US3723018A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic valve changeover apparatus for a turbine
Assignee: Hitachi Ltd
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Filing: 1971-12-16
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Granted: 1973-03-27
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Expires: 1991-12-16
Abstract
Abstract An automatic valve changeover apparatus for controlling the admission of steam to a turbine. During the starting-up operation of a turbine, the admission of steam is shifted from ''''full arc admission'''' to ''''partial arc admission'''' in accordance with electrical output signals from an output setter and a speed setter. The output signals of the output setter and the speed setter respectively control the opening of control valves and a steam stop valve in accordance with the detected open positions of these valves and the speed or output of the turbine.
Inventors
- 👤 Y Uchiyama
- 👤 Y Nakano
- 👤 T Kishigami
- 👤 R Arie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:53
CPC Classifications
F; F01; F01D; F01D17/00; F01D17/20; F01D17/22; F01D17/24; F01D17/10; F01D17/12; F01D17/18
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
168 words
An automatic valve changeover apparatus for a turbine comprising steam passage means having a steam stop valve and a plurality of control valves arranged therein, variable speed setter means for providing an output signal of a desired speed for the turbine, variable output setter means for providing an output signal of a desired output for the turbine, speed detector means for providing an output signal indicative of the rotor speed of the turbine, first means for controlling said control valves in accordance with the difference in signals from said speed detector means and one of said output setter means and said speed setter means, second means for controlling said steam stop valve in accordance with the difference of signals from said speed detector means and said speed setter means, and means for providing valve changeover output signals for varying at least one of said output setter means and said speed setter means when the steam admission to the turbine is shifted from full arc to partial arc admission.
Claim 2
Dependent Claim
168 words
An automatic valve changeover apparatus for a turbine comprising steam passage means having a steam stop valve and a plurality of control valves arranged therein, variable speed setter means for providing an output signal of a desired speed for the turbine, variable output setter means for providing an output signal of a desired output for the turbine, speed detector means for providing an output signal indicative of the rotor speed of the turbine, first means for controlling said control valves in accordance with the difference in signals from said speed detector means and one of said output setter means and said speed setter means, second means for controlling said steam stop valve in accordance with the difference of signals from said speed detector means and said speed setter means, and means for providing valve changeover output signals for varying at least one of said output setter means and said speed setter means when the steam admission to the turbine is shifted from full arc to partial arc admission.
Claim 3
Dependent Claim
32 words
An automatic valve changeover apparatus in accordance with claim 1, including means for disconnecting the output of said valve changeover means to said output setter means and to said speed setter means.
Claim 4
Dependent Claim
92 words
An automatic valve changeover apparatus in accordance with claim 1, wherein the turbine drives a generator and including load setting means for providing an output signal of a desired output for the generator, and means for providing output signals indicative of the opening position of said control valves and said steam stop valve, said valve changeover means being responsive to the signals of the opening position of said control valves and said steam stop valve and signals of the difference of signals from said load setting means and said speed detector means.
Claim 5
Dependent Claim
105 words
An automatic valve changeover apparatus in accordance with claim 1, wherein the turbine drives a generator and including load setting means for providing an output signal of a desired output for the generator, output detecting means for providing an output signal indicative of the generator output, and means for providing output signals indicative of the opening position of said control valves and said steam stop valve, said valve changeover means being responsive to the signals of the opening position of said control valves and said steam stop valve and signals of the difference of signals from said load setting means and said output detecting means.
Claim 6
Dependent Claim
40 words
An automatic valve changeover apparatus in accordance with claim 1, wherein said steam stop valve serves for controlling the output of the turbine when the admission of steam to the turbine is shifted from full arc to partial arc admission.
Claim 7
Dependent Claim
70 words
An automatic valve changeover apparatus in accordance with claim 1, wherein said variable output setter means includes means for providing a selected constant value output signal to provide fine adjustment of the output signal of said variable output setter means, and said variable speed setter means includes means for providing a selected constant value output signal to provide fine adjustment of the output signal of said variable speed setter means.
Claim 8
Dependent Claim
77 words
An automatic valve changeover apparatus in accordance with claim 1, including means for detecting the difference in steam pressure upstream and downstream of said steam stop valve and for providing an output signal indicative thereof, means responsive to a predetermined pressure difference for providing an output signal to said valve changeover means, said valve changeover means being responsive thereto for varying said speed setter means to provide an output signal for fully opening said steam stop valve.
Claim 9
Dependent Claim
38 words
An automatic valve changeover apparatus in accordance with claim 1, wherein said first control means include valve driving means for rotating a cam, said cam being arranged for opening each of said control valves in a predetermined sequence.
Claim 10
Dependent Claim
27 words
An automatic valve changeover apparatus in accordance with claim 8, wherein said second control means includes valve driver means for opening and closing said steam stop valve.
Claim 11
Dependent Claim
39 words
An automatic valve changeover apparatus in accordance with claim 1, wherein said variable speed setter means includes a reversible motor for rotating a slideable resistor, said motor being operated in accordance with output signals from said valve changeover means.
Claim 12
Dependent Claim
40 words
An automatic valve changeover apparatus in accordance with claim 10, wherein said variable output setter means includes a reversible motor for rotating a slideable resistor, said motor being operated in accordance with the output signals of said valve changeover means.
Claim 13
Dependent Claim
62 words
An automatic valve changeover apparatus according to claim 4, wherein said steam stop valve serves for controlling the output of the turbine when the admission of steam to the turbine is shifted from full arc to partial arc admission and including means for disconnecting the output of said valve changeover means to said output setter means and to said speed setter means.
Claim 14
Dependent Claim
70 words
An automatic valve changeover apparatus in accordance with claim 12, wherein said variable output setter means includes means for providing a selected constant value output signal to provide fine adjustment of the output signal of said variable output setter means, and said variable speed setter means includes means for providing a selected constant value output signal to provide fine adjustment of the output signal of said variable speed setter means.
Claim 15
Dependent Claim
76 words
An automatic valve changeover apparatus in accordance with claim 13, including means for detecting the difference in steam pressure upstream and downstream of said steam stop valve and for providing an output signal indicative thereof, means responsive to a predetermined pressure difference for providing an output signal to said valve changeover means, said valve changeover means being responsive thereto for varying said speed setter means to provide an output for fully opening said steam stop valve.
Claim 16
Dependent Claim
55 words
An automatic valve changeover apparatus in accordance with claim 14, wherein said first control means include valve driving means for rotating a cam, said cam being arranged for opening each of said control valves in a predetermined sequence, and said second control means includes valve driver means for opening and closing said steam stop valve.
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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) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |