Fans and Air Pollution Control for Sponge Iron Rotary Kilns

The process

Direct reduction of iron ore in a rotary kiln produces a hot off-gas full of fines that passes through an after-burner chamber and usually a waste heat boiler before the ESP and the ID fan. Shell air fans along the kiln inject air through ports, and shell cooling fans protect the refractory. Hard, continuous duties.

The gas

Rotary kiln off-gas after the after-burner chamber and waste heat boiler, carrying iron ore and coal fines. Among the harder duties for an ID fan: hot, heavily dust laden and continuous.

Fans in this process

Duty	What it does here	Type usually selected
ID Fan	Sits at the outlet of a boiler, kiln or furnace and draws the flue gas through the plant to the stack.	Backward curved, backward inclined and radial tipped
Combustion Air Blower	Feeds a burner with air at the pressure the burner register needs.	Backward curved and radial tipped
Shell Cooling Fan	Blows ambient air onto the rotary kiln shell in the burning zone to protect the refractory and the shell steel.	Axial
Dust Collector Fan	The fan behind a bag filter, cyclone or multiclone on a dust extraction system.	Backward inclined and radial tipped
Bag Filter Fan	Pulls the process gas through the filter bags and discharges the cleaned gas to the stack.	Backward curved and radial tipped
Dilution Air Blower	Injects ambient air into a hot flue gas stream to bring it down to a temperature the downstream bag filter or fan can accept..	Backward curved
Hot Air Fan	Circulates or supplies air at elevated temperature to a dryer, oven or kiln.	Backward curved and backward inclined

Air pollution control

Industries

Related processes