A twin tower gas drying system is disclosed for filtering unpurified gas to supply purified gas to a pneumatic system. The drying system includes a separator, two coalescers, two desiccant towers and a mechanism for controlling flow of unpurified and purified gases therethrough. The separator separates...http://www.google.es/patents/US5662727?utm_source=gb-gplus-sharePatente US5662727 - Twin tower air dryer for an air compressor unit
