IKA MF 10 Instrucciones De Manejo página 19

Grinding operation with impact grinding mill:
The suitable filter is pushed in and the door is locked before beginning
the grinding procedure.
.
Afterwards a collecting pan is fastened to the discharge cone (standard
ground joint NS 29). Suitable containers are e.g. Erlenmeyer flasks Pos.
Z3, round-bottomed flasks, test tubes made of either glass or plastic.
The containers are to be secured with a fixing clip Pos. Z2.
For heat sensitive materials or with ground materials that have a very
high increase in volume during cut up, it is advisable to use a two-
necked flask with a filter attached to its second (e.g. cotton wool, etc...).
The ground material is cooled from the air flow and no excess pressure
is created. For very critical ground materials (very fine powder after
being cut up) the ground material can also be sucked off by means of a
commercial vacuum cleaner with a suction tube adapted at the dischar-
ge cone. The powder is then in the vacuum cleaner bag where it can be
removed for further processing steps.
The ground material which has prepared to the correctfeed grain size is
filled into the funnel and then the cover Pos. P17 is applied. The speed
knob Pos. A12 is turned to the left stop (3000 1/min).
The mill is started by shifting the rocker switch Pos. A13 to Position 1.
First the green „Power" LED is lit and then „Overload" LED lights up
briefly before the motor smoothly starts. The speed can be set by tur-
ning the speed knob to the desired speed. A speed of more than 4500
1/min is recommended for impact grinding.
Now the ground material can be metered by turning the dosing sluice
Pos.P6 in a clockweise direction. You can hear if ground materials gets
into the grinding chamber and if too much materials has been metered
then the rotor speed decreases. This drop in speed is clearly indicated
by the lower grinding noises and the orange „Overload" LED lights up.
Metering of the ground material should only be resumed when the
speed has returned to the adjusted value or if the „Overload"-LED is no
longer lit.
If this is done then the mill becomes overloaded and switches off after
some time because of overheating. This is then indicated by the red
„Error" LED. In addition, a beep sounds to indicate that the millshould
be switched off using the rocker switch Pos. A13. The mill must then
MF10 0998 EU
cool off for a period in order to be able to start in again (see chapter on
Troubleshooting).
In addition, the ground material is no longer cut up the lower speed
when the unit is operated with an overload because the impact energy
no longer suffices for breaking the ground material. Keeping the ground
material in the grinding chamber and the ground material to heat up. In
extreme cases this can result in the ground material caking on the grin-
ding chamber parts which then entails a time-consuming cleaning ope-
ration.
If the funnel is empty then the mill remains turned until all of the ground
material from the grinding chamber is in the container. This is the case
if cutting up noises can no longer be heard.
When it comes to cleaning the grinding chamber experience has shown
that it makes sense to briefly switch the unit to maximum speed after
the grinding operation has been completed and only then to turn the
speed knob to the left stop. The mill is then shut off with the switch.
The filter is removed after opening the grinding chamber door and any
remaining ground material is wiped into the collecting pan.
Note: After longer grinding cycles the grinding chamber and the
filters may have an increased temperature. Protective personal equip-
ment should be worn in this case.
It may help to crush the ground material in serveral steps, i.e. a filter
with large perforations is used for pre-crushing and finer ones in each of
the following steps.
Advantages:
• fewer failures, e.g. due to clogged filters or overloading the motor
• less heat-up of ground material since the retention time of the
ground material in the grinding chamber is substantially reduced
• closer grain size spectrum for the final material
• normally less total grinding with better results as despite several
runs comminution is performed more quickly and more effectively
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