Metafilter
Principle
• Mechanism is surface filtration
• In this, metal rings contain semicircular projections,
which are arranged as a nest to form channels on the edges
• This channel offers resistance (strainer) to the flow of
solids (coarse particles)
• The clear liquid is collected into receiver from the top
Construction
• Metafilter consists of a series of metal rings
• These are threaded so that a channel is formed on the
edges
• It contains a grooved drainage column on which a series of
metal rings are packed
• These rings are
usually made up
of stainless steel
and have dimensions
of about 15.0
mm internal diameter and 22.0 mm
external diameter
• Each metal ring has a number of semicircular projections
(0.8 mm in thickness) on one side of surface
• The projections are arranged as a nest to form channels on
the edges
• These rings are tightened on the drainage column with a
nut
• Metafilters are also known as edge filters
Diagram of
metafilter
Working
For separation of fine particles, a bed of suitable
materials such kieselguhr is first built up.
The pack of rings serves essentially as a base on which the
true filter medium is supported.
Advantages
• Can be used under high pressures, without any danger of
bursting the filter medium
• Running cost are low, as separate filter medium is not
used
• Can be constructed
from a material
that can provide
excellent resistance to
corrosion and avoid contamination of sensitive products
• It is extremely versatile filter because fine as well as
large both type of particles can be separated
• Removal of cake can be carried out by simply back-
flushing with water
• Change over from one batch to another or one product to
another is easy
• Sterile products can be handled
Uses
Meta filters can be used for –
·
Clarification of syrups
·
Filtration of injection solutions
·
Clarification of insulin liquors
·
Filtration of viscous liquids can be achieved by
applying pressure