A scrap steel preheating type electric arc furnace and a method for improving a heating cold region of a side wall charging electric arc furnace are provided. The scrap steel preheating type electric arc furnace includes an electric arc furnace body and an inclined scrap steel preheating chamber. An included angle between the scrap steel preheating chamber and a horizontal plane is 30? to 65?. The scrap steel preheating chamber is connected with the electric arc furnace body. A dust removal pipe chamber is at an upper end. A material blocking tooth rake is on the scrap steel preheating chamber. A driving mechanism is below the material blocking tooth rake. Flue gas enters the scrap steel preheating chamber, penetrates through the material blocking tooth rake and the scrap steel and is sucked out by the dust removal pipe chamber. The scrap steel is preheated; then, the material blocking tooth rake is opened; and the preheated scrap steel slides to a center of the electric arc furnace body along a slot bottom of the inclined scrap steel preheating chamber. A falling angle of the scrap steel is changed through a method of matching the scrap steel preheating chamber with a large inclined angle and the material blocking tooth rake, thereby overcoming a problem of lateral stacking of the side wall charging electric arc furnace, reducing impact force of the scrap steel to the device and greatly enhancing reliability of the device.

The present disclosure is characterized by inexpensively treating an ammonia gas contained in an exhaust gas after nitriding without performing combustion, adsorption using an adsorption agent, or the like. A vacuum carburizing device of the present disclosure includes a heating furnace which heats a workpiece, an ammonia gas supply device which supplies an ammonia gas and nitrides the workpiece to the heating furnace, and a thermal decomposition furnace which thermally decomposes the ammonia gas discharged from the heating furnace after nitriding.

An enclosure of a steel-making furnace system includes a support structure including a frame that defines an interior, a supply line for supplying a cooling liquid from a reservoir, and a return line fluidly coupled to the supply line and the reservoir. A plurality of panels includes sinuously winding piping having an inlet and an outlet. The inlet is fluidly coupled to the supply line and the outlet is fluidly coupled to the return line. The frame includes a plurality of support members spaced from one another, where each of the plurality of support members defines a slot. Each of the plurality of panels is removably and slidably received with the slot for coupling to the frame.