| 摘要 |
<p>The performance of an open hearth furnace, such as one heated by producer or natural gas or by means of an oil and air burner, is improved during the melting period (see Fig. 1) by blowing oxygen through water-cooled lances 4 vertically into the flame 3 entering from the furnace end, and during the refining period, Fig. 2 (not shown), by adjusting and arranging the distances of the lances from the surface of the molten iron, e.g. by a lifting mechanism 6, to effect a wide superficial contact of oxygen and avoid or reduce to a minimum any Fe2O3 smoke. During both periods, the oxygen is blown at a pressure between 0.2 and 0.8 atmosphere in excess of atmospheric pressure, and leaves the lances at a velocity of between 50 and 250 metres per second. <FORM:0949834/C3/1></p> |
