Multi effect evaporators are a key component of industrial processing. In the sugar cane industry they provide high energy efficiency and good control resulting in good quality product. However the evaporation of water from the sugar juice results in scaling of the internal surface of the tubes, with decreasing heat transfer over a few weeks reducing throughput. A 10 hour stop is then required to clean the evaporators with chemicals. A method of increasing heat transfer and reducing the scaling rate would substantially improve the economics of raw sugar manufacture, which could then be transferred to other industries.
Swirl inserts have previously been used successfully in boiler air heater tubes to increase heat transfer (Mann and Dephoff, 2006). There is the possibility that swirl inserts can be used in evaporator tubes to change the flow patterns next to the internal tube surface, resulting in increased heat transfer and reduced scaling.
This project will used Computational Fluid Dynamics (CFD) simulations to study the boiling pattern effects of swirl inserts in evaporator tubes and the composition/s of the sugar juice close to the tube surface. Velocity, temperature and pressure drops will be predicted, as well as overall heat transfer change and scaling rates. The ANSYS software will be used to build the models and include Fluent and/or CFX for the simulations. The required hardware and software is available from QUT High Performance Computing (HPC at eResearch).
Outcomes for the project are:
- an improved understanding of boiling patterns in evaporator tubes
- a design to improve evaporator performance.
You can expect to learn skills in research, process engineering modelling, aided by supervision, assistance and feedback from researchers with a strong emphasis on delivery to industry.
Skills and experience
You will have a keen interest in understanding chemical engineering processes and prior skills and experience in computational modelling.
You may be eligible to apply for a research scholarship.
Contact the supervisor for more information.