Assignment on Continuous Horizontal Centrifuge

1. Assignment
on
Continuous Horizontal Centrifuge
Presented By
Md. Masum Billah
ID. Bhp-160101282
Department of Pharmacy
Northern University Bangladesh

2. Overview
oDefinition
oClassification
oPrincipal
oConstruction
oWorking principal
oAdvantage
oDisadvantage

3. Definition
Centrifugation is a unit operation employed for separation the constituents
present in a dispersion with the aid of centrifugal force.
Centrifugal force is used to provide the driving force for the separation. It
replaces gravitation forces in the sedimentation.
Centrifugation is particularly useful when separation by ordinary filtration is
difficult, for example, separating highly viscous mixtures mixture and colloidal
dispersions (particles size less then 5 mm)

4. Classification of Centrifuges
oSedimentation centrifuge
oFiltration centrifuge
o Perforated basket centrifuge
oNon perforated basket centrifuge
oSemi-continuous centrifuge
oContinuous horizontal centrifuge

5. Continuous horizontal centrifuges cont.
Figure. Construction of the Continuous horizontal centrifuge

6. Continuous horizontal centrifuge cont.
Principle:
This is a sedimentation centrifuge. The separation is based on the difference in
the densities of solid and liquid phases without borders barrier.
When the slurry is introduced through the shaft of the screw element into a
conical bowl, sedimentation of solids takes place due to centrifugal action.
The solids are lifted up by the screw element, while the liquid phase is
continuously drained.

7. Continuous horizontal centrifuge cont.
Construction: The construction of a horizontal continuous centrifuge is shown in
Figure. It consists of a cylindrical or conical bowl mounted horizontally and capable
of rotating at 50 to 65 revolutions per second.
The bowl has a diameter of about 0.5 metres. Within the bowl, a screw. conveyor
is placed which rotates in the same direction as the bowl, but at a slightly slower
speed.

8. Continuous horizontal centrifuge cont.
Working:
The bowl and the screw conveyor are allowed to rotate using suitable
power supply. The slurry is introduced through the shaft. The liquid
moves into the wider portion of the bowl. Sedimentation of solids
takes place due to centrifugal action.
The solids are listed by the screw element, while the liquid phase is
continuously drained. The solid material is carried towards outlet by
the conveyor and is discharged continuously. The solids are conveyed
to a dry 'beach' where they get dried.

9. Continuous horizontal centrifuge cont.
Uses:
Horizontal continuous centrifuge is used when a high proportion of solids is
present in the slurry,
Advantages:
1. Continuous centrifuge is very flexible in operation.
2. It is capable of handling solids as large as 10 to 15 millimeters or as small as a
few microns.
3. It can be used for slurries with concentrations ranging from 0.5 to 50%.
Variants

10. Continuous horizontal centrifuge cont.
Disadvantage
1. The machine can be very noisy can cause vibration
2. The device has a high energy consumption