Dryings of wood drying kiln
Drying process of wood drying kiln is divided into three phases, respectively, preheat treatment stage, intermediate stage of processing and normal drying stage.Must be strictly implemented in the process of drying drying process, good grasp of the temperature and time to prevent drying is not complete.
1, preheat treatment stage, the purpose is in before you make the wood drying heat through fully, and eliminate may already exist dry stress (produced in the process of air drying).Start the stove fan to the chamber in the heating, at the same time the light inside the boiler furnace chamber and wet (steam injection), temperature of 40 ℃ to 50 ℃, the temperature rises too fast, steam injection (wet), closed when moisture removal.To the chamber humidifying time depending on the wood species and thickness, generally 20 to 30 hours, about 1 to 2 days.Innovation circulation fan once every 4 hours in turning.
2, intermediate processing phase, intermediate processing was conducted in the process of kiln dry wet processing, its purpose is to eliminate the early stage of the generated surface tensile stress, in order to prevent the crack, dry or eliminate middle and late of surface hardening, late to prevent the internal crack.
Platoon is wet was conducted according to the running direction of the stove fan manual, when after the completion of the preheat humidification, stuffy kiln for 24 hours.Temperature is above 55 degrees can be wet, according to the fan to manually open or close the corresponding row of wet flap, platoon is wet time is fan once every 4 hours and the reversing, platoon is wet for 30 minutes.Temperature will gradually increased after the platoon is wet, but not more than 80 degrees.For easy to deformation or cracking of the wood, the platoon is wet and dry appropriate for a small amount of humidifying (steam injection), to eliminate the internal stress of lumber.Drying elm suggest humidifying 4 hours every 48 hours, humidification mouth closed when moisture removal.This operation need about 6 to 7 days.
3, normal drying stage, 9 days later, the temperature of 65 ℃ to 75 ℃, it is forbidden to overtemperature, stop the humidifying (steam injection), reverse circulation fan every 4 hours, moisture removal for 1 hour.Until dry. Takes about 4 to 6 days.
After the end of treatment, braised kiln 4-8 hours of sampling inspection, after passing the decreased slowly drying room temperature, when the temperature dropped to 40 ℃, before the kiln.