Kaeser DC Series desiccant air dryers

The DC series of desiccant dryers from Kaeser Compressors can lower the pressure dewpoint of the compressed air to -70°C. The company says they combine high energy efficiency and low maintenance costs, delivering frost protection for control valves and lines while producing dry compressed air for sensitive processes at a lower cost.

The DC 2.0 to 11.3 models can operate in, for example, 10 min cycles to achieve pressure dewpoints down to -40°C. During this process, the dryer switches between the two desiccant chambers only once every 5 min. This dramatically reduces the number of switching sequences between the chambers and resulting material wear on the valves and desiccant.

Long cycle times additionally reduce the amount of compressed air required to restore pressure following the desiccant regeneration phase. As an example, whereas 7.6% of the compressed air must be diverted for a 2 min cycle, this proportion falls to 1.3% with the 10 min cycle of the small DC units. This reduction makes them more efficient, saving energy and extending desiccant service life.

On/off control of the DC 2.0 to 11.3 series models allows for intermittent operation, which saves energy when there is frequent interruption of duty cycles. This employs ‘reverse regeneration’, where the regeneration cycle always uses up air from the downstream air receiver. A completely regenerated desiccant chamber is therefore always available each time the drying cycle restarts.