The process
Gas fired crematoria need an ID fan to hold the chamber under draft through the after-burner and any scrubber, with dilution air to protect the fan and stack. Quiet running matters at these sites.
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. |
Sits at the outlet of a boiler, kiln or furnace and draws the flue gas through the plant to the stack. It handles hot, dust-laden gas at large volume, so it is sized at the hot condition and checked at cold start. Client-stated blade types for the ID Fan in general: Backward curved, backward inclined and radial tipped.
Industries
Other fans in crematoria
ID 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.
