The process
Induction furnaces in foundries and mini steel plants emit fume at charging, melting and pouring. Side draft or canopy hoods take it to a bag filter, with the fan on the clean side and roof extractors handling the heat in the shop.
The gas at the fan
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.
Selection for this duty
| Blade form | Radial tipped, or backward inclined where the fan sits after the collector |
| Material of construction | Mild steel with replaceable wear liners on the blades and the scroll at the cut-off |
| Drive and bearings | Direct coupled or belt driven with a shaft cooling disc and bearings outside the casing |
| Also specified | Hard facing or liners on the blade pressure face |
| Density at the fan | At about 200°C the gas density is close to 0.75 kg/m³, 62% 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. |
Hoods, ducting and an exhaust fan that capture fume at source and deliver it to a scrubber, bag filter or stack. Fan material follows the fume: stainless steel, PP-FRP or rubber lined where it is corrosive. Client-stated blade types for the Fume Exhaust System in general: Backward inclined and radial tipped.
Industries
Other fans in induction furnace melt shops
Fume Exhaust System in other processes
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.