Washington – OSHA has released a bulletin with information on how to protect workers from carbon monoxide explosion hazards related to electric arc furnaces in the steelmaking industry.

A sensor system for monitoring and controlling the performance of the bottom electrode and the deflection of an electric arc in an electric steel making furnace includes an organized matrix of anode pins interspersed with refractory material and extending toward an electrically conductive plate secured to distal ends of the anode pins. A sensing device includes two temperature sensors at spaced apart locations along each of a distributed select group of anode pins for providing corresponding electrical signals and a current sensor responsive to electrical current flowing through the anode pins of the distributed select group of anode pins for providing a corresponding electrical signal. A controller responsive to the electrical signals derived at the anode pins of the select group operates the power supply and a display for monitoring the electrical performance of the elongated anode pins for heating by the electric arc in the furnace.

A roof system for an electric arc furnace includes a skew removably attached to the electric arc furnace, a lining of refractory material affixed to the skew, and a delta composed of a refractory material. The delta has at least one aperture capable of receiving an electrode. The delta fits onto and is supported by the refractory lining that is affixed to the skew.

A movable device for injecting oxygen and other technical materials into an electric arc furnace includes a housing situated above a portion of a step of a crucible and equipped with a cooling coil, an injection lance of oxygen and other technical materials, a supporting and moving system of the lance between minimum and maximum range points of the liquid bath level contained therein, positioned in the housing, an opening situated in the housing and facing the inside of the crucible in which the lance is transferably guided, and a scraping member disposed between the opening and the lance.

A method is provided to control the feed of a metal charge into an electric arc furnace having at least one electrode to generate an electric arc to melt metals. The method includes: a step of defining a “cover index CI” of the electric arc by the slag present above the liquid metal bath, in order to calculate which of the harmonics present in an electric feed quantity of the furnace are taken into consideration; a step of measuring the actual cover index CI value during a functioning cycle of the furnace; and a step of adjusting the speed of feed of the metal charge into the furnace based on the measured value of the cover index CI.

Toulouevski, Yuri N., author