Univeristy Of Agricultar Faisalabad SOLAR DRYER SUBMITTED BY:- Shafiq Ur Rehman Ag#-2015-ag-3270

CONTENT  WHAT IS SOLAR DRYER  WHAT IS THE NEED OF SOLAR DRYER  WHAT IS THE CONSTRUCTION OF SOLAR DRYER  PRINCIPLE OF SOLAR DRYER  ADVANTAGES OF SOLAR DRYER  WORKING OF SOLAR DRYER  IMPROVEMENT/ ADVANCEMENT IN SOLAR DRYER  LIMITATIONS OF SOLAR DRYER  CONCLUSION

WHAT IS SOLAR DRYER ? Solar dryers are devices that use solar energy to dry substances, especially food. There are two general types of solar dryers: Direct and indirect.solar energy food  DIRECT Direct solar dryers expose the substance to be dehydrated to direct sunlight. They have a black absorbing surface which collects the light and converts it to heat; the substance to be dried is placed directly on this surface. These driers may have enclosures, glass covers and/or vents to in order to increase efficiency.sunlight. Theyblackabsorbing surface efficiency  INDIRECT In indirect solar dryers, the black surface heats incoming air, rather than directly heating the substance to be dried. This heated air is then passed over the substance and exits through a chimney, taking moisture from the substance with it.chimneymoisture

WHAT IS THE NEED OF SOLAR DRYER ?  In rainy season and winters due to presence of moisture a foul smell develops in food grains and there is full possibility of development of pests.  It can also be used as filter.  It make us rid of spreading food grains which was required earlier at regular period of time.  Drying in the direct sun has the risk of damaging the complete harvest by rainfall  Dehydration of fruits, potatoes, onions and other vegetables  Seasoning of wood and timber

CONSTRUCTION OF SOLAR DRYER 1) Solar panel : 12 volt and 10 watt 2) Electric motor : 150 rpm 3) Black absorbing wooden chamber 4) Glass cover : traps the heat generated and act as insulator 5) Electric bulb (denoting sun) : 200 watt 6) Plastic container : To collect sand, pebbles, impurities

PRINCIPLE OF SOLAR DRYER Our solar dryer is based on two principles.  Conservation of energy in which one form of energy is converted into other form of energy.  Black body which absorbs the heat of the incident sunlight and makes the temperature of chamber more than the surrounding temperature.

Advantages of solar dryer  Much less time is required for drying as compared to direct drying because of black body.  Protection of the drying products from insects but also from birds, dogs, especially for drying meat and fish.  The product is hygienic because microorganisms, insects and flies are killed  Protection of rain  Protection of pollution by dust etc.  Protection of the wind which can blow away the food

Working of solar dryer Sunlight falls on the whole apparatus. Solar energy is converted into electric energy by solar panel and this electrical energy is converted into mechanical energy by electric motor which rotates the rod ( CONSERVATION OF ENERGY) Wooden chamber absorbs the sunlight and generates the heat and after some time inner temperature becomes much larger than the outer temperature. Covering glass restrict the flow of heat outside ( BLACK BODY ) It can also be used as filter by which dirt, sand, mustard seeds can be removed and can be collected in a plastic box below.

IMPROVEMENT / ADVANCEMENT IN SOLAR DRYER In our project there are four advancements in our knowledge :  Solar panel can be censored to the movement of sun as sunflower so that.  The electrical energy produced by solar panel can be stored in a battery which can be used when sunlight is not available.  Temperature censor can be used which can control over heating of food grains.  Automatic refilling of container.

Limitations of solar dryer  Not workable at night.  Efficiency decreases to a large extent on cloudy days.  Over heating may occur if regular attention is not paid.  Due to over heating it can decrease the quality of food.  Change in taste and flavor of food may occur if regular monitoring is not done.  We cannot get the accurate amount of sun rays and heat.

conclusion In a country like India where 300 days out of 365 days are sunny have a huge asset of solar energy. Government is also promoting the use of renewable sources of energy like solar energy by providing subsidies on solar pumps, solar water heater, solar panels, solar lights etc. son we should take advantage of these schemes. Use of solar energy costs us nothing just only solar panel, sunlight is free of cost and sun is a non finishing source of energy. Almost every year there are news of rotten food grains in newspaper which causes a huge loss to farmers but if we design those godowns on the concept of black body then such condition will not occurs.

THANK YOU ……