The process
Large sheds shed heat through the ridge with roof extractors and draw fresh air through louvers or supply fans. Evaporative cooling is added where the process heat is high.
The gas at the fan
Ambient air carrying light dust from the surroundings, enough to settle on blades over months but not to erode them. Inlet screens and a wheel that sheds deposit are the usual precautions.
Selection for this duty
| Construction | Axial fans in weatherproof cowls, or supply and exhaust units with filters as the air quality requires |
| Density at the fan | At about 35°C the gas density is close to 1.15 kg/m³, 95% 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 axial fan in a weatherproof cowl mounted on an inclined or flat roof, exhausting hot air from the ridge of a factory shed. Client-stated blade types for the Roof Extractor in general: Axial.
Industries
Other fans in factory shed ventilation
Roof Extractor in other processes
Induction Furnace Melt ShopsForge ShopsIron and Non-ferrous FoundriesDyeing and Finishing HousesWelding and Fabrication ShopsTyre Curing PressesShipyard Hull and Block FabricationGenerator and Engine RoomsCar Parks and TunnelsJute Mills
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.