Atmospheric drying of wood is commonly known as natural drying


Atmospheric drying of wood is commonly known as natural […]

Atmospheric drying of wood is commonly known as natural drying. Wood air drying is to stack the wood in an empty class yard or under a ventilated shed, and use the heat in the atmosphere to evaporate the moisture in the wood to dry it. Although the wood air drying method seems simple, the drying process involves many physical laws, such as combining atmospheric drying with other drying methods, which is a way to save energy.
In atmospheric drying, the energy of the drying medium comes from solar energy, and the circulation of the drying medium depends on the microclimate formed between and within the pile. In the wood pile, the air that absorbs moisture, due to the increase in density, this part of the humid air will drop, and the humid air with high humidity will rise, thus forming the circulation of air flow and making it dry.
However, the drying process is limited by natural conditions, and the drying process of wood cannot be controlled artificially. The drying time is long, the drying quality is low, and the final moisture content is limited by the region. Generally, it can only be dried to 10%-20%.
Air dry stacking method:
X-shaped stacking method: long and thin boards can be stacked into an X-shape, which can prevent the wood from discoloring.
Pad stacking method: Place a pad vertically and crosswise for each layer of boards.
Stacking method with poor vertical and horizontal without pads: From the first layer at the bottom of the pile, lay the boards in sequence according to the specified horizontal intervals, and then lay the second layer of boards at right angles.
The natural stacking method of wide timber piles: the first layer of panels does not leave any space in the horizontal direction, and the width of the panels is equal to a fixed number of meters, preferably equal to the length of the panels.
Drawer stacking method: use two boards as pads, and place them at both ends and in the middle of the stack.
Well-shaped stacking method: use this method for short and small wool.
Group pile stacking method: First, pile the boards of the same tree species and specifications into a small pile with a cross-section of 1.1*1m and a length of 2~6m, and then use a forklift to pile the small pile into a pile.
Atmospheric dryness requires a larger board yard, which requires a flat and dry terrain; a slight slope of 0.2%-0.5%, and drainage ditches around the board yard; no weeds and dirt on the site, and no tall buildings and buildings around the board yard. Trees, good ventilation; there are fire escapes inside and outside the board yard, and equipped with fire prevention equipment.
The pile of wood should be piled on the pile foundation, and the pile foundation should be improved by 0.4~0.6m. Reinforced concrete, brick, stone or wood paper cups can be used. The main purpose of setting the pile foundation is to have good ventilation to the ground and prevent rainwater from soaking the wood. The top of the pair must also have a roof to cover rain and light.