Demonstrate the use of a microwave dry substance transducer for controlling high grade boilings

Australian sugar factories currently use massecuite conductivity to control the feed rate of syrup and molasses to pans. Conductivity control is inexpensive and works well, although it does require close attention from pan operators since the conductivity value is affected by variations in the impurity composition in the cane supply.
Microwave transducers to measure massecuite dry substance (DS) are now being used in several overseas refineries and factories for control of the massecuite condition in pans. In SMRP 2023/202 it was shown that the Berthold microwave transducer provided a reliable measure of the massecuite DS in an A massecuite pan at Farleigh Mill (ASSCT paper 2024). During this project, a correlation was established with reasonable accuracy between the transducer DS output and factory samples. However, it was not possible to demonstrate the effectiveness of the DS transducer for control of the pan’s operation prior to the finish of the season. Challenges with the control parameters of the program were determined and could not be solved as the accurate correlation was only established near the end of the season.
The overall aim of this project is to demonstrate the use of a microwave dry substance transducer for controlling high grade boilings to a pre-defined DS profile as described by Broadfoot and Fraga (ASSCT paper 2023). Improved control will result in cost reduction due to less manual interaction than currently required with conductivity control. An absolute measure of massecuite concentration, is an important first step to reducing the manning requirements on the pan stage in Australian factories.
• Determine the accuracy of the calibration developed during the 2023 season against massecuite dry substance values during different periods of the 2024 season (to assess the effects of changed cane supply conditions). The instrument Berthold DS transducer is installed in Pan 9 at Farleigh Mill (190 t) and boils A massecuite and high-grade seed. If needed, an improved calibration will be developed. The SMRP determined an accuracy of ±0.2 DS is required (corresponding to a deviation in supersaturation of ±0.03).
• Evaluate the pan’s performance when using the DS transducer signal to control the pan to a pre-set DS profile, fitting the DS profile based on experience from the SMRP and comparing to the profile determined by Broadfoot and Fraga (2023 ASSCT).
• Compare with the effectiveness for pan control of using conductivity or dry substance, including an assessment of the need for manual intervention by operators. Prepare report and incorporate recommendations for other factories to implement pan control using microwave DS transducers.

• Determine the accuracy of the calibration developed during the 2023 season against massecuite dry substance values during different periods of the 2024 season (to assess the effects of changed cane supply conditions). The instrument Berthold DS transducer is installed in Pan 9 at Farleigh Mill (190 t) and boils A massecuite and high-grade seed. If needed, an improved calibration will be developed. The SMRP determined an accuracy of ±0.2 DS is required (corresponding to a deviation in supersaturation of ±0.03).
• Evaluate the pan’s performance when using the DS transducer signal to control the pan to a pre-set DS profile, fitting the DS profile based on experience from the SMRP and comparing to the profile determined by Broadfoot and Fraga (2023 ASSCT).
• Compare with the effectiveness for pan control of using conductivity or dry substance, including an assessment of the need for manual intervention by operators. Prepare report and incorporate recommendations for other factories to implement pan control using microwave DS transducers.