METHOD AND APPARATUS FOR REJUVENATING AND RECYCLING ASPHALT

摘要

A process for rejuvenating and recycling used asphalt and a machine including a pugmill mixing chamber for mixing crushed asphalt supplied thereto and for mixing water, calcium oxide and asphalt oil therewith is disclosed. The water and calcium oxide mixture react and chemically combine to form a calcium hydroxide filler material to thus fill the voids and gaps in the rejuvenated asphalt that would otherwise exist. The reaction, being exothermic, increase the temperature of the resultant asphalt based mixture to a level suitable for spreading of the rejuvenated material on a prepared surface. The asphalt oil is preferably preheated using a heat exchanger coil connected to a diesel engine radiator, which coil is immersed in an asphalt oil storage tank carried on the machine so that the viscosity of the oil may be reduced to a reasonable value suitable for pumping to the mixing chamber and spraying on the materials contained therein. A storage bin for storing granulated calcium oxide is positioned above the pugmill mixing chamber and contains an elongated opening in the bottom surface thereof which allows the bin to communicate with the chamber. A cylindrically-shaped rotatable metering device is positioned at the bottom of the bin over the opening and contains a series of elongated axially extending slots radially displaced around the metering device so that the slots carry a measured quantity of calcium oxide from the bin into the chamber through the opening as the device is rotated, the speed of rotation of the device thus determining the rate at which material from the bin is introduced into the chamber.