On the right track

27 August, 2020

Compressed air is vital when it comes to ensuring that essential applications on railway networks keep moving. Braking systems, pneumatically operated doors, self-levelling suspension, pantographs and even the train’s horn, are all reliant on clean compressed air to operate effectively and reliably.

Operators have to contend with the challenge of keeping the compressed air free of contamination, as moisture, foreign particulate and contaminated compressor oil affect the production of clean and dry compressed air. The consequences of contaminated compressed air can negatively affect train system reliability and performance leading to unscheduled maintenance, costly repairs and even system failure.

Tackling this issue has seen Norgren work with the Metro Trains network based in Melbourne, Australia, to develop an innovative compressed air dryer solution that enhances the operational efficiency and ongoing reliability of Metro Train’s entire Comeng fleet of 68 six- carriage rolling stock.

Steve Hill for Norgren says: “The Victorian Government and Metro Trains started to review the performance of its fleet in 2016 as part of the fleet’s interior and exterior refurbishment project. The legacy compressed air system was found to be ineffective in the way it removed water / moisture from the air system. This was causing premature failure to the components in the brake system and doors, potentially voiding the warranty on any repairs.” Working with Norgren, Metro Trains embarked on a six-month trial using six of the company’s AMT dryers to monitor the relative humidity levels. Norgren’s patented AMT air dryer solution uses Adsorbent Media Tube (AMT) technology. It is made up of a high level of adsorbent and a non-adsorbing durable polymeric binder such as polyether sulfone to create a more efficient and reliable way of removing moisture from compressed air.

Less pressure drop

Using this patented AMT technology, water vapour adsorption and desorption kinetics are faster and more efficient, allowing sustained high levels of performance with less pressure drop and often with less purge air consumption. Should the AMT media tubes become saturated, there is no deterioration, byproduct or chemical reaction.

The tubes are simply dried during the purge/regeneration process and returned to their original state continuing to function normally and removing the requirement for maintenance follow-up. In addition, the AMT structure is completely resistant to shock & vibration, can be mounted in any orientation and requires no regular maintenance. This also means there is no requirement for a post dust filter to catch the desiccant dust associated with traditional bead type rail dryers.