US3661732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for electroplating
Assignee: Production Machinery Corp
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Filing: 1970-06-01
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Granted: 1972-05-09
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Expires: 1990-06-01
Abstract
Abstract This invention concerns an improved method and apparatus for electroplating in which rinse solutions and fumes from electroplating operations are treated to recover values contained therein, and to simultaneously adjust the concentration and the temperature of the electroplating bath. Fumes and spray from the electroplating and rinsing operations are contacted with controlled amounts of a process solution comprising overflow rinse water mixed with electroplating bath solution. The liquidvapor contacting operation is controlled to evaporate water at a rate substantially equivalent to the rate of addition of rinse water to the process so that a water balance is maintained throughout the system, and to cool the process solution. The process is preferably conducted in apparatus comprising an electroplating tank, a rinse tank, a fume exhaust system, a heat exchanger and a liquid-vapor contacting means.
Inventors
- 👤 David A Withrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:10
CPC Classifications
C; C25; C25D; C25D21/00; C25D21/16; C25D21/18; Y; Y10; Y10S; Y10S204/00; Y10S204/13
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
32 words
The process of claim 1 including a rinsing step wherein the plated article is rinsed with rinse water upon emerging from the electroplating tank and the process solution comprises used rinse water.
Claim 2
Dependent Claim
92 words
The process of claim 2 further including carrying out the intimate liquid-vapor contact in a packed bed of large surface area elements adapted to facilitate liquid-vapor contact and wherein the process solution is sprayed upon the upper surface of the packed bed and passes downwardly therethrough and the fumes are passed upwardly through the packed bed to provide countercurrent contact between the process solution and the fumes whereby values contained in the fumes are dissolved into the process solution and is evaporated from the process solution whereby the process solution is cooled.
Claim 3
Dependent Claim
38 words
The process of claim 3 wherein gases leaving the packed bed are passed through a demisting means adapted to remove residual spray entrained therein by collecting suspended liquids in the gases before exhausting the gases to the atmosphere.
Claim 4
Dependent Claim
18 words
The process of claim 4 wherein the plating solution is an aqueous chromic acid soluTion for electroplating chromium.
Claim 5
Dependent Claim
32 words
The process of claim 5 wherein the aqueous chromic acid solution contains CrO3 and SO4 in such amounts that the weight ratio of CrO3 to SO4 is between about 50:1 and 250:1.
Claim 6
Dependent Claim
31 words
The process of claim 6 wherein a silicofluoride type catalyst is added to the chromic acid solution in an amount in excess of the amount which is soluble in the solution.
Claim 7
Dependent Claim
34 words
The process of claim 7 wherein the aqueous chromic acid solution is maintained at a temperature between about 105* F. and about 120* F. by adding thereto process solution withdrawn from the packed bed.
Claim 8
Dependent Claim
40 words
The process of claim 8 wherein prior to being passed into intimate liquid-vapor contact, the used rinse solution containing chemical values from the aqueous chromic acid plating solution is contacted with a cation exchange resin to remove trivalent chromium therefrom.
Claim 9
Dependent Claim
14 words
The process of claim 9 wherein the cation exchange resin is a sulfonate resin.
Claim 10
Dependent Claim
23 words
The process of claim 9 wherein the cation exchange resin is dissolved in an organic solvent to provide a liquid cation exchange medium.
Claim 11
Dependent Claim
52 words
The process of claim 9 further including a rinsing step in which the plated article is rinsed with rinse water upon emerging from the electroplating tank and wherein all of the used rinse water and at least a portion of the aqueous chromic acid solution are contacted with the cation exchange resin.
Claim 12
Dependent Claim
25 words
The process of claim 9 wherein the amount of water evaporated in the packed bed is substantially equivalent to the amount of overflow rinse water.
Claim 13
Dependent Claim
15 words
The process of claim 6 wherein fluoride catalyst is added to the chromic acid solution.
Claim 14
Dependent Claim
37 words
The process of claim 2 wherein used rinse water enters the process solution and an amount of water is evaporated from said process solution which is substantially equivalent to the amount of water entering said process solution.
