Abstract: Asphalt mix product is produced for delivery at a desired temperature and is comprised of a mixture of recycled asphalt product and virgin material in a specified, selected proportion of recycled asphalt product to virgin material. Recycled asphalt product is heated in an indirectly heated recycled asphalt product heater to an elevated temperature. Virgin material is heated, either in the same recycled asphalt product heater or in a separate virgin material heater, to a maximum temperature not exceeding a prescribed temperature above which damage to that heater will occur. The heated recycled asphalt product is mixed with the heated virgin material in the selected proportion of recycled asphalt product to virgin material to prepare the asphalt mix product for delivery at the desired temperature.

Abstract: Recycled asphalt product is heated within an indirectly heated recycled asphalt product heater by passing heated gases through heat exchange members within a drum while the recycled asphalt product is moved through the drum from one end to the other end of the drum. The heat exchange members provide conduits for the heated gases, the conduits extending from an inlet adjacent a source of heated gases to an outlet communicating with an exhaust, each conduit following a looped path and having two or more segments each with a longitudinal length extending from adjacent one end of the drum to adjacent the other end of the drum. The segments are arranged serially in a serpentine configuration, are generally parallel to one another, and are spaced apart radially within the interior of the drum.

Abstract: An improvement is provided for controlling the temperature of recycled asphalt product being processed in an indirectly heated recycled asphalt product heater, and the temperature of component parts of the heater itself, as the recycled asphalt product progresses through the heater and is heated by heat transferred from gases at an elevated temperature passed through the heater. Temperature sensors are placed at strategic locations within the heater and provide temperature information to a central processor arranged to receive information pertaining to temperature from the temperature sensors and to process the information and generate control signals. A controller arrangement controls the temperature of the heated gases entering a heat exchange arrangement within the heater in response to the control signals such that the temperature of the recycled asphalt product and the temperature of component parts of the heater are maintained within a desired predetermined range of temperature.