The Evaluation of Machine Performance and Hog Fuel Quality in the Salvage Logging of Pinewood Nematode-Infected Pinus Trees Using a Tub Grinder

Comminution is performed by using two main types of machines: grinders and chippers. Grinders are commonly used to treat contaminated wood biomass. In South Korea, cut-to-length harvesting is the main salvage logging method, and felled trees and residues often become dirtied during extraction, where logs are moved from the stump to the roadside using a small shovel. Therefore, grinders are preferred for the comminution of wood biomass for conversion into hog fuel. This study aimed to evaluate productivity and hog fuel quality as outcomes of wood biomass sorting. The productivities for unsorted residues and logs were 11.2 ± 1.48 ton/PMH0 and 12.4 ± 1.73 ton/PMH0 at a moisture content of 24%, respectively. Between 33.5% and 46.0% of the total hog fuel mass passed through the screen and reached an acceptable size (3.15 mm to 63 mm). The bulk densities of the two materials ranged from 132.4 kg/m3 to 148.8 kg/m3 on a dry basis. The results of this study suggest that sorting the feedstock has the potential to reduce the number of oversized particles in the hog fuel without screening.