Full Scale Measurements of Cooling Intensity and Homogeneity

Heat treatment of rolled materials requires designing cooling sections with sufficient and controllable cooling intensity. Cooling of flat products (strips, sheets and plates) without thermally inducted distortion requires reaching good uniformity of cooling. The most difficult problem is to keep cooling uniformity with variability of cooling intensity.

A test bench was built for the purpose of finding the optimal cooling strategy for a given technology. A steel sample embedded with thermocouples is heated to an initial start temperature in an electric furnace. The heated sample of real dimensions is instrumented with thermocouples is then moved into a cooling unit under the set of nozzles. This process of cooling is controlled to simulate running under the long cooling section used normally in the plant. Nozzles, pressures, and header configurations are tested. Heat transfer coefficient distribution is measured. HTC is strongly dependent on surface temperature.

The results gained from the heat transfer test are used in a numerical model of the temperature field in the cooled material. A virtual cooling section is created and possible temperature histories are computed. The resultant numerical model predicts the controllability of the cooling device and assists in the preparation and adjustment of fast simple control models.