Thermal model of rolls and sheets improvement by experimental study of cooling

The precision of thermal models is strongly influenced by the areas where the heat transfer is very intensive. In the thermal models of rolls behaviour and temperature field of a rolled product there is the agreement with physical reality strongly dependent on the proper description of intensity of water cooling. An experimental device for testing of various nozzles was built up. Water pressure up to 1 MPa and cooled surface up to the 950°C were used. The experiment covers not only the area of direct droplets impingement but the adjacent area as well. An inverse heat conduction method for heat transfer coefficient evaluation is presented. The results are available in the form of heat transfer coefficient distribution above the quenched surface in particular time instant or as the heat transfer coefficient history in a chosen surface point.