الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Drying is considered one of the most complex processes encountered in engineering, the drying of wood has a vital role in wood industry. This process enhances the mechanical properties and protects the wood against insect and fungal attack. Drying is process accompanied with a simultaneous heat and moisture transport within material and from its surface to the surroundings caused by a number of mechanisms. The moisture can be either transported to the surface of the material and then evaporated, or evaporated internally at a liquid vapor interface and then transported as vapor to the surface. Heat transfer depends on air temperature, relative humidity, air flow rate and exposed area of material. The physical nature of the material, including temperature, pore structure, and moisture content governs the rate of moisture transfer. Wood drying kiln is essentially an enclosed space where air velocity, temperature and humidity are controlled. An experimental study is performed to describe the heat and mass transfer process in drying of wood using kiln. The drying chamber made from isolated aluminum sheet with dimensions 0.7×0.5×0.3m. Hot air enters the chamber and flow over the sample to be dried. Two sensors are made to measure dry bulb and wet bulb temperature in the chamber. The temperature from air heaters can be controlled using temperature controller. The test rig is thermally insulated from the surroundings. The wood sample is placed over tow stands where the air flows over all the surface area of the sample. Speed of blower has controlled by a variable speed electric motor. Samples of wood are hardwood (Red Oak) and softwood (Beech Pine and Poplar). At all tests, measured data are recorded in a data sheet and for each time step the average conditions of temperature and moisture content are recorded in addition to mass of softwood material. The recorded data is used to determine different drying characteristics as well as heat and mass transfer coefficient during drying process.