The present invention relates to an improved method of and apparatus for collecting the fumes from a steelmaking furnace which is rotatable about an axis and known in the art as "Oxygen Steelmaking Furnace."
More particularly, this invention relates to an improved method and apparatus of fume collection during charging of molten metal and scrap used in modern steelmaking.
In the art of steelmaking in an oxygen steelmaking furnace oxygen is blown onto a charge of molten metal or scrap while the furnace is in an upright postion with its mouth opening generally upwardly. During the blowing of oxygen the furnace, in its upright position, is conventionally provided with a gas evacuation system including a hood which is aligned with the furnace mouth. In such a furnace, the operation is generally as follows:
I. Scrap is charged after the furnace is rotated in a first direction from the upright position into an inclined position; PA1 Ii. Molten iron is charged while the furnace is rotated into the inclined position; PA1 Iii. Oxygen is blown onto the charge after the furnace has been returned to an erect, or upright position; PA1 Iv. At the beginning of the blow fluxes are added; PA1 V. At the end of the blow temperature and sample are taken generally after the furnace is again rotated in the first direction into the inclined position; PA1 Vi. If the bath meets specifications the heat is tapped into a ladle by rotating the furnace in the opposite direction from the first direction; PA1 Vii. The slag is discharged by rotating the furnace 180.degree. from the blowing position and the cycle is completed; PA1 Viii. The furnace is rotated to the inclined position and the process is repeated.
During the charging of molten iron in the inclined furnace a very serious pollution problem occurs since the mouth of the furnace is not positioned under the hood which is used to take emissions during blowing. During the charging of molten iron such emissions are so violent, especially if the scrap is dirty or oily, that great quantities of fumes including a flaming tongue laden with smoke are released from the mouth of the furnace into the building. These polluting conditions cannot be withdrawn into the conventional hood whether it is of the open or closed type because the furnace is in its inclined position and the mouth thereof is not in registry with the point of entry of the hood. The hood is efficient in withdrawing emissions when the furnace is in its upright position but not in its inclined position to take the charge.