软木干燥中湿空气和过热蒸汽的外部传热

编号 zgly0000342537

文献类型 期刊论文

文献题名 软木干燥中湿空气和过热蒸汽的外部传热

学科分类 220.5550;木材加工与人造板工艺学

作者 PANGShusheng 

作者单位 WoodTechnologyResearchCentre  DepartmentofChemicalandProcessEngineering  UniversityofCanterbury  Christchurch  NewZealand 

母体文献 Chinese Journal of Chemical Engineering;中国化学工程学报: 英文版 

年卷期 2004,12(6)

页码 762-766

年份 2004 

分类号 TS655  TS652 

关键词 木材加工  软木干燥  湿空气  过热蒸汽  传热系数  窑干法 

文摘内容 In kiln drying of softwood timber, external heat and moisture mass transfer coefficients are important in defining boundary temperature and moisture content at the wood surface. In addition, superheated steam drying of wood is a promising technology but this has not been widely accepted commercially, partially due to the lack of understanding of the drying phenomena occurred during drying. In this work, experimental investigation was performed to quantify the heat transfer between wood surface and surrounding moist air or superheated steam. In the experiment, saturated radiata pine sapwood samples were dried using dry-bulb/wet-bulb temperatures of 60℃/50℃,90℃/60℃, 120℃/70℃, 140℃/90℃, 160℃/90℃, 140℃/100℃ and 160℃/100℃. The last two schedules were for superheated steam drying as the wet-bulb temperature was set at 100℃. The circulation velocity over the board surface was controlled at 4.2 m.s^-1. Two additional runs (90℃/60℃) using air velocities of 2.4 m.s^-1 and 4.8 m.s^-1 were performed to check the effect of the circulation velocity. During drying, sample weight and temperatures at wood surface and different depths were continuously measured. From these measurements, changes in wood temperature and moisture content were calculated and external heat-transfer coefficient was determined for both the moist air and the superheated steam drying。