To improve the heating quality and efficiency of reclaimed asphalt pavement (RAP)

reduce the installed power of microwave heating

and promote the application of ultra-high power microwave in hot recycling equipment

a microwave-hot air mixed heating method was proposed. Finite element analysis of microwave

hot air and microwave-low temperature hot air mixed heating demonstrated the advantages of microwave-low temperature hot air mixed heating over separate heating. The microwave-hot air hybrid heating process was analyzed

the multi-feeder microwave-hot air mixed heating chamber and antenna were designed

and the mixed heating finite element model was constructed on this basis. Factors affecting the mixing heating effect were simulated and analyzed

such as different heating heights

hot air temperatures

and hot air velocities. The heating effects of RAP in microwave heating

hot air heating and microwave-hot air mixed heating were compared and analyzed. The results show that the heating height of RAP can cause microwave interference in the mixed heating chamber and significantly affect the heating effect. Excessively high air temperature can lead to rapid surface scorching and aging of RAP. At heating distance of 50 mm and 100 mm

hybrid heating outperforms microwave or hot air heating alone

with efficiency improvements of 9.32% and 11.75%

respectively

compared to microwave heating

and surface heating efficiency enhancements of 124.7% and 92.9%

and underside heating efficiency improvements of 38.8% and 34.8%

respectively

compared to hot air heating. Additionally

uniformity is improved to varying degrees. This indicates that microwave-hot air mixed heating can significantly improve the heating efficiency of RAP

addressing the problems of low heating efficiency and poor uniformity of microwave heating alone. By combining the strengths of both methods

this approach ensures the heating quality of RAP

and provides a new method for the regeneration heating of RAP.