The Fisair DFRB & DFRD dessicant dehumidifiers provide maximum efficiency in retaining molecules of water vapour extracted from process air flow while the rotation assures continuous and uniform drying. A series of metal plates inside the unit ensures that the air flow supplied by the fan goes through different areas of the rotor. The rotor cross section is divided into three sectors separated by special seals:

– One air stream (process air) passes through the largest of the three sectors of the rotor and leaves the unit as dry air with a reduced moisture content.

– A second air steam (reactivation air) is first heated by a PTC (*) heater and is then able to penetrate the holes in the silica gel wheel, thereby extracting water vapour previously retained by the process sector and removing it to the outside air.

– This second or reactivation air flow passes initially through
 heat recovery section which minimises the heat losses between the above two sectors which can result from rotation of the rotor. This reduces the power consumption of the heater and minimizes the temperature rise of the process air flow.