Efficient Air Circulation and Drying in Industrial Drying Ovens: A Comprehensive Guide

Analysis of Air Circulation Method in Industrial Drying Ovens

The air circulation system of the industrial drying oven adopts a fan-driven circulation method, ensuring even and efficient airflow. The airflow is driven by a circulation motor (with a contactless switch), which powers the fan wheel to blow heated air through the heater. This hot air is then directed through ducts into the oven chamber. The used air is sucked back into the ducts, where it becomes the air source for the next cycle of heating, ensuring the uniformity of the internal temperature. Hot air industrial drying ovens are suitable for baking items that emit chemical gases, food processing, ink curing, paint film drying, and more. They are widely used in industries such as electronics, electrical machinery, communications, electroplating, plastics, hardware, chemicals, instrumentation, printing, pharmaceuticals, PC boards, powder coatings, impregnation, spraying, glass, wood products, and building materials for precision baking, drying, tempering, preheating, shaping, and processing. The internal heat circulation ensures uniform heating of the items being baked.

Industrial drying ovens utilize the principle of sublimation for drying. The material to be dried is rapidly frozen at low temperatures, then, under appropriate vacuum conditions, the frozen water molecules directly sublimate into water vapor and are released. The product dried using a freeze-drying machine is called freeze-dried material, and this drying process is known as freeze-drying. The material remains in a frozen state before drying, and the ice crystals are uniformly distributed within the material. The sublimation process avoids concentration effects caused by dehydration, preventing side effects such as foam generation or oxidation due to water vapor. The dried material has a spongy, porous structure, its volume remains virtually unchanged, and it easily dissolves in water to return to its original state. This process largely prevents the material from undergoing any physical, chemical, or biological degradation.

There are two main air circulation methods in industrial drying ovens: horizontal airflow and vertical airflow.

Horizontal Airflow: This method is suitable for items that are placed on trays for baking. In horizontal airflow, the hot air is blown from both sides of the chamber, allowing the items on the trays to be evenly bathed in hot air, resulting in excellent baking effects. In contrast, placing items on trays and using vertical airflow is not ideal. Vertical airflow, where the hot air is blown from above, can block the flow of heat, preventing it from reaching the lower layers of items, leading to poor baking results.

Vertical Airflow: This method is suitable for items placed on racks. Vertical airflow blows hot air downward. Due to the open structure of the rack, the airflow can circulate freely, ensuring that the hot air evenly bathes the items, leading to better baking effects.

The service life of industrial drying ovens and other equipment is directly proportional to the care and maintenance provided by users. Proper maintenance and care can extend the life of the equipment, reducing the need for repairs and saving costs. High-temperature industrial drying ovens also require careful maintenance. Routine upkeep is necessary not only to save costs but also to avoid unnecessary expenses.

Industrial drying ovens utilize a method where materials are continuously fed into the top of the machine through a circular feeder. The material first reaches the inner surface of the small heating plate at the top layer. With the mechanical action of rotating blades, the material is stirred and moved from the inside to the outside, gradually covering the entire surface of the plate and undergoing contact heating and drying. The material then falls from the outer edge to the second layer of the larger heating plate, where it is moved in the opposite direction by the blades and gradually moves from the outer to the inner part, eventually landing on the third layer of small heating plates. This process repeats as the material moves through the layers, receiving continuous heating and drying in the industrial drying oven.