of one of the blow bars of the rotor - or by the immediately following impact arm,
however less powerful impact at the first upper impact arm in the housing - or
by impact of another blow bar and the powerful impact at the second lower
impact arm. The cracked particles get their final shape by passing through the
grinding path.
Double rotor Impactors (Fig. 2) are equally or even more popular for Roll Press
applications where the product size requirement is 95% (-) 40mm. However,
fines generation are more which impacts on higher dust generat
Figure - 1 Figure - 2
2.7.2 Hammer Crusher
In single shaft hammer crusher, the heavy duty rotor consists of series of
hammers attached to the rotor by means of bolts/pins. The grinding takes
place by throwing the material against front or side wall. The output size is
controlled by the outlet grinding path or anvil gap adjustment. Sticky limestone is
difficult to crush in single shaft hammercrusher.
Double shaft hammer crusher is used for the sticky and wet material. It
consists of two rotors and material is crushed between the rotors and anvil. The
sticky material is cleaned by the rotating hammers at the grate avoiding
clogging problems. Generally, it is used where wet limestone with clay is to be
crushed. Fig.3 and 4 shows the hammer Crushers.
Major Parameter based on that single rotor or double rotor selection is decided:
- Single rotor hammer crusher takes feed size up to 1-1.5 mtr. Whereas double
rotor can take up to 1.5-2.0 mtr feed size. - Single rotor can consider for Soft or moderate hard limestone Mohs hardness up
to 3.5 whereas double rotor considered for above 3.5 Mohs hardness. - Sticky Material can be used in double shaft hammer crush
(^)