|
The steel processor first examined
three known technologies available to them: direct steam sparging,
graphite external units, and Teflon immersion heaters. All
three presented serious drawbacks to the steel processor's
operations and goals.
THE ANSWER: TANTALUM
Looking for an innovative alternative,
they turned to AstroCosmos Metallurgical, the world leader
in tantalum processing equipment fabrication. AstroCosmos
recommended tantalum immersion coils.
Even though an initial investment
for a tantalum system would be higher than for the other systems,
the steel processor recognized that AstroCosmos' tantalum
immersion coils would present the final best value. Key factors
were lower installation costs, little or no maintenance, greater
reliability, steadier operation, and higher production rates.
All these benefits were critical for an around-the-clock,
year-round operation. All would be multiplied as financial
benefits in such a 7-24 operation.
The system utilizes a total of
20 grid coil heaters varying between 48 and 78 square feet
of surface area each. Working from its 20 years experience
with such technologies, AstroCosmos Metallurgical designed
a system with particularly rugged, highly efficient grid coils
that employ an external baffle support cage, built-in steam
traps, and integral non-condensable vent lines.
PERFORMANCE BEYOND EXPECTATIONS
According to the steel processor,
the units have far exceeded their expectations. The maintenance
manager emphasized, "We've virtually eliminated any maintenance
requirements. We no longer need to sparge steam into the tanks.
And the facility continues to set new plant records for daily
and monthly production volumes.
"In fact, we've had no problems
whatsoever. And we fully expect the units to continue running
trouble-free for the next 20 years."
According to a company spokesperson:
"Over the last 10 years, AstroCosmos Metallurgical has
been working closely with the steel processing industry to
help processors take advantage of the inherent benefits of
tantalum coil fabrications when used in HC1 pickling solutions.
"Tantalum is completely
immune to corrosion for the complete spectrum of HC1 solutions,
up to and including boiling. When fabricated properly, the
material has a life expectancy of well over 20 years. Since
1988, five separate facilities have installed a total of 61
heaters--with no failures to date."
An AstroCosmos spokesperson further
emphasized that "the use of tantalum in this application
is going to grow steadily and very rapidly over the next few
years. This is because they can see the benefits. Plant operators
have a definite understanding of the costs associated with
unexpected down time and scheduled maintenance. They also
understand the costs of acid leaks and diluted acid disposal.
"And, in particular, if
they are operating an acid regeneration plant, they can operate
it much more efficiently by obtaining predictable acid concentrations
from their tanks.
"All things considered,
the tantalum immersion grid coils and external shell and tube
units represent today's state-of-the-art solution."
--------------------------------------------------------------------------------
Tantalum-Lined
Column Passes 10 Years Without Any Repairs,
Exceeds Cost-Savings Goals
SILICONE
PRODUCER'S EXPERIENCE DEMONSTRATES THAT AN INITIAL INVESTMENT
IN PREMIUM TECHNOLOGY CAN PAY BIG DIVIDENDS IN THE LONG RUN.
The ability of tantalum to achieve
outstanding performance in severe applications is dramatically
demonstrated by a silicone producer's decade-long experience
with its tantalum-lined column.
The column, fabricated by AstroCosmos
Metallurgical, the world's largest fabricator of tantalum
processing equipment for the chemical industries, recently
passed the 10-year mark with a record of: No repairs. No lost
production time. Operating cost savings that exceeded the
producer's most optimistic projections.
More than 10 years ago, the silicone
producer approached AstroCosmos Metallurgical, seeking ways
to reduce the costs associated with regular repairs and the
recurring downtime it was experiencing with its brick-lined
column.
AstroCosmos' solution was a 73-inch
diameter by 117-long, loose-lined tantalum column. The size
involved presented a special challenge, because it was at
that time the world's largest for this industry, and is still
believed to be the world's largest.
