The process
Fluid bed dryers need a supply fan at pressure to fluidise the bed through the distributor plate and an exhaust fan after the bag filter. Pressure on the supply side, moisture and fines on the exhaust side.
The gas at the fan
Exhaust from a fluid bed carrying fines and moisture at moderate temperature. Selected at the wet density with a wheel that tolerates light deposit.
Selection for this duty
| Blade form | Radial tipped, or backward inclined where the fan sits after the collector |
| Material of construction | Stainless steel wetted parts, with drains in the casing and a shaft seal |
| 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. |
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. Client-stated blade types for the ID Fan in general: Backward curved, backward inclined and radial tipped.
Industries
Other fans in fluid bed dryers and coolers
ID Fan in other processes
Bagasse Fired BoilersRice Husk Fired BoilersAFBC BoilersCFBC BoilersPulverised Coal Fired BoilersOil and Gas Fired BoilersWaste Heat Recovery BoilersBiomass Fired BoilersThermic Fluid HeatersHot Air GeneratorsRotary Lime KilnsVertical Shaft Lime KilnsGypsum Calcining PlantsSponge Iron Rotary KilnsBlast Furnace Hot Blast StovesSinter PlantsCoke Oven BatteriesElectric Arc Furnace SteelmakingSteel Reheating FurnacesHeat Treatment FurnacesFerro Alloy Submerged Arc FurnacesCopper and Zinc SmeltingGlass Melting FurnacesCeramic Tunnel and Roller Kilns
Services on this fan
Fan and System Performance TestingFan Energy AuditRetrofit of Low Efficiency FansRotor Replacement and Performance EnhancementDynamic Balancing and Vibration AnalysisCondition Monitoring and TroubleshootingInstallation, Commissioning and After-sales Support
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.