Abstract: Blast furnace installation having top gas recycling and process for operating same, in which the oxygen concentration of the oxidizing gas injected into the blast furnace is regulated as a function of the flow rate of the recycled top gas.

Abstract: The invention relates to a method of integrating a plurality of blast furnaces with a plurality of air gas separation units, in which the replacement blower available on the blast furnace site is used to feed compressed air into an air gas separation unit making it possible to enrich the blast-furnace blast with oxygen, this unit being stopped when one of the blowers of the blast furnaces has to be replaced with the blower used by the air gas separation unit.

Abstract: Blast furnace installation having top gas recycling and process for operating same, in which the oxygen concentration of the oxidizing gas injected into the blast furnace is regulated as a function of the flow rate of the recycled top gas

Abstract: The invention relates to a method of integrating a plurality of blast furnaces with a plurality of air gas separation units, in which the replacement blower available on the blast furnace site is used to feed compressed air into an air gas separation unit making it possible to enrich the blast-furnace blast with oxygen, this unit being stopped when one of the blowers of the blast furnaces has to be replaced with the blower used by the air gas separation unit.

Abstract: The invention relates to a method of integrating a plurality of blast furnaces with a plurality of air gas separation units, in which the replacement blower available on the blast furnace site is used to feed compressed air into an air gas separation unit making it possible to enrich the blast-furnace blast with oxygen, this unit being stopped when one of the blowers of the blast furnaces has to be replaced with the blower used by the air gas separation unit.

Abstract: The invention relates to a method for renovating a combined system consisting of a blast furnace supplied with an oxidant fluid received at least partly from an air/gas separation unit (ASU). The method consists in injecting, before renovation, at least 50% of the flow rate of the blower feeding the blast furnace into an ASU to produce oxygen whose purity is greater than 90% by volume of O2 which feeds the blast furnace, in controlling the blower airflow rate and the pressure of the air derived therefrom by a regulator which measures the flow rate and/or pressure at the input and/or output of a cleaning stage which is mounted upstream of the separation unit to control the flow rate and pressure of the air derived from the blower. The fluid feeding the blast furnace consists of pure oxygen or diluted by air produced by the cryogenic separation unit.

Abstract: The invention relates to a method for renovating a combined system consisting of a blast furnace supplied with an oxidant fluid received at least partly from an air/gas separation unit (ASU). The inventive method consists in injecting, before renovation, at least 50% of the flow rate of the blower feeding the blast furnace into an air/gas cryogenic separation unit in order to produce oxygen whose purity is greater than 90% by volume of O2 which feeds the blast furnace, in controlling the blower airflow rate and the pressure of the air derived therefrom by means of a regulator which measures said flow rate and/or pressure at the input and/or output of a cleaning stage which is mounted upstream of the separation unit in such a way that the flow rate and pressure of the air derived from the blower is controlled. The fluid feeding the blast furnace consists of pure oxygen or diluted by air produced by the cryogenic separation unit.

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: Electric arc oven for melting scrap iron of the type comprising a vat lined with an inner coating made of refractory material which is called the sole of the oven, lateral walls, a vault capping the upper opening of the vat, openings provided in the vault through which the electrodes extend, and a tapping nozzle or eccentric tapping hole. In this oven, the sole is provided with at least one device for injecting gas to stir the molten metal. The injection device includes a low injector formed of a compact block made of dense non-porous refractory material through which extend one or a plurality of, preferably less than 50, hollow metallic tubes or slits or channels along its entire height in the direction of gaseous blowing and permitting gas to pass therethrough.