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AssigneeThyssen Purofer GmbH
InventorsKlaus Altenhoner, Walter Jansen, Klaus Knop, Jan G. Reering
Estimating the term…
In a shaft furnace for the direct reduction of iron ore in which hot reducing gas is introduced at the bottom of the furnace and removed from the top of the furnace, means for recirculating at least a portion of the furnace exhaust gas are provided along with means for introducing fresh gas into the recirculated gas stream and means to heat the gas stream introduced into the furnace. The improvement comprises providing means for desulfurizing the fresh gas stream prior to its joining the recycled exhaust gas and providing for dust removal, sulfur and CO removal in the recycled gas stream prior to its joining the fresh gas stream.
An apparatus for the direct reduction of iron ore, especially iron-ore pellets, comprising in combination a shaft furnace for reducing the iron ore to iron with a reducing gas:
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Making spongy iron or liquid steel, by direct processes: selection or treatment of the reducing gases
Increasing the gas reduction potential of recycled exhaust gases: by adding additional fuel in recirculation pipes
By separation: of carbon dioxide
Process control or energy utilisation in the manufacture of iron or steel: controlling the physical properties of the gas, e.g. pressure or…
Term ended 13 Dec 1994 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
Our present invention relates to an apparatus for the production of sponge iron by the direct reduction of iron ore, especially in the form of iron-ore pellets, in a shaft-type reducing furnace in which the iron-ore pellets are introduced at the head of the furnace and sponge iron is withdrawn from the base thereof, the iron ore passing downwardly against a rising stream of a hot reducing gas consisting predominantly of carbon monoxide and hydrogen.
Direct-reduction plants for the production of sponge iron from iron ore have gained increasing importance in recent years because the direct reduction process eliminates the need for blast furnaces, can be carried out at relatively low cost with long-life equipment, and produces a relatively high-purity product which can be utilized in steel-making processes directly, i.e., without smelting and refining before being introduced into the steel-making process.
The process is also advantageous since it does not require the use of limestone or slag-generating materials in the reduction stage.
The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the sole FIGURE of the accompanying drawing which represents a flow-diagram illustrating a plant for the reduction of iron ore pellets according to the invention.
The plant according to the present invention basically comprises a shaft furnace 1 having a charging device 2 through which pellets can be introduced from above into the furnace and which serves to seal the latter to maintain an elevated pressure in the shaft furnace as may be desired. At its base, the shaft furnace is provided with a discharging device generally represented at 3 by which the reduced or sponge iron can be withdrawn.
As gas generator 4 is supplied with a hydrocarbon fuel or some other carbon-containing energy carrier is a high-sulfur hydrocarbon such as heavy oil (residual oil) and the oxygen carrier is oxygen or air, oxygen-enriched air, or oxygen carriers such as water vapor in which the oxygen is in a combined form.
A unit 5, e.g. a compressor, is provided to circulate a portion of the furnace exhaust gas from the top of the furnace 1 as will be described below.