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Howden Thomassen Compressors
HOWDEN THOMASSEN COMPRESSORS FOR CRYOGENIC GAS APPLICATIONS PROVIDING SPECIFIC SOLUTIONS FOR SPECIFIC CHALLENGES THOMASSEN TECHNOLOGY FOR BOIL-OFF COMPRESSORS HAS BEEN SPECIFICALLY DESIGNED TO OVERCOME THE SPECIAL CHALLENGES INHERENT IN THE PROCESS. BOIL-OFF COMPRESSORS CAN RUN AT TEMPERATURES AS LOW AS MINUS 160˚C.
START-UP AND RUN-DOWN SEQUENCES PRESENT SPECIFIC PROBLEMS.
At these extremes, steel can become brittle, introducing the risk of catastrophic fracture. All of the materials we use in compressors for boil-off applications have specially developed materials and coatings, fully tested to maintain their elasticity across the operating temperature range.
Over a short period, the temperature of the gas can change from around 120˚C to below minus 160˚C. Each individual part of the equipment, including the cylinder, piston, rider rings and cylinder rods, will expand or contract according to its geometry, mass and coefficient of thermal expansion. The calculations involved in ensuring that the compressor performs to specification during these periods of rapid change are exceptionally complex.
We have developed reliable systems for predicting the interactions between moving parts as temperatures change, allowing us to design bespoke compressors that maintain system integrity throughout the start and stop cycles.
A SYSTEMATIC APPROACH TO REDUCE MAINTENANCE TIME IN EXTREME LOW TEMPERATURE ENVIRONMENTS. BOIL-OFF GAS PLAYS A VITAL ROLE IN GAS TRANSPORT AND STORAGE.
HOWDEN THOMASSEN PISTON COMPRESSOR RANGE PERFORMANCE ENVELOPE Pressures
600 bar
8.700 psi
Power
24.800 kW
33.250 hp
Part of Howden’s Compressor Division, Thomassen Compression Systems was acquired by Howden in 2011.
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PASSION FOR COMPRESSION
Free Floating Piston (FFPTM)
Cross section of the Free Floating Piston (FFPTM)
BOIL-OFF GASES CONTAIN VIRTUALLY NO WATER VAPOUR BECAUSE OF THE LOW TEMPERATURES INVOLVED.
THE HOWDEN THOMASSEN COMPRESSORS FREE FLOATING PISTON SYSTEM.
Since most of the compressors used in these applications are of oil-free design, dry running can cause very high levels of wear. Research has shown that the effect of operating in the hydrocarbon mist typically found in a boil-off gas compressor can multiply the abrasion effect by a factor of 400 to 500 per cent.
The FFP TM system allows a very thin film of the pressurised boil-off gas to pass through precisely engineered apertures in the piston to form a thin gas layer, that supports the weight of the piston virtually without friction except during the machine start-up and shut-down periods. The volume of gas involved is very small, and is allowed for in the design stage so there is no loss of efficiency in the compressor’s performance.
That means that rider rings, always one of the most vulnerable abrasion points in oil-free compressors, have to be replaced four to five time more often. Our unique Free Floating Piston (FFPTM) system virtually eliminates rider ring wear, even in these extreme conditions, and thus removes one of the most significant causes of downtime.
THE THOMASSEN FFPTM HAS BEEN APPLIED IN A WIDE RANGE OF APPLICATIONS AND PROCESSES. The FFP TM system in our boil-off compressor is based on designs that have provided a tried and tested alternative to rider ring replacement for more than ten years.
It already has an installed base of over 250 installations worldwide and has proven its worth over millions of hours of troublefree operation. Like all Howden Thomassen Compressors products, our boil-off compressors come with a lifetime commitment to aftermarket advice, spares and retrofits. Support is provided through a global network of local bases offering fast access to unrivalled expertise and experience.
TYPICAL BOIL OFF APPLICATIONS INCLUDE:
• LNG at -160 degrees Celsius • Ethylene at -104 degrees Celsius • Propane at -42 degrees Celsius • Propylene at -48 degrees Celsius • Ammonia at -33 degrees Celsius
HOWDEN THOMASSEN COMPRESSORS GLOBAL OFFICE LOCATIONS For more information about our products for boil-off gas applications, please contact: Howden Thomassen Compressors Havelandseweg 8-a PO BOX 99 6990 AB Rheden The Netherlands Tel: + 31 (0) 26 4975200 Fax: + 31 (0) 26 4975201 Web: www.thomassen.com
© Howden Group Limited. All rights reserved. 2012