ABSTRACT

 A Mixed Mode Active Solar Dryer (AMMSD) primed with solar cell was developed for this purpose. Also, a Passive Solar Dryer (PSD) was developed along with the AASD. Open Sun Drying (OSD) was also performed during evaluation of the AMMSD and PSD. An economic feasibility study was performed on the dryers. Profitability indices was obtained for PSD, AMMSD and Grid charged Solar Dryer. The payback period obtained for PSD, AMMSD and Grid charged Solar Drying where 3.01yr, 10.641yr and 11.131 yr, respectively. The rate of return obtained for them where 26.298, 0.441 and 0.017 respectively. Net present worth for PSD, AMMSD (solar charged) and Grid charged Solar Drying was N7428.33, N-94980.625, and N- 97,122.62, respectively. Also, benefit cost ratio of 5.833, -1.58 and -Irrespectively was obtained. The efficiency of Active Mixed Mode Solar Dryer (AMMSD). Passive Solar Dryer (PSD) and Open Sun drying (OSD) was obtained as 32%, 42% and 30.8%, respectively. The total drying hour was 130, 126 and 152 for PSD, AMMSD, and OSD, respectively. The effective drying hour was 58, 56 and 68 for PSD, AMMSD, and OSD, respectively. Moreover, Cooking banana of 10mm sliced thickness, was successfully dried from 65.5% MC to 5% MC at a drying rate of 1.57(g/hr), 1.47(g/hr) andl.03(g/hr) for AMMSD, PSD, and OSD respectively. It was observed from the ANOVA, that within the drying rate, Drof sample in AMMSD and drying rate, Drof sample in PSD that fisher’s least significant difference of 0.321 was greater than absolute value of0.098 therefore there was no significant difference within the group. Significant difference was found within drying rate, Drof AMMSD and drying rate (Dr)of OSD because 0.341 was less than 0.521 absolute of the fisher’s least significant difference. Carbohydrate, protein, ash, fiber and fat content mean composition was determined by proximate analysis. The temperature in each drying chamber was also assumed to be uniform. The proximate analysis result showed that AMMSD dried Cooking banana samples had the highest carbohydrate mean composition of 70±0.03 (%) while 69.9±0.05 (%) is for PSD and 69±0.06 (%) for OSD. For protein composition, the mean composition was 4.03±0.03 (%) for AMMSD. 4±0.04 (%) for PSD, and 3.98±0.05 (%) composition for OSD. Khedjal method was applied in the determination of protein composition. The carbohydrate content was determined by subtracting sum of the percentage moisture, ash, crude lipid, crude protein and fiber from 100. There was significant difference of carbohydrate solar- dryer dried sample, open value for the fresh sample (P>0.05). the carbohydrate value for the fresh sample dryer dried sample and open sun difference of carbohydrate mean value of 70.4± 0.02(%) and AMMSD dried sample? passive sun dried sample at (P<0.05), respectively. The carbohydrate was not significantly different from the AMMSD dried sample : was significantly different from the passive dried sample (P><0.05)