Method and device for detecting variables in the outlet of a metallurgical vessel

Method for detecting at least one variable relating to a spout of a metallurgical vessel while metal melt passes through the spout of the metallurgical vessel, each of the at least one variable being selected from a group consisting of a proportion of slag during passage of the metal melt through the spout of the metallurgical vessel, a degree of wear of refractory parts defining an outlet channel of the spout, and an amount of solidified metal melt or plugging material in the outlet channel, the method comprising the steps of:

• heating the metal melt in the outlet channel using an induction coil of an induction heater, the induction coil surrounding the outlet channel;
• and
• monitoring the at least one variable using a supply and evaluation unit electrically connected to the induction coil and while the metal melt passes through the outlet channel and is being heated by the induction coil, by
• producing an alternating current with a predetermined frequency in the induction coil as the metal melt is being heated by the induction coil;
• and
• determining impedance of the induction coil resulting from the alternating current in the induction coil which varies relative to the at least one variable such that at least one value of the at least one variable is determined based on the determined impedance;
• whereby, based on the determined the at least one variable, a closure member for the spout is actuated, heating the metal melt in the outlet channel is adjusted or relining of at least one of the refractory parts defining the outlet channel is undertaken.