Rotary Heat Exchanger, also known as Thermal Wheel or Rotary Heat Exchanger, is an efficient heat transfer device widely used in industrial and construction fields, especially in ventilation systems and drying processes. It transfers heat energy from one airflow to another through a rotating wheel, with high heat recovery efficiency.
working principle:
A rotary heat exchanger consists of a circular wheel, typically made of metal (such as aluminum) or composite material, with numerous small channels or honeycomb structures inside. The wheel rotates slowly under the action of the driving device and is divided into two areas:
High temperature side: When high-temperature exhaust gas passes through the impeller, the heat is absorbed and stored by the impeller material.
Low temperature side: When the wheel rotates to the low-temperature fresh air side, the stored heat is released to the cold air, causing it to heat up.
This continuous rotation process achieves heat transfer while maintaining the separation of the two airflows, avoiding direct mixing.
Features and advantages:
Efficient heat recovery: The heat recovery efficiency can usually reach 70% -90%, far higher than many static heat exchangers.
Bidirectional function: Not only can it transfer sensible heat (temperature), but in some designs it can also transfer latent heat (humidity), if the surface of the wheel is coated with moisture absorbing material.
Strong adaptability: Suitable for scenarios with high air volume and high temperature difference, such as industrial drying, HVAC systems (heating, ventilation, and air conditioning).
Energy saving and environmental protection: By recovering heat from exhaust gas, energy consumption and carbon emissions are significantly reduced.
Application in drying process:
In drying systems, rotary heat exchangers are commonly used to recover heat from exhaust gases. For example:
Industrial drying (such as wood and textiles): When high-temperature and humid air is discharged, the impeller absorbs heat and transfers it to the incoming cold air, reducing the energy consumption of the heater.
Food processing: When drying grains or fruits and vegetables, a rotary heat exchanger can maintain a stable temperature while reducing operating costs.