Provided are a fixed-type electric furnace enabling continuous operation which allows melting without the interruption of power supply and tapping in a fixed state, and a fixed-type electric furnace and a molten steel production method using same. The fixed-type electric furnace comprises: a preheating furnace which is disposed on the side of a melting furnace and preheats an iron source (scrap) using exhaust gas from the melting furnace; a supply means for supplying the iron source, which has been preheated in the preheating furnace, to the melting furnace; the melting furnace comprising electrodes for melting the preheated iron source; and a fixed-type discharge means for discharging molten steel which has been melted in the melting furnace, wherein the preheating furnace is integrally connected to the melting furnace.

Apparatus for pre-heating and conveying a metal charge to a container of a melting plant, comprising at least a conveyor channel along which said metal charge is able to advance so as to be delivered to the container, and in which above said conveyor channel at least a hood is disposed which defines a tunnel inside which at least part of the fumes exiting from said container are able to advance. At least a zone of the hood comprises an expansion chamber located above at least a portion of said metal charge, and able to expand and keep said fumes inside it for a minimum desired time of at least 1.5 seconds before they go into contact with the metal charge.

A process for heating a metal feedstock (31) fed in continuous to a smelting furnace (30) through a second horizontal heating section (34) through which hot discharge fumes collected from said furnace (30) pass, said fumes exerting a heating phase of said feedstock (31), characterized in that, immediately before entering said second heating section (34), the feedstock (31) is subjected to a preheating phase by heating means other than the discharge fumes collected from the smelting furnace (30). In a plant for the embodiment of said process, said different heating means are envisaged inside a first preheating section (33), which is operatively connected with said second heating section (34) by means of an intermediate fume evacuation section (35), the fumes coming from said sections (33) and (34) being conveyed to said section. Said sections (33, 34) preferably have a tunnel configuration.