The process
Stenters circulate hot air through the fabric in each chamber with plug fans and exhaust the moist air carrying oil mist and lint. Exhaust fans and ducts are built for cleaning, with mist elimination or scrubbing where the oil load is high.
The gas at the fan
Air saturated with moisture from drying, with condensation on any cool surface. Drainage, a shaft seal and a material that tolerates wet running are part of the specification.
Selection for this duty
| Blade form | Backward curved or aerofoil for the best efficiency on clean gas |
| 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 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. |
Hoods, ducting and an exhaust fan that capture fume at source and deliver it to a scrubber, bag filter or stack. Fan material follows the fume: stainless steel, PP-FRP or rubber lined where it is corrosive. Client-stated blade types for the Fume Exhaust System in general: Backward inclined and radial tipped.
Industries
Other fans in textile stenters and dryers
Fume Exhaust System 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.
