Claims
- 1. Apparatus for the direct reduction of mineral iron comprising a vertical reduction furnace of the type with a gravitational load to achieve therein reactions of reduction of the iron mineral, said furnace comprising at least two different reducing zones disposed vertically distanced therebetween, feeding means to feed the mineral iron into said furnace from above, injecting means to inject a mixture of high temperature gas into said at least two different reducing zones, first removing means for removing the burnt gas from an upper part of said furnace, and the second removing means for removing the reduced mineral from the lower part of said furnace, characterized in that mixing means external to said furnace are provided for mixing at least a part of said burnt gas, which is at least pre-heated by heating means to a temperature between about 650E and 950EC, and a reducing gas based on H2 and CO arriving from a process outside said furnace, in order to produce a first mixture of gas, and subsequently injecting into said first mixture of gas at least a hydrocarbon and oxygen, so as to increase the temperature of said first mixture of gas between about 800E and 1150EC, in that first valve means are provided for controlling the quantity of said mixture of high temperature gas injected into each one of said at least two different reducing zones and in that second valve means are provided from controlling the quantity of said hydrocarbon and oxygen, in order to optimize the reducing and reforming process within the furnace.
- 2. Apparatus as in claim 1, characterized in that said second valve means are provided upstream of the inlets to said furnace in correspondence with said at least two different reducing zones, in order to supply said mixture of high temperature gas wherein the hydrocarbon is proportioned and controlled independently and autonomously in each of said at least two different reducing zones.
- 3. Apparatus as in claim 1, characterized in that said reducing gas comprises a second mixture of a variable and controlled percentage of said burnt gas and of gases arriving from outside processes.
- 4. Apparatus as in claim 1, characterized in that said first mixture of gas comprises exclusively said burnt gas and of hydrocarbons subsequently mixed with O2 or O2-enriched air.
- 5. Apparatus as in claim 1, characterized in that said reducing gas comprises a second mixture of a variable and controlled percentage of said burnt gas and of gas arriving from an outside catalytic reformer.
- 6. Apparatus as in clam 1, characterized in that said second removing means comprises at least two ends shaped like a cone or a truncated cone.
- 7. Apparatus as in claim 6, characterized in that said at least two ends shaped like a cone or a truncated cone are tapered downwards and each is provided with a corresponding lower aperture through which said reduced metallic iron are able to be selectively discharged in a controlled and independent manner.
- 8. Apparatus as in claim 6, characterized in that further injection means are provided to inject at least partly CH4 into said furnace in a zone between said second removing means and the lower of said at least two different reducing zones
- 9. Apparatus as in claim 1, characterized in that said further injection means is arranged in a zone of intersection between said at least two ends shaped like a cone or a truncated cone.
Priority Claims (1)
Number |
Date |
Country |
Kind |
UD98A000212 |
Dec 1998 |
IT |
|
Parent Case Info
[0001] This application is a divisional application of U.S. Ser. No. 09/457,711, filed Dec. 10, 1999.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09457711 |
Dec 1999 |
US |
Child |
09968014 |
Oct 2001 |
US |