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US 2012/0325053 A1Published application
Apparatus and methods for producing direct reduced iron
OwnerGiulio Grossiinventor
Life of this patent
Estimating the term…
Abstract
A hearth furnace for producing direct reduced iron is described. The furnace has first and second combustion chambers, each having a rotating hearth within it to receive iron oxide and reducing agent. A set of rabbles disposed over each of the rotating hearths interacts with the iron oxide and pushes the iron oxide towards an inside or an outside edge of each rotating hearth. The first combustion chamber having an outlet connected to an inlet of the second combustion chamber to receive materials pushed by the rabbles of the first combustion chamber to the first combustion chamber outlet. The furnace further comprising one or more gas transfer channels for transferring reduction gasses and heat between the second and first combustion chambers.
Claims20
A hearth furnace for producing direct reduced iron, comprising:
- a first combustion chamber;
- a first rotating hearth within the first chamber configured to receive onto its surface iron oxide materials from a first chamber inlet disposed over the first rotating hearth;
- and
- a first set of rabbles disposed over the first rotating hearth to interact with the iron oxide materials, the first set of rabbles configured to push the iron oxide materials on the surface of the first rotating hearth towards a first chamber outlet located towards one of an inside edge of the first rotating hearth or an outside edge of the first rotating hearth as the hearth and the first set of rabbles move relative to one another, the first set of rabbles being configured to interact with the iron oxide materials over the entirety of the surface of the rotating hearth between the inside and outside edge of the first rotating hearth;
- a second combustion chamber;
- a second rotating hearth within the second chamber, the second chamber having a second chamber inlet connected to the first chamber outlet of the first combustion chamber and configured to receive materials pushed to the first chamber outlet and direct the materials onto the second rotating hearth of the second combustion chamber;
- a second set of rabbles disposed over the second rotating hearth of the second combustion chamber, the second set of rabbles configured to push the materials received from the first combustion chamber onto the surface of the second rotating hearth towards a second chamber outlet of the second combustion chamber located towards one of an inside edge or an outside edge of the second rotating hearth of the second combustion chamber as the second hearth and the second set of rabbles moves relative to one another, the second set of rabbles being configured to interact with the received materials over the entirety of the surface of the second rotating hearth of the second combustion chamber between its inside and outside edges;
- and
- one or more gas transfer channels connecting the first and second combustion chambers, the gas transfer channel being wider than the chamber inlet of the second combustion chamber and configured to transfer reduction gases and heat from a reduction reaction of the received material in the second combustion chamber to the first combustion chamber.
6 more elements
A process for producing direct reduced iron, comprising:
- charging iron oxide materials onto a first rotating hearth in a first combustion chamber;
- moving the iron oxide materials by rotating the first rotating hearth, the iron oxide materials interacting with a first set of rabbles disposed over the first rotating hearth to direct the iron oxide materials towards a first chamber outlet and dropping through the first chamber outlet;
- receiving the dropped iron oxide materials from the first chamber outlet onto a second rotating hearth in a second combustion chamber through a chamber inlet of the second chamber;
- moving the iron oxide materials by rotating the second rotating hearth, the iron oxide materials interacting with a second set of rabbles disposed over the second rotating hearth to direct the iron oxide materials towards a second chamber outlet;
- and
- transferring reduction gases and heat from a reduction reaction in the second combustion chamber to the first combustion chamber through one or more gas transfer channels connecting the first and second combustion chambers, the gas transfer channels being wider than the chamber inlet of the second chamber,
- whereby the reduction gases and heat assist a reduction reaction in the first combustion chamber, and the reduction reactions in the first and second combustion chamber produce direct reduced iron from the iron oxide materials.
4 more elements
A hearth furnace, comprising:
- a combustion chamber;
- a rotating hearth within the chamber for receiving onto its surface iron oxide materials from a chamber inlet disposed over the rotating hearth, the rotating hearth surface having and being disposed within an inside edge and an outside edge;
- a solid projection extendible toward the surface of the rotating hearth and adjustable for placement of the projection tip onto a layer of material formed on the surface between the inside edge and outside edge to break the layer of material and expose a groove as the rotating hearth rotates;
- and
- a discharge chute configured to deposit an inert material onto the exposed groove.
2 more elements
A method for applying an inert material to a surface of a rotary hearth furnace, the method comprising:
- breaking a layer of material formed on the surface of the hearth furnace as the hearth furnace rotates with a cleaning device comprised of a solid projection extendible toward the surface of a rotating hearth within a chamber of the rotary hearth furnace;
- moving the broken materials to expose a groove in the materials;
- delivering the inert material to the exposed groove;
- and
- adjusting the position of the solid projection between an inside edge and an outside edge of the surface.
2 more elements
Dependencies are inferred from the claim text.