Patent ID: 8231262

Claim:
In an indirectly heated asphalt product heater wherein asphalt product is moved longitudinally along the interior of a drum from one to another of longitudinally opposite first and second ends of the drum, the drum having a drum wall, and heated gases are conducted, through heat exchange members, from a source of heated gases to an exhaust, each located respectively adjacent a corresponding end of the drum, the heat exchange members extending longitudinally along the interior of the drum between the opposite ends of the drum for isolating the heated gases from the interior of the drum, and consequently from the asphalt product in the drum, while providing heat to the asphalt product within the drum, the improvement wherein the heat exchange members comprise: a conduit for conducting heated gases from the source of heated gases toward the exhaust, the conduit having an inlet communicating with the source of heated gases and an outlet communicating with the exhaust, the conduit following a looped path and having longitudinally extending segments arranged consecutively in a serpentine configuration along the looped path, each segment having a longitudinal length extending from adjacent the first end of the drum to adjacent the second end of the drum and being subjected to thermal expansion and contraction in longitudinal directions in response to heating and cooling of the conduit resulting from conducting the heated gases along the looped path to provide heat along the interior of the drum; an inlet coupler coupling the inlet with the source of heated gases for longitudinal movement of the inlet relative to the drum along an inlet site adjacent the source of heated gases; and an outlet connector connecting the outlet to the drum for affixing the outlet against longitudinal movement relative to the drum at an outlet site adjacent one of the first and second ends of the drum; the conduit being dimensioned, configured and oriented for enabling longitudinal expansion and contraction of the conduit along the longitudinal length of each segment in response to heating and cooling of the conduit, while the outlet remains essentially stationary at the outlet site and any differential longitudinal expansion and contraction between the consecutively arranged segments is accommodated through movement of the inlet in the longitudinal directions.