Cassava screening machine is a
small machine used for obtaining starch from grated cassava. The machine
separates the pulp obtained from grating from the free starch. The
screening is done both manually and mechanically. Hand screening is a
manual screening whereas mechanical screening is done by machines which
are of following types :
- Rotating Screen
Rotating screen normally consists of a conical frame of hardwood,
fixed on a hollow horizontal axis covered with ordinary cloth or
phosphor-bronze gauze. The crude pulp is fed into the cone at the
narrow end. The rotation of screen allows the pulp to moves down to
the other end from where it is conveyed to the pulp tanks. As the
pulp moves, water is sprayed on it from number of openings in the
hollow shaft. Thus, by the time the pulp reaches the lower end of
the cone, it is more or less completely washed out. The flour milk
is collected in a cemented basin below the screen.
- Shaking screen
Shaking machines consist of inclined horizontal frame covered with
gauze. The frame is set into motion by means of an eccentric rod.
The fresh pulp is mixed with water in distribution tanks and is
carried by pipes to the higher end of the screen. The pulp remaining
on top of the screen is slowly pushed downward by the shaking motion
during screening process. The flour milk is collected below the
screen in a collector.
