Roll crusher

1. * Mehran University of engineering &
technology, jamshoro
Roll no: 14ch42
14ch24
Topic: Roll crusher
Subject: Particulate technology
Department: Chemical Engineering
Date: 18-10-2015
Assigned by: Prof: Dr: Khadija Qureshi
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*Contents:
* Introduction:
* Roll Crusher:
* Types of Roll Crusher:
* Working Mechanism:
* Advantages & Disadvantages:
* Short clip about Roll Crusher:

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Introduction:
Size Reduction involve reducing the size of particles so as to
get more products.
Forces involved are attrition, compression and impact And the
various equipment used for size reduction are such as hammer
mill, impactor, grinder, crushers:
Definition:
A crusher is a machine designed to reduce large rocks into
smaller rocks, gravel, or rock dust.
Different types of crusher are there such as jaw , compound ,
roll crusher etc.

4. *
Roll crushers are used for producing additional reductions
in the sizes of stone after the output of a quarry has been
subjected to one or more stages of prior crushing.
Roll crushers have a theoretical MAXIMUM reduction ratio
of 4:1. If a 2 inch particle is fed to the roll crusher the
absolute smallest size is 1/2 inch. Roll crushers will only
crush material down to a minimum particle size of about 10
Mesh (2 mm). A roll crusher crushes using compression,
with two rolls rotating about a shaft, towards the gap
between the Rolls. The particles are drawn into the gap
between the rolls by their rotating motion and a friction angle
formed between the rolls and the particle, called the nip
angle.
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Types of Roll Crusher;
1. Single Roll Crusher:
2. Double Roll Crusher:
3. Smooth Roll Crusher:
4. Toothed Roll Crusher:

6. *
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WORKING MECHANISM:
Rolls Crushers (High Pressure Grinding Rolls) consists of two
parallel rotating rolls turning together (in opposite directions), with
feed being directed through the moving gap between them. One
roll is fixed, and the other moveable, using hydraulic pressure. As
the ore moves through the gap, the hydraulic force behind the
moveable roll acts to crush the particles as they are forced
together into a crushed particle “bed”. Each roll is equipped with
its own motor,. One single rolls crusher can process up to 2,000
TPH of ore being fed to it. Operating with high pressures normally
results in a product that contains a significant amount of ultra-
fines (crushed particles less than 1mm), which provides a
favourable ore size distribution for ball mill feed.

7. *The roll crusher has a
simple structure, compact,
lightweight, reliable, low
cost and easy maintenance.
* they give a very fine
product size distribution
and they produce very little
dust.
*Coal is probably the largest
user of roll crushers
* The main disadvantage of
roll crusher is low
processing capacity.
*High wear, grinding teeth
vulnerable to hard material.
*High energy consumption.
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Roll Crusher:

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Roll Crusher:

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