Abstract: Herein is detailed a 3-rotor drying system (30,40,50) for producing technical air having a very low dew point comprising three rotary desiccant dryers (2,21,22), each rotary desiccant dryer (2,21,22) comprising a drying sector (2a,21a,22a) and a regeneration sector (2b,21b,22b), the rotary desiccant dryers (2a,21a) arranged in sequence and sharing a common regeneration-air flow path (9) for passing regeneration-air through the respective regeneration sectors (2a,21b,22b) of the rotary desiccant dryers (2,21,22) and a common intake-air flow path (6,7) for passing intake-air through the respective drying sectors (2a,21a,22a) of the rotary desiccant dryers (2,21,22) for dehumidifying the intake-air to product-air having a very low dew point.