Patent US1526749A successfully refreshed from Google Patents.
Patent US3881916A successfully refreshed from Google Patents.
US3881916A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of sponge iron
Assignee: GEA Group AG
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Filing: 1973-08-15
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Granted: 1975-05-06
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Expires: 1993-08-15
Abstract
Abstract Iron-oxide-containing materials (e.g. iron ores) are directly reduced in a rotary furnace to produce sponge iron, by using a solid carbon-containing reducing agent and oxygen-rich or other oxygen-containing gases. The oxygen-containing gases are injected into the furnace at one end thereof at a speed of at least 50 m/sec., substantially in the direction in which the furnace gases (combustion and combusting gases) flow through the furnace and approximately parallel to the longitudinal axis of the kiln. Nozzle blocks forming the wall of the furnace in the area of the end of the furnace at which the charge is introduced can be used for the injection of a part of the necessary amount of oxygencontaining gases.
Inventors
- 👤 Harry Serbent
- 👤 Wilhelm Thumm
- 👤 Horst Nagel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:17
CPC Classifications
C; C21; C21B; C21B13/00; C21B13/08; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/134
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
214 words
A PROCESS FOR PRODUCING SPONGE IRON IN AN ELONGATED ROTARY FURNACE HAVING A CHARGING END AND A DISCHARGING END, SAID PROCESS COMPRISING THE STEPS OF: INTRODUCING IRON OXIDE AND SUBSTANTIALLY ALL THE SOLID CARBONACEOUS REDUCING AGENT REQUIRED TO REDUCE SAID IRON OXIDE INTO SAID FURNACE AT SAID CHARGING END TO FORM SOLID CHARGE IN SAID FURNACE; DISPLACING SAID CHARGE IN SAID FURNACE FROM SAID CHARGING END TO SAID DISCHARGING END WHILE REACTING IT WITH SAID SOLID CARBONACEOUS REDUCING AGENT BETWEEN SAID ENDS; HEATING SAID CHARGE BETWEEN SAID ENDS TO A TEMPERATURE SUFFICIENT TO SUSTAIN REDUCTION OF THE IRON OXIDE BUT BELOW THE MELTING POINT OF THE CHARGE BY COMBUSTION OF PART OF SAID SOLID CARBONACEOUS REDUCING AGENT TO PRODUCE FURNACE GASES TRAVERSING SAID FURNACE SUBSTANTIALLY FROM ONE OF SAID ENDS TO THE OTHER OF SAID ENDS; AND INJECTING A STREAM OF OXYGEN-CONTAINING GAS INTO SAID FURNACE AT SAID ONE END COCURRENTLY TO THE FLOW OF THE KILN ATMOSPHERE SUBSTANTIALLY PARALLEL TO THE AXIS OF THE FURNACE WITH A VELOCITY OF AT LEAST 50 M/SEC AND SUFFICIENT THAT NO IMPINGMENT UPON SAID CHARGE OCCURS AND SAID STREAM MAINTAINS ITS IDENTITY OVER AT LEAST MAJOR PORTION OF THE LENGTH OF SAID FURNACE WHEREBY THE OXYGEN OF SAID STREAM IS CONSUMED CONTINUOUSLY IN THE SUCCESSIVE FURNACE ZONES.
Claim 2
Dependent Claim
214 words
A PROCESS FOR PRODUCING SPONGE IRON IN AN ELONGATED ROTARY FURNACE HAVING A CHARGING END AND A DISCHARGING END, SAID PROCESS COMPRISING THE STEPS OF: INTRODUCING IRON OXIDE AND SUBSTANTIALLY ALL THE SOLID CARBONACEOUS REDUCING AGENT REQUIRED TO REDUCE SAID IRON OXIDE INTO SAID FURNACE AT SAID CHARGING END TO FORM SOLID CHARGE IN SAID FURNACE; DISPLACING SAID CHARGE IN SAID FURNACE FROM SAID CHARGING END TO SAID DISCHARGING END WHILE REACTING IT WITH SAID SOLID CARBONACEOUS REDUCING AGENT BETWEEN SAID ENDS; HEATING SAID CHARGE BETWEEN SAID ENDS TO A TEMPERATURE SUFFICIENT TO SUSTAIN REDUCTION OF THE IRON OXIDE BUT BELOW THE MELTING POINT OF THE CHARGE BY COMBUSTION OF PART OF SAID SOLID CARBONACEOUS REDUCING AGENT TO PRODUCE FURNACE GASES TRAVERSING SAID FURNACE SUBSTANTIALLY FROM ONE OF SAID ENDS TO THE OTHER OF SAID ENDS; AND INJECTING A STREAM OF OXYGEN-CONTAINING GAS INTO SAID FURNACE AT SAID ONE END COCURRENTLY TO THE FLOW OF THE KILN ATMOSPHERE SUBSTANTIALLY PARALLEL TO THE AXIS OF THE FURNACE WITH A VELOCITY OF AT LEAST 50 M/SEC AND SUFFICIENT THAT NO IMPINGMENT UPON SAID CHARGE OCCURS AND SAID STREAM MAINTAINS ITS IDENTITY OVER AT LEAST MAJOR PORTION OF THE LENGTH OF SAID FURNACE WHEREBY THE OXYGEN OF SAID STREAM IS CONSUMED CONTINUOUSLY IN THE SUCCESSIVE FURNACE ZONES.
Claim 3
Dependent Claim
20 words
The process defined in claim 1 further comprising the step of forming said oxygen-containing gas by enriching air with oxygen.
Claim 4
Dependent Claim
19 words
The process defined in claim 1 wherein said stream is injected with a speed of at least 100 m/sec.
Claim 5
Dependent Claim
57 words
The process defined in claim 1 wherein said furnace has a closed head portion at said one end thereof, further comprising the steps of maintaining a slight superatmospheric pressure in said closed head portion; and gradually reducing said superatmospheric pressure over a part of the length of said furnace in the direction of flow of said stream.
Claim 6
Dependent Claim
20 words
The process defined in claim 4 wherein said part of said furnace is at most one-half of the length thereof.
Claim 7
Dependent Claim
18 words
The process defined in claim 4 wherein said part of said furnace is one-quarter of the length thereof.
Claim 8
Dependent Claim
22 words
The process defined in claim 4 wherein said super-atmospheric pressure in said closed head portion is at most 10 mm water column.
Claim 9
Dependent Claim
22 words
The process defined in claim 4 wherein said superatmospheric pressure in said closed head portion is at most 5 mm water column.
Claim 10
Dependent Claim
30 words
The process defined in claim 1 wherein said furnace has a free cross-section with a center and said stream is injected substantially at the center of the free cross section.
Claim 11
Dependent Claim
54 words
The process defined in claim 1 wherein a part of the oxygen requirement of the furnace is injected as a gas through nozzle blocks forming the furnace wall in the area of said charging end, said nozzle blocks having passages traversed by gas substantially flush with the surfaces of the blocks defining said wall.
Claim 12
Dependent Claim
28 words
The process defined in claim 10 wherein said part of the oxygen is introduced through said nozzle blocks over approximately one quarter of the length of said furnace.
Claim 13
Dependent Claim
25 words
The process defined in claim 10 wherein between 20 and 60 percent of said oxygen requirement is injected into said furnace through said nozzle blocks.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |