Improve your Plant, Improve the product quality

Prilling bucket

The quality of prills is strongly influenced by the bucket design. Stamicarbon developed a prilling bucket design suitable for larger plant capacities. This new design incorporated internals to avoid slipping between the melt and the bucket wall. These internals will restore the vortex again, which is a result of gravity and rotation forces. Ideally the liquid height (pressure drop) above every hole is similar assuring a very sharp size distribution.
Another advantage of this design is a more laminar flow through the prilling bucket holes leading to less dust formation. Less dust will also be the result of a lower melt temperature (less breakage of prills at the bottom of the prilling tower).
Many previous debottlenecking projects prove the potential benefits of this new design. Stamicarbon's prilling bucket provides a granulometry of 97.5 wt% between 1 and 2.4 mm.

Seeding system

Mechanical strength is especially important when the product needs to be stored after being subjected to a variety of handling operations. Poor mechanical strength leads to disintegration and dust formation and increased caking tendency.
Improvement of the impact strength is important if the prills are handled several times. Stamicarbon developed a unique technology to improve the impact strength of the prills.

Granulation

Key in the Stamicarbon granulation technology is the spraying nozzle principles, which leads to specific process characteristics and several advantages.
Granulation by means of low pressure film spraying results in much less dust generation in the granulator.
Summarizing the advantages of low-pressure film spraying are:

• limited dust production in the granulator;
• low spray energy per ton of urea;
• formaldehyde content can be low;
• high bulk density.

Pastillation

Stamicarbon and Sandvik Process Systems developed a new finishing technology for urea: the so called Pastillation Process. The design and supply of urea Pastillation Systems is a growth area with the Rotoformâ process proving an ideal solution for the solidification of molten urea.
Specific advantages are:
Very low NH₃ and dust emissions;

• A very low power consumption figure;
• More uniform product;
• Good crushing strength even without adding formaldehyde;
• Flexible production by switching on/off rotoformer lines;
• Possibility to produce controlled release urea and mixed fertilizer;
• Lower investment costs per ton urea.