Design and Development of Rasp Bar Mill for Size Reduction of Maize

Particle size affects many characteristics in the manufacturing process. Controlling the particle size helps to assure that the milled material will be consistent and repeatable with respect to firstly color, that is, uniform particles assure batch-to-batch color consistency, Secondly, flowability that is critical to packaging, tableting, weighing. Thirdly, uniformity, that is , consistent bulk density. Fourthly, density - helps control shipping costs and minimize dust. Fifthly, reconstitution, that assures the desired dissolution rate, Sixthly, chemical reaction that is vital for uniform, controlled chemical change. Finally, taste that allows precise portion control for consistent taste. The aim of this project is to design and develop a rasp bar mill for size reduction of maize seeds for different purposes. The fabricated rasp bar mill is capable of feeding maize around 60-180 kg/h, delivering of grits 60-90%, with sieve effectiveness 90-100% at a power requirement of 800-1400W,for different sieve perforation sizes of 5, 6, 7, 8 mm respectively.

ENGINEER, Vol. 47, No. 03, pp. 39-47, 2014