The process
Submerged arc furnaces for ferro manganese, ferro chrome and ferro silicon produce a hot fume dense with very fine oxide dust. Semi-closed furnaces take it through a cooling system to a large bag filter, and the main ID fan on the clean side is a large volume, continuous duty. Waste heat boilers on the furnace off-gas add an ID fan of their own.
The gas
Ferro alloy furnace fume carries very fine silica and metallic dust at high temperature. Fine dust packs into blade roots, so the wheel is chosen to shed it and the fan is placed after the bag filter.
Fans in this process
| Duty | What it does here | Type usually selected |
|---|---|---|
| Fume Exhaust System | Hoods, ducting and an exhaust fan that capture fume at source and deliver it to a scrubber, bag filter or stack. | Backward inclined and radial tipped |
| 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 |
| 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 |
| Combustion Air Blower | Feeds a burner with air at the pressure the burner register needs. | Backward curved and radial tipped |
