The AMT rail dryer: keeping compressed air on track
How the AMT rail dryer’s 10-year ‘fit and forget’ reliability is revolutionizing clean air for trains
Discover how we combined the best of both desiccant and membrane dryer technology to provide a robust, efficient, and long-lasting dryer like never before.
For rail applications that rely on compressed air systems, it’s essential for trains to have a constant supply of clean, dry, and contaminant-free air.
Whether it’s for braking systems, door controls, or self-levelling suspension systems, the consequences of moisture-filled or dirty air can be disastrous – leading to corrosion, erosion, and even a complete failure of critical components. Cue costly repairs and thousands of angry customers.
That’s why the right air dryer makes all the difference.
In this blog post, we’ll take a deeper look at the patented Adsorbent Media Tube (AMT) rail dryer, including:
What is the AMT rail dryer?
How does it change how design engineers approach compressed air drying for rail applications?
How does it address the unique challenges the rail industry faces?
What are the biggest challenges for compressed air systems in rail?
Air compressors on rail vehicles typically pull large volumes of ambient air, which is then compressed to power key systems like train doors, braking systems, and secondary suspension systems.
However, this intake of air also brings two major problems – moisture and airborne contaminants. When compressed, the water vapor and contaminants condense, forming a corrosive liquid that needs removing before it reaches downstream applications.
To make things worse, the lubricating oil used in compressors can degrade and combine with moisture to create acidic condensate, threatening important system components with erosion, corrosion, and other costly maintenance issues.
Traditional solutions for drying this compounded air include conventional desiccant and membrane dryers – but each has their own advantages and limitations.
In rail applications, air dryers endure constant exposure to shock, vibration, and extreme temperatures – and both desiccant and membrane dryers struggle to overcome these issues.
Desiccant dryers
Desiccant dryers use canisters filled with adsorbent beads to remove moisture from the air. It’s effective, but they also face issues related to vibration-induced wear. Over time, the beads erode and produce dust, which can contaminate downstream systems. This not only compromises the air purity, but as desiccant beads require frequent replacement every 6 to 36 months, it also increases maintenance requirements and costs.
Membrane dryers
Meanwhile, membrane dryers use a semi-permeable membrane which allows water vapor to escape the air stream. However, the delicate fibers – often only the width of a human hair – are susceptible to contamination, vibration, and breakage. A single fiber break can lead to a cascade of failures, which significantly impacts their reliability and requires full replacements. Their shorter life cycle – usually between 4 and 24 months – also makes them less cost-effective for rail applications.
Enter the IMI Norgren AMT rail dryer
Desiccant and membrane dryers have their benefits, but also drawbacks. Now, a new contender has entered the market, offering a blend of the best features from both technologies without their weaknesses.
The patented AMT rail dryer introduces Adsorbent Media Tube (AMT) technology to take compressed air drying to a whole new level. It’s specifically designed for the demands of the rail industry, and is packed with plenty of incredible benefits.
Adsorption, minus the degradation
Unlike traditional bead-based desiccants, the AMT dryer’s adsorbent media is made up of durable tubes to maximize surface area, providing faster moisture uptake and more efficient drying. These tubes are resilient to bulk water, so they can operate in saturated conditions without breaking down or needing frequent maintenance.
Resistance to vibration
Built for the rugged rail environment, the AMT dryer is robust, vibration-tested to EN 61373:2010 Category 1, Class B. Not only that, its adsorbent tubes withstand ongoing shocks and vibrations to keep their structure and functionality, offering performance you can depend on even over long service intervals.
No dust, no contamination
With the AMT rail dryer, there’s no clay binder and no risk of the adsorbent bead erosion you usually see in traditional desiccant dryers. This means no dust production, removing the need for downstream filters to catch particulates. Engineers can then avoid the frequent replacements associated with conventional dryers, cutting down on the maintenance and downtime.
‘Fit and forget’
Designed to operate for up to 10 years – or 30,000 service hours – the AMT dryer goes far beyond the usual lifecycle expectations for compressed air systems in the rail industry. With a “fit and forget” approach, engineers are freed up from the costly, time-consuming maintenance cycles usually needed for air drying equipment.
Flexible installation
The AMT dryer’s design allows for both horizontal and vertical mounting, giving engineers extra flexibility when designing or retrofitting rail systems. This adaptability helps to overcome the common issues around space and configuration on rail vehicles.
Independently validated
With a temperature range of -50°C to +80°C, and proven performance in various rail environments and real-world scenarios, the AMT dryer is specially engineered to withstand even the most challenging operating conditions. By reducing the dew point and keeping a consistently low pressure drop, the new dryer can deliver clean, dry, and contaminant-free air to critical applications further downstream. Ultimately, this minimizes the risk of equipment failure, keeping trains on tracks and customers happy.
Ready to take your rail system to the next station?
In a time when the rail industry has increasing demand for reduced emissions, increased efficiency, and minimal downtime, the AMT rail dryer is more than just a compressed air solution – it’s a strategic asset for design engineers focused on creating more resilient, cost-effective, and sustainable rail systems.
With its unmatched durability, low maintenance needs, and resistance to environmental stressors like vibration, shocks, and submergence in water, the AMT dryer combines the best of traditional dryers to make a robust solution built for the future of rail.
Discover how the IMI Norgren AMT rail dryer can transform your rail systems. Get in touch with our specialist team today to learn more.