Water And Temperature Change Model And Energy Consumption During High Temperature Drying Of Cottonwood

Veneer drying procedure essentially is a course of energy transfer and mass transfer. The qualitative analysis was developed to learn the change procedure of the water and temperature when the Cottonwood veneer was being dried. In the paper, the changing model was solved through the software of Delphi program. The experiment shows that the water and temperature change model can well reflect the rule of the changing.The relative humidity under high temperature can not be measured directly by the wet and dry bulb, so it was be confirmed by that of the simulate environment where the moist air is taken from the high temperature drying chamber. It shows that the method is feasible under the condition that no condensate takes place.Moisture unsteady-state diffusion of Cottonwood veneer during high temperature drying was tested and researched. The conclusions are as follows: The fiber structure is checked when the veneer is peeled, so the unsteady-state diffusion coefficient is higher than the normal lumber. When moisture content is above F.S.P., the moisture diffusion coefficients of Cottonwood veneer are increasing with moisture content decreasing; When moisture content is below F.S.P., the moisture diffusion coefficients are decreasing with moisture content decreasing. Moisture diffusion coefficients increase with medium temperature increasing and humidity decreasing.It shows that the bonding strength and the MOE, MOR of the plywood after being high temperature dried are not decreased. They accord with the National standard well.The energy consumption in high temperature drying procedure was researched at the end of the paper. The thermal efficiency is 6.1% higher than that of the normal drying process and the energy consumption per kilogram water is lower than that of the latter.