US3887529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preventing plugs in transfer conduits
Assignee: Phillips Petroleum Co
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Filing: 1973-12-20
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Granted: 1975-06-03
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Expires: 1993-12-20
Abstract
Abstract Plugging of a transfer conduit through which a plug-forming material is passed is prevented by flushing the conduit with a solvent which is subsequently flashed to prevent the solvent from interfering with processing of the plug-forming material.
Inventors
- 👤 Raymond G Rohlfing
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:16
CPC Classifications
B; B08; B08B; B08B9/00; B08B9/02; B08B9/027; B08B9/032; B08B3/00; B08B3/04; B08B3/08; C; C08; C08G; C08G75/00; C08G75/02; C08G75/0204; C08G75/0209
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
107 words
A METHOD TO PREVENT PLUGGING OF A TRANSFER CONDUIT THROUGH WHICH A PLUG-FORMING MATERIAL IS PASSED WHEN TRANSFERRED FROM A FIRST ZONE TO A SECOND ZONE, COMLPRISING: FLUSHING SAID TRANSFER CONDUIT WITH A LIQUID WHICH IS A SOLVENT FOR SAID PLUG-FORMING MATERIAL WHEREIN SAID SOLVENT IS AT A TEMPERATURE AND PRESSURE SUFFICIENT TO MAINTAIN SAID SOLVENT IN THE LIQUID PHASE IN SAID TRANSFER CONDUIT BUT WHICH CAUSES AT LEAST A SUFFICIENT PORTION OF SAID SOLVENT TO FLASH IN SAID SECOND ZONE TO PREVENT SAID SOLVENT FROM INTERFERING WITH THE PROCESSING OF SAID PLUG-FORMING MATERIAL IN SAID SECOND ZONE WHEN SAID SOLVENT IS INTRODUCED INTO SAID SECOND ZONE.
Claim 2
Independent Claim
107 words
A METHOD TO PREVENT PLUGGING OF A TRANSFER CONDUIT THROUGH WHICH A PLUG-FORMING MATERIAL IS PASSED WHEN TRANSFERRED FROM A FIRST ZONE TO A SECOND ZONE, COMLPRISING: FLUSHING SAID TRANSFER CONDUIT WITH A LIQUID WHICH IS A SOLVENT FOR SAID PLUG-FORMING MATERIAL WHEREIN SAID SOLVENT IS AT A TEMPERATURE AND PRESSURE SUFFICIENT TO MAINTAIN SAID SOLVENT IN THE LIQUID PHASE IN SAID TRANSFER CONDUIT BUT WHICH CAUSES AT LEAST A SUFFICIENT PORTION OF SAID SOLVENT TO FLASH IN SAID SECOND ZONE TO PREVENT SAID SOLVENT FROM INTERFERING WITH THE PROCESSING OF SAID PLUG-FORMING MATERIAL IN SAID SECOND ZONE WHEN SAID SOLVENT IS INTRODUCED INTO SAID SECOND ZONE.
Claim 3
Independent Claim
107 words
A method to prevent plugging of a transfer conduit through which a plug-forming material is passed when transferred from a first zone to a second zone, comprising: flushing said transfer conduit with a liquid which is a solvent for said plug-forming material wherein said solvent is at a temperature and pressure sufficient to maintain said solvent in the liquid phase in said transfer conduit but which causes at least a sufficient portion of said solvent to flash in said second zone to prevent said solvent from interfering with the processing of said plug-forming material in said second zone when said solvent is introduced into said second zone.
Claim 4
Independent Claim
107 words
A method to prevent plugging of a transfer conduit through which a plug-forming material is passed when transferred from a first zone to a second zone, comprising: flushing said transfer conduit with a liquid which is a solvent for said plug-forming material wherein said solvent is at a temperature and pressure sufficient to maintain said solvent in the liquid phase in said transfer conduit but which causes at least a sufficient portion of said solvent to flash in said second zone to prevent said solvent from interfering with the processing of said plug-forming material in said second zone when said solvent is introduced into said second zone.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein said plug-forming material is a polymer.
Claim 6
Dependent Claim
12 words
The method of claim 2 wherein said polymer is a poly(arylene sulfide).
Claim 7
Dependent Claim
12 words
The method of claim 3 wherein said poly(arylene sulfide) is polyphenylene sulfide.
Claim 8
Dependent Claim
12 words
The method of claim 3 wherein said solvent is an organic amide.
Claim 9
Dependent Claim
11 words
The method of claim 5 wherein said organic amide is N-methyl-2-pyrrolidone.
Claim 10
Dependent Claim
81 words
The method of claim 2 wherein said first zone is a reactor in which the polymer is formed; said second zone is a separator having a mixer-dryer attached thereto for processing the polymer, said mixer-dryer being driven by a pOwer means; and interfering with the processing of said plug-forming material arises when that portion of the solvent which did not flash in the separator causes the polymer to become pasty and the pasty polymer overloads the power means of the mixer-dryer.
Claim 11
Dependent Claim
69 words
The method of claim 1 wherein the plug-forming material is polyphenylene sulfide, the liquid solvent for the polyphenylene sulfide is N-methyl-2-pyrrolidone, the temperature of the N-methyl-2-pyrrolidone in said transfer conduit ranges from about 500* to about 550*F, the pressure of the N-methyl-2-pyrrolidone in said transfer conduit ranges from about 125 to about 175 psig, and the pressure in said second zone ranges from about 0 to about 10 psig.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |