Blast Furnaces Gas Flare Application

Eurotherm’s Visual Supervisor

Following its enormous success with packaged applications such as electrode breakage detection for the glass industry and automation of the sterilization process for hospitals, Eurotherm’s Visual Supervisor has now demonstrated its potential in the steel industry with it’s recent integration in a gas flare control system for a blast furnace.

The system consists of a flare tip located on top of a stack and is equipped with six circumferentially mounted natural gas pilot burners each monitored by one thermocouple. The main flame being itself monitored by four thermocouples or infrared sensors.

During normal flaring operations, the blast furnace gas pressure is controlled. Any increase is relieved by flaring the excess gas.

The application includes a pressure loop and a flow loop sharing one unique analogue output. The functionality is such that when the system is under pressure control, the flow loop output tracks the active control loop output. When flow control is selected, the pressure loop enters Track mode.

Under normal conditions, the operator has a choice of controlling either the gas pressure or the gas flow. Interlocking sequence permitting, the above is carried out by using the appropriate soft-key button on the Visual Supervisor mimic. An automatic switchover dictated by various furnace conditions is also built-in.