Retsch BB 100 - Manual (Page 15)

2/7/2012 Retsch GmbH
15
Working instructions
Target group: Laboratory technicians
General
The BB 100 is a rugged, floor-mounted unit which is used
primarily for preliminary crushing in preparation for final size
reduction.
Its continuous operating concept also makes the BB 100
suitable for integration into fully automatic and semi-automatic
processing lines.
The performance data, throughput rates and ultimate fineness
will depend on the fracture properties and hardness of the
product and on the gap width which is selected.
Grain size of feedstock product
The maximum grain size is determined by the size of the fill
hopper opening; in the BB 100 this is a maximum of 50 mm.
Properties of the product being crushed
Every hard and brittle product, exhibiting a hardness of greater
than 3 on the Mohs scale, can as a rule, be reduced with the BB
100.
Wet and oily product and that with a hardness index below 3
(Mohs scale) tend to be compressed and clump in the crushing
chamber, this being due to the pressure exerted by the breaker
jaws. It is for this reason that pre-crushing such material is
hardly possible.
Fig. 6
Fill volume
If the crushing chamber W is filled with more than 2/3 =300ml,
then the guide plates of the fill hopper could be damaged and the
moving breaker would force the product into the crusher
housing, behind the breaker arm. Fig. 6
The fill level will also influence the proportion of fine material
in the product or specimen after preliminary crushing; the fuller
the crushing chamber, the greater the share of fines.
If the crushing chamber W is filled with more than 2/3 =300ml,
then the fill hopper guide plates could be damaged; the moving
breaker arm would force product behind the breaker arm and
into the crusher housing.