US4371310A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal pump recirculation diffuser
Assignee: United States Department of the Navy
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Filing: 1974-07-23
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Granted: 1983-02-01
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Expires: 1994-07-23
Abstract
Abstract A recirculation diffuser for centrifugal pumps that produces a continuousrising head capacity curve and at the same time reduces levels of impeller vane-frequency sound and other high level acoustic flow tones. The conventional vane diffuser in the pump casing at the periphery of the rotary impeller is modified by separating one of the side shrouds from the diffuser vanes thereby creating a recirculation flow path around the vanes from the outside high pressure to the inside low pressure side.
Inventors
- 👤 John W. Henry, IV
- 👤 David E. Cassel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:33
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/445; F04D29/448; F05; F05D; F05D2250/00; F05D2250/50; F05D2250/52
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
77 words
A centrifugal pump for liquids having a casing with a vaned impeller rotatably mounted therein and a diffuser section at the periphery thereof comprising: a pair of facing shroud members forming the diffuser section of the casing; a plurality of hydrodynamically shaped diffuser vanes attached to at least one of said shrouds; and a recirculation flow path around said diffuser vanes from the outside high pressure side to the inside low pressure side of said diffuser vanes.
Claim 2
Dependent Claim
77 words
A centrifugal pump for liquids having a casing with a vaned impeller rotatably mounted therein and a diffuser section at the periphery thereof comprising: a pair of facing shroud members forming the diffuser section of the casing; a plurality of hydrodynamically shaped diffuser vanes attached to at least one of said shrouds; and a recirculation flow path around said diffuser vanes from the outside high pressure side to the inside low pressure side of said diffuser vanes.
Claim 3
Dependent Claim
40 words
The centrifugal pump of claim 1 wherein: one of said shroud members is separated from the edges of said plurality of diffuser vanes to form a gap between the shroud and the diffuser vane thus providing a recirculation flow path.
Claim 4
Dependent Claim
25 words
The centrifugal pump of claim 2 further comprising: spacers between the edges of said plurality of said plurality of diffuser vanes and said shroud members.
Claim 5
Dependent Claim
22 words
The centrifugal pump of claim 3 wherein: said spacers are thumbtack shaped, the head of which is 20 to 40 mils thick.
References Cited (Backward Citations)
US2360145A
Cited
US3381621A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-01-31 | 1986-08-02 | 1987-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-01-31 | 1990-08-02 | 1991-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-01-31 | 1994-08-02 | 1995-02-01 | $7700.00 | Window Closed / Lapsed |