Patent ID: 7669792

Claim:
An improvement in an indirectly heated recycled asphalt product heater wherein recycled asphalt product is introduced into a drum extending between a first end and a second end, and is heated by heat transferred from gases at an elevated temperature passed from a source of heated gases through a heat exchange arrangement, from an inlet location adjacent the first end of the drum to an exhaust location, the heat exchange arrangement including tubular heat exchange members extending between the first and second ends of the drum, the tubular heat exchange members being heated internally by the heated gases and contacted externally by the recycled asphalt product, the recycled asphalt product entering the drum at an entrance location and being discharged at a discharge location, the improvement comprising: a temperature control system for controlling the temperature of the recycled asphalt product, and the temperature of component parts of the heater, as the recycled asphalt product progresses through and is heated by the heater, the temperature control system including: a first temperature sensor placed at a first location adjacent the inlet location for sensing temperature pertaining to the temperature of the heat exchange arrangement and the heated gases at the inlet location; a second temperature sensor placed at one of a second location adjacent the exhaust location for sensing temperature pertaining to the temperature of the gases at the exhaust location, and a third location adjacent the discharge location for sensing temperature pertaining to the temperature of the heated recycled asphalt product at the discharge location; a central processor for receiving information pertaining to temperature from each of the first and second temperature sensors and processing the information to generate a control signal; and a controller arrangement for controlling the temperature of the heated gases entering the heat exchange arrangement at the inlet location in response to the control signal such that the temperature at the first location and the temperature at the one of the second and third locations are maintained within a desired predetermined range of temperature.