- 2070 Asar · 2 marks
Short note: Solar dryer
Short answer
A solar dryer uses solar heat to dry crops more quickly and cleanly than open sun drying. Types include direct, indirect, mixed-mode, and forced convection. Heated air reduces moisture, preserving quality. It is used in Nepal for chilli, genger, cardamom, and herbs.
Write a short note on solar dryer.
A solar dryer uses solar energy to remove moisture from agricultural products such as grains, vegetables, fruits, herbs, fish and timber. It is faster, cleaner and more hygienic than open sun drying, which suffers from dust, insects, birds and rain.
Types
- Direct (cabinet) dryer: the product is placed in a box with a transparent cover; sunlight strikes it directly.
- Indirect dryer: air is heated in a separate solar air collector and then passes over the product, so the product is not exposed to sunlight (keeps colour and vitamins).
- Mixed-mode dryer: combination of both.
- Forced convection dryer: a fan (often PV powered) drives the air flow.
Air in -> [Solar air collector] -> [Drying chamber with trays]
|
moist air out (chimney)
Advantages
- Saves fuel or electricity; uses free energy.
- Gives higher temperature and lower humidity, so drying is faster.
- Better quality of the product, protection from pests, and less loss.
- Used in Nepal for chilli, cardamom, ginger, apple, herbs, fish and tea in the hills.
Limits: depends on weather and sunshine, and needs initial investment.
✓ Answer checked by Claude Opus 5.5 (high effort)