Global Journal of Researches in Engineering, J: General Engineering, Volume 1 9 Issue 2

Cameras for the Drying of the Wood Fedor Mende Annotation- In the book are examined different methods of the drying of wood, and also construction of drying chambers for their realization. The universal drying chamber, which ensures the high quality of drying with the minimum expenditures of energy, is in detail described. Camera is fully automated and in all time of drying does not require the interference of operator. In spite of high characteristics, camera is so simple that for its production it does not require special equipment and expensive completing. Keywords: wood, drying, cameras, wood moisture, heat of evaporation. I. E ssence, P urpose and the V alue of the D rying of the W ood n the growing tree is contained a significant quantity of moisture. It is necessary for maintaining the vital activity of the cells of tree. Under the natural conditions of life of forest the moisture plays positive role also in each extinct tree. It contributes to development in the wood of microorganisms, therefore, to its timely biological destruction and to fertilizer of soil. With the use of the felled and processed wood appears the need for averting of its biological destruction, giving to wood the resistance to rotting. Most simply this is achieved by removal from the wood of almost entire moisture. Thus from the unstable raw material wood is converted into the very valuable material, which is been preservable long time. However, moisture in an excess quantity frequently is used for the protection of wood from the rotting. It is known from the practice that the underwater part of the piles, the flooded logs and T. p. remain long time - ten and hundreds years. The method of the flood of wood raw material for its seasonal storage widely is used in the plywood production, and the artificial overhead irrigation of the piles of logs - in the saw-mill.In this case of the wood by moisture air (including oxygen), necessary for the vital activity of the wood-attacking fungi, is displaced. Especially rapidly (in 1-2 months) in the summer time spoils felled, but not dressed and, therefore, not dried up in a short time, the wood of beech, birch and aspen; rot the damp boards, packed in the dense piles. Therefore it is necessary the log of these wood species, and also maple, ash, alder-tree, linden and others to urgently saw and then boards immediately to dry with the maximum permissible intensity. Basic factors of rotting the wood: the moderate temperature (5-40° C), atmospheric oxygen and its significant (but not close to maximum) humidity. For retaining the wood it is desirable so that as a result the dehydration in it would remain the less fifth part of the moisture with respect to the mass of wood itself, and in the case of storage the method of additional moistening the mass of moisture must be more than the mass of wood itself. The ratio of the mass of moisture to the mass of wood itself is called its humidity of . In the noted examples the wood moisture content is 0.2 (20%) and more (more than 100%). If wood will be found under operating conditions on open air, by atmospheric precipitations preliminary drying for the protection of wood from the rotting is useless in view of the inevitability of repeated moistening. The most economical and extended method of the dehydration of wood - this is its drying, achieved due to the supply to the moist material of heat by heated air (or combustion products) and the removal of the evaporated moisture by the same, but by partially moistened and cooled air. For transforming one kilogram of water into the vaporous state with the atmospheric pressure be required to spend about 2300 kJ (540 kcal) of energy. The process of evaporating the moisture with the aid of air can occur without its artificial preheating, which is characteristic for the atmospheric drying, when the heat of the surrounding air heated by the sun is used. Since the volume of the separating from the material vapor at a usual temperature of drying (50- 100° C) approximately in 1,2 - 1,7 thousand once is more than the volume of the evaporated water, vapor is fixed from the heated wood into the ambient air. Consequently, for the drying it is necessary with air to bring energy and to take away vaporous moisture, T. e. to accomplish air circulation using the material. The duration of the process of the drying of lumber in the special cameras is completely significant (1-60 days) depending on thickness and species of lumber.Since with the blowing lumber burst by dry air, the process of drying is carried out in the moist medium. For these purposes the moisture, which was evaporated from the wood, is used: left the pile moistened air repeatedly is preheated in the air stoves (or they add hot combustion products) and for a second time they direct into the same pile of material, the method of the recirculation of air uses. A quantity of moisture, which is contained in the freshly-felled or floatable wood, decreases because of runoff of it in the liquid state (mechanical dehydration) or the transformation of liquid into the vapor, ie change in its state of aggregation. Is most tempting the removal of moisture from the wood precisely in the liquid state, without the heat expenditure for its vaporization. It is I © 2019 Global Journals Global Journal of Researches in Engineering 13 Year 2019 ( ) Volume XIxX Issue II Version I J Author: e-mail: fedormende@gmail.com