Local total and radiative heat-transfer coefficients during the heat treatment of a workpiece in a fluidised bed
Data(s) |
01/01/2006
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Resumo |
The heat-transfer coefficients around a workpiece immersed in an electrically heated heat treatment fluidised bed were studied. A suspension probe designed to simulate a workpiece of complex geometry was developed to measure local total and radiative heat-transfer coefficients at a high bed temperature. The probe consisted of an energy-storage region separated by insulation from the fluidised bed, except for the measuring surface, and a multi-thermocouple measurement system. Experiments in the fluidised bed were performed for a fluidising medium of 120-mesh alumina, a wide temperature range of 110–1050 °C and a fluidising number range of 1.18–4.24. It was found that the workpiece surface temperature has a more significant effect on heat transfer than the bed temperature. The total heat-transfer coefficient at the upper surface of the workpiece sharply decreased at the start of heating, and then steadily increased as heating progressed, while a sharp decrease became a rapid increase and then a slow increase for the radiative heat-transfer coefficient. A great difference in the heat-transfer coefficients around the workpiece was observed.<br /> |
Identificador | |
Idioma(s) |
eng |
Publicador |
Pergamon |
Relação |
http://dro.deakin.edu.au/eserv/DU:30003829/n20060982.pdf http://dx.doi.org/10.1016/j.applthermaleng.2005.12.013 |
Direitos |
2006, Elsevier Ltd |
Palavras-Chave | #fluidised bed #heat transfer #radiation #heat treatment #metal |
Tipo |
Journal Article |