Patent ID: 7566162

Claim:
A method for producing hot mix asphalt using a high percentage of RAP, said method comprising: (a) providing a hot mix asphalt plant adapted to produce hot mix asphalt using a high percentage of RAP, said plant comprising: (1) a first dryer adapted to receive and mix virgin aggregates and RAP fines, said first dryer having an inner drum, a fixed outer sleeve and a mixing chamber defined therebetween; (2) a first burner assembly adapted to produce a first burner flame and a hot gas stream, said first burner flame and hot gas stream being adapted to heat and dry the virgin aggregates in the first dryer; (3) a second dryer adapted to receive coarse RAP; (4) a second burner assembly adapted to produce a second burner flame and heat and dry the coarse RAP in the second dryer; wherein the virgin aggregates are received in the inner drum, the RAP fines are received in the fixed outer sleeve such that they are not directly exposed to the hot gas stream produced by the first burner assembly, and the virgin aggregates and RAP fines are mixed in the mixing chamber; (b) conveying the virgin aggregates to the first dryer; (c) heating and drying the virgin aggregates in the first dryer; (d) conveying the RAP fines to the first dryer; (e) mixing the virgin aggregates and the RAP fines in the first dryer; (f) conveying the coarse RAP to the second dryer; (g) heating and drying the coarse RAP in the second dryer; (h) mixing the coarse RAP, the RAP fines and the virgin aggregates to produce hot mix asphalt.