Abstract: A liquid asphalt heating and mixing system having a double helix heat exchanger positioned within a liquid asphalt storage vessel and being connected to a fluid heater and circulator to feed hot oil through said heat exchanger for heating liquid asphalt within the storage vessel. An eductor mixer is centrally aligned longitudinally with the heat exchanger with an intake end positioned interiorly of the heat exchanger and a discharge end directed away from the heat exchanger. A liquid asphalt pump is connected to the eductor mixer and to the storage vessel to pump liquid asphalt from the storage vessel, through the eductor mixer and back to the storage vessel.

Abstract: A drum mixer is provided with a rotatable cylinder in which aggregates, reclaimed asphalt pavement and liquid asphalt are mixed to produce an asphaltic composition. The drum cylinder includes a first region, in which virgin aggregate is heated and dried by heat radiation and the stream of hot gases produced by a burner flame flowing in countercurrent flow to the aggregate itself to establish a highly beneficial heat transfer relationship. A second region doubles as combustion and mixing zones. In the mixing zone the reclaimed asphalt pavement and liquid asphalt is added and mixed with the aggregates. The combustion zone is formed along the center of the mixing zone by an elongated combustion assembly disposed along the central axis thereof. The combustion assembly and chamber extend from the discharge end of the drum through the mixing zone to the heating and drying zone to segregate the hot gases from the asphalt, thereby preventing degradation of the final product.