Bernardi Impianti - Milan (Italy)
A very beautiful stationary asphalt premix plant manufactured by Bernardi for an important customer in France. Note the large "bag house" and the huge hot mix storage.
This Company is probably one of the largest and more aggressive Asphalt Plant Manufacturer of Europe.
Traditionally these plants are of the stationary type and remain located in its initial erection place for many decades, delivering pre-mix to a more or less wide spread geographical area. Bag Houses and other sophisticated filtering means required more and more stringently for anti pollution reasons, get more and more bulky and heavy, making traditional Asphalt Plants always more stationary.
On the other hand job sites in the less developed countries (where the big construction jobs nowadays are) cry for mobile Asphalt Plants. Furthermore, even in the highly developed countries traffic jams slow down markedly the trucks transporting the Hot-Mix. So the influence zone of each stationary plant gets smaller and smaller. New stationary Asphalt Plants are however NOT permitted to be erected any more, so also in the more developed countries the need to use easy transportable plants gets bigger and bigger.
As we have seen, Niarb has accumulated a considerable experience in highly transportable Asphalt Plants during the co-operation period with both Simesa Milan and Wibau Germany.
When Bernardi asked Niarb for Technology Transfer in order to quickly designing a new line of "highly mobile" Premix plants, a very effective and fruitful co-operation started. Three size categories have been developed at the same time: a 70 tons/hour model, a 110tons/hour model and a 150 tons/hour model. All three based on a rather innovative principle solving the problem of making highly transportable the "batch" plant versions.
Technology of Asphalt Plants is characterised by the fact of solving the problem of producing hot pre-mix following two markedly diverging procedures: The "batch" system and the "drummix" system.
The traditional or "classic" batch system foresees to "dry screen" the hot and dry aggregates coming out from the "hot" Drum Dryer, to separate therewith the aggregates in 4-5 "classes". Thereafter to proportionate each class by weight (the "weight batching" operation) and to feed them into a separate mixer (the "pug-mill") for the final addition of hot bitumen, Fillers and other additives.
This is the final aspect of a "super Mobile" Pre-mix plant when placed (after a few hours erection time) on a job site. It doesn't look much different from a classic stationary Hot Mix Plant working following the "Batch" plant system, but its unsurpassed advantage is that it can be erected and carried away in less than two days time, while the traditional pre mix plant require several weeks!
The simplified "drum-mix" system makes use of the very same drum dryer for mixing the aggregates with bitumen and filler.
It is easily understandable that "drum-mix" plants are almost naturally transportable, thanks to their simplicity, while "batch" plants are much more difficult to transform into true mobile plants. The Niarb solution for "batch" plants is schematically shown in the pictures on the right.
On the other hand "drummix" plant are less and less accepted by the large Consulting Companies, due to their inherent difficulty to accurately proportioning the various granulametric classes of aggregates. Also the pollution contained in their exhaust gases is much more difficult to control.
This is becoming a very important issue even in the less developed countries.
When a Niarb Highly transportable "batch" plant is in place, it looks like a traditional stationary one.
During transport, however, each group is a truly compact "trailer", fully following the most stringent Road Traffic Rules.
The pictures here above and on the right show two groups (out of a Convoy of five) forming a 150 tons/h pre-mix plant.
The pictures shown here on the left and below describe the last erection phase of other Bernardi "super mobile" pre-mix plants manufactured following Niarb's design.
"Super-mobile" Asphalt plants can be mounted and put to work in few hours an can be disassembled and carried away in as little time.
This is a very precious advantage when contractors are called to work in less developed countries, where it is mandatory to rapidly do the job and quickly get away if political conditions change.
