Fans and Air Pollution Control for Cement Preheater Kilns

The process

The dry process kiln line is a chain of fans from the cooler to the stack. The preheater fan sets the kiln draft through the cyclone stages, the raw mill fan draws the hot gas through the mill, the cooler fans blow and exhaust the clinker bed, and the coal mill fan carries pulverised fuel to the burner. Every gas stream carries abrasive dust at temperature.

The gas

Kiln gas leaving the preheater carries fine raw meal dust at high temperature. The fan runs hot and dusty for years between stops, so wear liners, a shaft cooling disc and bearings outside the gas path are standard.

Fans in this process

Duty	What it does here	Type usually selected
Preheater Fan	Draws the kiln exhaust gas through the preheater cyclone stages.	Backward curved and radial tipped
Raw Mill Fan	Draws hot kiln gas through the raw mill and separator, drying the raw meal on the way and carrying the fine product to the collector.	Backward curved and radial tipped
Coal Mill Fan	Draws hot gas through the coal mill to dry and convey the pulverised coal to the burner or the fine coal bin.	Backward curved and radial tipped
Cooler ID Fan	Draws the clinker cooler exhaust through the cooler dust collector to the stack, holding the cooler hood under a slight negative pressure..	Backward curved and radial tipped
Cooler Vent Fan	Exhausts the surplus hot air from the clinker cooler after the secondary and tertiary air have been taken off, drawing it through the cooler dust collector..	Backward curved and radial tipped
Cooler Compartment Fan	Blows ambient air up through the grate of the clinker cooler.	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
Air Slide Blower	Supplies low pressure aeration air to the fabric of an air slide, fluidising cement, raw meal or gypsum so it flows down the slide..	Backward curved 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
Dust Collector Fan	The fan behind a bag filter, cyclone or multiclone on a dust extraction system.	Backward inclined and radial tipped
High Pressure Blower	Delivers combustion, aeration and conveying air where the system resistance runs to several thousand millimetres of water column in a single stage..	Backward curved and radial tipped

Air pollution control

Industries

Related processes