Chemical Engineering Transactions (Jun 2022)
The Effect of Moisture on Specific Energy Demand for Knife-milled Wheat Straw
Abstract
The paper analyzed the effect of moisture on specific energy requirements for knife milled wheat straw. The wheat straw with moistures of 3.1 wt %, 8.1 wt % and 22.9 wt % were comminuted under various rotors´ peripheral speeds and opening sizes, being at drum sieves of the knife mill with biomass flowrates 116.1-414.1 kg h-1 m-1 of the total length of installed blades in pair. The specific energy requirement of 0.28-40.12 kWh t-1 was identified to reach the final particle size D50 of 0.25-1.42 mm from the initial one of 2.67 mm. The Rittinger law precisely fits the experimentally determined values of specific energy requirements dependent on particle size characteristics and biomass moisture. The Rittinger constant was equal to 7.55-49.30 kWh mm t-1 for moisture ranges 3.1-22.9 wt % evincing its power-law dependence on biomass moisture.