OPEN HEARTH FURNACE AND METHOD FOR STEEL MELTING IN IT Russian patent published in 2007 - IPC C21C5/04 

FIELD: metallurgy, namely steel melting processes in open hearth furnaces.

SUBSTANCE: method comprises steps for creating during all stages of steel melting at different sides relative to cross axis of furnace superheating reducing zones due to feeding through plasmatrons natural gas and air to interface of melt metal and slag. At charging process natural gas and air are supplied to plasmatrons at volumetric relation of oxygen to natural gas a = 0.2 - 0.3; after charging to bath at least half of cast iron, said relation is increased from its value a till 0,35 - 0,5 and solid and liquid phases are subjected to action of plasma jet till complete melting of metal. Metal composition is corrected and when content of carbon in metal becomes less than necessary value factor a is decreased till 0.35. At excess content of carbon factor a is increased from 0.5 till 0.8. In lower part of working space of furnace in slope portion of rear wall plasmatrons are mounted by inclination angle 20 - 40° relative to cross axis of furnace. Outlet nozzles of plasmatrons are arranged in zone of interface melt metal and slag. In plan view projections of plasmatrons axes relative to lengthwise axis of furnace are inclined by angle 20 -80°.

EFFECT: shortened time period of melting process, lowered material and power consumption.

2 cl, 2 dwg