Title

Energy Balanced Scrap Preheating Furnace

Energy Balanced Scrap Preheating Furnace

Authorship

DENIER, GUY; HOUBART, MICHEL; KAELL, NORBERT; ROTH, JEANLUC

DENIER, GUY

I am this author

HOUBART, MICHEL

I am this author

KAELL, NORBERT

I am this author

ROTH, JEANLUC

I am this author

DOI

10.5151/2594-5327-C00153-2423-2435

Downloads

Abstract

Scrap preheating is an efficient method to reduce the melting energy costs and to increase the productivity, if some basic prerequisites are fulfilled concerning the energy-and time efficiency of the preheating process. Specially important is the scrap charging pattern, which must allow: to use high rates of fossil inputs and high arc power throughout the process to always maintain scrap across the process offgases to minimize the power-off times for charging. In case of using hot metal, the same targets apply, the hot metal charging technology being essential for avoiding time and energy losses at charging and for allowing high decarburization rates. The paper describes how the Finger Shaft Furnace built by Paul Wurth, equipped with traveling shaft and with a system charging hot metal under arc power, fulfills these objectives and achieves outstanding performances. Reported are industrial results of the Cockerill-Sambre furnace, which is tapping 170 tons with a productivity exceeding 200 t/h for a 65% scrap + 35% hot metal charge, and with energy consumptions of 210 kWh + 29 m³ Oxygen + 3 m³ gas per ton of liquid steel. For a 100% scrap charge, the consumptions are 310 kWh + 28 m³ Oxygen + 6 m³ per ton of liquid steel.

Scrap preheating is an efficient method to reduce the melting energy costs and to increase the productivity, if some basic prerequisites are fulfilled concerning the energy-and time efficiency of the preheating process. Specially important is the scrap charging pattern, which must allow: to use high rates of fossil inputs and high arc power throughout the process to always maintain scrap across the process offgases to minimize the power-off times for charging. In case of using hot metal, the same targets apply, the hot metal charging technology being essential for avoiding time and energy losses at charging and for allowing high decarburization rates. The paper describes how the Finger Shaft Furnace built by Paul Wurth, equipped with traveling shaft and with a system charging hot metal under arc power, fulfills these objectives and achieves outstanding performances. Reported are industrial results of the Cockerill-Sambre furnace, which is tapping 170 tons with a productivity exceeding 200 t/h for a 65% scrap + 35% hot metal charge, and with energy consumptions of 210 kWh + 29 m³ Oxygen + 3 m³ gas per ton of liquid steel. For a 100% scrap charge, the consumptions are 310 kWh + 28 m³ Oxygen + 6 m³ per ton of liquid steel.

Keywords

Electric Arc Furnace, Scrap preheating, Hot metal, Shaft with fingers

Electric Arc Furnace, Scrap preheating, Hot metal, Shaft with fingers