Epsilon Archive for Student Projects

Abstract

A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning. The results confirmed the differences in the saw particles characters with regard to particle size, shape and moisture content. There were marginal differences in heating value. Saw particles from first cutting and planning differs from each other based on the characters size, shape and moisture content. Saw particles from the first cutting and the second cutting gave the thickest fractions. The finest saw particles are produced at the grading. There were rather small differences in particle derived from thick and thin timber if fractional distribution, moisture content and form are observed. The feed rate provides differences in fractionation distribution and shape of the saw particles. The results of this study thereby show that it would be possible to assort the saw particles by its characteristics based on the characteristics they have received according to the cutting station they originated from.