Atlas Copco will supply 200 oil-free scroll compressors SFR 5 to Siemens Germany for its end customer ÖBB, the Austrian Federal Railways.
Photo credit: Atlas Copco
The compressors will provide oil-free air for the brake system, active tilting suspension and other auxiliary systems in the Siemens Desiro ML type train series.
Siemens Germany had several requirements for ÖBB’s compressor systems. The compressors had to be oil-free, equipped with an integrated dryer system, 25-liter aluminum air tank and all packed under a steel plate cover to protect the unit against powder snow, stone blast and heavy dust loads. The compressors had to generate at least 340 liters/min at 10 bar and without any winter preheating time before operation, offer full redundancy should a compressor ever fail, feature low noise and vibration levels, and have a total weight of less than 300 kg, including all equipment.
Atlas Copco’s Railway Competence Center developed a completely customized oil-free compressed air solution with a fully integrated maintenance-free membrane dryer and proven railway core components. Atlas Copco chose a 100 percent oil-free 5.5 kW SFR 5 scroll compressor directly driven by a 400VAC 50 Hz electric motor. The SFR 5 is a simple, highly reliable compressor package design, providing 400 l/min at 10 bar after the dryer. It incorporates a minimum of moving parts; a shaft-driven cooling fan; corrosion-resistant materials and sturdy construction to withstand external vibrations, shock loads and projectiles. The SFR 5 performs in temperatures from -25°C to +50°C, optional up to +75°C, and is designed to withstand extreme weather conditions.
The air treatment is carried out by a fully integrated water separator, fine pre-filter and a maintenance-free membrane dryer that supplies clean, dry, oil-free compressed air with a quality class of at least 2.2.0 acc. to ISO 8573-1.
Compact, less noise, less vibration
At 1200 L x 800 W x 480 mm H and with a total weight of only 240 kg, the compact air supply unit is mounted under the train’s floor with access to the unit’s two air filters, hour counter and electric connectors. The membrane dryer is placed in a horizontal position along the inside of the unit since no further access space is required to maintain it.
The new oil-free units operate at a noise level of 72 dB(A) and a very low vibration level of 21 Hz, which increases passenger comfort.
The SFR 5 features long service intervals, which further reduces its overall life cycle costs, and is backed by Atlas Copco’s service network in Austria.
The 200 compressors, plus 12 additional units for parallel test operation, are scheduled for delivery between June 2014 and August 2017.