Computational Fluid Dynamics (CFD) modelling is a powerful technique that simulates the interaction of fluids and gases with fixed surfaces. SRI uses the latest licensed CFD tools to help with equipment design, process troubleshooting and boiler performance and upgrade issues.
Our team has the knowledge and capability to apply CFD tools to many different flow-related problems, and the experience to validate CFD recommendations against factory results.
SRI has used CFD on the following research and consulting projects:
SRI Short Retention Juice Clarifiers
CFD modelling was used to model the flow of juice and sediment within the clarifier, using a range of conditions to optimise the clarifier configuration and size for various flow rates. The outcome was near-perfect upward plug flow the clarified juice, giving low turbidity even at design flowrates.
In 2012, our design team used CFD modelling to develop a new clarifier design that offers higher throughput, lower turbidity and lower fabrication costs. The new clarifier design are now undergoing trial in select Australian sugar mills and is planned for future release to the global sugar industry. CFD modelling was an integral to the project and highlights SRI’s deep knowledge of the clarification process.
SRI Robert Evaporators
SRI’s Robert Evaporators are designed from first principles to achieve optimal flow patterns, high heat transfer, maximum steam/ vapour economy and minimal carryover. CFD modelling was used to establish the key dimensional relationships for Robert Evaporators of varying sizes, including the placement of inlet and outlet pipework to maximise circulation at different rates. This is especially important for evaporator design – the evaporator station will lose overall efficiency as fouling occurs, the brix profile within each evaporator vessel will change, and throughput will slowly reduce until cleaning is scheduled.
SRI’s design and understanding of process and CFD modelling techniques, means that mills can operate for longer between cleaning stops. SRI Robert Evaporators give mills a higher throughput for longer periods thereby extending the time between cleans.
SRI Vacuum Pans
SRI’s batch and continuous vacuum pans have been designed using CFD modelling as crucial inputs to SRI’s ‘reference’ design for both batch vacuum pans and continuous vacuum pans. Circulation is a major consideration in any vacuum pan, especially at the low-grade end of crystallisation where viscosity plays a major role in pan performance.
CFD modelling was used to examine the impact of phase change, bubble dynamics, crystallisation and surface effects on vacuum pan efficiency. For stirred vacuum pans (both batch and continuous configurations), CFD modelling was used in a research project to determine the optimal dimensional relationships for stirrer impeller designs.
Sugar Mill Boilers (Bagasse Combustion Systems)
SRI’s experts use CFD to model the flow of gas and bagasse particles, from inside the furnace during combustion, through superheaters, air heaters, economisers and scrubbers, and finally to the stack.
High wear areas are identified and boiler modifications can be tested to fix the issue. Areas of high and low heat flux can be determined, and adjustments made by altering under-grate and secondary airflows. The opportunities for wear and corrosion reduction are many, and CFD modelling is a robust technique that allows modifications to be tested outside the harsh environment of an operating boiler.
CFD modelling can also be used to examine heat flux around wall areas, superheaters and economisers – optimisation can provide a boiler with a maximum continuous rating (MCR) boost at low cost. CFD modelling is also used to examine the behaviour of flue gases as they traverse wet and dry scrubbers, with relatively simple changes impacting wear rates and assuring environmental compliance.
Correctly applied, CFD modelling is a valuable tool that can solve many flow-related issues in sugar mills and sugar refineries.
SRI’s CFD modelling services are available to SRI clients on a commercial basis.
For more information contact SRI.