FRITSCH LABORETTE 24 with V-shaped channel - Manual (Page 7)

2.2.1 Operating principle
A channel made of stainless steel is set in vibration by an electromagnet.
A funnel made of stainless steel, which is fastened to a height-adjustable
pillar, dips into this channel.
The material to be conveyed is filled into the funnel. When the feeder is
switched on, the amount of outflowing material is determined by the
distance between the funnel and the channel.
The electrical control system determines the oscillation amplitude of the
vibrating channel and hence the amount and flow rate of the material
conveyed.
The solid cast housing contains an electrically controlled magnet. Four
permanently flexible springs carry the armature of this magnet together
with a work plate, which is fastened to it. As a result, the work plate is
pulled when the magnet is switched on and can spring back when it is
switched off. The cast housing and magnet on the one side and the
armature and work plate with feeder on the other side form a vibratory
system. Its natural frequency is influenced, for example, by the weight of
the material to be conveyed.
The desired feed rate is achieved under all operating conditions; pro-
cessor-controlled electronics ensure a reproducible oscillation amplitude
due to the adjustment of the frequency of the frequency generator to
the natural frequency of the channel.
The interface installed in the control system of the feeder allows the
feed rate to be stopped by means of an external signal. This, in turn,
allows the conveyed quantity to be controlled, for example by applying a
DC voltage (within a range of 5-30 V) or with a computer / RS232 serial
interface. The "remote control" of the vibratory feeder makes work con-
siderably easier while at the same time ensuring reproducible operations
for the process control or routine work in the laboratory.
2.3 Obligations of the operator
Before using the LABORETTE 24, this manual is to be carefully read and
understood. The use of the LABORETTE 24 requires technical knowledge;
only commercial use is permitted.
The operating personnel must be familiar with the content of the oper-
ating manual. For this reason, it is very important that these persons
actually receive the present operating manual. Ensure that the operating
manual is always near the device.
The LABORETTE 24 may exclusively be used within the scope of applica-
tions set down in this manual and within the framework of guidelines
put forth in this manual. In case of non-compliance or improper use, the
customer assumes full liability for the functional capability of the LABOR-
ETTE 24 and for any damage or injury arising from failure to fulfil this
obligation.
Safety information and use
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