SOLAR BOX TYPE DRYER
Solar dryers used in agriculture for food and crop drying ,for industrial drying process, dryers can be proved to be most useful device from energy conservation point of view. It not only save energy but also save lot of time, occupying less area, improves quality of the product, make the process more efficient and protects environment also.
Solar dryers circumvent some of the major disadvantages of classical drying. Solar drying can be used for the entire drying process or for supplementing artificial drying systems, thus reducing the total amount of fuel energy required..
Solar radiation use for drying is one of the oldest applications of solar energy. It was used since the dawn of mankind mainly for food preservation but also for drying other useful materials as cloths, construction materials, etc. The first installation for drying by solar energy was found in South France and is dated at about 8000 BC. Solar heat was the only available energy source to mankind until the discovery and use of wood and biomass. Until to day in remote small communities, not only in the so-called third world regions, but also in the western countries, people take advantage of solar radiation to dry and preserve small amounts of food.
Solar drying has not yet widely commercialized. Solar dryers are equipment, generally of small capacity and based rather on empirical and semi-empirical data than in theoretical designs. The majority of the numerous solar dryer designs, which are available, are used mainly for drying of various crops either for family use or for small-scale industrial production.
In this chapter on “Solar Drying” various direct and indirect solar drying applications and some of the numerous solar dryers are described. A very short historical description of solar drying through the centuries is also given. Some drying phenomena, independently of the type of energy used, and the general laws that govern drying methods by convection are shortly analyzed in order the reader to easily follow the details of the solar drying procedure. Special solar collectors used in drying and methods of coupling to the various solar dryers are described as an indirect solar thermal energy source. At the end an example of drying of grapes to produce black current raisins, by indirect solar radiation, is given as well.
|Uniform drying of products|
|Option to dry products in shade|
|Suitability for rural / remote places|
|Drying temperature in desirable range|
|Light weight and easy to handle|
|Solar box type dryer 4feet by 5feet|
|2 solar fan|
|2 ms net tray with clear nalli sheet|
|Paper sheet reflector|
|Maximum temperature 60 to 65%|