Patent US3639073A successfully refreshed from Google Patents.
US3639073A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal pump
Assignee: Sundstrand Corp
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Filing: 1970-04-23
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Granted: 1972-02-01
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Expires: 1990-04-23
Abstract
Abstract A two-stage centrifugal pump assembly adapted to produce high pressures from the second stage with a plurality of centrifugal sealing impellers associated with the second stage for the purpose of reducing the pressure drop across a mechanical seal associated with the second stage to minimize the second-stage sealing loss, there being provided a bypass from the low-pressure side of the first stage impeller to the sealing impellers of the second stage for delivering pumped fluid to the second-stage sealing impellers in a manner to prevent heating and boiling in the second-stage sealing impellers, there being also provided an alternate provision for supplying a noncorrosive compatible buffer fluid as the sealing fluid to the inlet of the sealing impellers in the second stage which also maintains the sealing impellers cool and at the same time isolates the impellers and the main impeller shaft from the corrosive fluid being pumped.
Inventors
- 👤 Richard Beck Jr
- 👤 Homer E Gravelle
- 👤 James A Ferguson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 03:59
CPC Classifications
F; F04; F04D; F04D1/00; F04D1/06; F04D1/063; F04D1/04; F04D29/00; F04D29/18; F04D29/22; F04D29/2261; F04D29/2266
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
105 words
A centrifugal pump assembly, comprising: a first-stage pump unit having a main impeller, an inlet and an outlet, a second-stage pump unit having a main impeller, an inlet and outlet, said first- and second-stage pump units having common drive means, said second-stage pump unit having inboard seal means, centrifugal seal means between said inboard seal means and said second-stage impeller, centrifugal seal means being constructed to deliver fluid toward said secondstage impeller at a pressure in excess of the first-stage discharge pressure and means responsive to flow from the firststage pump unit for delivering fluid to the centrifugal seal means of the second-stage pump unit.
Claim 2
Dependent Claim
105 words
A centrifugal pump assembly, comprising: a first-stage pump unit having a main impeller, an inlet and an outlet, a second-stage pump unit having a main impeller, an inlet and outlet, said first- and second-stage pump units having common drive means, said second-stage pump unit having inboard seal means, centrifugal seal means between said inboard seal means and said second-stage impeller, centrifugal seal means being constructed to deliver fluid toward said secondstage impeller at a pressure in excess of the first-stage discharge pressure and means responsive to flow from the firststage pump unit for delivering fluid to the centrifugal seal means of the second-stage pump unit.
Claim 3
Dependent Claim
27 words
A centrifugal pump assembly as defined in claim 1, wherein said centrifugal seal means includes a plurality of impellers coaxially positioned with respect to the second-stage impeller.
Claim 4
Dependent Claim
27 words
A centrifugal pump assembly as defined in claim 2, wherein each of said seal impellers includes an annular backplate with radial blades facing said inboard seal means.
Claim 5
Dependent Claim
129 words
A centrifugal pump assembly, comprising: a first-stage pump unit having an impeller, and axial inlet on one side of the impeller and an outlet, a second-stage pump unit having an impeller and an axial inlet connected to the first-stage outlet on one side of the impeller, and an outlet, said second-stage impeller being supported and driven by a shaft, inboard seal means sealing said shaft on the side of said second-stage impeller opposite the second-stage inlet, centrifugal seal means on said shaft between said inboard seal means and the second-stage impeller, and means for conveying a portion of the main pump fluid from the inlet of the first-stage pump unit to the centrifugal seal means to minimize boiling of the fluid as it passes through the centrifugal seal means.
Claim 6
Dependent Claim
129 words
A centrifugal pump assembly, comprising: a first-stage pump unit having an impeller, and axial inlet on one side of the impeller and an outlet, a second-stage pump unit having an impeller and an axial inlet connected to the first-stage outlet on one side of the impeller, and an outlet, said second-stage impeller being supported and driven by a shaft, inboard seal means sealing said shaft on the side of said second-stage impeller opposite the second-stage inlet, centrifugal seal means on said shaft between said inboard seal means and the second-stage impeller, and means for conveying a portion of the main pump fluid from the inlet of the first-stage pump unit to the centrifugal seal means to minimize boiling of the fluid as it passes through the centrifugal seal means.
Claim 7
Dependent Claim
127 words
A centrifugal pump assembly, comprising: a first-stage pump unit having an impeller, an axial inlet on one side of the impeller and an outlet, a second-stage pump unit having an impeller and axial inlet connected to the first stage outlet on one side of the impeller, and an outlet, said first and second pump units having common drive means, said second-stage impeller being supported and driven by a shaft, inboard seal means supporting said shaft on the side of said second-stage impeller oPposite the second-stage inlet, centrifugal seal means on said shaft between said inboard seal means and the second stage impeller, and means responsive to inlet flow to the first-stage pump unit for conveying a cool buffer fluid to said centrifugal seal means to minimize boiling.
Claim 8
Dependent Claim
127 words
A centrifugal pump assembly, comprising: a first-stage pump unit having an impeller, an axial inlet on one side of the impeller and an outlet, a second-stage pump unit having an impeller and axial inlet connected to the first stage outlet on one side of the impeller, and an outlet, said first and second pump units having common drive means, said second-stage impeller being supported and driven by a shaft, inboard seal means supporting said shaft on the side of said second-stage impeller oPposite the second-stage inlet, centrifugal seal means on said shaft between said inboard seal means and the second stage impeller, and means responsive to inlet flow to the first-stage pump unit for conveying a cool buffer fluid to said centrifugal seal means to minimize boiling.
