The process
Fluid bed granulators and tablet coaters need conditioned, filtered inlet air at controlled temperature and an exhaust through a dust collector. The exhaust fan is selected against the filter and the product, in stainless steel with wash-down access.
The gas at the fan
Filtered, conditioned supply air through pre, fine and HEPA filters. The fan is selected against the filter pressure drop as it loads, at low noise.
Selection for this duty
| Blade form | Backward curved or aerofoil for the best efficiency on clean gas |
| Material of construction | Mild steel |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Density at the fan | At about 22°C the gas density is close to 1.20 kg/m³, 99% 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. |
Pulls the process gas through the filter bags and discharges the cleaned gas to the stack. Works on the clean side, so the blade can be chosen for efficiency, with the filter pressure drop added to the duty. Client-stated blade types for the Bag Filter Fan in general: Backward curved and radial tipped.
Industries
Other fans in pharmaceutical coating and granulation
Bag Filter Fan 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.
