A method and a system are for the control of a gas-containing hidden flow of molten metal in a space defined by a tubular device. From measurements in at least one predetermined layer of the metal flow in the space, an indication is obtained of the appearance of the flow which is compared with stored values. The result of the comparison is used for controlling at least one flow-affecting parameter in such a manner that a desired type of flow is provided at least in the layer.
Godkänd; 2001; 20081016 (cervante)