Brochure

26 | Fisher
®
Olefin Production Solutions
Distillation Feed Control Valve
The efciency of a distillation column depends on the amount of
contact between the vapor rising and the liquid falling through
the column. If the amount of vapor and liquid traveling through
the column becomes too great, the column can “ood”. When
ooding occurs, the efciency of the distillation column is
dramatically reduced, with corresponding drops in product purity.
An accurate feed control valve is critical to the success of efcient
column operation. A problem feed control valve can cause feed
ow oscillations, making the distillation column difcult to
control. As a result, the heat added by the reboiler oscillates as
well, overheating and underheating the column. The effect of the
swing, depending on design, can take anywhere from minutes to
hours to reach the ends of the column. A control valve with high
rangeability should be considered to maintain control.
Distillation Reflux Control Valve
Increasing column reux will improve the purity of the overhead
product. This requires more heat for the reboiler to vaporize the
lighter components in the reux. A precise throttling control
valve will assist to balance reux needs and reduce variability. A
poorly operating reux control valve will result in the same ow
instabilities as a problem feed valve. Product purities will oscillate
and column efciency will suffer. A control valve providing minimal
variability will assist in stable and predictable column performance.
ENVIRO-SEAL systems are available for a
wide range of pressure and temperature
conditions in non-environmental and
environmental applications. Click on or
scan the QR code to learn why they are
a good choice for your facility.