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The basis for
solid-liquid separation in the PF-60 series is the centrifugal forces
created in the body of the separator. As the pressurized process
carrying fluid1 enters tangentially into the entrance chamber of
the separator, it starts a downward helical flow. This downward
spiral motion causes high centrifugal forces to act on the carrying
fluid. The solids in suspension are pushed to the wall of the separator
and then move downward to the accumulation chamber (underflow)2
at the bottom of the separator. The clean process fluid then reverses
its axial direction and moves upward in a helical flow exiting the
separator (overflow)3.
There are many factors that can contribute to the success of the
solid-liquid separator. It is important to understand and consider
several issues when installing a hydrocyclone separator on a process
system: system flow, velocity of the process fluid through the separator,
pressure loss, specific gravity of the carrying fluid and particulate
to be removed, and the purge cycle.
It is vital
that the velocity of the carrying fluid be kept high in order to
develop centrifugal forces in the body of the separator. Puroflux
separators are designed with varying flow rates to insure that the
separator selected will perform as expected.
Flow rate versus
pressure loss are given for various PF-60 series separators to aid
in selection (see individual specification sheets). The ideal operating
pressure drop through a Puroflux separator is between 4-10 psi.
It is also important to note that the specific gravity of the solid
to be separated from the carrying fluid must be higher than the
specific gravity of the carrying fluid. The greater the specific
gravity of the contaminate, the higher the removal efficiency of
the separator. Puroflux separators can remove particulate as low
as 45 micron (nominal) with a specific gravity greater than 1.2
on a recirculating basis.
Purging is necessary to eliminate the high concentration of solids
build-up in the separator’s accumulation chamber and can be
performed while the separator remains on-line. The level of contaminates
in the process system will dictate the purge frequency and may warrant
the use of an optional recovery system. If a recovery system is
used, the separator will purge constantly at a low flow rate.
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