DEVELOPMENT OF A WET YELLOW MAIZE MASH SIEVING MACHINE

Abstract

Wet sieving is still a manual operation in tropical crop processing. It is a time consuming operation. Most of the existing wet sieving machines are available in large scale industries and they are too sophisticated to operate and maintain by local processors. In this study, a low-cost simple prototype wet sieving machine was designed, fabricated and tested using locally available materials to solve the problems associated with sieving of wet agricultural products in Nigeria. The machine consists of a sieving compartment operated by a crank through vibratory and reciprocating mechanism obtained with the use of an eccentric cam and springs arrangement, collecting trays and outlets. The test considered feed rare Q, at three levels: 0.85 g/s, 1.7 g/s and 4.3 g/s and concentration X, at Three levels 12.23%, 14.44% and 22.77%. The study showed that the machine performance coefficients and sieving capacity decreased with increasing concentration and feed rate. Higher performance and sieving capacity was achieved at a treatment combination X₂Q₂ where the performance coefficients and sieving capacity are 76.42% and 7.5 g/s respectively. A unit of the machine costs N9.780 as at April 2009. It requires little maintenance.