On-line monitoring of C seed magma using the ITECA Crystobserver to improve performance

A microscope system, the Crystobserver (supplied by ITECA, France), was installed on the C seed evaporating crystallizer at Condong Mill, Australia, to monitor the crystal development in real-time. The system provides a high-quality image and measures important parameters such as average crystal size and number of crystals in the image. Analysis of data collected over two seasons confirms that the system is reliable in obtaining images with sufficient clarity to assist the operators in remotely monitoring the crystal development from shortly after slurry addition. The reliability of the measurements is satisfactory once the crystals are larger than 30 µm through to near the end of the C seed when the crystal density in the screen is high. The operators have found the Crystobserver to be very beneficial, allowing them to take corrective actions such as changing the amount of slurry addition or the purity of the feed syrup more quickly. The software in the system stores historical data from several strikes, including images and key parameters that can be accessed readily. The installation, microscope and software features and potential benefits to a raw sugar mill are described.