A calculation method of obtaining desorption isotherms of beech (Fagus moesiaca) wood

Abstract

This paper presents the specific methods to obtain sorption isotherms. Sorption isotherms were first obtained experimentally for 20 degrees C and 100 degrees C and then, by using the presented method, isotherms were also obtained for 50 degrees C and 80 degrees C. The same treatment can be applied in finding any isotherm sorption in the temperature range between 20 degrees C and 100 degrees C. The experiments were carried out on beech (Fagus moesiaca) and sample dimensions were 3x3x3cm. Based on the results of the experiment by regression analysis, the most suitable analytic formula was proposed. It relates temperature and air humidity with the equilibrium moisture content in wood. Experimental results were compared with psychrometric tables and Bramhall's formula for desorption curves with good agreement. This proves that the method presented in this paper is precise and efficient to decrease the time needed to obtain sorption isotherms experimentally.