Internally Heated Air Dryer

We are offering internally heated air dryer.
The drying unit has 2-vessels filled with activated alumina or molecular sieves desiccant. One vessel remains in drying cycle for 4 hours, while other vessel simultaneously regenerates at atmospheric pressure. Around 3% flow of dryer capacity is used as purge for regeneration. Electrical heaters are provided in a central finned stainless steel pipe in both drying vessels. Heating cycle is for 2 hours and in this time hot purge air increases desiccant temperature to around 1000c. At this temperature regeneration is complete (due to dry air purge). Dew point achieved is around (-) 400 c. If still lower dew point is required, air purging rate is slightly increased to 5% for (-) 600 c and to 7.5% for (-) 800 c dew point.