Dr Floren Plaza

Senior Research Fellow, Faculty of Engineering

PhD (University of Southern Qld)

Biography:Floren Plaza has approximately 24 years experience in delivery to industry in factory research, consulting, maintenance, reliability, and capital projects.  Floren has a proven record of delivering improvements through the application of Computational Fluid Mechanics (CFD) for fluid flow for equipment including boilers and process vessels, and the application of Finite Element Analysis (FEM) to the structural analysis of equipment.  Floren also has some experience in the application of Discrete Element Methods (DEM) to industry problems, including coupling of DEM with CFD, and a particular interest in the development of solid mechanics models and their coding into commercial software. Boiler skills include site inspections, measurements and application of modelling to deliver:

1. Assessment of boiler efficiency and capacity performance.
2. Identification of causes of boiler problems such as dust emissions.
3. Boiler modifications for improved combustion performance, heat transfer performance, reduced wear of convection bank, air heater and economiser tubes, and reduced corrosion of air heater tubes.  The economic benefits obtained are substantial, for example, increasing the convection bank tube life by 50% has a benefit of approximately $500,000 over 10 years in Australia.

Overseas boiler modifications carried out including in Nicaragua, Argentina, Mauritius, and China.  Responsible for tendering and supervision of capital projects in Australian sugar factory including the delivery of furnace and convection bank re-tubes, water pumps and air compressors to the value of ~$4 million.                                                                                                                                                                   Detailed involvement in energy studies and environmental audits as well as many process projects, for example, the design, supervision of drafting and manufacturing, and operation of portable pilot evaporators at sugar factories.                                                                                                                                                 Detailed involvement in experimental equipment design. For example, the design, drafting, manufacturing, and commissioning of a permeability and diffusivity rig for sugar cane straw that can measure properties in two directions for the same material sample.                                                                                                           In 2003 Floren Plaza was awarded a PhD entitled ´Measuring, modelling and understanding the mechanical behaviour of bagasse´.  The multi-disciplinary project was aimed towards understanding the behaviour of sugar cane materials during the extraction of juice from sugar cane and how to model that behaviour.  A special soil direct shear test geometry was designed to measure the mechanical (compression, shear and volume) behaviour of sugar cane prepared cane and bagasse which could cope with the large deformations experienced by sugar cane materials.  It was shown that prepared cane and bagasse behave like a soil, that is, that bagasse exhibits critical state behaviour at the large range of pressures that are present in the milling process (3 kPa to 20 MPa).   Then statistical analysis was carried out using specialised Parameter Estimation software (PEST) to show which material parameters, and their values, could be determined from different parts of the data.  A critical state elastic-plastic material model from the soil literature was modified and showed improved reproduction of bagasse behaviour than existing models available in commercial software.  Subsequently, preliminary modelling was carried out using the finite element package ABAQUS of the three roll pressure feeder of an Australian milling unit using the measured material parameters and the improved material model.  The project provided a platform from which the milling process could be better understood and improved.

Projects (Chief investigator)

• Strategies to minimise impacts of processing existing soft cane varieties, and industry cost/benefit analysis
• Technical and Financial assessment of natural flocculant production from Australian bagasse biomass

Projects

• Assess operations at each Australian factory to identify opportunities for improvement
• Biogas from sugarcane
• Development and evaluation of a pilot scale bagacillo removal system from juice
• Development of factory training for the Australian Sugar Industry
• Evaluate the operational performance and industry application for the final evaporator design at Victoria Mill
• Mercurius Australia

Additional information