Basics of Wood Drying

Abstract

Drying is one of the most important processing steps in the production of timber and many of the wood composites. During this process, freshly cut timber, veneer, strands, or wood particles of various shapes and sizes are placed in specially designed chambers where under controlled ambient conditions most of the water present in the pores and cell walls of wood is removed. This water extraction is necessary for further utilization, performance of wood, and longer service life.Wood drying is classified as a separation operation and water needs to be removed from a multiphase system consisting of a complicated solid structure. Therefore, the drying operation can be elucidated by treating it as a simultaneous heat, mass, and momentum transfer set of phenomena involving phase change of water within the complex material that is wood. This chapter provides a basic and applied description of wood drying from the fundamental moisture and thermal energy transfer to modeling and thereafter, a description of the most common practices related to this followed by the wood products industry worldwide.