Abstract
Broken pellets and fines are produced during mechanical handlings of wood pellets. The resistance to air flow was measured for clean pellets and for pellets mixed with 1 to 20% broken pellets (fines). A pellet diameter was 6 mm. The lengths ranged from from 6 to 12 mm. Clean pellets were defined as particles that remained on a 4 mm screen. A typical sieve analysis showed 30% of the mass of particles passed through the 4 mm screen were smaller than 1 mm. The airflow rates used in the experiment ranged from 0.004 to 0.357 ms-1. The corresponding pressure drop ranged from 1.9 Pa m-1 to 271 Pa m-1 for clean pellets and from 4.8 to 1100 Pa m 1 for pellets mixed with 10% fines. The pressure drop increased for pellets mixed with increasing fines content. Coefficients of Hukill and Ives’ equation were estimated for clean pellets and a multiplier was defined to calculate pressure drop for pellets mixed with fines.