The purpose of wood drying is to reduce the moisture content in the wood, the moisture content will directly affect whether the wood products will split and deform. The energy consumption of wood drying accounts for about 40%-70% of the total energy consumption of wood product processing. The heat loss during the drying process is very large, and the cost of energy costs is increasing.
Nowadays, the energy-saving and quality problems of wood drying have attracted much attention from the wood industry. After years of research and development, our dryer can effectively remove moisture from wood while ensuring product quality. As an advanced modern drying technology, it can save energy and reduce emissions, Which greatly improves the economic efficiency of enterprises.
What is the fastest way to dry wood for woodworking?
Fresh wood contains a lot of moisture which will continue evaporating in a certain environment. If the water evaporates naturally, wood will shrink, crack, bend, deform and even ferment, which will damage the quality of wood products. Therefore, wood has to be dried on a controllable basis before made into wood products. The correct drying process can overcome the defects mentioned above, and enhance its mechanical strength and processability. Reasonable drying methods to increase the value of wood are an important technical measure and the first and necessary step in the production of wood products.
In the process of wood drying, in addition to the drying method, we must also consider energy saving, environmental protection, and cost reduction. For different wood and wood products for different purposes, the required moisture content in the wood is also different. our wood dryer has the capability of drying varieties of wood such as logs, rosewood, cabinet-wood, etc. It can really solve the problems that customers are faced with in the drying process.
Factors affecting wood drying
- Wood temperature and humidity: During the wood drying process, it is necessary to gradually change the temperature and humidity of the wood drying environment. If the temperature and humidity difference between the wood and the environment is too large, the wood may be damaged during the drying process. The temperature and humidity measuring instrument can be used to monitor the status of the wood in real-time, and then adjust the working status of the heating and dehumidification system in the cabinet by the intelligent control system.
- The moisture content of wood: Different products require different moisture content. So that we adopt the resistance-based moisture meter to prevent limitation and deviation arising from measurement and to provide an effective technology-based guarantee for the accurate performance of the moisture content for wood.
- Drying methods: Different drying methods will also have certain impacts on the finished wood products. For example, conventional natural drying will cause irreversible damage such as shrinkage and bending of the wood. Therefore, choose different drying methods according to different wood and wood uses is also important.
The process of wood drying lumber
The moisture in wood is mainly divided into free water and bound water. The increase or decrease of free water only affects the weight of the wood. However, the change of the bound water can not only cause the wood to shrink and expand, but also affect the physical and mechanical properties. The moisture content in the wood will directly affect whether the wooden product will crack and deform. What needs to be removed during the drying process is all the free water and most of the bound water.
The drying process of wood mainly includes: Preheating stage, drying stage, final equilibrium treatment, cooling treatment.
Low-temperature preheating: Preheating refers to slowly increasing the temperature of the wood to a certain temperature before drying, so that the temperature of the core layer and the surface layer of the wood tends to be consistent. It will provide conditions for the wood to enter the drying stage. The heating speed should not be too fast, it depends on the type, thickness and moisture content of the wood.
Drying stage: The drying stage is divided into uniform drying treatment and deceleration drying treatment. When the wood moisture is above the fiber saturation point, the temperature, humidity and wind speed are under certain conditions, the free water in the wood will move to the surface and evaporate from the surface of the wood. At this time, the evaporation of water is basically carried out at a uniform speed, which is a uniform drying stage. When the free water has evaporated, the bound water starts to move and evaporate. With the continuous decrease of bound water, more and more energy is needed to evaporate water, and the rate of decrease of moisture content will be slowed down. Therefore, when the wood moisture is below the fiber saturation point, it is the decelerating drying stage.
Final equilibrium treatment: When the wood reaches the final moisture content requirement, the wood needs to have a balanced treatment. It can further reduce the moisture content gradient of the wood along the thickness direction so that the stress generated during the drying process of the wood can be eliminated and reduced. The purpose of the balance treatment is to keep the temperature and humidity of the final environment consistent with the moisture content of the final product.
Cooling stage: When the final moisture content of the wood reaches the requirement and after the balance treatment, in order to avoid the damage of the wood caused by the rapid drop in temperature. The wood should finally go through a cooling process at an appropriate speed.
Tips about wood kiln dryer
The wood drying equipment which wants to dry wood on a controllable basis must have three basic functions: Heating, humidity control and ventilation. Heating is the most basic function. Adjustment of humidity is used to provide the high-humidity environment necessary for some phases to prevent the wood from cracking and deforming. The ventilation device must ensure that the wet and hot air goes through the pile of wood evenly so as to make the water in the dried wood well-distributed.
If the temperature is not high, for example, the temperature is below 54°C, moisture can’t be removed from the wood effectively if the moisture content is below 15%. Generally, it needs to raise the drying temperature to 71°C or above.
The drying cabinet shall be thermal-insulation and resistant to air loss. In terms of thermal insulation, the cabinet structure shall have a small thermal capacity to reduce heat loss, which is equal to or less than the mechanical equivalent of heat. No humidifying equipment is installed in the heat pump drying cabinet. If the water vapor overflows, it is definite that the drying condition is hard to change. Therefore, the cabinet shall have good air impermeability.
Keep the airflow in the cabinet stable. It is best if the airspeed is 1m/s.
Common types of wood
Our dryer can not only dry some common wood, including Ash, Oak, Elm, Pine, etc. It can also dry some other products like artificial wood.