The Effect of Particle Size Distribution on Pressure Drop through Packed Beds of Cooked Wood Chips

✍ Scribed by Quak Foo Lee; Chad P. J. Bennington

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 825 KB
• Volume: 83
• Category: Article
• ISSN: 0008-4034
• DOI: 10.1002/cjce.5450830416

✦ Synopsis

Abstract

The pressure drop of process liquors through columns of wood chips determines the operability, efficiency and control of both batch and continuous pulp digesters and the quality of the pulp produced from them. Pressure drop was measured through columns of industrial white spruce chips (produced with a chipping head‐rig) as a function of the chip size distribution and the extent of delignification. Flow resistance depended on the porosity of the chip bed which was affected by the kappa number of the chips (which affected their flexibility) and chip size distribution, the compaction forces applied to the column, and the liquid superficial velocity. The chip beds were compressible and inelastic. Previous work from the literature using the Ergun equation to characterize pressure losses through chip beds is examined and compared with results of this work.