What the fans do here
Rotary, fluid bed, spray and belt dryers all need a hot air fan to push heated air into the product and an exhaust fan to pull the moist, dust-laden air out through a cyclone or bag filter. The exhaust fan is sized at the hot, wet condition, and axial fans are used where the pressure is low.
Applications in this industry
| Application | What it does | Type usually selected |
|---|---|---|
| Hot Air Fan | Circulates or supplies air at elevated temperature to a dryer, oven or kiln. Selected at the hot density with the shaft and bearing arrangement built for continuous hot running. | Backward curved and backward inclined |
| ID Fan | Sits at the outlet of a boiler, kiln or furnace and draws the flue gas through the plant to the stack. It handles hot, dust-laden gas at large volume, so it is sized at the hot condition and checked at cold start. | Backward curved, backward inclined and radial tipped |
| Dust Collector Fan | 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. | Backward inclined and radial tipped |
| Combustion Air Blower | Feeds a burner with air at the pressure the burner register needs. Sized for the burner turndown range, and often fitted with an inlet silencer. | Backward curved and radial tipped |
Processes in this industry
Hot Air GeneratorsGypsum Calcining PlantsCeramic Body Spray DryersFood and Dairy Spray DryersRotary DryersFluid Bed Dryers and CoolersBelt and Tray DryersPlywood and Wood ProcessingRice Mills and Paddy Dryers
Equipment supplied
Centrifugal Fans
0.3 to 120 m³/s, 25 to 3120 mmWC single stage. Six blade configurations, three drive arrangements.
Cyclonic Separator
Coarse dust pre-collector. Low cost, low maintenance, low pressure drop. To 90% down to 30 micron.
Bag Filter
Fabric filters in polyester, polypropylene, Ryton and Nomex. Efficiency to 99.9% down to 5 micron.
Axial Fans
0.3 to 70 m³/s, 3 to 75 mmWC. Direct drive, belt drive and bifurcated. Fixed or variable pitch impellers.
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.