HEAT EXCHANGE IN THE SYSTEM MOULD - RISER - AMBIENT. PART I: HEAT EXCHANGE COEFFICIENT FROM MOULD EXTERNAL SURFACE

摘要

The subject of the paper is heat exchange in the system casting - riser - ambient. The examinations were focused on evaluating temperature dependence of the coefficient of heat exchange from mould external surface (or from riser thermally insulated surface) to ambient. The examinations were carried out for the surface temperatures of 200-800°C. On the basis of the performed examinations it was slated that the relationship α_(ext.eff) vs. surface temperature can be described by a polynomial of 3rd degree with accuracy of 90-95% and that the α_(ext.eff) coefficient significantly depends on the examined material mass density.