Solar Dryer
The process of removing unwanted moisture from a product using solar energy is called solar dryer. Safe storage of many agricultural (cereals, tea, coffee, tobacco, etc.), horticultural (fruits, vegetables), and industrial products (chemicals and pharmaceuticals, etc.) Drying for various purposes such as further processing and quality improvement. Farmers, painters, potters, and housewives all use the inexhaustible heat of the sun to dry in their daily lives. The method of drying in the sun is old. Yet this method has survived to this day as it is inexpensive. But drying in the open has some disadvantages such as:
- The final product is almost always contaminated with dust, sand, debris, animal manure, etc., and polluted gases in the atmosphere.
- They are spoiled by stray cattle, animals or ignorant children.
- Directly drying the product, usually in open sunlight, affects its original color.
- Drying does not happen as expected. Drying has to be stopped in cloudy or rainy weather.
- Sometimes even organisms like fungi feel the final product.
A device that scientifically removes moisture from a product from the heat of the sun is called a solar dryer. The scientific method of drying is ideal, fast, attractive as well as hygienic. In addition, this method retains the original aroma, color, vitamins, etc. of the final product. Cereals, vegetables and fruits are less wasted by drying in a solar dryer. They are protected from waste pests and save a lot of energy. The drying quality is also high.
The design of a solar dryer or solar dryer is decided based on the material to be dried inside it. There are two types of solar dryer or solar dryer cabinet size and hence large size. The cabinet size solar dryer can be easily rotated from one place to another and its capacity is to dry the product up to 1 to 25 kg per day. The cabinet-sized solar dryer dries grains, vegetables and fruits directly using the heated air with the help of solar energy passing through a transparent cover and this type of solar dryer does not use any other type of energy. This involves heating the material by circulating hot air through natural circulation. The large capacity solar dryer is durable and has the capacity to dry 25 to 1000 kg of product per day. This type of solar dryer is used to heat the air and dry the material indirectly using a flat plate collector. One square meter of air can be removed in the form of two liters of water vapor per day by a flat plate collector with a black surface for heating. This involves heating the material by circulating hot air through natural or artificial diffusion. In this about 60 to 70 C. As much temperature as can be obtained. In this the required temperature is maintained by controlling the rate of air flow. Rotating hot air sucks up part of the water in the object.
Drying in this plant dries the material as well as retains its natural color, properties etc. The use of this system in the agricultural sector is increasing so that perishable foods can be dried and stored for a long time. It is important that the distinctive aroma of the fruit is preserved after drying. Special care is required to dry tobacco leaves, tea, coffee etc. Delicate items should dry quickly. Baking salt from seawater is also a form of drying.
Solar drying machines have not been as popular as they should have been because of the initial investment required. Lack of knowledge about the benefits of controlled sakvani has also hampered its acceptance. Large scale use of proper type of drying machines can save a large amount of wasted waste.
In this way, farmers can take advantage of drying machines by installing them on the roof of their farm or house. And by drying agricultural products, this dried producer can earn maximum by selling.
Time for
drying of some food |
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The name of the object |
Weight of the substance before drying (grams) |
Water content before drying (percent) |
Water content after drying (percent) |
Drying time (hour) |
Green chili |
300 |
86 |
7 |
10-12 |
Mango |
300 |
85 |
7 |
8-10 |
Onion |
300 |
87 |
7 |
15-17 |
Amla |
300 |
91 |
7 |
15-17 |
Coriander |
300 |
88 |
10 |
6-8 |
Ginger |
300 |
85 |
7 |
7-10 |
Potatoes |
300 |
85 |
5 |
6-8 |
Tomatoes |
300 |
95 |
10 |
17-20 |