Rolling process is most common industrial process used for
making large length cross section like sheets and
plates of steel and aluminum for structure and other works. Rolling mills are
used to perform rolling process. These machines are available in different shapes and size according to requirement of the process and due to
technical issues. Every rolling mill consist minimum two rolls. These numbers
can extend according to the process requirement. Today we will discuss about
all types of rolling mills used in manufacturing industries.
Types of rolling mills:
According to the number and arrangement of rolls, this
machine can be classified into following types.
Two High Rolling Mill:
This mill consist two rollers arranged as shown in figure.
Both the rollers rotate in opposite direction for desire movement of work
piece. Work piece is feed between the rollers which apply a compressive force and tends to plastically deform work piece and convert it into desire shape.
This machine can further classified into two types. The
first one is two high non reversible machine in which the rollers can rotate in
only one direction (Either clockwise or anticlockwise) and thus work piece can
feed only in one direction (Either left to right or right to left). One big
problem arises in this machine is that every time the work piece carried back
over the front side of mill to feed again for reduction in thickness.
The other one is two high reversible machine in which both
the rollers can be rotate in both directions. In this machine no need to carry
work piece at front side. We have to just change the direction of rotation of
rollers to again pass the work piece through rollers for decrease thickness.
Three High Rolling Mill:
This type of rolling mill consist three rollers arrange parallel
to each other. In this machine the middle roller rotate in opposite direction
of other two rollers. This machine is used to reduce two times thickness in one
pass. In this machine, the work piece is feed between bottom and middle roller
in one direction and top and middle rollers in opposite direction. This machine
can handle two work pieces in single run.
Four High Rolling Mill:
These machine consist four rollers (two small and two big).
These rollers are arranged as shown in figure.
Small rollers are in direct contact with work piece and rotate in
opposite direction. Big rollers works as backup rolls and they also rotates in
opposite direction with each other and also with contact roller. This machine
is used for cold rolling where high rigidity required.
Tandem Rolling Mill:
Tandem rolling is also known as continuous rolling in which
two or more set of four high rolling mill arranged in a series in which each
set is called stand. These stands are arranged so they can roll the work piece
in decreasing cross section. It is used for rolling thick work piece in single
pass.
Cluster Rolling Mill:
In this type of rolling mill, each of working roller is
backup by two or more of larger backup roller. These rollers are arrange as shown
in figure. This machine is used for rolling hard material.
Planetary Rolling Mill:
In this type of rolling machine, a large backup roller is
surrounded by various numbers of planetary working rollers as shown in figure.
Each planetary roll gives constant reduction. It is used to reduce large
thickness in single pass of steel strip. Its rolling capacity is more than
cluster machine but less than tandem rolling machine.
This is all about types of rolling mill. If you have any
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