The spiral separator can be divided into high weir type and submerged type.
Actually, the classifying procedure still depends on the
different sinking speed of particles.
The mechanical classifier is
mainly used as an assistant equipment of grinding machines to
pre-classify and check classification, and sometimes, it is also used as
ore washer for ore with clay, and as desliming and dehydration for
slurry.
According to the difference of transferring equipments,
mechanical classifiers can be divided into screw classifier, target classifier, and floating chute classifier.
The spiral separator
has simple structure, and easy to be operated.
The classifying chute
has a large obliquity, which makes it easier to connect with ore
grinding equipment, so it is used widely.
Other kinds of classifiers are
still used in China, but we have stopped producing them.
The outer shape of chute classifier is a oblique rectangle chute with an obliquity of twelve degree to eighteen point five degree.
The bottom
is in the shape of a half circle.
One or two lengthwise bearings are
installed in the chute, and along the bearings, some spiral plates are
installed continuously.
The spiral bearing will rotate with the
operation of the upper transferring part.
As for the double screw, the
spiral plates are making extraverted rotation seen from the up.
The ore
slurry if fed from the side of the chute, and the sinking classifying
surface is built on the bottom of the chute.
Course particles sink to
the bottom, and pushed up by spiral plates, and the dehydration will be
done in this transferring procedure.
The classifying process of screw
classifier is almost the same with that of mud bucket.
There is a frame
in the lower part of the classifying chute, but there is no elevator
equipment on the upper part of the beam.
This beam is used to adjust the
distance between spiral plates and the chute bottom, and uplift the
spiral bearings when stopped, in case that the spiral plates might be
swollen by ore sand.
The spiral separator can be divided into high weir type and submerged type.
The overflow weir of the high weir is higher than the center of
the lower spiral bearings, but lower than the upper line of the spiral
plates.
The length of classifying surface is not too large, and the
surface could feel the stirring of spiral plates directly, so this kind
of classifier is suitable for course classification, and the classifying
granularity is mostly larger than 0.15 non.
The lower spiral plates of
submerged classifier are totally under the surface, and the classifying
area is large and stable, which is suitable for fine classification, and
the classifying granularity is under 0.15 non.
Its overflowing
efficiency is much high.
Besides, there is also a kind of low weir
spiral classifier whose classifying surface is lower than the lower
spiral bearings.
