US3666871A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Continuous charging of an electric arc steelmaking furnace
Assignee: Steel Company of Canada Ltd
•
Filing: 1970-06-18
•
Granted: 1972-05-30
•
Expires: 1990-06-18
Abstract
Abstract A method of steelmaking in a three phase direct arc electric furnace having a slag covered bath of molten iron bearing metal. The furnace is charged through its roof by at least three ducts and includes propelling means for directing the charge toward the bath at an angle to the horizontal in the range 40-80*.
Inventors
- 👤 Gee Wing Thom
- 👤 Keith Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:09
CPC Classifications
C; C21; C21C; C21C5/00; C21C5/52; C21C5/527; F; F27; F27D; F27D3/00; F27D3/18; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
55 words
The process of claim 1 in which the step of charging by propelling the discrete iron-bearing material is performed by ejecting the material from at least three ducts, each duct being located radially outward of an electrode and spaced from the electrode a distance sufficient substantially to prevent the propelled charge from striking the electrode.
Claim 2
Dependent Claim
40 words
The process of claim 1 in which the step of charging by propelling the discrete iron-bearing material is performed by impinging the charge against the upper surface of the slag whereby the slag tends to be pushed toward the electrodes.
Claim 3
Dependent Claim
59 words
The process of claim 1 in which the step of charging by propelling the discrete iron-bearing material is performed to increase the heat transfer to the bath by propelling the material with a momentum such that it penetrates into the slag while substantially in a solid state thereby providing bubble formation points to increase boiling action within the furnace.
Claim 4
Dependent Claim
13 words
In the process of claim 1, propelling the subsequent charge with compressed air.
Claim 5
Dependent Claim
19 words
In the process of claim 1, propelling the subsequent charge through openings in the furnace roof toward the bath.
Claim 6
Dependent Claim
36 words
The process of claim 1 in which the step of charging by propelling includes the step of providing particles of a diameter approximately in the range 0.18-0.63 inches with a mean size of about 0.375 inches.
Claim 7
Dependent Claim
33 words
In the process of claim 1, in which the step of charging by propelling includes the step of providing a charge from the group comprising sponge iron, lime, iron ore and combinations thereof.
Claim 8
Dependent Claim
55 words
The process of claim 8 in which the step of charging by propelling the discrete iron-bearing material is performed by ejecting the material from at least three ducts, each duct being located radially outward of an electrode and spaced from the electrode a distance sufficient substantially to prevent the propelled charge from striking the electrode.
Claim 9
Dependent Claim
40 words
The process of claim 8 in which the step of charging by propelling the discrete iron-bearing material is performed by impinging the charge against the upper surface of the slag whereby the slag tends to be pushed toward the electrodes.
Claim 10
Dependent Claim
59 words
The process of claim 8 in which the step of charging by propelling the discrete iron-bearing material is performed to increase the heat transfer to the bath by propelling the material with a momentum such that it penetrates into the slag while substantially in a solid state thereby providing bubble formation points to increase boiling action within the furnace.
Claim 11
Dependent Claim
36 words
The process of claim 8 in which the step of charging by propelling includes the step of providing particles of a diameter approximately in the range 0.18-0.63 inches with a mean size of about 0.375 inches.
References Cited (Backward Citations)
US3210129A
Cited
US3472649A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |