Vast applications of solar dryer

Chandigarh, May 4 (UNI) Solar energy can help farmers and agri-based industries supplement different energy requirements with a once for all solution in the form of renewable energy.

With the advent of solar dryers, crops, grains and fruits can be protected, dry faster and more uniformly and produce a better quality product than traditional methods of drying in the open as it is considered the simplest and the least expensive method of drying naturally after harvest.

The disadvantage of the open-air method was that crops and grains were subject to damage by birds, rodents, wind and rain and contamination by dust and dirt.

Punjab Energy Development Agency engineer Ravinder Singh said solar cabinet dryer is basically designed as an easy-to-assemble dryer with integral solar hot air collectors, with the principle that air is heated by means of solar energy at no cost against heating of air by means of electricity and can generate hot air with temperature ranges from 40 degree to 100 degree centigrate.

Mr Singh said the air heated in the solar collector moved either by natural or forced by a fan, up through the material being dried, the hot air picks up the moisture from the material and exhausted in the atmosphere.

The rate of the drying depends on the size of the solar dryer, airflow, amount of material, moisture content, humidity in the air and the average amount of solar radiation available during the drying season, he added.

The PEDA engineer said that solar dryers are designed and manufactured as per the specifications like required hot air, temperature, quantity of the material to be dried, initial moisture content of the product. A dryer of 7.1 cubic meter costs arround Rs 2.50 lakh with a pay-back period of about one year, he added.

On the vast applications of solar dryer in agricultural and agro-industiries, he said that it is used in drying spices like chillies, coriander, pepper, turmeric, dehydration of fruits and vegetables like mango, sapota, grapes, banana, papaya amla, carrot, beeroot, potato, bitter gaurd and many more, also it is very helpful in drying herbs like tulsi, neem and others which need to be protected from direct sun lights.

The solar dryer is also used for medicinal plants, cashew, paddy, mushroom, tea leaves, coffee beans, marine food, tobacco, wheat, seeds and many more applications wherever hotair is needed.

Apart from help in reducing fuel consumption and air pollution, the solar dryers, in addition improves quality of the end-product, he added.

The another agriculture application of solar energy is in greenhouse heating, the solar greenhouses are designed to utilize solar energy for both heating and lighting as needed to maintain temperature necassary to grow plants in the colder months.

The other application of solar dryers are for livestock and dairy farming as they often need water and heating, like pig and poultry farm raise animals in enclosed buildings, where it is necessary to carefully control the temperature in winters and air quality to maximize the health and growth of the animals. These facilities need to replace the indoor air regularly to remove moister, toxic gases, odors and dust.

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