Mass Diffusivities of Radiata Pine in Superheated Steam Drying
Superheated steam drying is an energy saving and effective drying technology, in which the waste heat is recycled with the loop system and the moisture removal is much faster than that of conventional low temperature drying. The computation methods for the estimation of wood mass diffusivities were evaluated and the first ten terms of the analytic solution of Fick’s Second Law was considered sufficiently accurate, but Crank’s method was rejected, due to its large errors. The experimental data show that higher temperature significantly accelerated the drying rate. In addition, no visible surface or internal checks have been found in the superheated steam dried samples (dry-bulb temperature 160, 180, 200, 220 oC). The highly effective super heated steam drying is definitely an advantage. However, samples were browned when dried above 220 oC, which may be regarded as the critical temperature for quality control.
Sihai Jiao, Zhengyi Jiang and Jinglong Bu
H. W. Liu et al., "Mass Diffusivities of Radiata Pine in Superheated Steam Drying", Advanced Materials Research, Vols. 146-147, pp. 357-360, 2011