Development and Performance Evaluation of a Mini Multipurpose Flash Dryer

Abstract

Drying, as one of the oldest forms of preserving agricultural products, has evolved over the years with the development of improvised drying systems such as the flash dryer for processed agricultural products. A mini flash dryer was locally fabricated and designed and fabricated considering domestically available power sources of charcoal and cooking gas. It was evaluated using basic staple foods (cassava, cornstarch, and beans) mashes obtained from Bodija market, processed, milled, and weighed in 1 kg samples. A Data logger (ECB-DU4AWC, China) was used to measure the temperature and relative humidity of ambient air and exhaust air leaving the heat exchanger while a CO2 monitor (2CO9, China) was used to check for safety of air. Key variables were moisture content, drying time, temperature, and relative humidity while Performance indicators such as the Final moisture content (FMC), drying efficiency, and efficiency of the heat exchanger. The average capacities of the flash dryer for cassava mash, cornstarch, and bean mash were 37, 40, and 25.2 kg h-1, respectively. The average efficiencies of the flash dryer on cassava mash, cornstarch and bean mash were 81, 69 and 59 %, respectively. The cost of production of the machine was estimated to be N304,050. The developed mini multipurpose flash dryer performed well with a reasonable level of efficiency on cassava mash and corn mash. However, the machine performed well by reducing the drudgery associated with their drying operation.