US3623962A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reducing electrolytic sludge formation
Assignee: National Steel Corp
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Filing: 1968-07-31
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Granted: 1971-11-30
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Expires: 1988-07-31
Abstract
Abstract Method and apparatus for decreasing sludging in a stannous-tin electrolyte used in continuous-strip electroplating by continuous deaeration of the electrolyte which removes gases absorbed when the electrolyte is exposed to ambient atmosphere and by decreasing the opportunity for the electrolyte to absorb oxygen. A barometric leg, or other suitable pressure isolation means, is arranged to separate the path for continuous replenishment of electrolyte into an atmospheric pressure loop and a subatmospheric pressure loop. Desorption performance and efficiency is increased by operation at or below the vapor pressure of the electrolyte at the operating temperature for the system and by use of a vapor condenser on the vacuum side of the deaeration means used. Improved results are obtained by providing an inert gas shield during collection of electrolyte splash-over and carryout from the plating cells and also by injection of an inert gas into the electrolyte after deaeration and prior to exposure of the electrolyte to ambient atmosphere. The inert gas steps operate to reduce the opportunity for oxygen absorption.
Inventors
- 👤 Louis C Beale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:49
CPC Classifications
C; C25; C25D; C25D3/00; C25D3/02; C25D3/30; C25D21/00; C25D21/04; C25D5/00; C25D5/003
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
40 words
The apparatus of claim 1 wherein the deaerating means comprises a deaerating chamber at subatmospheric pressure for receiving electrolytic solution from the plating-cell means and further including pressure isolating means located between the solution collection means and the deaerating chamber.
Claim 2
Dependent Claim
13 words
The apparatus of claim 2 including vacuum pump means communicating with the chamber.
Claim 3
Dependent Claim
21 words
The apparatus of claim 2 including means for increasing surface exposure of the electrolytic solution upon entry into the deaerating chamber.
Claim 4
Dependent Claim
79 words
The structure of claim 1 in which the solution collection means includes sump means for receiving and accumulating electrolytic solution from the plating-cell means and further including transfer means for delivering electrolytic solution from the sump means to the deaerating means, such transfer means including a barometric leg located between the sump means and the deaerating means permitting the deaerating means to be operated under vacuum conditions and to be pressure isolated from the plating-cell means and sump means.
Claim 5
Dependent Claim
23 words
The apparatus of claim 5 including level control means for the sump means for controlling delivery of electrolytic solution from the sump means.
Claim 6
Dependent Claim
28 words
The apparatus of claim 3 in which a condenser means is connected between the vacuum pump means and the deaerating chamber for condensing vapors from the electrolytic solution.
Claim 7
Dependent Claim
21 words
The apparatus of claim 7 including means for returning condensate to the deaerated electrolytic solution being returned to the plating-cell means.
Claim 8
Dependent Claim
31 words
The apparatus of claim 1 further including means for adding an inert gas to the solution collection means to at least partially shield electrolytic solution being collected from contact with oxygen.
Claim 9
Dependent Claim
73 words
The apparatus of claim 2 in which the solution collection means includes trough means for receiving splash-over and carryout of electrolytic from the plating-cell means, sump means for accumulating such electrolytic, and downcomer means interconnecting the trough means and sump means, with the sump means being enclosed and vented to the atmosphere through the downcomer means and the trough means, and means for adding an inert gas under pressure to the sump means.
Claim 10
Dependent Claim
46 words
The apparatus means of claim 1 including means for introducing an inert gas into the deaerated electrolytic solution, such means being located to introduce inert gas into the conduit means for returning electrolytic solution to the plating-cell means between the deaerating means and the plating-cell means.
Claim 11
Dependent Claim
101 words
In a continuous-strip electrotinplating operation, utilizing an electrolyte subject to sludge formation responsive to oxygen dissolution, a process for reducing electrolytic sludging by reduction of gas dissolution in the electrolyte comprising the steps of maintaining a deaerating means at subatmospheric pressure for receiving electrolytic solution after exposure to ambient atmosphere in plating-cell means, deaerating electrolytic solution by circulating the electrolytic solution from the plating-cell means through the deaerating means, and returning the deaerated electrolytic solution to the plating-cell while substantially preventing contact of the electrolytic solution with ambient atmosphere during and subsequent to deaeration prior to delivery into the plating-cell means.
Claim 12
Dependent Claim
51 words
The process of claim 12 in which deaeration of electrolytic solution is carried out by maintaining a deaerating chamber under vacuum conditions with the pressure range extending to below the vapor pressure of water at the temperature of the electrolytic solution, and pressure isolating the deaerating chamber from the plating-cell means.
Claim 13
Dependent Claim
61 words
The process of claim 12 in which deaeration of the electrolytic solution is carried out by maintaining a deaerating chamber under vacuum conditions with the pressure range extending below the vapor pressure of water at the temperature of the electrolytic solution and further including the step of condensing vapors from the electrolytic solution on the vacuum side of the deaerating chamber.
Claim 14
Dependent Claim
17 words
The process of claim 14 further including the step of returning condensate to the deaerated electrolytic solution.
Claim 15
Dependent Claim
40 words
The process of claim 12 further including the step of shielding the electrolytic solution after leaving the plating-cell means and before delivery to the deaerating chamber with an inert gas to substantially prevent contact of such solution with ambient atmosphere.
Claim 16
Dependent Claim
33 words
The process of claim 12 further including the step of injecting an inert gas under pressure into the electrolytic solution after exit from the deaerating chamber and before return to the plating-cell means.
Claim 17
Dependent Claim
28 words
The process of claim 13 including the step of increasing the surface area of the electrolytic solution exposed to the vacuum conditions upon entry into the deaerating chamber.
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) | 1974-11-29 | 1975-05-31 | 1975-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-29 | 1979-05-31 | 1979-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-29 | 1983-05-31 | 1983-11-30 | $7700.00 | Window Closed / Lapsed |