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NEW TECHNOLOGIES

Flowserve dry gas seals

for supercritical CO 2

centrifugal compressors

What’s the most reliable way to
manage Supercritical CO and,
2
in parallel, achieve the lowest
emissions? To answer the question,
Flowserve has tested the state-of-

the-art Gaspac Dry Gas Seal design
®
under the most severe conditions

n sCO application, the extreme power density
2
(power to inertia ratio) is challenging for the cen-
trifugal compressor design as it requires special
verifi cation of its components, but on the other
hand, this allows a smaller size machine, with
Ibenefi ts in terms of footprint and cost.
Fig 1: sCO Gaspac DGS Tester
®
2
To meet the high performance
required, the compressor needs condition was never experienced before and for
this reason Flowserve decided to perform a test
“to be equipped with an on Gaspac DGS in supercritical
®
advanced dry gas seal solution CO conditions to verify the seal The combination of high
2
performances in design and off-
that provides high pressure, design conditions. speed, high temperature
temperature, and speed “and high pressure together
capability together with a low with supercritical CO
®
leakage GASPAC dry condition was never 2
gas seal for sCO experienced before and
To meet the high performance required, the com- application 2 for this reason Flowserve

pressor needs to be equipped with an advanced Dry gas seals in the compressor decided to perform a
dry gas seal solution that provides high pressure, world are widely utilized for CO
®
2
temperature, and speed capability together with services for decades, but the test on Gaspac DGS
a low leakage. In case of compressor pressurized sCO application is stretching in supercritical CO
2
stop, CO within the loop may be cooled, below the the DGS technology to unex- 2
2
critical temperature turning into liquid phase. This plored environments combining conditions to verify the seal
condition may lead to fl ood the DGS and further- at the same time a supercriti- performances in design and
more, CO may become solid (dry ice formation) cal gas, high pressure, eleva- off-design conditions
2
after expansion with potential blockages for the ted temperature and highspeed
seal and vent line. range. Flowserve has delivered
®
The combination of high speed, high temperature since the mid 90´s Gaspac dry gas seals for CO
2
and high pressure together with supercritical CO compressors and in 2012 the fi rst DGS was delive-
2
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