Evaluation of Fuel Quality, Throughput Rate and Energy Consumption During Non-Industrial Wood Chip Production with Three PTO Driven Chippers

Physical wood chip quality is essential for failure-free and low emission combustion in small-scale boilers ≤100 kW. In Bavaria, these furnaces are often operated by farmers or private forest owners that produce their own fuels using small to medium sized PTO-driven chippers. As secondary fuel processing steps such as industrial screening usually too expensive owners, the selection of suitable raw materials process parameters directly high during chipping deemed especially relevant this user group. present study, three commonly used chippers ≤150 kW, i. e. a drum, spiral disc chipper where evaluated terms quality, throughput rate energy consumption production. Chipping was done stem European beech Norway spruce. Machine settings were ones recommended manufactures production fuels. Additional variants included use different crown residues willow varying machine including blunt knives, increasing cut length, large screen mesh sizes increased PTO speeds. Representive samples taken after each trial analysed physical properties according international standards solid biofuels but also continuously measuring image analysis device determine particle length shape. For all mobile chippers, chips with size class »P31s« revised ISO 17225-4:2021 could be produced when assortment. Fine content chips, particles ≤3.15 mm, lowest drum chipper, knives narrow meshes chipping. At same time, shape factor (PSF) bulk indicating rather broken surface structure compared clean particles. Throughput decreased produced, g. spirals applied. This trend particularly pronounced due grinding material. All applied