Norgren, an international market leader in pneumatic motion and fluid control technologies, has launched an innovative new compressed air dryer designed specifically for the rail sector. Made from a highly engineered polymer material, the new air dryer delivers greater efficiency and optimised performance for the customer.

The dryer system boasts an average service free life of up to six years or 18,000 hours along with improved moisture uptake and a reduced purge air requirement. Vibration tested to BS EN 61373:2010 standard, the new dryer provides a robust, durable yet compact solution.

A clay binder is often used in a conventional air dryer to support the desiccant, adsorbing water and storing it until it is ready to be regenerated through heat or air flow. Norgren’s innovative dryer uses adsorbent media tube (AMT) technology which houses the desiccant within an extruded polymer tube, ensuring the moisture can be regenerated faster and more economically. Not to be confused with membrane drying technology, the AMT is extruded in a water bath, hence it is totally resistant to bulk water.

Contamination is also a problem for standard air dryers, as the clay binder can wear and break down when vibrated. This causes dust to be generated, contaminating downstream systems and reducing the dryer performance. With the new AMT material, the same desiccant material is extruded into tubes, ensuring no change in structure or deterioration in performance and eradicating the dust contamination found in standard dryers.

Dryers can be susceptible to contamination by oil carry-over from the compressor. For this reason, the new range has been equipped with a multi-stage pre-filtration system, making it a complete air filtration and drying system. Designed for the harsh environment of the global rail industry and capable of operating at -50°C to +120°C, the full system consists of:

  • 40 micron and five micron filters for bulk water and solid particulate removal
  • Coalescing filter for oil/water aerosol removal and sub-micron particulate removal
  • Carbon filter for oil vapour removal
  • Single or twin-column AMT dryer

Compressed air travels through the high efficiency filtration system where debris, moisture, oil and oil and chemical vapours are removed from the air before it reaches the AMT dryer itself, freeing it to remove the water vapour for an extended period of time.

Norgren’s Mark Wrigley said: "The AMT air dryer has been specifically developed to deliver engineering advantage through its optimised performance and long-lasting capabilities. Its unique and patented formulation allows the moisture-laden adsorbing drying media to be regenerated faster whilst reducing energy consumption. The solution was specifically designed to deliver a step change for compressed air drying for the railway industry, thus providing engineering advantage and ensuring trouble-free life between major overhaul schedules.

"The AMT’s unique design means its performance is not compromised by either orientation or vibration, while its compact design results in weight saving benefits. With the advantage of fast adsorption kinetics, the technology offers an effective and energy efficient solution for the international rail sector."