Vortex flowmeters help optimize efficiency and energy usage for arc furnaces
MORE s.r.l. has reduced energy consumption and optimized the quality of steel produced from its electric arc furnaces by using Rosemount 8800 Vortex flowmeters from Emerson Process Management. The flowmeters are being used to measure and optimize oxygen used in the steel making processes more accurately than earlier technologies the company had tried. Optimization of the oxygen-fuel ratio is critical to minimizing conversion costs, reducing oxygen and fuel consumption, and avoiding rework. In addition, accurate control of oxygen improves furnace safety and reduces environmental impact.
Based in Gemona del Friuli (UD), Italy, MORE supplies a wide range of technologies and auxiliary equipment for electric arc furnaces used in the steel-making industry. These include sidewall injector systems used with chemical energy packages such as oxygen, carbonaceous fuels, lime, and other fines. These chemicals are injected into the furnace during the melting process to improve steel quality and provide additional energy from exothermic reactions, helping to reduce overall energy consumption.
MORE had been using differential pressure (DP) flowmeters to measure the oxygen flow in its electric arc furnaces. However, the capabilities of the existing meters made it difficult to meet customer demand for more accurate control, as well as changing process requirements. More accurate instruments with a broader measurement range were required.
Always eager to use the best available technology for its furnace installations, MORE decided to evaluate vortex flowmeters since this technology is recognized as being both accurate and suitable for challenging applications.
"We tried vortex meters from various other manufacturers but found that their products were not sturdy enough, or they were too sensitive to vibrations that resulted in an unreliable measurement and consequently, poor control of the oxygen-fuel ratio," said Roberto Urbani, purchasing manager, MORE s.r.l. "Using Rosemount vortex flowmeters eliminated these problems, delivering the accurate and reliable measurements we required."
In addition, to meet customer demands for greater flexibility in their furnace installations, the 25:1 turn-down range of the 8800 helps optimize gas heaters, 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 means there are no potential leak points, reducing maintenance requirements and enhancing safety. The meter body design eliminates all ports and crevices that can affect the ability of the sensor to measure flow, and the isolated sensor design eliminates the need to break process seals for sensor replacement.
Accurate oxygen control is critical for steelmaking. Too much oxygen causes over-oxidation (decarburization), which requires expensive re-work to obtain steel of suitable quality. It also creates over-heating, which can damage the furnace. Too little oxygen, on the other hand, slows production. The application therefore demands measurement devices that enable accurate control of the injector feed oxygen-fuel ratio.
Emerson Process Management
Edited by Peter Welander, firstname.lastname@example.org