David Frey, Vice President for
Market and Product Development at AstroCosmos, stated that
"AstroCosmos was the right choice for the job. We were
up to the challenge, because of our experience in fabricating
hundreds of large tantalum equipment each year and facilities
which are ample to handle such extreme sizes.
"However, our design capabilities
were just as important. If the size was unique, the design
was even more so. For example, we designed the column with
proprietary convolutions to accommodate possible vacuum conditions.
This huge column was supplied as a single package. This included
ladders, platforms, skirt and related fixtures."
The silicone producer reported
that, while its initial investment was significantly higher
than other available technologies, they went ahead because
their life-cycle cost estimate projected a "final best
value" for tantalum. The subsequent unbroken performance
and final cost analysis proved that their original cost-savings
estimates were "understated." Their actual savings
went far beyond expectations.
Reflecting upon this experience,
a company spokesperson commented; "Tantalum's natural
corrosion resistance and durability, combined with AstroCosmos'
special design features, result in high-performance products
that repeatedly achieve greater productivity, more reliability,
longer life and true cost effectiveness. When we demonstrate
this to our prospective customers, they find it an easy decision
to go with the technology that is best in the long run."
--------------------------------------------------------------------------------
"Impossible-to-Build"
Reactor Vessel Completes 5 Years' Trouble-Free
Service, Thanks to Advanced Zirconium Technology
PRODUCER OF WATER TREATMENT CHEMICALS FINDS THIS
REACTIVE METAL EASILY SOLVES ITS "UNSOLVABLE" PROBLEMS.
When a major producer of water
treatment chemicals was told more than five years ago that
the reactor vessel they needed was "impossible,"
they determined to search even harder for a "can-do"
supplier. Today, after five years of steady production, with
no maintenance nor repairs, they're mighty glad they stuck
to their objectives.
They found their "can-be-done" fabricator in AstroCosmos
Metallurgical. Their materials solution in zirconium. And
their equipment design in Astro's advanced technologies. Recalling
that experience, a company spokesperson stated: "When
a customer is told by suppliers that something they need can't
be done, they naturally are turned-off. When we're presented
with such a dilemma, we're turned-on by the challenge to prove
it really can be done."
It all began when the chemicals
producer sought a solution to the problems it constantly faced
with its glass-lined reactor vessel, which just could not
stand up to the rigorous demands involved with the process.
Reactive metals seemed like a logical path to follow, with
one of these metals sought as the best candidate for lining
the vessel. After extensive corrosion testing, they zeroed-in
on zirconium 702 alloy, with low oxidation treatment, as the
best course to take.
Fabricators the producer initially
contacted were taken aback by the fact that the process would
require four different heating zones, with a fast cycle rate
of pressure/temperature, and high stress conditions. "Next
to impossible" was their typical response to the producer,
with a flat-out "Impossible!" included.
Such unacceptable responses led
them to AstroCosmos Metallurgical, which offered a lengthy
history of fabricating process equipment in zirconium. This
is why Astro's answer of "Sure, it can be done"
came quickly. Even if the actual design and fabrication certainly
were not "easy."
Offering his recollections of
that challenge, David Frey, Vice President for Market and
Product Development, explained; "We built the vessel
using explosion-clad technology, which is a high-strength
bonding technique. We attached a zirconium liner to a l.25-inch
carbon steel substrate. By using a steel substrate we gained
both unit strength and cost savings. For example, we were
able to fabricate the half-pipe coils from carbon steel substrates.
"A key factor in the design
and fabrication process was our extensive use of finite element
analysis (FEA), to determine the high-stress points during
the heating and cooling modes.
"However," Mr. Frey
emphasized, "the basic reason we were able to do this
at all was because we had so much experience in bonding and
welding noble metals involving so many kinds of equipment,
applications and process chemicals. "There's always something
new and challenging in any customer requirement that presents
unique or highly demanding processes. But underlying it all
is the fact that, so often, we've 'been there, done that'.
It does make it so much easier for us to reject out-of-hand
any claims that something just can't be done. "Fact is,
we've found that most times it can be done!"
|
