What is the process flow of a tunnel oven? Tunnel ovens are known for their large loading capacity and simple operation. Their large loading capacity suggests that their operating principles must be different to achieve such high throughput.
Today, I'll explain the working principles of the tunnel drying oven: After being loaded onto trays, the materials, along with the trays and carts, enter the tunnel drying oven's entrance. A transmission mechanism brings them into the tunnel, and the cart's speed is adjustable.
Cold air enters the centrifugal fan from the fresh air inlet. After being heated by a finned heat exchanger, it is then sent into the tunnel oven, where it fully contacts the wet materials and exchanges heat. The moisture in the materials is evaporated into water vapor, which then enters the air ducts on the sides of the oven along with the hot air. Some of the wet air is exhausted through the dehumidification outlet, while the rest is drawn in by the centrifugal fan and recycled.
Due to the different moisture content of the materials in each drying unit, the ratio of dehumidification volume to circulating air volume varies from unit to unit. The hot air temperature also varies throughout the drying process. In the early stages of drying, when the moisture content of the materials is higher, a higher hot air temperature can be used; in the later stages of drying, when the moisture content is lower, a lower hot air temperature can be used.