The process
Shaft kilns burn lime in a packed bed with combustion air forced up through the charge by a high pressure blower and exhaust drawn off the top by the kiln fan. Pressure is the issue on the air side, dust and temperature on the exhaust side.
The gas at the fan
Kiln gas with lime dust, hot and abrasive, and hygroscopic where moisture is present. Wear protection and a design that resists caking on the blades.
Selection for this duty
| Blade form | Radial tipped with wear liners, or straight radial where the dust is coarse |
| Material of construction | Mild steel with replaceable wear liners on the blades and the scroll at the cut-off |
| Drive and bearings | Direct coupled, shaft cooling disc, bearings in a pedestal outside the gas stream, allowance for thermal growth |
| Also specified | Hard facing or liners on the blade pressure face |
| Density at the fan | At about 300°C the gas density is close to 0.62 kg/m³, 51% of standard air. Pressure developed and power drawn fall in the same ratio, so the selection is made at this density and the motor is checked at cold start. |
The fan behind a bag filter, cyclone or multiclone on a dust extraction system. Placed on the clean side where possible so the blade can be chosen for efficiency. Client-stated blade types for the Dust Collector Fan in general: Backward inclined and radial tipped.
Industries
Other fans in vertical shaft lime kilns
Dust Collector Fan in other processes
Bagasse Fired BoilersRice Husk Fired BoilersAFBC BoilersCFBC BoilersPulverised Coal Fired BoilersWaste Heat Recovery BoilersBiomass Fired BoilersThermic Fluid HeatersCement Preheater KilnsVertical Roller Raw MillsBall Mill Raw GrindingCement Grinding MillsClinker Grate CoolersCement Plant Coal MillsCement Packing and DispatchRotary Lime KilnsGypsum Calcining PlantsSponge Iron Rotary KilnsBlast Furnace Hot Blast StovesSinter PlantsCoke Oven BatteriesElectric Arc Furnace SteelmakingInduction Furnace Melt ShopsLadle Furnaces and Secondary Metallurgy
Services on this fan
Information needed to select or quote
- Duty point. Volume flow and static pressure at the fan inlet, with the gas density and temperature or the conditions to derive it.
- Operating conditions. Site altitude, normal operating temperature and continuous or intermittent duty.
- Gas stream. Dust loading and particle size, corrosive species, moisture, upset temperature and any tendency of the material to deposit on the impeller.
- Mechanical. Rotation viewed from the drive end, discharge orientation and motor power.