Researchers have investigated the effect of chipper type on productivity, power demand, fuel consumption and product quality.A commercial drum and disc chipper with the same diameter capacity were compared. They were the Pezzolato PTH 300 G drum chipper and the Pezzolato H880/250 disc chipper, and were both new chippers powered by the same tractor (a 100 kW Case New Holland 140). The chippers were fed the same feedstock types and both used a two-blade configuration. The machines were fed poplar sawmill residue, poplar branches, poplar logs and chestnut logs. The material was fresh, consisted of lengths of approximately 2 m (6.6 ft), and had moisture contents of between 44% and 52%.
The results showed that the disc chipper had better fuel efficiency than the drum chipper, using 19% less fuel per unit product. This was due to its simpler design where the processing and discharge system are integrated. However, the drum chipper was 8% more productive per machine hour. The drum chipper produced smaller chips with a higher fines percentage. The chippers were both more productive when fed with logs compared to branches or sawmill residue.
This research appeared in Silva Fennica, 2013, Vol. 47(2). The authors were: R Spinelli, E Cavallo, L Eliasson and A Facello. Access at http://www.silvafennica.fi/article/930