Principles of Tray Dryer:
A Tray Dryer operates on the principle of convection drying, where heated air circulates over the trays containing the wet material.
The moisture from the material is transferred to the air and carried away, leaving the material dry.
Construction
Chamber: An insulated enclosure to maintain heat.
Trays: Perforated trays hold the material to be dried, allowing air to pass through.
Heating System: Heaters (electric, steam, or gas) provide the necessary heat.
Air Circulation: Fans circulate hot air to ensure uniform drying.
Exhaust System: Removes moist air from the chamber.
Working
Loading: Material is spread evenly on the trays.
Heating: Heaters raise the temperature inside the chamber.
Air Circulation: Fans circulate hot air over the material.
Moisture Removal: Moist air is exhausted out of the chamber.
Monitoring: Temperature and humidity are monitored and controlled.
Uses
Drying pharmaceuticals, food products, chemicals, and powders.
Merits
Uniform Drying: Even distribution of heat and air.
Simple Operation: Easy to operate and maintain.
Versatility: Suitable for a wide range of materials.
Demerits
Slow Process: Can be slower compared to other drying methods.
Labor Intensive: Requires manual loading and unloading.
Energy Consumption: Can be energy intensive.