The process
A waste heat boiler sits on the exhaust of a kiln, furnace or engine and lowers the gas temperature before the dust collector and fan. The ID fan after the boiler handles the gas of the source process at reduced temperature, and dampers divert the gas around the boiler when it is out of service.
The gas at the fan
Exhaust from a kiln, furnace or engine after a waste heat boiler. Temperature and dust depend on the upstream process; the fan is selected at the hot condition with the dust load of the source.
Selection for this duty
| Construction | Absorptive annular design in mild steel; stainless steel where the gas is wet or corrosive |
| 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. |
An absorptive silencer at the fan inlet, outlet or in the duct, cutting fan noise with minimum pressure loss. Client-stated blade types for the Fan Silencer in general: Silencer.
Industries
Other fans in waste heat recovery boilers
Fan Silencer in other processes
Information needed to select or quote
- Gas volume and temperature. Actual flow at the inlet, normal and upset temperature, moisture.
- Dust or pollutant. Inlet loading, particle size distribution, whether it is abrasive, sticky, hygroscopic or combustible; for gases, the species and concentration.
- Required outlet. The emission limit or clean gas concentration the unit must meet.
- Site. Available space and height, material of construction preferences, and how the collected material is to be discharged.
