Solar dryers – A boon to the agricultural industry
First, let’s know what exactly drying is,
The process of removing liquids/moisture content from solid materials by evaporation is drying at its simple.
Goals of drying
This process is intentionally done
- To increase the storage period
- To reduce transport weight
- To increase Quality
The evolution of dryers
Exposing food grains in sun has been an ancient drying practice especially in India. Today’s industrialization and urbanization demand controlled drying to retain flavor, quality, and appearance in terms of long periods. Though coal, oil and firewood have been used in conventional dryer models, the energy crisis has been an inevitable reason for the emergence of dryers.
Goals of dryers
- To maintain quality over a long period
- To retain freshness, colour and odor over a long period
- To reduce the drying time
- To contribute towards a sustainable environment
Dryers in the agricultural industry
There are many types of dryers to cater the various industrial needs. Agriculture, accounting for about one-third of the Global Domestic Product is on the verge of many agricultural developments. But, knowing the difference before adopting sustainable and non-sustainable methods would escape the country from increased poverty and reduced biodiversity. Adopting efficient and sustainable practices should be a thumb rule that would boost the economy’s prosperity.
The main dryer that meets the requirements of the agricultural industry in a sustainable way and contributes to the booming of the agricultural industry is solar dryers.
As an important application of solar energy, Solar dryers are immensely beneficial in the agricultural industry. The main reason to shift from direct drying under the sun is the contamination of dirt and insects.
The main two types under solar dryers are
- Direct solar dryers
- Indirect solar dryers
Direct solar dryers
As the name indicates, direct solar dryers are nothing but they are dryers through which the item to be dried will be exposed directly under solar radiation through a transparent material covering the structure. Affordability is its advantage and having no control over the heat absorption is its disadvantage.
Indirect solar dryers
Again, as the name suggests this does not involve crop drying under direct sunlight. The solar radiation absorbed by the collector (a black insulated surface) has the effect of turning the light into heat. Once the light gets absorbed and converted to heat, the solid surface with aluminum foil lining makes the heat possible to get delivered at the required temperature on cold, windy and sunny days. The air circulating outside gets passed over the collector surface and gets heated, which is then used to dry the food inside the dryer. Though Cost inefficiency is it’s the main disadvantage, control over temperature overrides the disadvantage.
Why should you consider buying a solar dryer?
- Solar dryers are one of the sustainable agricultural innovations which slash costs, adds shelf life to fresh produce and boosts income.
- These solar dryers can save around 30% of the farm produce being lost every year due to the lack of proper storage and preservation methods.
- To safeguard the produce from wind, insects and rain.
- Though technological and non-sustainable methods prevent rotting, they fail to retain original taste, freshness, odor and nutrients.
- Solar dryers promise you a year’s shelf life without the lack of freshness, odor, taste, nutrients etc.
- To prevent food and income loss.
- The drying process is eco-friendly and hygienic.
- Low operation and maintenance costs
- Longer life
The limitation of solar energy except sunny days makes the drying process slow when compared to other conventional dryers.