The process
Sulphur burning and metallurgical acid plants move gas through the converter and absorption towers with a main blower, and vent the tail gas through a scrubber. Materials follow the acid concentration at each point.
The gas at the fan
Fume from pickling, acid handling or reactor vents, corrosive and often wet. PP-FRP, FRP or rubber lined construction, with the motor outside the gas path.
Selection for this duty
| Blade form | Backward curved or aerofoil for the best efficiency on clean gas |
| Material of construction | PP-FRP, FRP or MS rubber lined, with the motor outside the gas path |
| 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 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. |
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 sulphuric acid plants
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.
