FRITSCH PULVERISETTE 25/19 - Manual (Page 4)

Cutting mill combination „pulveristte19“ – „pulverisette 25“ page 1
This operating manual is meant only as a supplement to the operat-
ing manual for the individual machines pulverisette 19 and pulver-
isette 25
1 Short description of machine function
1.1 Pre-grinder p-25 model 2
Grain size of the feed:
The grain size of the feed depends on the grinding ability (the tenacity)
of the material to be ground, e.g. metals, tyre rubber, and other tena-
cious synthetic materials such as PVC, PA, ABS etc. Leather and similar
material can only be fed in a small grain size range of 10-30mm. For less
tenacious materials like wood, paper, PCB material, minerals, etc. the
grain size of the feed can be up to 50mm.
Other deciding factors are as follows:
• Feed quantity /time
• RPM of the motor and torque
• Geometry of the slicer blades
• Sharpness and condition of the slicer blades
• Gap width between the fixed and rotating blades
• Sieve size or final fineness, condition of the sieves (degree of
obstruction)
• Air flow-rate (depending on degree of obstruction)
For mixed materials such as shredder waste (without metal component),
a medium grain size of approx. 20-30mm is found to be ideal for trouble
free operation.
A simple bulk material funnel is sufficient for feeding the sample. For
woolly material from seat fillings found in automobile shredders, the air
current is not sufficiently powerful. Therefore, an additional pushing de-
vice must be utilized.
1.2 Sample splitter
The sample splitter is intended to lessen the quantity of samples for the
fine crusher. This way, the requirements for the repeatability of division
are not too high. However, it must be ensured that the sample is not
fractioned, that is to say, not pulverized into light and heavy or fine and
rough components.
The rate of division, that is, the quantity of samples passing through,
depends on the sample material and final fineness of the pre-crusher.
This is adjusted by covering the openings.