US3770501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for removing coatings from metals
Assignee: UPTON IND INC US
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Filing: 1971-12-23
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Granted: 1973-11-06
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Expires: 1991-12-23
Abstract
Abstract Thermochemical procedure and equipment for the substantially airless stripping of organic base coatings from objects by volatilization of the coating material as immersed in a molten salt bath. The procedure is carried out in a shroud-like objectreceiving retort. This retort, when immersed at least in part at an open bottom thereof penetrating in said bath, is substantially sealed hermetically against entry of external atmospheric air to its interior. The bath is heated in a conventional pot by conventional immersion heating means; and the interior of the retort is conditioned during immersion, as by being placed and held under partial vacuum or by introducing an inert gas, to greatly reduce air content in the space therein above the bath, thus creating a nonoxidizing atmosphere. The retort is shown as being by preference sealed at its top by a removable gas tight cover. Volatilization continues for a relatively very brief time period, the resulting vapor product and possible gas arising to the conditioned retort space above the bath level. During this volatilizing period, or directly before and thereafter and with the retort still sealed and bottom-immersed in the bath, its interior above the salt level is evacuated, as by a vacuum pump. The volatilization vapor, minimal product of combustion, smoke and the like are piped in a closed system to conventional incinerator, filter and/or scrubber means prior to discharge to atmosphere. The retort is then unsealed and placed in position for rinsing and removal of the stripped object or objects therefrom.
Inventors
- 👤 E Kemper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:03
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/28
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
138 words
A method of removing organic base coating material from an object, comprising disposing said object in a partially exposed but otherwise sealed retort, immersing the retort and the thus disposed object in a molten salt bath, with the object being substantially totally immersed and the retort at least sufficiently immersed that the partial exposure thereof is sealed by a portion of said bath, the bath being at a temperature sufficiently elevated to volatilize said material, creating and maintaining a reduced oxygen atmosphere in a space in the thus sealed retort above the level of said bath portion therein, maintaining said immersion for a time period sufficient to cause volatilization of said coating material and escape of its volatilization product to said space, and voiding the escaped product from said space prior to removing the object from the retort.
Claim 2
Dependent Claim
18 words
The method of claim 2, in which the volatilization product is voided under a condition of partial vacuum.
Claim 3
Independent Claim
139 words
A method of removing coating material from an object, comprising immersing said object in a molten volatilization bath, creating and maintaining a reduced oxygen atmosphere in a space above the level of the bath, which space is sealed against entry of external air thereto when said object is so immersed, maintaining said immersion for a time period and at an elevated temperature sufficient to cause volatilization of said coating material and escape of the volatilization product to said space, and withdrawing the escaped product from the space in which the immersed object is disposed in a retort which is also at least partially immersed in the volatilization bath, being filled to a predetermined level with a portion of the bath in which the object is immersed, the sealed space being in said retort and above said predetermined level therein.
Claim 4
Dependent Claim
23 words
The method of claim 1, in which said reduced oxygen atmosphere is created by placing said sealed space under a substantIally sub-atmospheric pressure.
Claim 5
Dependent Claim
29 words
The method of claim 2, in which said reduced oxygen atmosphere in the retort is created by placing said sealed space in the latter under a substantially sub-atmospheric pressure.
Claim 6
Dependent Claim
29 words
The method of claim 4, in which said reduced oxygen atmosphere in the retort is created by placing said sealed space in the latter under a substantially sub-atmospheric pressure.
Claim 7
Dependent Claim
30 words
The method of claim 2, in which said reduced oxygen atmosphere in the retort is created by introducing a normally substantially non-oxidizing gas into said sealed space of the retort.
Claim 8
Dependent Claim
30 words
The method of claim 4, in which said reduced oxygen atmosphere in the retort is created by introducing a normally substantially non-oxidizing gas into said sealed space of the retort.
Claim 9
Dependent Claim
23 words
The method of claim 1, in which the object is suspended during the volatilizing immersion thereof in said retort portion of said bath.
Claim 10
Dependent Claim
23 words
The method of claim 2, in which the object is suspended during the volatilizing immersion thereof in said retort portion of said bath.
