Abstract: A charge of scrap is melted in a furnace (1) with post-combustion of the fumes by injection of an oxygenated gas into the space in the furnace above the charge. During periods of post-combustion, the oxygenated gas is injected in the form of several jets each having a flow rate comprised between about 400 and 1200 Nm.sup.3 /h and an injector (11, 12) outlet speed comprised between about 50 and 150 m/s, preferably between about 500 and 900 Nm.sup.3 /h and between about 70 and 125 m/s. Several groups of injectors (11, 12) are used, having an outlet tangential component relative to the vertical axis (X--X) of the furnace (1), successive groups of injectors being disposed at different levels (N.sub.1, N.sub.2) and oriented in alternate circumferential directions.

Abstract: A furnace comprises a space overlying a charge into which space opens at least one oxygenated gas injector passing through the periphery of the furnace to deliver within this space a jet of gas that is nonradial relative to a vertical axis of the space. Each injector comprises a) a head (14) disposed within the thickness of the wall (1) of the furnace and having a gas passage having an axis (11) inclined at a predetermined angle (.alpha.) to an axis (15) that is substantially radial relative to the vertical axis of the space overlying the charge and b) a substantially cylindrical body (16) prolonging the head and the gas passage within the furnace along this substantially radial axis (15), itself substantially perpendicular to the wall (1) through which it passes. The injector is useful in an electric furnace for melting scrap for the production of steel.

Abstract: The tubular rod (7) for sampling, mounted in a duct for the evacuation of fumes for example from a heat treatment or a melting furnace, includes an extractor tube (8) extending in a closed sleeve (9) comprising an inlet (11) and an outlet (12) of cooling fluid, the extractor tube having an end part opening outside the sleeve by means of an opening (10) for sampling fumes and a connecting part (14) extending outside the sleeve for connection to a circuit of analysis including a suction pump. The opening (10) is advantageously directed in counter-current with respect to the direction of circulation (F) of the fumes (11). Application such as for process control in an electrical furnace for the production of steel with injection of oxygenated gas.

Abstract: Process for melting a furnace charge, with post-combustion of the smokes by njecting an oxygenated gas in the furnace atmosphere as a series of jets flowing according to a tangential component in the space between electrodes and cylindrical furnace partition of the furnace, in a direction of injection so as to produce a rotary gas current about the vertical axis of the furnace and preferably in at least two series as two stepped levels to produce gas currents which rotate in opposite directions. Applications to electrical furnaces for the production of steel or ferro-alloys.