Agglomeration: Combustion Technology
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Adapted from: “The Making, Shaping, and Treating of Steel”, 10th Edition, Association of Iron and Steel Engineers, 1985, p.311 |
Equipment
Combustion Technology
Energy Consumption
Process Description
The grate kiln system (graphic) consists of a straight grate for drying and preheating the pellets to 1900° F, a rotary kiln for heating to the final hardening temperature of 2400°F and a horizontal rotary hearth for cooling and heat recuperation. Either oil, gas, or a coal burner is placed at the discharge end of the kiln. Hot gases produced in the kiln are used for downdraft drying and preheating of the pellets. Hot air from the cooling zone is used for combustion.The sinter plant uses a radiant hood ignition furnace over the bed with the combustion air preheated b cooling the finished sinter. This ignition hood is up to 25% of the length of the sinter bed. Temperature in the hood starts at 2100°F at the start of the hood to about 1500°F at the exit. Wind-boxes beneath the grate create down-draft combustion that ignites the coke breeze in the mixture and ensures even heating of the entire bed.