The present asphalt plants, as well as answering to the demands of the producers of hot mix asphalt, both for the productive capacity and for the quality of finished product, still have the possibility to be improved especially concerning the reduction of the consumptions, the ecology, the resistance to the wear and the simplification of the technical maintenance.
Our Company, introducing on the market the new plant MET (Multi Ecological Tower) wants to reach this aim.
The innovation substantially concerns the tower of the batch stationary asphalt plants. It is a new and different method of ensiling and dosing the hot aggregates, to be used, with the same advantages, either when the plant is provided of screen or not. The novelties introduced in the MET contain some applications that, integrated in an experimented complex, allow to solve problems that till today they had not found satisfactory answers.
The novelty of the constructive solution is rather simple: it has been changed the shape of the storage bin of the hot aggregates coming from the drier; the traditional hopper (more or less big) divided in more sectors, has been replaced by cylindrical elements, each one of them arranged to storage a single size-grading. Each bin is placed on few stands of which one is fitted with a loading cell; the storage bins and the weighing hoppers forms a unit contained in insulated panels that make it isolated and proof toward the external environment.
As you can note, the innovation doesn't introduce special characters but allows to solve some important matters. One of these concerns the output of the pre-batchers and the possibility of their adjustment in feedback. Previously, the level indicators used, for numerous reasons and causes, didn't offer enough guarantee and stability of signal. For this reason it was not rare the situation that some material already processed into the drier was wasted. On the contrary, the loading cell applied in correspondence of one of the stand of each storage bin of the MET cannot state the exact weight of the material inside but it will give a linear and constant signal corresponding to the level of the contents.
In this way the speed of extraction from the pre-batchers will be controlled through the software of the plant accordingly to its needs. It's interesting to specify that the method MET can be used both on the small production plants, and on the "hot stocks type". In both cases, and also in the sizes between, except for the dimensions of the silo and frame, the only difference will be the thickness of the insulating panels. All the described advantages join plants of small, medium and big capacity: they can be therefore checked independently from the capacity and from the availability or not of the screening unit and the hot mix silo.
You can have plants with a large deposit of hot material
above a big capacity mixer and without hot mix silo or a
small deposit above a mixer with discharge into hot mix silo
or even more solutions among the different possibilities.
Another novelty of the MET is to have installed a weighing
system for each granulometric classification.
In fact, to each of the granulometric classifications in the
plant corresponds, as already said, a storage bin fitted
with a weight indicator and under each of them there's a
hopper for the complete weighing.
