Horizontal Bowl centrifuges are also known as decanters and
are primarily used for separation of liquids from appreciable
amounts of solids. Decanters can separate over 50% (v/v) solids
from liquids on a continuous basis. Typical applications includecleaning
of tank bottoms, waste oil cleaning, waste water treatment,
sludge dewatering in industries etc.
The sediment formed by the solid particles is continuously removed
by the screw conveyor, which rotates at a different speed than
the bowl. As a result, the solids are gradually "ploughed" out
of the pond and up the conical "beach". The centrifugal force
compacts the solids and expels the surplus liquid. The dried
solids then discharge from the bowl. The clarified liquid phase
or phases overflow the dam plates situated at the opposite end
of the bowl.
A decanter centrifuge separates solids from one or two liquid
phases in one single continuous process. This is done using
centrifugal forces that can be well beyond 3000 times greater
than gravity. When subject to such forces, the denser solid
particles are pressed outwards against the rotating bowl wall,
while the less dense liquid phase forms a concentric inner
layer. Different dam plates are used to vary the depth of
the liquid - the so-called pond - as required.