Moisture content during and after high- and normal-temperature drying processes of wood

• Published in: Drying technology 2018-04, Vol.36 (6), p.751-761
• Main Author: Baranski, Jacek
• Format: Article
• Language: English
• Subjects: Beech; Drying; Heat and mass transfer; Kerf; Moisture; Moisture content; Process parameters; Sawing; Steam; superheated steam drying; Temperature; Thermocouples; Wood; wood drying; wood moisture temperature dependency
• ISSN: 0737-3937; 1532-2300
• DOI: 10.1080/07373937.2017.1355319

The aim of the article is to present the results of moisture content of wood during and after the high-temperature steam and air-steam mixture drying processes and after an open air-drying process. The knowledge of moisture content changes of wood in the process of its drying is one of the important parameters to economy drying process and to keep the quality of dried wood. Wood samples, namely, spruce (Picea abies K.) and beech (Fagus silvatica L.) from the northern part of Poland, were subject to steam, air-steam mixture and, air-drying, respectively, with a temperatures about 105, 80, and 25°C. The samples of thickness 70 mm and length about 1,050 of spruce, and about 1,500 mm of beech were used. They were machined by the modern narrow kerf frame sawing machine. Temperature of the cross section of dried wood was measured by thermocouples, wood moisture content was determined during process using moisture sensors. Measurements of moisture content for steam-dried and air-dried samples, as reference, allowed to reveal the effect of drying process on moisture content of wood. It has been recognized that steam wood drying causes almost constant amount of moisture in treated material in comparison to air-drying one.