Overview
The Natural Draft Tray Dryer is a thermally insulated drying cabinet where heated air rises naturally (by buoyancy) over multiple trays loaded with wet solid material. There is no forced air circulation, making it suitable for studying natural convection drying kinetics under gentle conditions. Students obtain drying curves (moisture content vs. time), drying rate curves, and identify the constant rate and falling rate periods of drying. The experiment provides data for design of batch dryers used in food, pharmaceutical, ceramic, and agricultural industries where delicate materials require gentle heat exposure.
Specifications
| Number of trays | 4 to 8 |
| Tray size | 300 mm x 200 mm (approx.) |
| Temperature range | ambient to 120 degrees C |
| Temperature controller | PID type |
| Air circulation | natural draft |
| Weighing | digital balance (manual periodic) |
| Insulation | mineral wool lined cabinet |
| Power supply | 220V AC, 50 Hz |