VHE Economizer for deodorization and physical refining of fats and oils0 pages

Application
This high-performance heat exchanger is specially designed
to recover heat by cooling the deodorized edible fats and oils
in deodorization and physical refining plants and – at the
same time – heating the incoming oil. This cooling takes
place under vacuum and sparging steam conditions.
The VHE Economizer is part of the Alfa Laval SoftColumn™
deodorization concept, but is also available as a retrofit
component for installation in other deodorization systems
– irrespective of origin.
Operating principles
The hot deodorized oil enters the VHE Economizer at one
end of the shell side, which is under vacuum, and flows
through a special system of channels and baffles until it
reaches the outlet connection at the other end. It is then
pumped out for final cooling and storage. A level transmitter
installed on the shell controls the oil level on the shell side.
The cold oil enters the VHE Economizer under pressure on
the tube side and flows through a multipass tube system until
it reaches the outlet connection at the other end. The sparge
steam is injected through perforated tubes located on the
bottom of the shell, below the heating tubes.
Counter-current flow between the incoming oil and
deodorized oil is maintained by a special design of the
tubes and baffles on the shell side.
To avoid cross-contamination and provide fast draining during
stock changes, the heat exchanger is fitted with a special
fast-drain valve arrangement on both sides.
Design features
The VHE Economizer is designed to achieve a high level of
heat recovery by cooling the deodorized oil under vacuum
and sparge steam conditions, while heating the incoming oil.
Under full sparge steam conditions, this gradual cooling
means the oil is treated gently and the quality improves. The
sparge steam also acts as stripping to remove volatiles that
might form during the cooling phase, and to improve the heat
transfer rate.
The large heat transfer surface area and the counter-current
flow result in a very high oil-to-oil heat transfer rate, which
normally means a heat recovery exceeding 75%, depending
on the size, application and operating parameters.
The low liquid level and channel system with baffles ensure
that the oil follows the desired path. The first oil that enters is
The VHE Economizer
For deodorization and physical refining of fats and oils
VHE Economizer