Sonic furnace monitoring apparatus

A sonic control system, in a metallurgical furnace including a lance, a lance drive, and a liquid cooling circuit, for controlling a lance cooled by a liquid cooling circuit, the lance injecting at least one substance into the melt of said metallurgical furnace for improving the resultant metal composition, there being injection control means for controlling the rate of substance injection, said sonic control system comprising:

• a hydrophone mounted in sonic communication with said liquid cooling circuit, for obtaining a sonic input from said metallurgical furnace;
• a sonic analyzer having data transmission means linking said sonic analyzer to said hydrophone and linking said sonic analyzer to computer means;
• said computer means including memory means for storing predetermined sonic signature data;
• said computer means for converting the sonic input from said hydrophone to an operating sonic signature data, for comparing the predetermined sonic signature data to the operating sonic signature data and thereby generating first control signals responsive thereto;
• and
• first control means for operating said injection control means responsive to said first control signals.

A method of providing sonic inputs to a control system for controlling a lance of a metallurgical furnace, the lance cooled by a cooling liquid, comprising the steps of:

• a) placing a hydrophone in sonic communication with the cooling liquid;
• b) obtaining sonic inputs transmitted through the cooling liquid;
• and
• c) transmitting sonic inputs obtained in step b) to automatic data processing means for generating control signals responsive to sonic inputs.