Recently VELCO installed a desulphurization installation at the ladle furnace of a carbon steel producer in the southwest of Turkey.
The customer has initial sulphur contents up to 500 ppm which shall be reduced to 50-100 ppm. For this purpose VELCO designed an installation for the depth injection of lime fines and CaSi.
The injection material is supplied either by silo-truck or in BIG BAGs and stored in a 25 qm silo. An injection machine type UNIDOS 2,5 is placed under this silo which transports the desulphurization material over a distance of approx. 30 m to the injection manipulator type LMI that is placed at the ladle furnace. For injection the manipulator is turned through 50º. The desulphurization agent is injected via a monolithic lance which is dipped into the melt for approx. 3,0 m. The exchange of the lances is done in parking position of the manipulator. The lance clamping is effected hydraulically. The machine is operation with a vessel pressure of approx. 5 bars. Capacities of 60-100 kg/min. are achieved.
The movements of the lance manipulator are frequency inverter controlled and monitored by encoders and limit switches.
An amount of 400 – 800 kg desulphurization agent is injected for a charge weight of 130 – 150 t. The depth injection is quicker and more efficient than the wire feeding.
The installation is controlled and visualized from the furnace control station.
The set values as well as the conveying rate to be injected are preset and recorded by the furnace control.