Asphalt mixture prepn. - by drying additives in inner heated drum and blending with bitumen and fillers in outer drum in which mixture is degassed

摘要

Asphalt mixt., composed of additives, fillers and bitumastic bonding agents, is pred. in a heated rotary drum composed of two oppositely directed, co-axial, frusto-conical sections which diverge in the feed direction. The additives are dried in the inner drum, and heated in contra-flow. The dried additives are then discharged into the uter drum which is heated indirectly to maintain the temp. prevailing in the inner drum. Additives entering the outer drum are intermixed with the bonding agents during their joint movement towards the discharge opening and at the same time the mixt. is degassed. Mixt. can be prepared continuously or in batches at desired locations are required periods.