The process
Rotary and reverberatory furnaces for secondary lead emit fume with lead oxide and sulphur dioxide. The furnace off-gas is cooled, filtered in a bag filter and scrubbed, and the building is held under negative pressure for hygiene.
The gas
Fume from arc, induction or reverberatory furnaces, hot and carrying fine metallic oxide dust. Temperature is handled by dilution air or a cooler ahead of the filter, and the fan sits on the clean side where possible.
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 |
| Ventilation Fan | Moves air through a plant or building for fresh air supply, heat removal and fume dilution where the system is ducted. | Backward inclined and forward curved |