Prof Peter Heggs
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Prof Peter Heggs
PhD (Leeds), FREng, CEng, CSci, FIChemE Visiting Research Professor |
Engineering Science of Unit Operations in Process Engineering
Heat, mass and momentum transfer, packed bed operations, adsorption/desorption, operability, control, design, heat exchangers, process integration, extended surface heat transfer, boiling and condensation.
Research Interests
Fluid Flow, Heat and Mass Transfer, Pressure Drop
The interactions between heat, mass and momentum effects in any simulation of a chemical process must be specified accurately in order to provide good predictions of the outcomes. In packed bed operations - catalytic reactors, adsorption/desorption, thermal regenerators, filters and packed separation towers, it is essential to have excellent contact between the fluid and the surfaces of the packing. Equally important is the flow distribution of the fluid within the packed bed. The prediction of pressure drop in these systems still relies completely on the use of empirical correlations, which require the accurate measurement of the properties of the packed bed - bed voidage, particle size distribution, surface roughness and the method of packing the bed. The geometry and size of the packed bed and the connecting pipework are also critical parameters in the search for the best design for reliable and safe operation of the process.
Many of the above comments apply to the design and operation of heat exchangers, where the packed bed is the heat transfer surface - tubes, plates, extended surfaces and now very compact etched surfaces. The uniform distribution of flow in these devices will provide efficient operation irrespective of the heat transfer. This is of great importance in the design and operation of compact heat exchanger catalytic reactors.
Hence it is still very necessary to perform experimental trials on process equipment and on scaled down versions in order to update the predictive correlations for use in the mathematical models. Recent experimental results from an industrial vertical thermosyphon reboiler have revealed natural circulations around of the loop at 30 times the feed flow! A mathematical simulation has been developed to predict this behaviour. Similar circulations have been measured and predicted for a flooded evaporator in a refrigeration storage unit.
The effect of solid particles on the gas hold-up within hte fluid in agitated vessels has alsos been measured. At the present time it is not possible to simulate theses types of phenomena.
Experimentation and mathematical simulation of process systems is still an integral part of my research and long may it be so.
Selected Publications
Ooi, T.H., Benson, H.R.S. and Heggs, P.J., Reflux Condensation under Vacuum of a Methanol/Water Mixture with Plain tube and Tube Inserts, Heat Transfer Engineering, Vol. 26, Number 7, pp. 3 -10, Sept 2005.
Lane, H.J. and Heggs, P.J., Extended Surface Heat Transfer: The Dovetail Fin, Applied Thermal Engineering, Vol. 25, pp. 2555 – 2565, 2005.
Cooke M. and Heggs P.J., Advantages of the Hollow (concave) Turbine for Multi-Phase Agitation under Intense Operating Conditions, Chemical Engineering Science, Vol. 60, pp 5529 – 5543, 2005.
Marin L., Elliott L., Heggs P.J., Ingham D.B., Lesnic D. and Wen X., Parameter identification in two-dimensional fins using the boundary element method, Numerical Heat Transfer Part A: Applications 50(4) 315-344, 2006.
Pichitvittayakarn W., Narataruksa P., Heggs P. J. and Tia S., Effects of Fluid Flow on Coconut Milk Fouling at Pasteurization Temperatures(70-74.5°C), Songklanakarin Journal of Science and Technology, Vol.28 (6), 2006.
Alane A. and Heggs P. J., The Re-Commissioned Thermosyphon Reboiler Research Facility in the Morton Laboratory, WIT Transactions in Engineering Sciences, Vol. 53, pp 337-350, 2006.
Rivero J. C. S. and Heggs P. J., The Re-Commissioning of a Vent and Reflux Condensation Research Facility for Vacuum and Atmospheric Operation, WIT Transactions in Engineering Sciences, Vol. 53, pp 371-380, 2006.
Heggs P. J. and Somasundram I. M., Fin Performance Ratios Greater than Unity: Not Just A Theoretical Aspiration, Applied Thermal Engineering, 27, 951-961, 2007.
Cooke M., Heggs P. J. and Rodgers T. L., The Effect of Solids on the Dense Phase Gas Fraction and Gas-Solid Mass Transfer at Conditions Close to the Heterogeneous Regime in a Mechanically Agitated Vessel, I.Chem.E, Vol.86(8), Part A, Chemical Engineering Research and Design, pp 869-882, 2008.
Narataruksa P., Triatana P., Pana-Suppamassadu K., Heggs P. J. and Tia S., Dynamic Simulation of Plate and Frame Heat Exchangers undergoing Food Fouling: Coconut Milk Fouling Case Study, ScienceAsia, Vol. 34 (2), pp 229-237, 2008.
Sacramento J. C. and Heggs P. J., The Role of Flooding in the Design of Vent and Reflux Condensers, Applied Thermal Engineering, in Press.