US 4,740,989 AGranted

Plant for producing steel from scrap

AssigneeVoest-Alpine Aktiengesellschaft

InventorsOthmar Steipe, Harald Berger

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Abstract

A plant for the production of steel from scrap and optionally fluxes includes a shaft furnace section having a bottom to receive a liquid sump of premelt and heating means laterally entering into the lower part of its interior. A hearth type furnace section is integrally connected with the shaft furnace section, into which the premelt is transferable from the shaft furnace section. In order to produce steel from scrap without addition of pig iron and with an energy supply as low as possible, the lower part of the shaft furnace section is designed to diverge downwardly with respect to the upper part receiving the scrap column, the heating means disposed in this lower part are designed as plasma burners, the hearth type furnace section follows immediately upon the lower part of the shaft furnace section, and the hearth type furnace section includes at least one further heating means operated with electric energy for the treatment of the premelt transferred from the sump of the shaft furnace section, in particular an electric arc aggregate.

Claims13

Dependent claims

In a plant for producing steel from scrap, wherein an aggregate furnace construction is employed comprised of a shaft furnace section integrally connected to a hearth type furnace section, said shaft furnace defining a first interior with a bottom for receiving a liquid sump of premelt, said first interior communicting with a second interior defined by said hearth type furnace section which has a bottom into which said premelt is transferable, the improvement wherein:

said shaft furnace section is comprised of an upper portion for receiving scrap and for supporting it as a column,
said upper portion extending downwardly and diverging outwardly to provide a lower portion of said shaft furnace having a frustoconical configuration,
first heating means comprising a plurality of plasma burners spaced peripherally around said frustoconical lower portion each of said burners entering laterally into said shaft furnace section and directed downwardly towards the column of steel scrap supported within said furnace section,
the hearth of said hearth type furnace being contiguous with and a lateral extension of the sump part of said shaft furnace section,
and at least one electrically operable second heating means extending into the hearth of said hearth type furnace section to further heat said premelt transferred from the sump part of said shaft furnace section.

2 more elements

Dependencies are inferred from the claim text.