The air heater includes four heating units (H2-H5,
40kW). Air temperature can be adjusted between 10C
and 160C. For the experiments carried out, only two units
(H3, H4) were used. After passing the heater, the air is led
into the drying chamber via the through flow (X) or the
over flow (U) unit, respectively. Air temperature is measured
using Pt-100 s placed at the respective inlets (f, k,
0.2 K). A precision pyrometer (h, Heitronics KT15II; 0.2 K) is installed in the top of the drying chamber for
non-invasive determination of surface temperature