An experimental study of boiling in calandria tubes : SRDC final report JCU021

Abstract

Raw sugar processing relies heavily on process equipment employing calandria-based heating systems to concentrate highly viscous sugar solutions, such as evaporators or vacuum pans. The design of these unit operations is based largely on experience and lacks a rigorous basis. Due to the high capital cost of these components, this situation is highly undesirable. The main aim of this project is to develop an experimental apparatus that can be used to measure viscous boiling phenomena in a single calandria tube, boiling molasses and massecuites. Data gathered will be an invaluable resource to assist with the development of models that can be used to assist with the design of full-scale equipment.The single tube boiling circuit that resulted from this project was developed using sound engineering principles. The mechanical design of the circuit itself was complemented with a userfriendly control and data acquisition system that assists the experimenter in controlling various aspects of the equipment. While most of the work was done by JCU staff and undergraduate students, collaborations with SRI staff were instrumental in finishing the project.The main deliverable of this project is the commissioned boiling circuit apparatus. This equipment is currently being used on a follow-up project, SRI129, to evaluate the boiling behaviour of viscous fluids, such as molasses and high-grade massecuites.It is anticipated that there will be a significant financial benefits to the Australian sugar industry, since more rigorous designs of vacuum pans will be possible for the first time. It is hoped that further research can be supported in order to continue the present studies.