US3717330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High viscosity finisher
Assignee: DuPont Canada Inc
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Filing: 1971-06-03
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Granted: 1973-02-20
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Expires: 1991-06-03
Abstract
Abstract A self-wiping multiple screw element mixer of conical configuration useful as a polymerizer/finisher for the preparation of high viscosity polymers such as polyamides, polyesters, etc.
Inventors
- 👤 B Pinney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:23
CPC Classifications
B; B01; B01F; B01F27/00; B01F27/80; B01F27/92; B01F27/922
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
168 words
An apparatus for finishing high viscosity synthetic polymers comprising: an enclosed vessel having an interior surface throughout its length in the shape of two intersecting conical frustums with axes parallel and substantially vertical, the base of the frustums being displaced upwards with respect to the apexes, an entrance and a vent in the upper portion of the vessel and a discharge in the lower portion of the vessel; two interengaging helical screw elements rotatably supported on shafts passing through seals in the base of the vessel, the screw elements when co-rotated conform to the interior surface of the vessel such that the screw elements effect a complete cleaning of the interior surface and wherein the screw elements interengage uninterruptedly along their length such that each element effects a complete cleaning of the adjacent element, the bottom portion of the screw elements forming a pressure generating zone, and the top portion of the screw elements forming a mixing zone having a hollow center described by the co-rotating screw elements.
Claim 2
Independent Claim
168 words
An apparatus for finishing high viscosity synthetic polymers comprising: an enclosed vessel having an interior surface throughout its length in the shape of two intersecting conical frustums with axes parallel and substantially vertical, the base of the frustums being displaced upwards with respect to the apexes, an entrance and a vent in the upper portion of the vessel and a discharge in the lower portion of the vessel; two interengaging helical screw elements rotatably supported on shafts passing through seals in the base of the vessel, the screw elements when co-rotated conform to the interior surface of the vessel such that the screw elements effect a complete cleaning of the interior surface and wherein the screw elements interengage uninterruptedly along their length such that each element effects a complete cleaning of the adjacent element, the bottom portion of the screw elements forming a pressure generating zone, and the top portion of the screw elements forming a mixing zone having a hollow center described by the co-rotating screw elements.
Claim 3
Dependent Claim
28 words
The apparatus according to claim 1 in which the vent in the upper portion of the vessel is coincident with the hollow center between the co-rotating screw elements.
Claim 4
Dependent Claim
25 words
The apparatus according to claim 1 in which the vent in the upper portion of the vessel is in the form of a removable sleeve.
Claim 5
Dependent Claim
37 words
The apparatus according to claim 1 in which the vent in the upper portion of the vessel is coincident with the hollow center between the co-rotating screw elements and is in the form of a removable sleeve.
Claim 6
Dependent Claim
118 words
A mixing apparatus comprising a vessel having an interior surface throughout its length in the shape of at least two intersecting conical frustums with axes parallel and substantially vertical, the base of the frustums being displaced upwards with respect of the apexes, at least two inter-engaging helical screw elements rotatably mounted within the vessel which when co-rotated conform to the interior surface of the vessel such that the screw elements effect a complete cleaning of the interior surface and wherein the screw elements inter-engage uninterruptedly along their length such that each element effect a complete cleaning of the adjacent element, and wherein the screw elements when co-rotated describe a hollow center in the mixing zone of the vessel.
Claim 7
Dependent Claim
118 words
A mixing apparatus comprising a vessel having an interior surface throughout its length in the shape of at least two intersecting conical frustums with axes parallel and substantially vertical, the base of the frustums being displaced upwards with respect of the apexes, at least two inter-engaging helical screw elements rotatably mounted within the vessel which when co-rotated conform to the interior surface of the vessel such that the screw elements effect a complete cleaning of the interior surface and wherein the screw elements inter-engage uninterruptedly along their length such that each element effect a complete cleaning of the adjacent element, and wherein the screw elements when co-rotated describe a hollow center in the mixing zone of the vessel.
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) | 1976-02-20 | 1976-08-21 | 1977-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-20 | 1980-08-21 | 1981-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-20 | 1984-08-21 | 1985-02-20 | $7700.00 | Window Closed / Lapsed |