Ammann dryer drum retrofit reduces odour

Replacement RAH100 dryer unit reduces odour and keeps asphalt plant neighbours happy

A RETROFIT to an Ammann asphalt mixing plant is reducing odour emissions and pleasing neighbours. An Ammann RAH100 dryer replaced the existing component on a decades-old plant owned by Asfalt Productie Limburg (APL) in Heusden-Zolder, Belgium. It is the first RAH100 to be employed in the country.

The mixing plant is located close to a residential area, with many neighbours nearby. The retrofit reduces odour emissions significantly.

Key to this environmental improvement is the RAH100’s advanced, proprietary heating technology. Specifically, the dryer utilizes a warming system that minimizes odour while still producing mix of an extremely high quality.

Whilst mitigating odour was the main concern, the new dryer also resulted in better-quality mix because the gentle heating process protects the bitumen.

The RAH100 counterflow dryer allows new asphalt to be made with 100% recycled asphalt (RAP), but whilst APL have an interest in using more RAP, it was the RAH100’s innovative heating technology that spurred them to go ahead with the retrofit.

The RAH100 consists of two connected sections. One is a hot gas generator that contains a burner and forces hot gas toward the second section, a counterflow dryer.

The RAP enters at the far end of the counterflow dryer section and moves toward the heat chamber. At the end of the counterflow dryer, the material is transported to an accompanying silo. The heated material leaves the dryer before the temperature becomes excessive, which reduces both fumes and odour.

The revamped plant is fully cladded and features a silencer and cover on the elevator head to reduce sound.