Title: Experimental investigation and numerical simulation of heat transfer in quenching fluidised beds

Authors: W.M. Gao, L.X. Kong, P.D. Hodgson

Addresses: School of Engineering and Technology, Deakin University, Geelong, Vic. 3217, Australia. ' Centre for Advanced Manufacturing and Research, University of South Australia, Mawson Lakes, SA 5095, Australia. ' School of Engineering and Technology, Deakin University, Geelong, Vic. 3217, Australia

Abstract: Fluidisation characteristics at different surfaces of a work-piece of complex geometry are conducted in a fluidised bed at various conditions including fluidising number, bed temperature and fluidising medium. The quenching of the work-piece is performed experimentally. In particular, the major frequency and energy of the pressure fluctuations are measured as a function of either fluidising velocity or heat transfer position and the results are used to develop a mathematic model. A computational model is developed to simulate gas dynamics and heat transfer between the fluidised bed and the work-piece surface, as well as simulating the temperature within the work-piece. The predicted cooling curves are in good agreement with the experimental results. Based on the simulation results, the flow characteristics of the gas and the temperature of the dense gas-solid phase near the work-piece surface are analysed to understand the heat transfer mechanism in the fluidised bed.

Keywords: quenching; heat transfer; modelling; pressure fluctuation; numerical simulation; heat treatment; fluidised beds; fluidisation; workpiece surfaces; fluidising velocity; gas dynamics; cooling curve.

DOI: 10.1504/IJMPT.2005.007958

International Journal of Materials and Product Technology, 2005 Vol.24 No.1/2/3/4, pp.319 - 338

Published online: 06 Oct 2005 *

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