A vacuum dryer is a method of drying wood by stacking it in a closed container and drying it under conditions below atmospheric pressure. Under vacuum conditions, the boiling point of water decreases and the evaporation rate increases, thereby accelerating the drying rate of wood at lower temperatures. During the drying process of wood, on the one hand, surface moisture evaporates into the surrounding air; On the other hand, the internal moisture continuously moves towards the surface. So we need to accelerate the drying speed and try to speed up the movement of moisture inside the wood. In addition, under vacuum conditions, the boiling point of water decreases, causing the evaporation rate of water inside the wood to accelerate, and the moisture content gradient on the wood surface to increase, preventing severe evaporation of water on the wood surface and cracking of the wood surface. While the moisture on the surface of wood evaporates violently, it also absorbs a large amount of vaporization heat, causing the wood surface to cool. These factors all accelerate the movement of moisture inside the wood towards the surface. Under vacuum conditions, the air inside the drying device cannot be heated using the usual methods. To solve the heating problem of wood during vacuum drying, continuous heating is used to vacuum dry. Vacuum drying can eliminate the surface hardening and cracking phenomenon that is prone to occur under atmospheric pressure drying. The pressure difference between the interior and surface of vacuum dried wood is large, and under the pressure gradient, water quickly moves to the surface. At the same time, it can improve the drying rate, shorten the drying time, and reduce equipment operating costs. In addition, under low pressure conditions, the oxygen in the drying medium causes less discoloration of the material due to thermal and oxidative effects, and can basically maintain the natural color of the material.
Therefore, vacuum drying equipment is a fast drying equipment. It is also an environmentally friendly drying equipment.
1, The wood vacuum dryer adopts continuous heating to quickly heat up the wood and achieve fast drying time. 2, Automatic drainage, automatic heating of wood both inside and outside, uniform heating, good quality, and able to maintain the natural color of the wood. 3, Vacuum negative pressure water absorption reduces the temperature of the wood drying process, causing the wood to vaporize at low temperatures, making it less prone to cracking, and improving the dehydration rate of the wood. 4, Environmentally friendly and non polluting. 5, Vacuum drying has many characteristics such as sterilization, insect killing, and environmental protection, which can shorten the drying cycle and further ensure the quality of wood drying. Especially suitable for drying thick, hard, large section wood or square wood (conventional drying methods require a long time), precious wood such as rosewood, chicken wing wood, yellow pear, rosewood, etc. At the same time, secondary drying of small batches and expedited wood after moisture regain is also used.