Problem definition-
- Decreased efficiency of the solar convection dryer.
Objective-
- To increase the efficiency of the dryer.
Work done-
First we removed the top glasses of the collector or absorber.
We removed the dust over the glasses and then we washed the glasses.
We allowed the glasses to dry and then we removed the dust over the collector plate.
We cleaned the collector plate and washed it by water.
We allowed it to dry for some time and then we coloured the collector plate by using black paint.
We fixed the glasses on the collector by using gasket. We used new gasket for this purpose.
We changed the bottom and back side plywood of the dryer housing. For this purpose we first removed the both side plywood and then we took the dimensions of the bottom and back side and we cut the desired size plywood in the workshop.
Then we made the 5 inch diameter hole at the middle of the back side plywood of housing for fixing the exhaust fan.
Then we fixed the bottom side and back side plywood with the help of self lock screws. Then we applied the touch-wood at both the plywood for protecting plywood from the weathering.
Then we removed the broken glass of the housing which is at the front side of the housing. And replaced it with the acrylic sheet.
Then we covered the roof glass with the plastic sheet which is broken at the corner.Then we removed the trays of the housing and cleaned it.
Then we fixed the thermocole sheets at the back side of the collector plate as an insulation to reduce the heat loss. In this process we first took the dimensions of the back side of the collector plate and according to that we cut the desired size thermocole and we fixed it at back side of the collector plate and then we tied these thermocole with the help of the binding wire.
Then we fixed the exhaust fan of 12 V voltage and 0.34 ampere current rating.
Conclusion:
The temperature readings before working on the dryer in casing were about 30 degree celcius to 35 degree celcius, after working on dryer it is about 45 degree celcius to 55 degree celcius. Therefore we increased the efficiency of dryer by incresing temperature readings. We achieved that by doing above work done.