RAP Heating System

The RAP Heating System is a critical component of the Recycled Asphalt Pavement (RAP) System, specifically designed to preheat reclaimed asphalt pavement material. Its primary role is to elevate the temperature of the cold, aged RAP material to a specified range (typically 120-150°C) before it enters the mixing chamber with virgin aggregates and bitumen. This process reduces the viscosity of the aged binder in the RAP, improves its workability, ensures proper coating with new bitumen, and is essential for achieving a homogeneous, high-quality recycled asphalt mix. The system directly impacts the efficiency of the recycling process and the final performance of the hot mix asphalt.

The system typically employs indirect heating methods, such as a rotary drum with an external burner or a dedicated parallel-flow heating drum, to avoid direct flame contact with the RAP material, which can cause excessive smoke and degradation of the aged binder. Heated air or hot gases are circulated around the RAP as it is conveyed through the drum, transferring thermal energy to raise its temperature uniformly. Temperature sensors and control systems regulate the heat input to achieve the target discharge temperature.

Typical parameters for such systems include a heating capacity of 1000–5000 kW, an operating temperature range of 120–180°C, and a temperature control accuracy of ±5°C. Fuel consumption may range from 10–50 kg/h depending on fuel type and capacity, while thermal efficiency is typically 85–92%. Electrical power for fans, pumps, and controls is 30–150 kW, with a supply voltage of 380–690 V AC (three-phase, 50/60 Hz) per IEC 60038. Operating pressure is 1.0–1.6 MPa, and noise level at 1 m distance is 75–85 dB(A) per ISO 3744. Ingress protection is IP54–IP65 per IEC 60529. Materials of construction include carbon steel (Q235B) or stainless steel (304) per GB/T 700. Weight ranges from 5000–20000 kg, and footprint from 20–80 m².

These values are directory reference ranges and must be confirmed with the legal manufacturer or supplier for the specific model and application. Standards listed are procurement references, not proof of certification or compliance.

The system typically employs indirect heating methods, such as a rotary drum with an external burner or a dedicated parallel-flow heating drum, to avoid direct flame contact with the RAP material, which can cause excessive smoke and degradation of the aged binder. Heated air or hot gases are circulated around the RAP as it is conveyed through the drum, transferring thermal energy to raise its temperature uniformly. Temperature sensors and control systems regulate the heat input to achieve the target discharge temperature.