US4248809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for detecting damage of blast furnace inside wall repairing materials
Assignee: Nippon Steel Corp
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Filing: 1979-02-27
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Granted: 1981-02-03
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Expires: 1999-02-27
Abstract
Abstract In repairing a blast furnace wall by injecting and solidifying a refractory material on the inside wall of the furnace from outside the furnace, a line consisting of metallic coaxial lines or metallic parallel lines insulated from each other is embedded in the refractory material and the variation of the length of this line is measured through an electric signal to detect the remaining thickness of the injected and solidified refractory material in the furnace wall part. By such detection, the damage of the repaired part of the blast furnace can be known with the lapse of time.
Inventors
- 👤 Toshihiko Sakai
- 👤 Sumio Kobayashi
- 👤 Takao Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:49
CPC Classifications
C; C21; C21B; C21B7/00; C21B7/24; C21B7/04; C21B7/06; F; F27; F27D; F27D21/00; F27D21/0021
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
79 words
A method of detecting damage of inside wall blast furnace repairing materials, comprising the steps of: injecting a solidifying refractory material into the furnace wall from the exterior thereof, embedding electrically conductive lines insulated from each other into the partially solidified refractory material, impressing step pulses on said embedded lines, measuring the propagation time between the steps in the reflected waveform of said step pulses; and determining the remaining thickness of said refractory material from the measured propagation times.
Claim 2
Independent Claim
79 words
A method of detecting damage of inside wall blast furnace repairing materials, comprising the steps of: injecting a solidifying refractory material into the furnace wall from the exterior thereof, embedding electrically conductive lines insulated from each other into the partially solidified refractory material, impressing step pulses on said embedded lines, measuring the propagation time between the steps in the reflected waveform of said step pulses; and determining the remaining thickness of said refractory material from the measured propagation times.
Claim 3
Dependent Claim
32 words
The method according to claim 1 wherein said line is inserted and embedded through an injecting port on the mantle of the blast furnace just before said refractory material begins to solidify.
Claim 4
Dependent Claim
48 words
The method according to claim 1 wherein the embedded depth of said line is the sum of the thickness of the remaining furnace wall expected to be formed, the thickness of the remaining furnace wall firebrick, the thickness of the mantle and the length of the injecting pipe.
Claim 5
Dependent Claim
17 words
The method according to claim 1 wherein the characteristic impedance of said line is 20 to 300Ω.
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) | 1984-02-03 | 1984-08-04 | 1985-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-03 | 1988-08-04 | 1989-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-03 | 1992-08-04 | 1993-02-03 | $7700.00 | Window Closed / Lapsed |