The process
The rotary dryer takes hot air from a furnace and the cooler takes ambient air, both through the product bed with exhaust fans that pull the dust-laden air through cyclones and scrubbers.
The gas at the fan
Dryer exhaust with heavy carry-over of the dried material and the moisture it gave up. Dust goes to a cyclone and bag filter, and the fan behind them handles warm, wet gas with residual fines.
Selection for this duty
| Blade form | Radial tipped with wear liners, or straight radial where the dust is coarse |
| Material of construction | Mild steel with replaceable wear liners on the blades and the scroll at the cut-off, with a casing drain for the moisture |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Also specified | Hard facing or liners on the blade pressure face; casing drain at the lowest point |
| Density at the fan | At about 120°C the gas density is close to 0.90 kg/m³, 75% 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. |
Delivers combustion, aeration and conveying air where the system resistance runs to several thousand millimetres of water column in a single stage. Client-stated blade types for the High Pressure Blower in general: Backward curved and radial tipped.
Industries
Other fans in fertilizer rotary dryers and coolers
High Pressure Blower 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.
