Publication - FOLDABLE DOME TYPE SOLAR DRYER – A NEW DESIGN
Base of the dryer is made by plywood board and bottom side of the board is covered by M.S. sheet. Upper side of the board is covered by aluminium sheet which is painted dull black by automobile muffler paint.
Longitudinal side of the dryer base is hinged in two places to make it three parts- bottom and two sides. When the dryer base is to be kept in folded position, both sides of the base can be folder upward keeping bottom part in horizontal position as usual. During folded position, a hinged strip acts as a lock to hold two sides firmly attached with each other in parallel position. Eight numbers of caster wheels are provided at the base of the dryer base. Four numbers wheels are attached with bottom part of the dryer base and each side part is provided with two wheels. These caster wheels are fitted for easy adjustment and transportation.
Single aluminium tray fabricated by aluminium screen and aluminium “L” channel is to be placed on dryer base during operation. The tray is painted black with dull black pain and bottom of the tray is provided with four numbers roller wheels for easy placement and removal from dryer inside. Five numbers Aluminium strips are given to parabolic shape for formation of a parabolic dome. Both longitudinal ends of aluminium sheet which is attached at the top of the plywood board are bent to make both side slide channels. Parabolic shape strips are bent horizontal at both ends and placed inside of slide channels so that, these can be slide longitudinally on the dryer base.
To make solar dryer roof cover, UV resistant transparent parabolic shape polythene dome with both end covers is made by the use of silk thread in a sewing machine. Cold air entry holes are provided at the bottom end of one end cover and hot air outlet holes are provided at the top of opposite end cover. This polythene dome is then attached with parabolic shape aluminium strips by screws and washers. When parabolic aluminium strips slide nearer to each other, the polythene dome is folded and when strips slide towards longitudinal ends then the dome is covered the whole dryer base as a dome shape roof.When to keep the dryer in folded position, all aluminium strips with polythene dome are brought longitudinally towards the middle position of the dryer base so that, all strips with folded polythene dome can be accommodated on the bottom part of three fold base. Thereafter, both sides of the base are to bring vertically upward.