The working principle of the rapid drying kiln for coniferous wood
1. Preheating treatment:
First, the control system only opens the steam injection valve, and preheats by steam injection through the evaporation water tank in the kiln. The dry bulb temperature (Td) and the wet bulb temperature (Tw) in the kiln rise synchronously. The rapid 3-hour steam injection makes the drying medium in the kiln reach Td = Tw = 9 0 ℃ or more. Then, depending on the thickness of the dry sheet, keep it for different times to preheat the sheet.
2. Drying stage:
After the preheating treatment is completed, it enters the drying stage. At this time, the control system automatically controls the execution components of the equipment according to the set process benchmark. In order to reduce the surface hardening of the wood, improve the drying quality, prevent the color from deepening, meet the quality requirements of furniture materials, and at the same time dry the radiata pine board quickly when the moisture content is high, in the high moisture content range, higher than conventional drying, low Drying is carried out at high drying temperatures. In addition, because the temperature and humidity during the preheating treatment are relatively high, after the preheating treatment is completed, the temperature is lowered while the temperature difference between the dry and wet bulbs is increased, and the moisture will move from the inside to the outside under the combined action of the temperature gradient and the moisture content gradient. Move for faster drying. When cooling down, turn on the intake and exhaust fans at the top of the drying kiln, and the fans run normally. In this drying stage, the equipment control system is divided into different drying stages according to the set time benchmark. Each drying stage correspondingly increases the drying temperature and widens the temperature difference. The highest stage temperature can reach 105 ℃~110 ℃, which not only ensures The wood quality in the drying process again achieves fast drying.
3. Cooling and final humidity control treatment:
After drying, in order to eliminate the residual stress in the board and ensure the drying quality, the board should be sprayed and steamed to adjust the humidity. In the steam spraying and humidity control treatment, the temperature is first lowered, and when the temperature drops below 100°C, the steam spraying treatment is performed. In addition, during the cooling process, the moisture content of the sheet will be further reduced under the action of the temperature gradient. Turn on the intake and exhaust fans when cooling down, and the fans run normally. After the cooling is completed, the steaming treatment time is maintained for different times according to the thickness of the plate, and finally the final humidity adjustment treatment is carried out.
Our main products cover Conventional Wood Drying Kilns,Track Type Veneer Drying Kilns,Heat Pump Drying Kilns,food drying chambers and so on.If you are interested, welcome to contact me.
