Scarfing apparatus

摘要

A scarfing apparatus which allows a greater diagonal stand-off distance from a slab during preheating and scarfing is disclosed. The apparatus includes a manifold and head assembly for receiving and distributing oxygen and fuel gas. Upper and lower preheat blocks extend from the manifold and head assembly. The blocks are spaced to define an oxygen scarfing slot and discharge orifice of predetermined size for receiving a flow of scarfing oxygen from the manifold and head assembly. A plurality of preheat nozzle inserts are mounted within the upper preheat block adjacent to each other in a row substantially across the width of the upper preheat block. Each nozzle insert includes a central bore through which a flow of oxygen is received from the manifold and head assembly and discharged through the insert. Longitudinally extending, substantially parallel flutes are positioned on the outer surface of the nozzle inserts and form fuel gas flow channels which receive fuel gas from the manifold and head assembly and deliver the fuel gas in a substantially parallel, concentric flow around the central flow of oxygen to prevent a sharp fuel gas flow intersection with the oxygen to maintain the momentum of the oxygen adjacent the nozzles as it exits the central bore. The nozzle inserts may be readily replaced when damaged. A method of initiating preheating of a slab with the scarfing apparatus of the present invention also is disclosed.