Storage, dosing and transport system for titanium dioxide and carbon black

The key principle of this process is the fluidization of materials, which exhibit behaviors similar to category C dust (according to the Geldart Classification) and which require total containment conditions, to avoid direct contact with operators and to prevent, through local ventilation systems, the dispersion of dust in the air.

With the aim of ensuring a constant supply of raw and auxiliary materials to the production cycles, 10 storage silos are used for product storage, arranged in parallel with a capacity of 50 m3 each, 8 FIBC emptying stations with WLL 2000 kg and a bag cutting cabin with a screw compactor, necessary to compress and reduce the volume of the bags containing the transported material.

By exploiting the drag force exerted by the air sucked by a vacuum pump, the product is directed to the silos and poured into the collection hoppers below, made with a circular plan with a conical bottom, as well as a rectangular plan with a pyramidal bottom, with a minimum inclination of the walls of 60° on the horizontal plane.

The unloading section is established by the design specifications, which define the hourly mass flow rate, precision of the required doses, determined by the latency time, constant and regular flow of the material.

To guarantee total sealing and prevent the escape of dust into the environment, the big bag emptying stations are equipped with locking devices and automatic tensioning of the sack unloading sleeves. The bag-cutting cabin is instead equipped with a glove box with a dust collection hood connected to centralized suction systems.

Each component of this “recipe” is dosed in succession in a homogenizing weighing hopper, until the selected batch is completed. In this way, the powders find the right degree of compositional homogeneity and uniformity in the hopper, thus improving the flow threshold due to the reduction of intermolecular forces.

The preferential condition of expansion of the granular layer is achieved in the IDEALTEC Srl aero-mechanical conveyors, which allow a decisive step to help improve the flowability of the material.

The large volumes, distributed on two floors with an adjacent large independent space, host 3 aero-mechanical transport lines, modular and expandable, capable of penetrating the internal environments by drawing a linear, curvilinear and angular path.

The drag force exerted by the flow of flow – generated by the flexible transport organs – induces the state of fluidization of the material, significantly increasing its mobility and propagation speed.

Crossed by the motion of the aerated flow, regulated at the right speed, the particles see the limit shear stress to the flow disappear and remain in continuous suspension up to the discharge points of each line. The increase in the flow profile also prevents the formation of aggregates and facilitates uniform particle dispersion in the fluid current.

Thanks to the shape and size of the conveyor discharge units, the air flow reduces its speed, separating itself from the solid particles and heading towards the return pipe. The particles, due to the centrifugal force, are instead delivered to the dispersers, separated from the air and with an amplified exposure surface, so that the liquid phase penetrates the solid matter, filling its microporosities.

This wetting process, with accelerated dispersion times, facilitates heat disposal, excludes the use of large filter surfaces and cyclones at the terminal evacuation point.