The process
Hazardous, medical and municipal waste incinerators hold the furnace under draft with an ID fan that sits after the quench, scrubber, bag filter and carbon injection. The gas at the fan is wet and acidic. Combustion air and secondary air blowers serve the primary and secondary chambers.
The gas at the fan
Flue gas after the quench and scrubber is wet, acidic and still carries fine dust. The fan is in stainless steel or lined construction, with a shaft seal and drains, sized at the saturated density.
Selection for this duty
| Blade form | Radial tipped, or backward inclined where the fan sits after the collector |
| Material of construction | Stainless steel on all wetted parts, grade to suit the gas analysis |
| Drive and bearings | Direct coupled or belt driven with a shaft cooling disc and bearings outside the casing |
| Also specified | Casing drain at the lowest point |
| Density at the fan | At about 200°C the gas density is close to 0.75 kg/m³, 62% 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. |
The fan behind a bag filter, cyclone or multiclone on a dust extraction system. Placed on the clean side where possible so the blade can be chosen for efficiency. Client-stated blade types for the Dust Collector Fan in general: Backward inclined and radial tipped.
Industries
Other fans in waste incinerators
Dust Collector 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.
