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P a r r I n s t r u m e n t C o m p a n y
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O p t i o n a l F i t t i n g s
Gas Entrainment Impellers
Gas Entrainment Impeller with Hollow Shaft
Removeable Baffle Set
P
arr offers a series of gas
entrainment impellers
for users who want to obtain
maximum gas dispersion
into a liquid system. This is
obtained with a unique impel-
ler attached to a hollow stirring
shaft through which gases
are continuously recirculated
from the head space above
the liquid through the impeller
into the liquid phase. As with
all impellers, the speed of the
stirrer creates a vacuum at the
tip of the impeller. Gas enters
openings near the top of the
shaft and is pulled through
dispersion ports located at the
tips of the impellers. In the
Parr system with dispersion
ports located at the very tips
of the impellers, the higher the
stirring speed — the higher the
vacuum — and the higher the
driving force for this very effec-
tive gas dispersion system.
These impellers are offered
as a complete package which
includes the impeller, the hol-
low shaft with coupling, and
any required foot bearings and
brackets for the intended reac-
tion. The baffles are a separate
option which must be ordered
individually.
The gas entrainment stirrers
may be ordered as an optional
stirrer when purchasing a
new reactor system or easily
installed in an existing system
in the field. With the wide
variety of reactor head styles
and magnetic stirrers furnished
on Parr reactors it is best to
contact us with the numbers
stamped on the head of your
vessel so that we will be able
to furnish the correct gas
entrainment assembly for a
particular reactor system.
Since these gas entrainment
impellers operate best in the
1000-1200 rpm range, users
will want to ensure that their
stirrer drive system is set up to
deliver these operating speeds;
alternate pulleys and belts are
available to convert existing
reactor systems.
Baffles
Because it is the relative
speed of the tip of the impeller
to the liquid phase that gov-
erns the mass transfer, baffles,
which impede the rotation of
the liquid with the impeller,
can greatly enhance the opera-
tion of these gas entrainment
impellers. While some natural
baffling is provided by the
internal thermowell, dip tube
and cooling coils, the remov-
able baffles are recommended
for use with these gas entrain-
ment impellers. These baffles
may also be beneficial with
the more traditional turbine
type impellers for certain
applications.
Gas Entrainment Impeller
