The process
Pneumatic ash conveying needs high pressure blowers for the conveying air, bag filters on the silo vents, and air slides and fluidising blowers at the silo bottom.
The gas at the fan
Extraction air from crushers, screens and transfer points, carrying abrasive mineral dust. Radial wheels with wear protection ahead of the collector, or efficient wheels behind it.
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 |
| 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 |
| Density at the fan | At about 35°C the gas density is close to 1.15 kg/m³, 95% 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. |
Supplies low pressure aeration air to the fabric of an air slide, fluidising cement, raw meal or gypsum so it flows down the slide. Client-stated blade types for the Air Slide Blower in general: Backward curved and radial tipped.
Industries
Other fans in ash handling systems
Air Slide Blower in other processes
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.
