Eco-friendly technology is the priority!

Eco-friendly technology is the priority!

If an asphalt mixing plant has already provided you with faithful service for more than 40 years, you can certainly consider it to have been a successful investment. Yet if this “antique” of machine technology is broken down into parts and transformed into a future-oriented Recycling Priority Plant (RPP) – a plant whose priority is to produce asphalt with an extremely high RAP material rate – the cost-effectiveness reaches a whole new level. BENNINGHOVEN recently completed an order of this type for its long-standing customer Joos Umwelttechnik GmbH.

BA RPP 4000 – Breisach, Germany

New BA 4000 RPP mixing tower

The centerpiece of the new plant at Breisach is a BENNINGHOVEN mixing tower of type BA 4000 with a mixing capacity of 320 t/h. A parallel drum in counterflow and a hot-gas generator ensure the gentle, indirect heating of granulated RAP to deliver a high level of environmental friendliness and maximum RAP material rates. This unique innovation enables RAP material rates of 90 + X% to be achieved – higher than with any other recycling system on the market. This innovation, which was presented e.g. at Bauma 2016, takes account of stricter emissions limits, specifically those set by the new German Technical Instructions on Air Quality Control (TA-Luft).

Delivering added value

“Just replacing the steel wouldn’t get us very far – after all, our plant was working perfectly,” said Johann Joos, operator of the asphalt mixing plant, which is located in Baden near to the border with France. What he required was real added value. And that‘s what BENNINGHOVEN delivered in spades! The new technology will allow the largest road construction company in the Freiburg region to produce recycled asphalt to practically any formulation in the future. In addition to the hot feed system comprising a parallel drum with a hot-gas generator, BENNINGHOVEN have also retrofitted a cold feed system: a multivariable feed hopper for a RAP material rate of up to 40%. Meanwhile, the preliminary batching units and other parts of the existing plant were retained.

“Recycled materials are becoming increasingly important around the world. Equipped with RPP mixing towers and parallel drums with hot-gas generators, our customers are excellently positioned for the future.”

Ralf Port, Key Account Manager, BENNINGHOVEN Sales

RAP material rates of 90 + X%

The new BENNINGHOVEN mixing tower of type BA 4000 meets the highest requirements for modern asphalt production. This is due to, amongst other things, an EVO JET 4 combination burner for oil and coal dust with 23.7 MW of output, 6-fold screening, a hot bin section with a 170-t capacity in 7 bins and mixed material loading silos with a capacity of 420 t. Other new components included a housing, a filler tower and a modern and user-friendly control system – the BENNINGHOVEN Control System BLS 3000.

Parallel drum in counterflow with a hot-gas generator

BENNINGHOVEN parallel drum in counterflow with a hot-gas generator

This unique BENNINGHOVEN innovation takes account of the fact that many markets are looking to achieve an RAP rate of 90%. The challenge here is to bring the RAP material to the processing temperature of 160°C while keeping emission levels within the normal range and taking care not to burn the bitumen. To achieve even higher RAP material rates while at the same time minimizing the level of emissions, BENNINGHOVEN are doing things their own way and heating the RAP material in the counterflow, which results in higher material and lower exhaust gas temperatures. This process is made possible by using a hot-gas generator as direct firing would “burn” the RAP material with its bitumen content but the hot-gas generator only heats it indirectly.