초록 ▼

An improved method and apparatus for producing hot mix asphalt wherein flights provided in a mixer drum for cascading aggregate and asphalt across the mixer drum are constructed to establish a plurality of cascade zones, having differing cascade densities, in different portions of the mixer drum. Hi

An improved method and apparatus for producing hot mix asphalt wherein flights provided in a mixer drum for cascading aggregate and asphalt across the mixer drum are constructed to establish a plurality of cascade zones, having differing cascade densities, in different portions of the mixer drum. High density cascade zones are provided to maximize the transfer of heat to aggregate; to shield cooler portions of the drum from hotter portions thereof, and to capture fines which would otherwise pass through the drum.

대표청구항 ▼

In a method of heating and drying aggregate using a rotating drum having the input end thereof higher than the output end thereof, comprising the steps of: (a) producing a flame in the drum extending from the input end thereof toward the discharge end thereof; (b) introducing the aggregate radially

In a method of heating and drying aggregate using a rotating drum having the input end thereof higher than the output end thereof, comprising the steps of: (a) producing a flame in the drum extending from the input end thereof toward the discharge end thereof; (b) introducing the aggregate radially into the input end of the drum around the flame; (c) repeatedly cascading the aggregate through and around a medial portion of the flame as the aggregate gravitates toward the discharge end of the drum; and then (d) repeatedly cascading the aggregate through and around the remaining, terminal portion of the flame entirely across the drum in a higher density of aggregate across the drum than in step (c) as the aggregate continues to gravitate toward the discharge end of the drum. In a method of making hot mix asphalt using a rotating drum having the input end thereof higher than the output end thereof, comprising the steps of: (a) producing a flame in the drum extending from the input end thereof to a medial portion of the length of the drum; (b) introducing aggregate radially into the input end of the drum around the flame; (c) repeatedly cascading the aggregate through and around a medial portion of the flame as the aggregate gravitates toward the discharge end of the drum; (d) repeatedly cascading the aggregate through and around the remaining, terminal portion of the flame entirely across the drum in a higher density of aggregate across the drum than in step (c) as the aggregate continues to gravitate toward the discharge end of the drum; (e) injecting asphaltic oil into the drum between the flame and the discharge end of the drum; (f) mixing the aggregate and asphaltic oil in the remaining portion of the drum as the aggregate continues to gravitate toward the discharge end of the drum to form the hot mix asphalt; and (g) discharging the hot mix asphalt from the discharge end of the drum.