Claim 15
Dependent Claim
23 words
The process of claim 1 wherein said plating solution is an aqueous solution and water is evaporated therefrom in said liquid-vapor contacting step.
Claim 16
Dependent Claim
21 words
The process of claim 16 wherein air is added to the fumes passed through intimate liquid-vapor contact with the process solution.
Claim 17
Dependent Claim
12 words
The process of claim 1 wherein the process solution is plating solution.
Claim 18
Dependent Claim
47 words
The process of claim 1 including a rinsing step wherein the plated article is rinsed with rinse water upon emerging from the electroplating tank, and an amount of water substantially equal to the amount of water entering the rinsing step is evaporated in the liquid-vapor contacting step.
Claim 19
Dependent Claim
25 words
The process of claim 1 including carrying out the intimate liquid-vapor contact in a packed bed of large surface area elements which facilitate liquid-vapor contact.
Claim 20
Dependent Claim
104 words
In combination with apparatus for continuous electroplating, which apparatus includes an electroplating tank, and a gas hood for collecting fumes at least from the electroplating tank, the improvement comprising; fume conduit means connecting said hood with the vapor inlet of a liquid-vapor contacting means, liquid conduit means connecting said electroplating tank with the liquid inlet of said liquid vapor contacting means, means for passing fumes from said gas hood and liquid from said electroplating tank through intimate liquid-vapor contact one with the other in said liquid-vapor contacting means, and conduit means for conducting contacted liquid from said liquid-vapor contacting means into said electroplating tank.
Claim 21
Dependent Claim
60 words
The combination of claim 21 wherein said liquid-vapor contacting means is a packed bed, said means for passing the collected fumes is a blower adapted to pass the fumes upwardly through said bed, and said means for passing the process solution is a distributor adapted to spray the solution evenly over said packed bed so that it flows downwardly therethrough.
Claim 22
Dependent Claim
21 words
The combination of claim 22 further including demisting means to collect suspended liquids containeD in gases issuing from the packed bed.
Claim 23
Dependent Claim
67 words
The combination of claim 23 further including a tower in which said packed bed and said demisting means are placed with the demisting means being the uppermost, a lower chamber in said tower forming a reservoir for collecting liquid passing through the packed bed and for providing solution to be sprayed onto the packed bed and means for pumping liquid in said reservoir to the packed bed.
Claim 24
Dependent Claim
35 words
The combination of claim 24 wherein a cation exchange tower is provided between said rinse tank and said reservoir so that rinse water can be treated by the cation exchanger before passing into said reservoir.
Claim 25
Dependent Claim
33 words
The apparatus of claim 21, further including a rinsing tank to rinse plated articles, and conduit means connecting said rinsing tank in flow communication with the liquid inlet of said liquid-vapor contacting means.
Claim 26
Dependent Claim
111 words
In an electroplating process from which fumes are generated, including a. a plating step carried out in an electroplating tank containing a plating solution, and b. a rinsing step in which the plated article is rinsed with rinse water, the improvement comprising: passing fumes generated from the process through intimate liquid-vapor contact with a liquid process solution which contains plating solution withdrawn from said electroplating tank, whereby water contained in said liquid process solution is evaporated, thereby cooling and concentrating said solution, and chemical values contained in said fumes are dissolved in said liquid process solution, and returning the thus value enriched and cooled liquid process solution to said electroplating tank.
Claim 27
Dependent Claim
12 words
The process of claim 27 wherein said process solution is plating solution.
Claim 28
Dependent Claim
12 words
The process of claim 27 wherein said process solution is rinse water.
Claim 29
Dependent Claim
37 words
The process of claim 27 wherein rinse water enters the process solution and an amount of water is evaporated from said process solution which is substantially equivalent to the amount of rinse water entering said process solution.
Claim 30
Dependent Claim
21 words
The process of claim 27 wherein air is added to the fumes passed through intimate liquid-vapor contact with the process solution.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |