Pan seeding systems

When slurry is used as seed for pan boiling, the technological and economic demand that the product crystallizate be low in aggregates and free of fine crystals cannot be met. As the total surface of the slurry crystals is too small, the supersaturation increases during the crystal formation phase beyond the metastable region, because in this phase crystal growth cannot cope with the concentration of the solution.

Secondary nucleation, but formation of aggregates in the first place, deteriorates the product quality. In addition, a large percentage of the slurry crystals added are remelted due to the uneven supersaturation profile in a conventional pan. However, this (from a crystallization technology point of view) difficult seeding phase decisively influences the quality of the final product. To make this phase easier to control, it proved to be good to separate it from the boiling process, in terms of both time and space.


Standard 1st-seed cooling crystallizers

Net volume 2.1 4.2 5.0 6.8 10.0 15.0    
Diameter m 1.4 1.8 2.0 2.0 2.4 2.6    
Max. total height m 4.4 5.3 6.0 6.0 6.3 7.2    
Cooling surface 11.3 19.0 21.0 27.0 44.0 61.0    


  • Simple process control due to crystallization being limited to the growing and tightening phases
  • Excellent product crystal quality along with good centrifuging ability of massecuite
  • Use of high dry substance feed solutions without addition of water, even for high-purity solutions
  • Optimum syrup washing and reduced wash water consumption by centrifugals
  • Reduced sugar house steam requirements
  • Flexibility of installation of 1st-seed system
  • Optimum adaptation to product requirements