More s.r.l. is a supplier for electric arc furnaces based in Italy. A critical function of its heaters is the ability to accurately measure oxygen-fuel ratios in the steel-making process. Too much oxygen causes over-oxidation (decarburization), which requires expensive re-work to obtain steel of suitable quality. It also creates overheating, which can damage the furnace. Too little oxygen, on the other hand, slows production.
Steel making demands accurate control of the injector feed oxygen-fuel ratio. To address this critical function, More uses the Rosemount 8800 Vortex flowmeter. The company chose this flowmeter because its adaptive digital signal processing (ADSP) and mass-balanced-sensor design deliver accurate oxygen-fuel ration measurement by eliminating the impact of vibrations on measurement accuracy. According to More, this level of accuracy was not possible with the differential pressure (DP) flowmeters traditionally employed by the company.
More also reports that the 8800 increases its flexibility in furnace installations. This is due to the 25:1 rangeability of the 8800, which helps to optimize gas heaters by providing greater opportunities to vary the characteristics of the steel for different applications. And while DP flow meters can have up to 30 leakage points, the gasket-free sensor design of the 8800 eliminates potential for leak points. Leak-free operation of the flowmeter is possible because the meter body design eliminates all ports and crevices that can affect the ability of the sensor to measure flow. In addition, the isolated sensor design eliminates the need to break process seals for sensor replacement.
"By implementing Emerson’s Rosemount vortex technology, we have been able to build electric arc furnaces that guarantee optimum furnace efficiency for users in terms of productivity and steel quality," says Roberto Urbani, More’s purchasing manager. "Over-oxidation is no longer an immediate concern, thereby extending the furnace life cycle. Energy consumption and ambient pollution have also been reduced."
