Large moisture evaporation rates from sapwood and heartwood samples of Douglas fir (Pseudotsuga menziesii Franco) green wood

Pseudotsuga menziesii

Franco) green wood were dried in order to establish moisture evaporation rates from their end faces. Experiments were carried out separately for heartwood and sapwood because of high differences in their initial moisture contents. Drying tests were conducted at the constant set value of equilibrium moisture content of 12% and two different temperatures of 30 °C and 60 °C. The moisture evaporation rate was expressed by the flux density of evaporated water. The maximum values and the run of the rate in the whole range of moisture contents were compared for heartwood and sapwood as well as for both drying temperatures. The constant drying rate period was not identified even for green sapwood. The obtained data can be used to establish the initial and boundary conditions for wood drying modelling.