Claim 11
Dependent Claim
23 words
The method of claim 4, in which the object is suspended during the volatilizing immersion thereof in the retort portion of said bath.
Claim 12
Dependent Claim
43 words
The method of claim 2, in which said bath portion enters the retort from the bottom of the latter as the object and retort become immersed, said sealed retort space to which the volatilization product escapes being at the top of the retort.
Claim 13
Dependent Claim
43 words
The method of claim 4, in which said bath portion enters the retort from the bottom of the latter as the object and retort become immersed, said sealed retort space to which the volatilization product escapes being at the top of the retort.
Claim 14
Dependent Claim
43 words
The method of claim 11, in which said bath portion enters the retort from the bottom of the latter as the object and retort become immersed, said sealed retort space to which the volatilization product escapes being at the top of the retort.
Claim 15
Dependent Claim
43 words
The method of claim 12, in which said bath portion enters the retort from the bottom of the latter as the object and retort become immersed, said sealed retort space to which the volatilization product escapes being at the top of the retort.
Claim 16
Dependent Claim
102 words
Apparatus for removing by volatilization a coating material from an object, comprising an object-receiving retort having means to seal the interior thereof as at least partially immersed, along with an object received therein, in a volatilizing bath, said retort having an exposed portion at which the bath enters the thus immersed retort, means for maintaining the bath at a temperature sufficiently elevated to volatilize said material, means for creating a reduced oxygen atmosphere in a space of the retort above the bath portion therein, the volatilization product escaping to said space, and means for voiding said product from said space after volatilization.
Claim 17
Dependent Claim
34 words
The apparatus of claim 17, in which said retort has an open bottom affording said closed portion, and means sealing the top of the retort above the level of the bath entering the same.
Claim 18
Dependent Claim
35 words
The apparatus of claim 17, in which said retort has an open bottom affording said closed portion, and means releasably sealing the top of the retort above the level of the bath entering the same.
Claim 19
Dependent Claim
41 words
The apparatus of claim 19, in which said sealing means is a cover removable from the remainder of the retort before and after volatilization, the cover being provided with a fitting-type connection assisting in the creation of said reduced oxygen atmosphere.
Claim 20
Dependent Claim
29 words
The apparatus of claim 17, in which said retort has means for lowering and raising the same relative to the bath respectively before and after immersion of the retort.
Claim 21
Dependent Claim
29 words
The apparatus of claim 19, in which said retort has means for lowering and raising the same relative to the bath respectively before and after immersion of the retort.
Claim 22
Dependent Claim
22 words
The apparatus of claim 17, in which said retort is in fixed relation to the bath before, during and after immersion thereof.
Claim 23
Independent Claim
105 words
A method of treatIng an object to separate organic and inorganic materials thereof as subjected to treatment, comprising immersing said object in a molten volatilization bath, creating and maintaining a reduced oxygen atmosphere in a space above the level of the bath by evacuating said space, which space is sealed against entry of external air thereto when said object is so immersed, maintaining said immersion for a time period and at an elevated temperature sufficient to cause volatilization of the organic material, escape of the organic volatilization product to said space and said separation of said materials, and withdrawing the escaped product from the space.
Claim 24
Dependent Claim
92 words
Apparatus for treating an object to separate organic and inorganic materials thereof as subjected to treatment, comprising an object-receiving retort having means to seal the interior thereof as thus subjected, along with an object therein, to a volatilizing environment, means for maintaining said environment at a temperature sufficiently elevated to volatilize said organic material, a vacuum pump for creating a reduced oxygen atmosphere in a space of the retort adjoining said atmosphere, the gaseous product of the organic material escaping to said space, and means for voiding said product from said space.
Claim 25
Dependent Claim
99 words
Apparatus for treating an object to separate organic and inorganic materials thereof as subjected to treatment, comprising an object-receiving retort having means to seal the interior thereof as at least partially immersed, along with an object therein, in a volatilizing bath, means for maintaining said bath at a temperature sufficiently elevated to volatilize said organic material, means for creating a reduced oxygen atmosphere in a space of the retort above the bath therein, the gaseous product of the organic material separating from the inorganic material and escaping to said space, and means for voiding said product from said space.
References Cited (Backward Citations)
US3448509A
Cited
US3615815A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |