The process
Threshing, conditioning, cutting and drying of tobacco generate fine dust at every transfer. Dust extraction fans with bag filters on the primary line, hot air fans on the dryers, and conditioning for the processing floor.
The gas at the fan
Fine, slightly sticky dust from cutting and blending, with moisture from conditioning. Bag filter on the system, fan on the clean side, wheel easy to clean.
Selection for this duty
| Blade form | Radial tipped, or backward inclined where the fan sits after the collector |
| Material of construction | Mild steel |
| Drive and bearings | Direct coupled or belt driven; belt drive where the duty point may need tuning at site |
| Also specified | Access doors on the scroll and a wheel that can be cleaned in place |
| Density at the fan | At about 40°C the gas density is close to 1.13 kg/m³, 94% 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 tobacco primary processing
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.
