Evaporation of moisture from the wood surface always takes place at a certain temperature, humidity and air velocity. Under normal circumstances, the humidity of the air in the drying kiln is always less than 100%, while the temperature of the air is much higher than normal temperature. Therefore, the equilibrium moisture content of the air is lower than that of the wood surface, and the moisture on the wood surface evaporates into the air. How quickly water evaporates from the wood surface depends on the temperature and humidity of the air. When the air temperature rises or the humidity decreases, the evaporation rate of water on the wood surface is accelerated; on the contrary, the lower the air temperature, the greater the humidity, and the slower the evaporation rate of surface water.

What are the basic concepts of wood drying, do you know?

Wood drying refers to the process of using external energy to convert water in wood into steam and expel it. The drying of wood can be divided into two categories: natural drying and artificial drying.

Internal stress, also known as internal force, is caused by uneven drying shrinkage. For example, when the surface of wood has started to dry and shrink, and the interior of the wood is still moist, the surface may dry and shrink while the interior does not, resulting in internal stress. When a straight and dry wooden board is sawed into a thin plate, it should immediately experience a phenomenon of warping, which is a manifestation of internal stress in wood. If a sawn wooden board has a convex surface facing inward, it indicates external tension and internal pressure.

As a heat exchange device that can continuously output heat, boilers are used in almost all fields of production. They not only have high efficiency but also greatly reduce the labor cost of enterprises. So, what are the selection methods for steam boilers used for drying wood? What is the special type of dry boiler? Let's learn about Zhongzheng Boiler together.

By usage environment According to the usage environment, it is divided into outdoor grade carbonized wood and indoor grade carbonized wood.

The mature heat treatment processes abroad mainly include Thermo Wood from Finland, Plato Wood from the Netherlands, and Correction from France.

Chemical modification of wood: Chemical reactants react with hydroxyl groups in the wood cell wall polymer, leading to the formation of covalent bonds between the reactants and the wood matrix Wood thermal modification: Heating wood leads to a certain degree of degradation of its components, resulting in the desired improvement in wood properties Wood surface modification: Chemical, physical, or biological (enzyme) reagents are applied to the wood surface to achieve the desired performance improvement.

For a person engaged in wood drying production, it is best to have diligent eyes, ears, legs, mind, mouth, and learning.

In the drying room of the automatic system, the operator needs to input various parameters into the control system according to the drying benchmark conditions, and then start the operating device to make each actuator work and control according to the set values. The operator's job during duty is to record in detail the temperature of the drying medium and the specific values of the electromagnetic field. The automatic operating system has relatively low labor intensity for operators, but operators must have basic knowledge of wood drying production technology, be familiar with and master the specific performance of drying equipment. Otherwise, if problems occur during the wood drying process, they will be helpless, leading to drying defects in the wood and affecting the drying quality.