Dispersion fan


  • Dispersion of odorous emissions

  • Plume abatement

  • Polishing technique (e.g. after biofilter )


A dispersion fan is strongly diluting the waste gas in such a way that the odour concentration of the plume upon arrival at ground level (neighbourhood) is very low or non-detectable by humans. Another application is to minimise the visual pollution of a wet plume after e.g. a wet scrubber or thermophilic biofilter. 

The dispersion fan usually is installed at ground level or in/on the roof of a building. It aspires the waste gas together with an excess of odour-free outside air and vertically blows-out the air mixture (> 200 000 m3/h) at very high speed (> 20 m/s). As a result of this, the odorous air is strongly diluted and emitted at considerable height. The dilution effect of this technique is similar as for a chimney, but it prevents the civil works/building permits needed for a chimney and also prevents the visual pollution caused by a chimney.

The dispersion fan is equipped with a frequency drive and a weather station, allowing to install different operating regimes (flow rates) as a function of e.g. wind speed, wind direction, production activity, …

It is clear that this technique can only be used for applications where the pollutant concentration is not in conflict with the local emission limits since it only results in a dilution and not a removal of the pollutants.


Dispersion fan - scheme


Dispersion fan for odorous emissions

Dispersion fan after thermophilic biofilter