatically begin operation again after a mechanical
or current supply failure.

Correct use

The RW28 basic stirrer are suitable for stirring and mixing liquids
with low or high viscosity. They are designed for use in the labo-
ratory. For proper use the units have to be fastened to a stand by
means of a cross sleeve after assembly of the extension arm (cf.
spare parts diagram, p. 77).
Unpacking
Please unpack the machine carefully and inspect for damage. It is
important that any transit damage should be noted at the time of
unpacking. In certain circumstances it may be necessary to in-
vestigate immediately (post, rail or freight forwarder).
The guarantee covers: One RW28 basic stirring machine in accor-
dance with the type ordered, a chuck key and operating instruc-
tions.
RW280597EU

Useful facts

In buying this machine you have chosen a high quality product.
Ease of use is guaranteed with its handy shape and simple ope-
ration. The housing offers protection against ingress of liquids.
The materials used and their precise identification make recycling
possible and simple, and enables re-use of the parts. The speed
can be infinitely adjusted between 60 and 1400 rpm 50 Hz; 72
and 1680 rpm 60Hz. The machine can be operated continuously
and warms up during operation. The generously proportioned
cooling surfaces enable distribution and transference of heat to
be as even as possible. The two metre long mains lead makes it
possible to work on stands - even with high glass apparatus under
vapour extraction hoods - without extension leads. The precision
stirrer shaft is designed as a hollow shaft to allow the stirrer
shanks to be inserted.
Drive
The method of operation of the motor is characteristic of the
operating behavior of the RW 28 basic units. The motor can be
infinitely adjusted via a friction wheel drive unit but is operated in
one position only. The power output, rotational speed and torque of
the motor are regarded as constant and are optimized for this
operating position. After the friction wheel drive the motor power
output is transmitted to the off-drive shaft of the stirrer via either
the first or second stage of the subsequent manually adjustable
toothed gear train.
Neglecting all losses, the power at the off-drive shaft during power
transmission (conversion) is always as great as the power output
of the motor. The gear train merely provides rpm and torque
conversion, which can be described in purely theoretical terms by
the characteristic curve plotted in Fig. 1.
Friction wheel wear is kept low by a helical clutch matched to the
gear train. The down-pressure required at the friction wheel is ad-
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