DEVELOPMENT OF A SMALL CAPACITY DRYER FOR VEGETABLES

High moisture content vegetables undergo microbial attack soon after h arvesting/picking. The post-harvest losses of these commodities in dev eloping countries are very high mainly due to lack of storage and proc essing facilities. The development of processing facilities close to t he growing areas is necessary to reduce the losses. The technology for dehydration of vegetables is either traditional or very advanced Henc e the need for an intermediate level technology was realized and an ef fort was made to solve this problem by developing a small scale dryer. The dryer was tested with different vegetables (cauliflower, cabbage and onion). At a constant air inflow rate of 0.33 m3/s, it took about 11 h to reduce the percent moisture content dry basis/wet basis from 1 260.56 dry basis (92.65 wet basis) to 8.69 (8), 14 h from 1233.33 (92. 50) to 8.69 (8) and 12 h from 900 (90) to 8.11 (7.5) with inlet air te mperatures of 65, 55 and 56-degrees-C respectively for 50 kg batches o f cauliflower, cabbage and onion slices. The overall energy utilizatio n efficiencies of the dryer for these vegetables were 30.83, 28.21 and 29.51% respectively. The cost of the dryer was Indian Rs 12000 (US $4 80) and the estimated costs of processing cauliflower, cabbage and oni on slices were Rs 2-16 (US $0.086), Rs 2.76 (US SO.11) and Rs 2.37 (US $0.095) per kg of raw material.