Direct ironmaking or steelmaking apparatus using self-reducing iron oxide pellets
AssigneeChaparral Steel Company
InventorsRichard T. Jaffre, Harry D. Hunt
Life of this patent
Estimating the term…
Abstract
Apparatus for preheating self-reducing pellets for direct use in ironmaking or steelmaking in which a preheat chamber contains the pellets and is primarily externally heated using waste exhaust gases and secondarily heated directly by using an internal preheat burner. The preheat chamber gases are vented into the external heating chamber where any CO present is post-combusted to produce CO.sub.2 with the energy from the post-combustion used to contribute to external heating of the preheat chamber.
Claims34
Apparatus for preheating self-reducing iron oxide pellets for direct use in an ironmaking or steelmaking furnace including:
- a source of self-reducing iron oxide pellets containing sufficient carbon to reduce the iron to metallic form;
- a preheat chamber between the source of pellets and the ironmaking or steelmaking furnace and having a feed end and a discharge end;
- an external heat chamber in heat transfer relationship with the preheat chamber for utilizing waste heat as the primary energy source to provide heat to the preheat chamber;
- a flame chamber associated with the pellet discharge end of the preheat chamber and the iron or steel furnace;
- an internal heat generating source in the flame chamber for providing hot gases as needed directly to the interior of the preheat chamber as a secondary heat source;
- a pellet feed chamber associated with the feed end of the preheat chamber and the pellet source for receiving a predetermined charge of pellets from the pellet source;
- and
- a charging device associated with the pellet feed chamber for transferring the predetermined charge of pellets to the interior of the preheat chamber for heating to a temperature sufficient to enable the preheated pellets to be transferred substantially directly to the iron or steel furnace without being disintegrated by thermal shock, to at least partially reduce the iron in the iron oxide to metallic form, to combine carbon with oxygen, and to generate hot waste gases.
Apparatus for preheating self-reducing iron oxide pellets for direct use in an ironmaking or steelmaking furnace including:
- a source of self-reducing iron oxide pellets;
- a rotating preheat chamber for preheating the iron oxide pellets;
- a waste heat supply chamber surrounding and at least partially encompassing the rotating preheat chamber and coupled to a waste heat source for receiving and transferring waste heat gases to the exterior of the rotating preheat chamber;
- the waste heat supply chamber serving as the primary heat source for the preheat chamber;
- a secondary heat source for assisting in producing a positive pressure in the interior of said preheat chamber to maintain an oxygen free environment;
- a pellet charging device for receiving a pellet charge from the pellet source and transferring the charge to the interior of the rotating chamber for preheating;
- and
- a pellet discharging device for discharging the preheated pellets substantially directly into the ironmaking or steelmaking furnace.
Apparatus for preheating self-reducing iron oxide pellets and transferring the preheated pellets to an ironmaking or steelmaking furnace including:
- a waste heat source;
- a rotating cylindrical preheat chamber;
- means for providing said preheat chamber with a substantially oxygen free environment therein during the reduction process:
- said preheat chamber having a pellet feed end and a pellet discharge end;
- the preheat chamber receiving external heat from the waste heat source to preheat the self-reducing iron oxide pellets therein;
- and
- pellet transfer means for transferring the preheated pellets substantially directly to the ironmaking or steelmaking furnace.
Dependencies are inferred from the claim text.