For fats and oils deodorization and physical refining plant0 pages

For fats and oils deodorization and physical refining plants
Scrubber
Application
This highly efficient, structured packed column is designed to
condense and recover free fatty acids (FFA) and other
volatiles from the deodorization process and to prevent carryover
of these materials to the vacuum system. The scrubber
is a part of the Alfa Laval SoftColumn™ deodorizing concept,
but can also be offered as a retrofit component for other
deodorizers – irrespective of make.
Working principle
Cooled fatty acid distillate is pumped to a gravity distributor
or spray nozzles located on top of structured packing. The
distillate flows down the structured packing as a thin layer. At
the same time, distillate vapours from the deodorizing column
travel in a countercurrent flow to the cooled distillate. In this
manner, vapours from the stripping section of the deodorizing
column are condensed and collected for further cooling, recirculation
and draining. A wire-mesh demister is located at the
top of the scrubber to prevent remaining small fatty matter
droplets from entering the vacuum system.
Design features
The Alfa Laval Scrubber is based on structured packing technology,
which uses a high surface area to improve contact
between the vapours and the condensate, thus increasing
the condensation efficiency.
Due to the efficiency of the structured packing, the required
recirculation flow rate is very much reduced. This packing is
self-cleaning due to the turbulent flow.
The scrubber is designed for low velocities at the vapour inlet
and outlet nozzles, reducing entrainment.
The vapours inlet nozzle is specially designed and positioned
to allow even distribution of the vapours across the entire
cross-section of the bottom of the packing, so all the packing
surface is used for condensation.
The condensate distributor on top of the structured packing
guarantees an even distribution over the entire cross-section
of the packing, so all the packing surface are wetted and
used for condensation.
The demister is assembled before the vapour outlet nozzle to
the vacuum system in a zone of low velocity. This ensures
that most of the small droplets are retained.
There is a side-mounted manhole with illuminated sight glass
to allow visual inspection of the distributor operation and performance
of the scrubber, as well as easy access for maintenance
of the distributor, packing and demister. The manhole
and sight glasses are sealed with double O-rings to assure
hermetic sealing. The system as a whole is designed for a
low overall pressure drop.
Installed Scrubber