The process
Treatment plants evaporate reject streams with MVR, scrub odour from the tanks, and aerate biological stages with blowers. Corrosion resistance throughout.
The gas at the fan
Saturated vapour, often with dissolved solids and a low pH. Wetted parts in stainless steel, a shaft seal rated for the vapour, drain points and a casing designed for condensate.
Selection for this duty
| Blade form | Backward curved, in stainless steel, at the tip speed the pressure ratio demands |
| Material of construction | Stainless steel on all wetted parts, grade to suit the gas analysis |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Also specified | Casing drain at the lowest point |
| Density at the fan | At about 90°C the gas density is close to 0.97 kg/m³, 81% 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 water and wastewater treatment plants
Fume Exhaust System in other processes
Coke Oven BatteriesElectric Arc Furnace SteelmakingInduction Furnace Melt ShopsLadle Furnaces and Secondary MetallurgyForge ShopsFerro Alloy Submerged Arc FurnacesAluminium Smelters and Cast HousesCopper and Zinc SmeltingIron and Non-ferrous FoundriesHot Dip Galvanising LinesChemical Reactor and Tank VentsEffluent Treatment and Zero Liquid Discharge PlantsSolvent Recovery PlantsFertilizer Granulation PlantsSulphuric Acid PlantsFood Ovens and FryersPaper Machine Dryer SectionsPulp Mills and Recovery BoilersTextile Stenters and DryersDyeing and Finishing HousesAutomotive Paint ShopsPickling and Acid Treatment LinesWelding and Fabrication ShopsTyre Curing Presses
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.