Solar Tunnel Dryer

The solar tunnel dryer is a polyhouse dryer suitable for drying of most of the food crops. It consists of a tunnel type semi-cylindrical drying chamber provided with windows to allow the ambient air to enter the dryer. An exhaust fan is provided to evacuate the moist air from the dryer. A sliding door is also provided to facilitate easy handling of the produce. Trolleys and trays (50 Nos.) are provided to hold one tonne chilli for drying. The maximum temperature of the air inside the dryer was observed to be 53-54°C. The drying time of 43-45 hours is required to dry one tonne byadagi chilli against 70 hours required for open sun drying.  Saving in drying time was observed to be about 40 -60 per cent by using this dryer for drying Byadagi chilli. The dryer can  also be used for drying grapes, sapota, figs, mango, amla, fish etc.

Detailed Specifications of Solar Tunnel Dryer             

Particulars	Specifications
Length x width x height	9.1 x 3.0 x 3.2 m
Floor area	27.3 m2
Polythene cover	UV stabilized thermic sheet
Height of the dome	1.2 m
Door (Sliding type)	1.2 m
Door (Sliding type)	2 x 1.5 m
Ventilators	1.0 x 0.3 m
Exhaust fan	300 mm dia., 0.125 hp, 1400 rpm
Aluminium tray	1.0 x 1.0 x 0.15 m
No. of  trays	48 for one tonne capacity STD
No. of tiers in each trolley	3 No
No. of trays in each tier	8 No.
Min. clearance between the trolleys	0.3 m
Ground clearance for the lower tier	0.3 m
Width of alley way between two rows of trolleys Clearance between the trolley and the wall	0.125 m