OPTIMIZATION OF THE CLEARANCE ANGLE IN INDUSTRIAL DISC CHIPPER

摘要

Wood chips used for chemical pulp must be of relatively uniform size. The penetration of the pulping chemicals and thus the cooking time, is considerably determined by chip length. The clearance angle (pull-in angle) is a significant parameter of the knife positioning in the disc chipper, that affects the length of the chips." In many production plants, this angle is wrong set depending on the diameter of the chipped wood. This causes problems in obtaining the appropriate length of the chips. The disc chipper in one of the industrial plants in Poland was investigated because it produced chips with smaller lengths from the assumed. This also induded the numerical calculations to optimize the clearance angle. In the disc chipper, the variability of the clearance angle (alpha) along the cutting edge of the knife (helical knives) gives the possibility of improving the quality of the wood chips. Simulations to determine the variability of the clearance angle on the radius of the disc of chipper assuming the continuity of cutting wood in the chipper was also performed.