Automatic modular systems offer up to 10,000 - 12,000 kg/h capacity for stable and gentle drying, all without requiring either compressed air or cooling water. Good quality process in drying plastic granulate materials involves management and control of the 10 factors influencing the drying process: type of material, granule size, bulk density, temperature, dew point, residence time, specific airflow, initial air moisture content, final residual air moisture content, viscosity.

 

Drying effectiveness is also determined by the speed of migration of water molecules from centre of granules to the outer surface. The lower the dew point, the better the final result. This will be better also as it concerns the final moisture that will be obtained in less time. Ability of air to absorb and remove the moisture depends on how low the air dew point is and the moisture having a low dew point, the temperature at which it condenses on relatively cool surfaces.

 

Moreover, for the treatment of highly hygroscopic polymers, the following factors cover a main role:

1.   constant performance

2.   automatic variable airflow

3.   high performance with constant dew point at –65° C

All of these factors have been taken into account by Italian plastics ancillary equipment producer MORETTO in the design of a new drying system for plastics, particularly for the PET treatment.

By means of zeolite, a mineral of volcanic origin, as molecular sieves, a lower energy consumption compared to the conventional dryers is reached. This kind of drying is also the basis of the new MORETTO project dedicated to the PET treatment. It is the FLOWMAX system which combines efficaciously the technology of the new X MAX dryers and the Flowmatik device.

In this way, it is possible to meet large drying volumes, up to 5,000 kg/h, through combination of between 3 and 10 modular design X MAX dryer units. The particular feature of the new X MAX drying systems is the constant performance. In fact, X MAX is a multi-tower system at constant performance. While a dryer is in regeneration, the other units continue in operation until they too are submitted one after the other to regeneration. Not only does this ensures a steady process, but also it guarantees the rotation of the X MAX units for the regeneration which can be also in 72 hours or up to 100 between a cycle and the following one in the same drying tower.

Another interesting feature is the automatic regulation of the air according to the necessity. The control of the drying group can reduce the airflow of all the machines in parallel but it will be possible to switch off the unit which is not necessary, modulating from 50% to 100% those ones necessary for the production. This allows to get low energy consumptions but also an added benefit in terms of control of both the thermal stress of the material which is dried and the fluctuation in its viscosity which is reduced to a minimum.

The plus of X MAX dryers are further improved with the coupling with the Flowmatik system that allows to configure the innovative FLOWMAX system. The efficiency of FLOWMAX is proved by some features which make it suitable to satisfy the most demanding requirements:

   Extreme modularity: the dryer can be composed by from 3 up to 10 dryers with a maximum number of 32 connected hoppers.