Development of a machine for chopping wood residues
CAD software and FEM analysis were used to modify the drum of threshing machine into machine for chopping wood residues. The operating parameters that affecting the performance of the chopping machine are drum speed (450, 1000 and 1200 rpm), three stages of serrated disk arrangement clearance between drum flail knives (0.7, 1.5 and 3 cm) and three levels of feeding capacity (W1 300, W2 = 360 and W3 = 420 kg.h-1). The developed machine was operated by the addition of two types of knives (sharp free knives + serrated discs) to the original knife existing already in the machine. The machine was evaluated in terms of production capacity, cutting efficiency, power requirements and energy consumption. Using the modified (serrated) saw disk mill and flail knives reduced the energy requirement for chopping and raised fine degree of the chopped materials and solve the clogging problem. The cutting productivity and cutting efficiency raised with reducing the clearance between flail knives (0.7, 1.5 and 3 cm) while the power requirements and energy consumption reduced.