The process
Fabrication shops capture welding fume at source with arms and hoods into cartridge filters, and clear the general shop air with roof extractors and wall fans.
The gas at the fan
Fine metallic fume from welding and cutting, captured at source and taken to a cartridge filter. Light dust, ambient temperature; the fan is sized for the hood capture velocities and the filter pressure drop.
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 welding and fabrication shops
Roof Extractor in other processes
Induction Furnace Melt ShopsForge ShopsIron and Non-ferrous FoundriesDyeing and Finishing HousesTyre Curing PressesShipyard Hull and Block FabricationGenerator and Engine RoomsCar Parks and TunnelsFactory Shed VentilationJute 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.