This is a simple alternative for medium & bigger capacities where heatless dryer become uneconomical due to heavy purge losses. In this type of dryer the regeneration is accomplished with a very small portion of dried air/gas, which is circulated in the tower duly filled with desiccant and embedded with heating elements. The advantage to this type of dryer is that purge loss is reduced to almost 3-5% dew point upto (-80 °c) can be achieved.


  • Capacity: 200 CFM to 1000 CFM
  • Dew Point: -60 to -80 deg C ADP
  • Purge Loss: 5-10

Process Description

This is improved version of heat less 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.

A typical representation for the plant is shown in the figure 2.0 below:

FIGURE: Internally Heat Reactivated Type Dryer Drawing


  • Synthetic Fiber Industry
  • Chemical Process Industry
  • Air Curtains
  • Other Miscl. Industrial Applications


Product Air Dryer
Plant Capacity 20 CFM to 500 CFM
Product Specifications Dew Point: -40 to -60 deg C ADP

Purge Loss: 12-15