Method and apparatus for detecting level of molten metal

A method of detecting a level of molten metal existing within a mold having at least two opposite side walls, comprising the steps of:

• disposing a transmission coil and a receiving coil opposite to each other and each facing the outer surface of the opposite side wall of the mold interposed between said coils;
• applying an AC voltage to said transmission coil for producing an alternating magnetic flux such that at least a part of said alternating magnetic flux passes through said mold and the molten metal, if any, and reaches said receiving coil;
• and
• determining a voltage value of a component of the AC signal induced in said receiving coil, said component being in phase with the AC voltage applied to said transmission coil;
• and
• determining the level of said molten metal on the basis of said voltage value.

A method of detecting a level of molten metal existing within a mold having at least two opposite side walls, comprising the steps of:

• disposing a transmission coil and a receiving coil opposite to each other and each facing the outer surface of one of the opposite side walls of the mold interposed between said coils;
• applying an AC voltage to said transmission coil for producing an alternating magnetic flux such that at least a part of said alternating magnetic flux passes through said mold and the molten metal, if any, and reaches said receiving coil;
• and
• determining a phase difference between the phase of the AC signal induced in said receiving coil and the phase of the AC voltage applied to said transmission coil;
• and
• determining the level of said molten metal on the basis of said phase difference.

An apparatus for detecting a level of molten metal existing within a mold having at least two opposite side walls comprising:

• a transmission coil and a receiving coil positioned opposite to each other and each facing the outer surface of the opposite side wall of the mold interposed between said coils;
• means for applying an AC voltage to said transmission for producing alternating magnetic flux such that at least a part of said alternating magnetic flux passes through the mold and the molten metal, if any, and reaches said receiving coil;
• and
• means for determining the level of the molten metal on the basis of at least one of a voltage value and a phase of an AC signal induced in said receiving coil by said alternating magnetic flux.

An apparatus for detecting a level of molten metal existing within a mold having at least two opposite side walls comprising:

• a transmission coil and a receiving coil positioned opposite to each other and each facing the outer surface of the opposite side wall of the mold interposed between said coils;
• means for applying an AC voltage to said transmission for producing alternating magnetic flux such that at least a part of said alternating magnetic flux passes through the mold and the molten metal, if any, and reaches said receiving coil;
• and
• means for detecting a voltage value of an AC signal induced in said receiving coil in phase with said AC voltage applied to said transmission coil;
• and
• determining the level of the molten metal on the basis of said voltage value of the AC signal induced in said receiving coil.

An apparatus for detecting a level of molten metal existing within a mold having at least two opposite side walls comprising:

• a transmission coil and a receiving coil positioned opposite to each other and each facing the outer surface of the opposite side wall of the mold interposed between said coils;
• means for applying an AC voltage to said transmission for producing alternating magnetic flux such that at least a part of said alternating magnetic flux passes through the mold and the molten metal, if any, and reaches said receiving coil;
• means for determining a phase difference between the phase of the AC signal induced in said receiving coil and the phase of the AC voltage applied to said transmission coil;
• and
• means for determining the level of the molten metal on the basis of said phase difference.

A method of detecting the level of molten steel existing with a mold having at least first and second opposite side walls of continuous casting equipment, comprising the steps of:

• disposing a transmission coil on the first side wall and a receiving coil on the second opposite side wall at the outside of said side walls of said casting equipment;
• applying an AC voltage to said transmission coil for producing alternating magnetic flux such that at least a part of the alternating magnetic flux passes through said mold and said molten steel, if any, and reaches said receiving coil;
• and
• determining the level of the molten steel on the basis of at least one of a voltage value and a phase of an AC signal induced in said receiving coil by said alternating magnetic flux.

An apparatus for detecting the level of molten steel existing within a mold having at least first and second opposite side walls of continuous casting equipment comprising:

• a transmission coil on the first side wall and a receiving coil on the second opposite side wall disposed at the outside of the side walls of said casting equipment;
• means for applying an AC voltage to said transmission coil to produce alternating magnetic flux so that at least a part of the alternating magnetic flux passes through the mold and the molten steel, if any, and reaches said receiving coil;
• and
• means for determining the level of the molten steel on the basis of at least one of a voltage value and a phase of an AC signal induced in said receiving coil by said alternating magnetic flux.