US4413946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vented compressor inlet guide
Assignee: Dresser Rand Co
•
Filing: 1981-08-20
•
Granted: 1983-11-08
•
Expires: 2001-08-20
Abstract
Abstract To provide reduction in temporary conditions of excess load on the thrust bearing, a labyrinth positioned contiguous to a leakage aperture in the high pressure side of a single stage overhung compressor rotor affords controlled leakage to a venting circuit in communication with a lower pressure system. A pressure switch responsive to pressure levels in the venting circuit prevents compressor start at pressures above the set point of the switch while a backpressure valve in the venting circuit when operative maintains a predetermined pressure level therein. When the thrust bearing is operating at speeds sufficient to enable acceptance of the load imposed by compressor pressure, an override solenoid valve serves to close the backpressure valve and operably shut the venting circuit.
Inventors
- 👤 Dale F. Marshall
- 👤 Ted C. Evans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:36
CPC Classifications
F; F04; F04D; F04D27/00; F04D27/02; F04D27/0207; F04D27/023; F04D29/00; F04D29/05; F04D29/051; F04D29/0513; F04D29/0516
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
176 words
In a centrifugal compressor having an overhung rotor including a shaft mounted for rotation, an impeller secured to said shaft for rotation therewith and a thrust bearing supporting said shaft against thrust loads imposed thereon, the improvement comprising apparatus for limiting the thrust load imposed against said rotor and comprising means in combination for controllably venting the low pressure side of the compressor exposed to said rotor and including: (a) an aperture defined through a compressor wall from an inlet on the low pressure side of the compressor; (b) labyrinth means for substantially sealing flow from said aperture to permit only a predetermined controlled leakage therepast; (c) conduit means for communicating leakage from the outlet of said aperture to a relatively lower pressure receiving source; and (d) presettable control means operative at a set point correlated to the allowable thrust load design capacity of said thrust bearing and responsive to values of pressure in said conduit means to open and close said conduit means to leakage flow at pressure above and below the set point, respectively.
Claim 2
Dependent Claim
176 words
In a centrifugal compressor having an overhung rotor including a shaft mounted for rotation, an impeller secured to said shaft for rotation therewith and a thrust bearing supporting said shaft against thrust loads imposed thereon, the improvement comprising apparatus for limiting the thrust load imposed against said rotor and comprising means in combination for controllably venting the low pressure side of the compressor exposed to said rotor and including: (a) an aperture defined through a compressor wall from an inlet on the low pressure side of the compressor; (b) labyrinth means for substantially sealing flow from said aperture to permit only a predetermined controlled leakage therepast; (c) conduit means for communicating leakage from the outlet of said aperture to a relatively lower pressure receiving source; and (d) presettable control means operative at a set point correlated to the allowable thrust load design capacity of said thrust bearing and responsive to values of pressure in said conduit means to open and close said conduit means to leakage flow at pressure above and below the set point, respectively.
Claim 3
Dependent Claim
28 words
Apparatus according to claim 1 including override means operable to inactivate said control means for closing said conduit means at a predetermined minimum operating speed of the compressor.
Claim 4
Dependent Claim
27 words
Apparatus according to claim 2 in which said control means includes a backpressure regulator operable to maintain pressure in said conduit means below predetermined maximum pressure levels.
Claim 5
Dependent Claim
37 words
Apparatus according to claim 3 in which said override means includes sensing means operable to determine operating speed of the compressor and effective at high operating speeds to inactivate said backpressure regulator for closing said conduit means.
Claim 6
Dependent Claim
32 words
Apparatus according to claim 4 in which said sensing means comprises a differential pressure sensor operative in response to the differential in pressure between the suction and discharge pressure of the compressor.
Claim 7
Dependent Claim
22 words
Apparatus according to claim 5 in which said labyrinth means comprises a labyrinth seal positioned contiguous to the outlet of said aperture.
Claim 8
Dependent Claim
36 words
Apparatus according to claim 5 including second pressure sensor means responsive to pressure levels in said conduit means for preventing compressor startup when the pressure level in said conduit means is above a predetermined maximum level.
References Cited (Backward Citations)
US2470565A
Cited
US2839071A
Cited
US3009631A
Cited
US3292845A
Cited
US3327932A
Cited
US3487993A
Cited
US3688504A
Cited
US3727400A
Cited
US3804477A
Cited
US3971219A
Cited
JPS54153302A
Cited
US4251985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-07 | 1987-05-09 | 1987-11-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-07 | 1991-05-09 | 1991-11-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-07 | 1995-05-09 | 1995-11-08 | $7700.00 | Window Closed / Lapsed |