Patent ID: 6390810
Filing Date: 2002-05-21
Classification: F27B,F27D

Abstract:
A rotary hearth furnace for reducing a feed material comprising:a rotating hearth disposed in an enclosure and mounted for rotary movement, the enclosure including an annular inner wall, an annular outer wall and a roof, the enclosure operatively sealed to the hearth and divided into a plurality of zones including at least a loading zone, an preheat zone, a process zone and a discharge zone, the process zone further divided into three sequential quadrants (1, 2, and 3), each quadrant having an entry area and an exit area; said preheat zone operating in a temperature range of from 1800 degrees Fahrenheit to 2200 degrees Fahrenheit, said process zone operating in a temperature range of from 2300 degrees Fahrenheit to 2600 degrees Fahrenheit, a plurality of burners positioned in at least the outer wall or the inner wall of the enclosure to provide a controlled temperature within the rotary hearth furnace; and a flue for the furnace enclosure to exhaust combustion gases from the rotary hearth furnace, the flue positioned between the exit area of the preheat zone and the entry area of quadrant 1 of the process zone, said flue including at least one afterburner chamber for further combustion of the exhaust combustion gases and collection of particulates from the rotary hearth furnace, said after burner chamber including a water spray quench to reduce the combustion temperature for NOx control.