Asphalt production plant with pre-dryer assist

1. A method for making asphalt concrete, said method comprising:

(a) providing an assembly that includes

(i) a direct dryer for heating virgin aggregate material, said direct dryer being adapted to generate warm exhaust gas while heating said virgin aggregate material;

(ii) a pre-dryer for heating recycled asphalt product and/or recycled asphalt shingles, said pre-dryer using the warm exhaust gas from said direct dryer to heat the recycled asphalt product and/or recycled asphalt shingles; and

(iii) means for conveying the warm exhaust gas from said direct dryer to said pre-dryer;

(b) heating the virgin aggregate material in said direct dryer;

(c) conveying the warm exhaust gas from said direct dryer to said pre-dryer;

(d) heating the recycled asphalt products and/or recycled asphalt shingles in said pre-dryer by indirect contact with the warm exhaust gas; and

(e) mixing the heated virgin aggregate material and the heated recycled asphalt products and/or recycled asphalt shingles.

2. The method of claim 1 wherein the heated virgin aggregate material and the heated recycled asphalt products and/or recycled asphalt shingles are mixed with an additional amount of asphalt cement.

3. The method of claim 1 wherein recycled asphalt fines are mixed with the recycled asphalt products and/or recycled asphalt shingles.

4. The method of claim 1 which includes:

(a) providing an assembly wherein the direct dryer comprises a fixed outer drum and a rotating inner drum;

(b) providing an assembly that includes a controller that is adapted to:

(i) operate the direct dryer by rotating the inner drum of the direct dryer at a base level of approximately 8 rotations per minute;

(ii) reduce the rotational speed of the inner drum when the temperature of the warm exhaust gas generated by the direct dryer falls below a predetermined minimum temperature;

(iii) increase the rotational speed of the inner drum when the temperature of the warm exhaust gas generated by the direct dryer rises above a predetermined maximum temperature.

5. The method of claim 1 which includes:

(a) providing an assembly wherein the direct dryer includes a direct dryer burner;

(b) providing an assembly that includes a controller which is adapted to:

(i) increase the amount of excess air in the direct dryer burner when the temperature of the warm exhaust gas generated by the direct dryer falls below a predetermined minimum temperature;

(ii) decrease the amount of excess air in the direct dryer burner when the temperature of the warm exhaust gas generated by the direct dryer rises above a predetermined maximum temperature.