• Publications

Online measurement of sugar crystallization with a portable non-intrusive instrument

SIT 2019 Conference Paper


This paper presents results from a measurement campaign at a sugar refinery with a novel non-intrusive measurement technique for crystallization diagnostics. By measuring batch-to-batch development of key crystal properties, we demonstrate a quick and effective approach for crystallization control, monitoring and troubleshooting. The developed measurement system is based on the photometric stereo technique including a digital color camera and three LED lights illuminating the crystal suspension from three directions. The measurement system can be installed on a standard sight glass of a boiling pan, and it provides real-time measurement results on crystal size distribution and massecuite flowability. As the instrument does not require direct contact with the suspension, the installation can be done while the boiling pan is in operation, and the instrument is truly portable in nature. The portability allows quick studies in various locations, e.g. for studying mixing and homogeneity of the crystal population in the pan. The accuracy of the new technique is demonstrated by comparing crystal size distributions measured with the system to results acquired by sieving and traditional transillumination-based process microscopy.