ABSTRAKT

The heat transfer process at the aluminium heat treatment furnaces can be characterised basically through the forced convection. In order to determine the heating up time and to estimate the maximum temperature difference a serial experience has been carried out at a model of a most often applied furnace.
The model was able to simulate the heat transfer of air/flue gas among the opening of aluminium slab-charge in heat treatment furnaces. In this parametric study the following parameters were considered: the Reynolds number, the slot among the charge and the length of flow. We paid attention particularly to the heat transfer phenomena at the beginning, transient phase of heating up process.
The discussion of the experimental results led to the determination of coefficient a as a function of above mentioned parameters taking into account the temperature-time relationship as well.
The investigated parameters had been chosen according to the conditions of most often applied industrial furnaces. The changing of heat transfer coefficient during the whole process and its local distribution made possible a more exact calculation. The results were applied at an operating aluminium heat treatment furnace of 60t capacity.