Keeping trains on track
From pneumatic doors to self-levelling air suspension to train horns, rail networks rely on compressed air systems. Without a supply of clean, dry air, components fail due to corrosion and trains grind to a halt. Costly for train companies and frustrating for passengers.
For years trains have relied on aftercoolers, adsorbent beads or membrane dryers to remove moisture and impurities from the air. But these methods are often unreliable and need frequent replacements. Keeping our rolling stock on track requires a reliable and durable dry air system. And the key to this is absorbent fibre technology.
Environmentally friendly gas separation
At Bath, we’ve been making and testing adsorbent materials for over 20 years. Unlike absorption where fluid dissolves into a liquid or a solid, adsorption sees molecules form an adhesive film along a surface or membrane. This means these materials are totally resistant to bulk water and there’s no by-product or chemical reaction when they are saturated.
Air compressors are mainly found under the body of a train carriage. They draw in air from the atmosphere surrounding them, which usually contains water vapour and contaminants. As the air is compressed these impurities are compacted together, then they are cooled to form a liquid that can be easily removed by depressurisation. This process requires a large pressure drop from beginning to end.
Separating gases at a reduced pressure drop uses less energy, which is better for the environment and a much more sustainable option for industry. Our patented hollow fibre method allows us to do just that. These structured, straight channels reduce friction and drag to keep the pressure drop low compared to adsorbent bead-filled dryers.