Drying wood

Drytech drying machine use for drying wood

Fresh wood contains a lot of moisture which will continue evaporating in a certain environment. If 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. It is an important technology-based measure to make reasonable use of wood and to add its values and a e primary and necessary procedure to produce wood products.
Energy consumption of drying wood accounts for 40-70% of the total of producing the wood products. The drying process wastes heat too much with the energy consumption of 30%. The energy cost in the drying process occupies more than 50% of the total drying cost. As imbalance between supply and demand of energy is increasing and the environmental problem caused by the atmospheric greenhouse effect is more and more severer, the wooden industry pays greater attention to the energy-saving wood-drying process. In the past twenty years, many drying technologies have been developed. Among them, the heat pump drying process has posted a better performance in saving energy. DRYTECH wood dryer has the capability of drying varieties of wood such as logs, rosewood and cabinet-wood, and really solves the problems customer are faced with in the drying process.
Factors influencing the wood drying
Wood temperature: Measure and control the dry-bulb temperature to adjust the working status of the heating system so as to control the temperature in the cabinet.
Wood humanity: Measure the difference between dry-bulb temperature and wet-bulb temperature to adjust the dehumidification amount and the working status of the spraying system to automatically control the humanity in the cabinet.
Moisture content of wood: Adopt the resistance-based moisture meter to prevent limitation and deviation arising from measurement and to provide effective technology-based guarantee for accurate performance of the moisture content baseline for wood.

How to dry wood with DRYTECH dryer
The wood drying equipment which wants to dry wood on a controllable basis must have the three basic functions: heating, adjustment of humanity and ventilation. Heating speaks for itself. Adjustment of humanity is used to provide the high-humanity environment necessary for some phases to prevent 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.
In the early drying process, the performance coefficient (COP) of the heat pump unit is high due to high relative humanity of the wood to be dried. As the drying process goes on, the COP will decline due to decrease of the relative humanity, resulting in lower performance of the unite on a negative basis.
If the temperature is not high, for example, the low-temperature heat pump is below 54°C, moisture can’t be removed from the wood in case the moisture content is below 15%. Generally, it is necessary 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 the 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 air flow in the cabinet stable. It is the best if the air speed is 1m/s.