The working principle of the three return rotary dryer is mainly through three return cycle operation, the use of hot air and humidity induction technology to efficiently dehydrate and dry the materials. Here's the explanation:
1.‌ First return (heating stage):
After the wet material enters the three return rotary dryer, it comes into contact with the inner wall of the drum at high temperature and begins to lose water.
The high temperature on the inner wall of the drum heats the material to a higher temperature, evaporates the water in the material, and prepares for the subsequent drying process
2.‌ Second leg (intensive de-watering stage):
The rotation speed of the drum is properly reduced, the residence time of the material in the drum is extended, and the contact chance between the material and the inner wall of the high-temperature drum is increased.
Increase the air volume of the fan, provide enough hot air to quickly evaporate and take away the water in the material, strengthen the dehydration effect of the material ‌.
In this return trip, the rotary dryer usually sets up an exhaust heat exchange to recover the heat energy in the wet air, which is used to reheat the fresh hot air, and realize the recycling of heat energy.
3.‌ Third return (cooling and collection stage):
The rotation speed of the drum is increased again, and the residence time of the material in the drum is shortened.
The air volume of the fan is reduced to provide cold air to cool the material to avoid deterioration or damage caused by overheating of the material.
After this stage of treatment, the moisture of the material has been reduced to a low level to meet the needs of production or use.
In addition, the three return rotary dryer also uses humidity sensor to check the material humidity, automatically adjust the drying time and temperature, to ensure that the material in a short time to achieve the ideal drying state ‌. Its structure consists of spring plate, roller ring, bearing with seat, motor, gearbox and other key components, these components cooperate to realize the drying process of materials.
In general, the three-return rotary dryer achieves efficient dehydration and drying of materials by recycling heat and wet air, as well as three-return cycle operation and humidity sensing technology.