SRDE Heatless Desiccant Compressed Air Dryers
High Efficiency Compressed Air Drying & Purification for Demanding Rail Applications
SRDE Heatless Desiccant Compressed Air Dryers are a next-generation solution, purpose-built to perform reliably in the most demanding environments found in the rail industry where failure is not an option. Designed to outperform traditional desiccant technologies, SRDE is redefining the air purification industry with unparalleled results.
Patented Skroll® Technology
Performance
Engineered for flexibility, security, easy installation and complete reliability
With Skroll® media at the core of its ultra compact design, the SRDE sets a new benchmark in adsorption drying technology—ensuring continuous, high purity compressed air supply even in the most demanding rail & mobile environments.
Compressed air systems are constantly exposed to harmful contaminants such as dirt, condensed water and oil aerosols, all of which can reduce efficiency, increase maintenance costs, and lead to premature
equipment failure. APSL SRDE dryers are engineered to remove these contaminants, delivering clean air that meets the strict quality classes defined in ISO 8573-1.
By ensuring compressed air is purified to the required standards, APSL dryers help protect critical system components, improve operational reliability and extend equipment lifespan. The result is reduced downtime, lower lifecycle costs and greater confidence in performance across even the most demanding rail operating conditions.
The SRDE Heatless Desiccant Compressed Air Dryer incorporates our unique Skroll® adsorption media within a high performance twin column system, specifically engineered to maximise air quality, system reliability and cost efficiency in demanding rail environments.
- Flexibility - Compact design is easy to install
- Long life - 5 Years or 25,000 hours of operation
- Stable performance - Maintains performance over a lifetime of operation
- Reliability - Designed to operate in arduous conditions and recover from misuse
- Security - High Tensile Aluminium housing anodised for corrosion protection
- Low temperature - Designed to operate down to -40°C
Shock & Vibration tested to EN61373:2010 Class 1 Category B, and MIL-STD-810H:2019
Corrosion tested to ISO9227:2017 – 1,000 hours
Cold Temperature tested to EN 60068-2-1:2007 -40°C/°F & Park tested (7 days at -50°C)
Dry Heat tested to EN 60068-2-2:2007 +85°C/185°F
Damp Heat tested to EN60068-2-30:2006 +55°C/131°F
Fire & Smoke compliant to EN45545-2:2013 (HL3)
Serialised – providing traceability of materials of construction & testing, manufactured in an ISO9001:2015 Lloyds Register facility
The filter body is manufactured from high tensile aluminium bar which is Anodised for maximum corrosion protection both internally & externally
Ozone resistant
Operating Principle
This SRDE dryer uses the pressure swing adsorption (PSA) principle of drying compressed air, utilising two identical columns fitted with advanced Skroll® adsorption medium specifically developed for use in compressed air dryers operating in arduous conditions. Compressed air dryers containing Skroll® adsorption medium have been developed with a particular focus on robust design for application in rail transportation where reliable performance and minimum servicing is required. It operates to provide stable Dew Point Suppression (DPS) throughout its operating range of temperatures and pressures of typically ≥40°C.
In operation, compressed air passes through the SRDE adsorption column ‘A’ (see image below) where moisture is adsorbed and the air is subsequently dried. Simultaneously, a small amount of this dry air is depressurised and counter-flowed, via the Non-return Valve (NRV) orifice, down through column ‘B’ (see image below) and exhausted to atmosphere. The result is that column ‘B’ becomes regenerated to a dry state ready for use once again.
The dryer controller periodically switches the control solenoid valves, reversing the function of each column and therefore ensuring the continuous supply of clean and dry air. The cycle time is typically 1 minute per side, 2 minutes per complete cycle.
Control valves are normally closed to ensure a continuous supply of air in the event of a temporary interruption to the power supply to the dryer controller. Skroll® drying medium will recover from this condition once normal operation is resumed and power restored.
Media
Skroll® Media
At the heart of every SRD dryer is the patented Skroll® adsorption medium technology which is proven to outperform other desiccant media with its unique performance characteristics and revolutionary design.
Skroll® is the future of adsorption technology...
Contact us to see why Skroll® should be an integral part of your air & gas systems...