there are two types of drying heat source for veneer dryer, thermal oil furnace or hot air furnace.
For example, the 1.7-2.2mm veneer core that is dried by rotary cutting technology ,the oil temperature of the thermal oil furnace can usually reach 200°C to 280°C. The hot air that is then exchanged through the heat exchange can usually reach 140°C-180°C. By contrast, hot air furnaces can usually exchange heat above 200°C-240°C. Judging from the drying temperature alone, hot air furnaces is better. However, if the temperature is too high, it is easy to have internal cracks which make great damage to the veneer. Moreover, hot air furnace has high shrinkage rate.
Thermal oil furnaces have strict implementation standards. There is no uniform standard for the manufacturing process of hot air furnaces so the quality of it is uneven which means high after-sales maintenance costs. Moreover, the hot air oil furnace is far less stable than the thermal oil furnace, so more care is required .
Which is better to heat up in wood drying equipment, the thermal oil furnace or a boiler furnace?
In the process of rotary cutting and slicing, if the wood needs to be steamed, mostly use a steam boilers. In the process of heating up water through steam and boiling wood, the speed of heating up and boiling process faster. If by means of thermal oil furnace, the secondary heat exchange process is required.
If the wood doesn’t need to be steamed in the process of drying through hot air, the oil temperature is high. If exchange to hot air by heat exchange, the oil temperature is higher in terms of drying cost, the thermal oil furnace costs lower per unit of drying than steam boilers.