Retsch BB 300 - Manual (Page 16)

07/02/2012 Retsch GmbH 16
Notes on working procedures
Target group: Laboratory technicians
General
The BB 300 is a robust free-standing machine which can
predominantly be used for preliminary pulverisation of hard or brittle
materials.
The performance data, throughput and achievable final fineness are
dependent on the breakage behaviour and hardness of the process
material, and on the gap width set.
Input grain size
The maximum input grain size is determined by the size of the intake
opening, and is max. 130 mm on the BB 300.
Quality of process material
In principle, any hard and brittle process material with a Mohs
hardness >3 can be crushed in the BB 300.
Moist or greasy process material with a Mohs hardness <3 tends
merely to compact or cake in the crusher chamber as a result of the
pressure applied by the crusher jaws.
Crushing is hardly possible in such cases.
Capacity
Fig.7
If the crusher chamber W is filled more than 2/3 (3500ml), the guide
plates on the feed hopper can be damaged and process material
conveyed by the moving crusher arm into the crusher casing behind
the crusher arm. Fig.7
The quantity of material in the machine also influences the proportion
of fines in the pre-pulverised sample material. The more material in
the crusher chamber, the higher the proportion of fines can be.
If the crusher chamber W is filled more than 2/3 (3500ml), the guide
plates on the feed hopper can be damaged and process material
conveyed by the moving crusher arm into the crusher casing behind
the crusher arm.