Vertical Vibratory Mixers in Flour-Mixing Technology

Abstract

The food industry is currently demonstrating a tendency to substitute traditional high-humidity raw materials with their dry analogues. This research introduces new designs of vertical vibrating mixers that could preprogram flour mix quality. The vertical continuous vibration mixers designed for granular materials showed a good potential for a wider scope of application. The experiment involved high-quality wheat flour, sugar, salt, egg powder, and powdered milk, as well as three vertical mixers, i.e., a lifting mixer, a flow mixer, and a cascade mixer. Wheat flour entered the working body of the mixer and came into a stable vibration-boiling state in layers of ≤ 35 mm with a vibration amplitude of 4.5 mm and a frequency of ≥ 20 Hz. The speed rate of the flour increased together with the oscillation frequency of the working body and the size of the perforation area but went down as the layer grew wider. The efficiency increased following the increase in the perforation area on the spiral surface and depended on the maximal thickness of the dough layer. The flow vibrating mixer proved to be the most effective one. The frequency of pulse feeding of ingredients into the mixer was ≤ 50% (Vc ≤ 14.5%) to obtain flour mixes of satisfactory quality while good-quality mixes required 25% average time the particles spent in the mixer (Vc ≤ 6%). The results obtained can be used to design technological lines for flour mix production.