Precise crystallization control facilitates high crystal quality, yield and profitability

In sugar manufacturing, crystallization control is a critical process in obtaining high production yield and quality. After the phase of producing syrup in evaporators, the syrup flows to vacuum pans and the process of crystallization can be started. Industrial crystallization involves the formation of a particulate crystalline phase from a thermodynamically metastable solution. The product crystals will need to be produced by using the driving force of supersaturation for crystallization. This process is started with the action of seeding.

Supersaturation in the crystallization process

Sugar crystal growth in a supersaturated sugar solution takes place as a result of the transfer of sucrose molecules from the bulk of solution to the surface of the crystal by diffusion. The main driving force is supersaturation, which increases the rate of diffusion of sucrose molecules to the crystal surface, and thus the growth of crystals is determined mainly by the degree of supersaturation of the sugar solution. Increase in supersaturation increases the rate of crystallization. In addition, the effect on crystal quality should not be ignored. The supersaturation level of the massecuite is also an important quality parameter for the sugar crystallization process, as it determines the seeding point, affects the quality of crystals and the overall cost of production.

The crystallization control process

In the crystallization process, thick sugar juice or syrup is evaporated in a vacuum pan in order to achieve a state of supersaturation. Supersaturation being the force that drives crystal nucleation and growth. Once the state of supersaturation is reached, seeding is executed by adding a small amount of fine seed crystals to initiate the process of crystallization and the growing of sugar crystals. The process continues until a desired crystal size has been reached, and a panful is ready to be discharged.

Inmec In-line Brix Sensors

Compared to other Brix measuring solutions, the Inmec In-line Brix sensors further improve the efficiency of this process by relying on state-of-the-art digital microwave measurement technology, sophisticated and novel measuring algorithms, and a durable sensor design. These key qualities ensure that the Inmec Brix Sensors are able to provide our customers with industry leading measuring resolution, stability and reliability for the crystallization control process. The In-line Brix sensor is installed through the wall of a vacuum pan in a way which enables highly accurate, reliable and consistent Brix and temperature measurement. These measurements are used to guide the crystallization control process, ensuring optimal crystal quality, yield and overall profitability.  

For more on improving your crystallization control process, see our In-Line Brix sensors and get in touch. 


Vacuum pan

 In-Line Brix sensor installed in a vacuum pan.

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            3. J. McGinty, N. Yazdanpanah, C. Price, Jj. H. ter Horst and J. Sefcik, CHAPTER 1:Nucleation and Crystal Growth in Continuous Crystallization, in The Handbook of Continuous Crystallization, 2020, pp. 1-50
            4. A. Umo and S. Alabi Advances in Super-Saturation Measurement and Estimation Methods for Sugar Crystallisation Process. International Journal of Food Engineering Vol. 2, No. 2, December 2016
            5. D. Kulkarni, Cane Sugar Manufacture in India, New Delhi: The Sugar Technologists Association of India, 2009.