| THEORY OF OPERATION
Heat reactivated dryer are used when one needs air of very low dew point. In this design desiccant is regenerated at higher temperature with little dry air purge. Due to dry air purge and thermal regeneration, residual moisture loading on desiccant becomes low and this gives low dew points.
The drying unit has 2- vessels filled with activated alumina desiccant. One vessel remains in drying cycle for 4-hours while other vessel is simultaneously regenerated at atmospheric pressure. Around 3 to 5% flow of air dryer capacity is used as purge for regeneration. Electrical heaters are provided in a central finned stainless pipe in drying vessels. Heating cycle is for 2-hours and in this time desiccant temperature increase up to 100 to 150 degree celcius. at this temperature regeneration is complete. Dew point achieved is around and above (-) 60 degree celcius.
These dryers are some more costly than heatless type but are more suitable for Dew points lower than (-) 60 degree celcius to
(-) 80 degree celcius and purge loss is also less than the Heatless type i.e. around 3 %.
SALIENT FEATURES
1. A fully automatic unit requiring no attention of the operator. Heaters switch on/off and all valves operation is fully automatic.
2. Low purge air requirement as compared to heat less type dryers.
3. Counter-current preheated dry air purge provides maximum removal of adsorbed moisture with minimum gas purge loss.
4. As heating is done desiccant life increases because moisture is removed effectively due to heating.
CAPACITIES OFFERED
5 NM3 / HR TO 5000 NM3 / HR
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