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GEA Niro Method No. A 23 a |
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1. Principle
Flowability is the ability of a
powder to flow, and it is measured as the time in seconds necessary for a given
volume of powder to leave a rotary drum through a slit of a certain
size.
2.
Scope
This method may be used for all
powders, dairy and non-dairy products.
3.
Apparatus
1. Motor with gear suitable for running at 30
rpm.
2. Stainless steel drum as shown in Fig.
1.
3. Stop watch.
4.
Procedure
1. Determine the bulk density tapped 100 times in
g/cm3 by using GEA Niro Analytical Method A 2
a.
2. Weigh out an amount of powder ± 0.1 g corresponding to:
A = B x 25
A = amount
of powder in g
B = bulk density in g/cm3 tapped 100
times.
3. Pour the powder into the drum and put on the
lid.
4. Start the drum (set at 30
rpm) and the stop watch simultaneously.
The drum should rotate so that the
powder that is not leaving the drum through the slits is broken up by the metal
rod 24° later.
This is very important when measuring sticky
products.
5. When the last powder has
left the drum, stop the watch and record the time.
6. The determination has to be
made in duplicate.
5.
Result
Flowability = average time in sec.
Record the results in
sec.
Two determinations must not differ
more than shown below, if they do, repeat the analysis.
Flowability
;
Reproducibility
< 30
sec.
;
20% relative
> 30
sec.
;
10% relative
6.
Remarks
The method is in principle not
designed for powders containing agglomerates >4 mm.
However, when testing
powders containing some agglomerates >4 mm, the watch should be stopped,
when powder ceases to flow out of the drum.
7.
Reference
Own
experience.
Fig
1. Drum for determination of flowability
This
equipment is not delivered by GEA Niro
This
equipment is not delivered by GEA Niro