This is improved version of heatless dryer where purge air loss is very very low
due to regeneration is achieved by dry air at low pressure and at high temperature.
To achieve this heaters are provided in each tower to heat the purge air to around
180 Deg C, which enhances its moisture carrying capacities. This hot purge air at
low pressure is passed through the desiccant bed to regenerate the Activated Alumina.