Modeling Pine and Birch Whole Tree Drying in Bunches in the Cutting Area

Abstract

Natural drying is practiced to improve the quality of fuel wood. The purpose of this study is to obtain the mathematical model of natural drying of whole trees stacked in bunches in the cutting area. To do this, an experimental study of natural drying of whole trees with different diameter was carried out from March to October 2015. Whole pine and birch trees were sorted according to their diameter and placed in bunches in the cutting area. During the next 7 months, the moisture content of wood and ambient parameters were constantly measured. As a result, the mathematical model describing the change in moisture content of the trees in bunches in the cutting area in the process of natural drying was developed. The resulting mathematical model makes it possible to determine the change in the average moisture content of wood depending on the following factors: diameter of a tree trunk, cumulative precipitation, relative humidity and ambient temperature, average wind speed and duration of natural drying. The developed mathematical model allows to predict changes in moisture content of wood in the process of natural drying. During the experiment, in the process of natural drying from March to October, it decreased from 52% to 27% on average. The results can be used to improve the efficiency of fuel wood production. The proposed mathematical model can be used in practice for predicting the outdoor wood moisture content change of whole trees packed in stacks for natural drying, and therefore, to determine the optimum drying time.