LF ladle refining furnace

LF ladle refining furnace is the equipment for refining in the ladle after the electric furnace or converter is tapped. LF ladle refining furnace consists of ladle, furnace cover, electrode heating system, and argon stirring system. Argon gas is blown into the breathable brick installed at the bottom of the ladle to stir the molten steel to complete the reaction between steel and slag. The function of the furnace cover is to close the refining chamber to maintain the reducing atmosphere. Using three-phase electrodes, slagging and molten steel heating are carried out by arc heating, and a sliding nozzle is installed at the bottom of the ladle for pouring.

The electric arc heating system used in LF ladle refining is the same as the steelmaking electric arc furnace. The arc generated between the three graphite electrodes and the slag molten steel is used as the heat source. The heating equipment is basically the same as the electric furnace. The difference is that there is no melting process in the LF furnace. Moreover, the ambush heating method is adopted, so compared with the electric furnace, a lower secondary voltage and the smallest possible center circle can be used, and the submerged arc heating method has a protective effect on the furnace lining due to the small radiant heat. At the same time, the heating efficiency is relatively high, and the heat utilization rate is good.

The secondary side of the transformer used in the LF ladle refining furnace is usually divided into several levels of voltage, but there is no need to carry out load adjustment, so the equipment is simpler and has good reliability. During refining in the LF ladle refining furnace, the steel liquid level is relatively stable, and the current fluctuation is small. There is no short-circuit impulse current caused by the collapse of the charge when the electric furnace melts the charge, so the current density can be selected larger.

The LF ladle refining furnace adjustment system must have a high sensitivity automatic adjustment system to reduce and prevent the electrode from contacting the molten steel to cause carbon increase.

LF ladle refining furnace has the functions of electric arc heating under normal pressure, bottom blowing argon stirring, temperature measurement and sampling, fine adjustment of alloy composition, deoxidation, desulfurization and removal of impurities, so as to obtain high purity molten steel.