Abstract:
A method for producing asphalt using a high percentage of RAP (recycled asphalt pavement) in the total aggregate raw material. A counterflow rotary drum dryer is used to dry the raw material. The extent of the burner flame in the dryer is limited such that the RAP does not come into direct contact with the flame. The hot gases leaving the dryer pass to a wet scrubber.
Abstract:
A portable paving material mixing apparatus includes a material hopper, a rotatable mixing drum, and a discharge bed, all configured to be supported on a vehicle trailer. A burner heats material within the mixing drum. Embodiments of the mixing apparatus include a rejuvenator application system suitable for hot mix asphalt, cold mix asphalt, hot in-place recycling, and asphalt based concrete mixing. The apparatus rapidly processes a batch of material sufficient to fill 5-7 potholes, has sufficient carrying capacity to process multiple mixer batches, and stores prepared material in the discharge bed while the next batch is being prepared in the mixing drum. The apparatus enables a more efficient, less equipment-intensive paving repair process without the need for a separate millings loader or hot box.
Abstract:
A method of making hot mix asphalt using recycled asphalt in which tertiary air is mixed with products of combustion at an exit of a refractory-lined chamber to produce hot controlled temperature process air, the temperature of the tertiary air being increased while the temperature of the products of combustion is decreased to adjust a temperature of the hot controlled temperature process air. Particles of the recycled asphalt are heated by exposing the particles to the hot controlled temperature process air in the rotary counter-flow dryer and mixer and moisture is removed from the recycled asphalt with the hot controlled temperature process air.