After cooling the fertilizer granules must be sieved according to their size so as to allow them to be scattered over the field effectively and efficiently with mechanical means. For this purpose, we study, design, manufacture and install systems that sieve the granules and pulverize those that are too large. For the sieving process we adopt vibrating screens while to grind coarse granules we use mills with articulated hammers or roller mills .
Before being stored in the warehouse granules of the appropriate size are treated on a static fluidized bed, to be stabilized. After stabilisation the granules can be placed inside coating cylinders and covered with substances that prevent them from sticking to each other, in order to reduce the formation of lumps in the storage piles or in the packing bags.
All the machines that we study and construct are designed to reduce the problems related to fertilizer adhesiveness and to limit the corrosiveness of the fertilizers themselves.
Sieving a fertilizer is often a complex undertaking despite the apparent banality of the operation.
There are many aspects that are very difficult to manage, like product temperature, stickiness, dustiness, chemical corrosiveness.
We study, choose and install vibrating screens specific for the different fertilizer kinds.
Based upon our experience, we have studied and optimized a specific mill for grinding granulated fertilizer in a highly efficient way.
We manufacture this mill, with articulated hammer and contrast roll, that consists in a steel frame and two rotors,
the first with hinged hammers and the second with a smooth cylindrical surface.
Under the mill a special screw conveyor is placed to gather the grinded fertilizer and to avoid the dispersion of the dust into the environment.
We design, manufacture and install static fluidized beds for the cooling and stabilization of fertilizers.
This equipment consists in a static casing with a special horizontal grid over which fertilizers can slide.
The advancing of the fertilizer is due only to the fluidization of the air flow
and therefore the static fluidized bed doesn’t need any mechanical motion.
Air injection into the casing below the grid, is given by a first fan,
while a second fan forms a suitable depression to suck the air into the upper part of the grid.
To ensure the correct balancing of pressure inside the casing, the two fans are controlled by an inverter.
The grid has a particular configuration and is made in special corrosion-resistant material that has a very low possibility of sticking to the fertilizer.
The fertilizer is cooled on the fluidized bed with high efficiency thanks to the combined effect of two physical phenomena: the intimate contact between the product granules and the cooling air and the sub-cooling assured by the evaporation of the residual product moisture.
We design, manufacture and install drum machines for coating granulated fertilizers. The granules can be covered with inert substances that reduce the amalgamation of fertilizers in storage piles or inside the packaging bags.