- → Biofilter
- → Bioscrubber
- → Biotrickling filter
- → Water scrubber
- → Acid scrubber
- → Caustic scrubber
- → Oxidative scrubber
- → Reductive scrubber
- → Solvent scrubber
- → Liquid jet gas ejector scrubber
- → Gas jet liquid ejector scrubber
- → Venturi scrubber
- → Wet dust separator
- → Bubble reactor
- → Dry scrubber
- → Dispersion fan
- → Stripper
Dispersion of odorous emissions
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.