Patent US5084094A successfully refreshed from Google Patents.
US5084094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for cleaning a liquid metal bath for hot dipping of a steel strip
Assignee: Sollac SA
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Filing: 1990-11-21
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Granted: 1992-01-28
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Expires: 2010-11-21
Abstract
Abstract The present invention relates to a method for cleaning a liquid metal bath, in particular a zinc or zinc-aluminum bath intended for the continuous production of a steel strip coated by immersion in a coating zone (5a), according to which method the metal coating bath (2) is cycled continuously between the coating zone (5a) and a cleaning zone (5b), the rise of solid intermetallic compounds contained in the said bath to the surface is brought about in the cleaning zone (5b), the rise of the said compounds in accelerated and the cleaned bath (2), the iron content of which is close to or below the solubility limit, is led back to the zone (5a). The invention also relates to an apparatus for carrying out the method.
Inventors
- 👤 Bernard Francois
- 👤 Robert Haaser
- 👤 Pierre Commun
- 👤 Jean-Paul Hennechart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:23
CPC Classifications
C; C23; C23C; C23C2/00; C23C2/003; C23C2/0034; C23C2/00342; C23C2/00344; C23C2/04; C23C2/06; C23C2/12; C23C2/325; C23C2/34; C23C2/36; C23C2/40
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
95 words
The method for cleaning a liquid metal bath intended for the continuous production of a steel strip coated by immersion in the bath, comprising: continuously cycling the metal coating bath from a coating zone to a cleaning zone and back to the coating zone; causing the solid intermetallic compounds contained in the bath to rise to the surface of the bath in the cleaning zone; accelerating the rise to the surface in the cleaning zone of the solid intermetallic compounds; and removing the risen compounds from the surface of the bath in the cleaning zone.
Claim 2
Independent Claim
95 words
The method for cleaning a liquid metal bath intended for the continuous production of a steel strip coated by immersion in the bath, comprising: continuously cycling the metal coating bath from a coating zone to a cleaning zone and back to the coating zone; causing the solid intermetallic compounds contained in the bath to rise to the surface of the bath in the cleaning zone; accelerating the rise to the surface in the cleaning zone of the solid intermetallic compounds; and removing the risen compounds from the surface of the bath in the cleaning zone.
Claim 3
Dependent Claim
51 words
Method according to claim 1, wherein that the temperature of the bath in the cleaning zone 60 between 435° and 460 C. and preferably between 440° and 450° C., the temperature of the bath in the coating zone being between 440° and 490° C. and preferably between 460° and 470° C.
Claim 4
Dependent Claim
25 words
Method according to claim 1, wherein the rise of the solid intermetallic compounds is accelerated increasing the aluminum concentration of the bath in cleaning zone.
Claim 5
Dependent Claim
27 words
Method according to claim 3, wherein the aluminum concentration of the bath in the cleaning zone is between 0.15 and 0.70% and preferably between 0.20 and 0.30%.
Claim 6
Independent Claim
148 words
An apparatus for cleaning a liquid metal bath intended for the continuous production of a steel strip coated by immersion in the bath, comprising: means containing the bath defining a coating zone and a cleaning zone; means for continuously cycling the liquid metal bath between said coating zone and said cleaning zone and vice versa; means for effecting the rise to the surface of the bath, in said cleaning zone, of the solid intermetallic compounds contained in the bath; and means for accelerating the rise of the said solid intermetallic compounds, said cycling means including at least one variable speed pump and in that the said variable speed pump which withdraws the polluted liquid metal bath from said coating zone via piping and transmits it to said cleaning zone at a level which is between half and two thirds the height of the bath in said cleaning zone.
Claim 7
Independent Claim
148 words
An apparatus for cleaning a liquid metal bath intended for the continuous production of a steel strip coated by immersion in the bath, comprising: means containing the bath defining a coating zone and a cleaning zone; means for continuously cycling the liquid metal bath between said coating zone and said cleaning zone and vice versa; means for effecting the rise to the surface of the bath, in said cleaning zone, of the solid intermetallic compounds contained in the bath; and means for accelerating the rise of the said solid intermetallic compounds, said cycling means including at least one variable speed pump and in that the said variable speed pump which withdraws the polluted liquid metal bath from said coating zone via piping and transmits it to said cleaning zone at a level which is between half and two thirds the height of the bath in said cleaning zone.
Claim 8
Dependent Claim
34 words
Apparatus according to claim 5, wherein the variable speed pump takes up the cleaned liquid metal bath from the lower part of the cleaning zone and transmits it through piping into the coating zone.
Claim 9
Dependent Claim
41 words
Apparatus according to claim 5 wherein the rise effecting means includes means for cooling the bath in said cleaning zone to maintain the temperature of the bath in said cleaning zone below the temperature of the bath in the coating zone.
Claim 10
Dependent Claim
37 words
Apparatus according to claim 5, wherein the rise accelerating means includes ingots which are introduced into the cleaning zone and the average aluminum content of which is between 0.30 and 0.80% and preferably between 0.40 and 0.50%.
Claim 11
Dependent Claim
59 words
The method defined in claim 1 wherein the rise to the surface is accelerated by lowering the temperature of the bath in the cleaning zone to below that in the coating zone in order to lower the solubility limit of iron in the cleaning zone so that the iron content of the cleaning bath is about the solubility limit.
Claim 12
Dependent Claim
40 words
The method defined in claim 1 wherein the rise to the surface is accelerated by local stirring of the bath in the cleaning zone by introducing a neutral gas into the lower part of the bath in the cleaning zone.
References Cited (Backward Citations)
US2734819A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-27 | 1995-07-29 | 1996-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-27 | 1999-07-29 | 2000-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-27 | 2003-07-29 | 2004-01-28 | $7700.00 | Window Closed / Lapsed |