Chemical Engineering June 2015 - 24

Newsfront
High-Performance Internals
Boost Tower Capacities
New materials and designs help processors improve efficiency and reliability
Raschig USA
newer designs do work, " notes Portillo.
Strategies to increase capacity, reduce
foaming and fouling and increase reliability
top the wish lists of chemical processors
running distillation and mass-transfer operations.
Fortunately, for each issue there is
a solution.
FIGURE 1. The Raschig
Super-Ring offers a grid-like
structure that provides a
lower resistance to gas flow,
reduces pressure drop and
results in improved capacity
compared to earlier packings
In BrIef
INCrEASING CAPACITy
FOAmING ANd FOULING
rELIABILITy
A
s in other areas of chemical manufacturing,
processors want more
efficiency from their distillation and
mass-transfer operations. Increasing
capacity, finding solutions to issues such
as foaming and fouling that slow the process
down, and lengthening lifetimes are high on
their list of priorities. As a result, vendors of
trays and packings are rethinking and redesigning
their products to provide column internals
that make the process more effective.
" In essence, it's about the hydraulics
of contacting and separating vapors and
liquids, " explains Juan Portillo, manager,
Chemicals/Gas Applications Engineering,
with Sulzer Chemtech, USA, Inc. (Tulsa,
Okla.; www.sulzer.com). " By striving to make
the process more efficient, improvements
are brought to the market to benefit the customers.
A lot of what we're doing has to do
with the shape and streamlining designs of
the column internals. "
For example, he says, one of his company's
newest packings has a smooth S-shaped
transition that allows more vapor flow and
less liquid hold up, and their random packings
have an open and uniform structure
that minimizes both vapor and liquid stagnation
within the packed bed. " When you
step back and look at the designs, you can
see why they should work from a hydraulic
standpoint. And, when you look at the results
and the operating data, you know the
24
Increasing capacity
" American processors are still somewhat recovering
from the economic crisis of 2008,
and, as a result, they are putting more emphasis
on doing more with what they have, " says
Brad Fleming, general manager with the Process
Equipment Technology division of GTC
Technology US LLC (Houston; www.gtctech.
com). " While there are fewer large, capitalintensive
greenfield projects taking place in
the states, we see a lot of revamps aimed at
increasing capacity with minimal capital investment.
There's a big push to squeeze the
most out of existing infrastructures. "
As a result, providers of internals are busily
retrofitting existing columns with products
designed to boost column efficiency. " Often,
they want more capacity from an existing
shell, so we replace traditional trays and
packings with high-performance internals
that allow processors to increase throughput,
feed and product flowrates of the tower. "
In many cases, swapping traditional internals
for high-performance versions is a
simple, low-cost way for processors to improve
performance, resulting in increased efficiency
or higher product quality or purity.
What is it about high-performance internals
that makes the difference? In some
cases it involves merely enhancing the
physical features of traditional or existingstyle
equipment. An example of this would
be replacing a traditional valve tray that features
a round floating valve with a valve tray
that offers smaller valves, which are more
aerodynamically efficient. In other cases, the
higher performance comes from completely
new concepts, as high-performance strucChemiCal
engineering www.Chemengonline.Com june 2015
http://www.gtctech http://www.sulzer.com http://www.Chemengonline.Com
Chemical Engineering June 2015

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