Using the impact detachers at the head of the reduction system in the wheat flour milling process

Abstract

In flour mills impact detachers are most commonly applied to support the grinding of clean middlings (clean endosperm with minimal bran contamination) at the head of the reduction system supplementing the roller mill before sifting. However, using the impact mills, the conditions for controlled milling are less favorable and could result in deterioration of the flour quality. The purpose of this work was to examine the effect that impact detachers have on the milling results on the front passages of the reduction system. The streams entering and leaving the impact detachers applied on the different reduction passages (1M, 2M and 3M) in the industrial mill were intercepted and employed in the experiments. The changes in the particle size distribution and ash content of the material were followed. Results show that impact detachers significantly increase the degree of particle size reduction of the feed. Under dominant impact forces both endosperm and bran particles are fractured limiting their use to the passages with the low ash content of the stock (<0,6%). Otherwise, the fractured bran particles would pass into the flour causing the deterioration of the flour quality.