Analysis and Testing of a Natural Convection Solar Dryer for the Tropics

Table 1

Design considerations and assumptions.

S/N	Parameters	Description
1	Location	Lagos, (long 3°24′, lat 6°27′N)
2	Drying period	October
3	Solar irradiation, Lagos (October)	15.4 MJ/m^2/hr [10]
4	Annual relative humidity of Lagos taken over a ten-year period	80% [11]
5	Food products	Plantain
6	Mode of heating	Indirect
7	Number of glazing	1
8	Glazing materials	Glass
9	Loading provision	Door at the back of cabinet
10	Number of trays	2
11	Air outlet provision	Chimney at the top of cabinet
12	Air circulation mode	Natural convection
13	Drying capacity	10 kg
14	Thickness of plantain fillets	3 mm
15	Construction materials	Wood, glass, mild steel sheet
16	Insulation used	Glass fiber
17	Thickness of mild steel sheet	3 mm
18	Thickness of glass	4.5 mm
19	Thermal conductivity of glass, W/mK	0.84 [12]
20	Transmittance of glass	0.81
21	Emissivity of: glass	0.94 at 72°F [13]
22	Mild steel	0.2–0.32 [13]
23	Paint, flat black lacquer	0.96–0.98 [13]
24	Black or white lacquer	0.80–0.95 [13]
25	Thermal conductivity of mild steel, W/m°K at 38°C	50.0
26	Sky temperature	32°C
27	Dimension of collector case	1.0 m × 1.0 m × 0.2 m
28	Dimension of collector channel	1.0 m × 0.5 m × 0.1 m
29	Initial moisture content of plantain, 𝑚𝑖	70% [14]