Patent ID: 6672751
Filing Date: 2004-01-06
Classification: E01C

Abstract:
A counter-flow aggregate dryer for an asphalt plant, said dryer comprising:a rotatable cylinder having first and second ends with an internal passageway communicating therebetween and having first and second zones, with each said zone having first and second ends; a support framework carrying said cylinder in a substantially horizontal orientation; a drive motor mounted on said framework and engaged with said cylinder to rotate said cylinder about the central longitudinal axis thereof a primary aggregate feeder with a material discharge extending within said first end of said cylinder to deliver aggregate material to said first zone of said cylinder whereby rotation of said cylinder transports said aggregate material from said first end of said cylinder, through said first and second zones, to said second end of said cylinder; a burner mounted adjacent said second end of said cylinder to generate a hot gas stream in said second zone of said cylinder to flow toward said first end of said cylinder in a countercurrent direction to the flow of aggregate material within said cylinder in order to heat and dry the aggregate material within said first zone; ductwork adjacent said first end of said cylinder to receive said hot gas stream discharged therefrom; and a secondary burner, including a fuel supply line and a primary combustion air blower, mounted adjacent aid first end of said cylinder in contact with said hot gas stream discharged from the first end of said cylinder to elevate the temperature of said discharged hot gas stream prior to delivery to air pollution control equipment, but apart from said aggregate material to avoid additional heating of said aggregate material.