Effect of Chipper Type, Biomass Type and Blade Wear on Productivity, Fuel Consumption and Product Quality

The study determined the time consumption, fuel consumption and chip size obtained with two different industrial chippers, working with logging residues (tops and branches), thinning material and pulpwood. Specific time consumption per oven dry tons (odt) was 83% higher for the less powerful disc chipper, and chipping forest residues resulted in a 35% increase in specific time consumption compared to chipping thinning material. What is more, the interaction between the two factors pointed at a different suitability of the two machines to chip different materials, since the difference in specific time consumption between the drum and the disc chipper was larger when chipping forest residues rather than thinning. Specific time and fuel consumption of the more powerful drum chipper increased by 30% and 39%, respectively, when working with dull blades compared to working with sharp blades. The best product quality was obtained when applying the disc chipper to pulpwood material. However, the same machine produced more fines when fed with forest residues.