Claim 9
Dependent Claim
51 words
A centrifugal pump assembly as defined in claim 4, wherein said centrifugal seal means includes a plurality of impellers each coaxially mounted on said shaft and having a plurality of radial blades facing said inboard seal means, said impellers being arranged to deliver fluid serially from one seal impeller to another.
Claim 10
Dependent Claim
33 words
A centrifugal pump assembly as defined in claim 6, wherein said seal means includes a plurality of radial stationary blades adjacent the main impeller side of each of the centrifugal seal means impellers.
Claim 11
Dependent Claim
68 words
A centrifugal pump assembly as defined in claim 4, including a shaft supporting and drivingly connected to said first-stage impeller, said first-stage impeller being an open impeller so that the pressure along the shaft is substantially the same as the first-stage inlet pressure, said means for conveying inlet fluid including a bypass passage communicating with the first-stage shaft for bleeding pump fluid to the second-stage centrifugal seal means.
Claim 12
Dependent Claim
31 words
A centrifugal pump assembly as defined in claim 5, including passage means in said second-stage unit between said inboard seal means and the centrifugal seal means for conveying the buffer fluid.
Claim 13
Dependent Claim
58 words
A centrifugal pump assembly as defined in claim 9, said first-stage unit having an impeller shaft and an inboard bearing surrounding said shaft, centrifugal seal means on said first-stage shaft between said first-stage inboard seal and said first-stage impeller, and passage means connected with said first-stage unit for directing buffer seal fluid to said first-stage centrifugal seal means.
Claim 14
Dependent Claim
207 words
A centrifugal pump assembly, comprising: a first-stage centrifugal pump having housing means, a main impeller mounted in said housing means, a shaft supported for rotation in said housing means, an axial inlet to the impeller in the housing, an outlet for the impeller in said housing means, a mechanical seal surrounding said shaft in said housing means, bleed passage means in said housing means for conveying pumped fluid from between the impeller and the mechanical seal, a second-stage centrifugal pump having a housing means, a main impeller mounted in said housing means, a shaft in said housing means rotatably driving said impeller, an axial inlet in said housing means for the second-stage impeller, an outlet in said housing means for said second-stage impeller, a mechanical seal on the inboard end of the second-stage shaft, a plurality of seal impellers on said shaft between said second-stage impeller and said second-stage mechanical seal, said seal impellers having a plurality of radial vanes facing said second-stage mechanical seal, said housing means being constructed to deliver seal fluid radially from one seal impeller to another, and passage means between said second-stage mechanical seal and said seal impellers for delivering pump fluid from said first-stage pump means to the second-stage seal impellers.
Claim 15
Dependent Claim
207 words
A centrifugal pump assembly, comprising: a first-stage centrifugal pump having housing means, a main impeller mounted in said housing means, a shaft supported for rotation in said housing means, an axial inlet to the impeller in the housing, an outlet for the impeller in said housing means, a mechanical seal surrounding said shaft in said housing means, bleed passage means in said housing means for conveying pumped fluid from between the impeller and the mechanical seal, a second-stage centrifugal pump having a housing means, a main impeller mounted in said housing means, a shaft in said housing means rotatably driving said impeller, an axial inlet in said housing means for the second-stage impeller, an outlet in said housing means for said second-stage impeller, a mechanical seal on the inboard end of the second-stage shaft, a plurality of seal impellers on said shaft between said second-stage impeller and said second-stage mechanical seal, said seal impellers having a plurality of radial vanes facing said second-stage mechanical seal, said housing means being constructed to deliver seal fluid radially from one seal impeller to another, and passage means between said second-stage mechanical seal and said seal impellers for delivering pump fluid from said first-stage pump means to the second-stage seal impellers.
Claim 16
Dependent Claim
141 words
A centrifugal pump assembly, comprising: a first-stage centrifugal pump unit having a housing means, an impeller rotatably mounted in said housing means, a shaft supporting said impeller in said housing means, an axial inlet in said housing means for said impeller, an outlet in said housing means, a mechanical shaft seal surrounding said shaft at the inboard end thereof, a seal impeller on said shaft between said mechanical seal and said impeller, passage means in said housing for conveying a relatively cool buffer fluid between said mechanical seal and said seal impeller, a second-stage centrifugal pump unit having a housing means, common means for driving said first- and second-stage pump units, a seal impeller rotatably mounted in said second-stage housing means, and means responsivE to rotation of said first-stage centrifugal pump unit for delivering sealing fluid to the second-stage seal impeller.
Claim 17
Dependent Claim
141 words
A centrifugal pump assembly, comprising: a first-stage centrifugal pump unit having a housing means, an impeller rotatably mounted in said housing means, a shaft supporting said impeller in said housing means, an axial inlet in said housing means for said impeller, an outlet in said housing means, a mechanical shaft seal surrounding said shaft at the inboard end thereof, a seal impeller on said shaft between said mechanical seal and said impeller, passage means in said housing for conveying a relatively cool buffer fluid between said mechanical seal and said seal impeller, a second-stage centrifugal pump unit having a housing means, common means for driving said first- and second-stage pump units, a seal impeller rotatably mounted in said second-stage housing means, and means responsivE to rotation of said first-stage centrifugal pump unit for delivering sealing fluid to the second-stage seal impeller.
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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) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |