US3665895A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for variable-pressure operation of a forced-flow vapor generator
Assignee: Sulzer AG
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Filing: 1970-12-07
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Granted: 1972-05-30
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Expires: 1990-12-07
Abstract
Abstract The enthalpies of the working mediums leaving the respective evaporators in the plant are maintained at a difference of at least 30 kcal/kg when the load approaches or exceeds the critical pressure range. The working medium fed to the downstream heating surfaces is drawn chiefly from the evaporator having the highest enthalpy while the working medium which is recirculated is drawn chiefly from the evaporator having the lowest enthalpy.
Inventors
- 👤 Josef Sauter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:04
CPC Classifications
F; F22; F22B; F22B29/00; F22B29/02; F22B29/023; F22B29/026; F22B35/00; F22B35/06; F22B35/08; F22B35/083; F22B35/086; F22B35/10; F22B35/105
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
194 words
A process for variable-pressure operation of a forced-flow vapor generator operated at high outputs close to the critical pressure and having at least two evaporator tube systems traversed by parallel flows of working medium and each comprising of plurality of tube lengths arranged in parallel and covering a boiler wall over at least part of the length thereof and heating surfaces downstream of the evaporator tube systems, said process including the steps of drawing some of the working medium from the evaporator tube systems for circulation to a first point upstream of the evaporator tube systems while directing the remainder of the working medium from the evaporator tube systems to the heating surfaces downstream thereof for superheating therein; producing a difference of at least 30 kcal/kg between the enthalpies of the working medium leaving the evaporator tube systems when the load reaches or exceeds the critical pressure range; and drawing the working medium for superheating chiefly from the evaporator tube system from which the working medium leaves at the highest enthalpy while drawing the working medium for circulation chiefly from the evaporator tube system from which the working medium leaves at the lowest enthalpy.
Claim 2
Dependent Claim
194 words
A process for variable-pressure operation of a forced-flow vapor generator operated at high outputs close to the critical pressure and having at least two evaporator tube systems traversed by parallel flows of working medium and each comprising of plurality of tube lengths arranged in parallel and covering a boiler wall over at least part of the length thereof and heating surfaces downstream of the evaporator tube systems, said process including the steps of drawing some of the working medium from the evaporator tube systems for circulation to a first point upstream of the evaporator tube systems while directing the remainder of the working medium from the evaporator tube systems to the heating surfaces downstream thereof for superheating therein; producing a difference of at least 30 kcal/kg between the enthalpies of the working medium leaving the evaporator tube systems when the load reaches or exceeds the critical pressure range; and drawing the working medium for superheating chiefly from the evaporator tube system from which the working medium leaves at the highest enthalpy while drawing the working medium for circulation chiefly from the evaporator tube system from which the working medium leaves at the lowest enthalpy.
Claim 3
Dependent Claim
51 words
A process as set forth in claim 1 wherein at a load in the pressure range below the limit of the critical pressure, the evaporator tube system with the lowest discharge enthalpy carries water at saturated-steam temperature while the evaporator tube system with the highest discharge enthalpy carries superheated working medium.
Claim 4
Dependent Claim
57 words
A process as set forth in claim 1 which further comprises the step of passing the working medium of lowest enthalpy to a water separator, sepaRating vapor and water from said working medium for feeding of the vapor to the heating surfaces and feeding of the water to said first point upstream of the evaporator tube systems.
Claim 5
Dependent Claim
42 words
A process as set forth in claim 3 wherein at least two evaporator tube systems are each connected to a water separator with said separators being connected in common on the water side to form a single water level in said separators.
Claim 6
Dependent Claim
50 words
A process as set forth in claim 3 which further comprises the step of introducing feed water into the flow of working medium at least between the evaporator tube system of lowest enthalpy and the level of water in the water separator to condense saturated vapor in the water separator.
Claim 7
Dependent Claim
39 words
A process as set forth in claim 5 which further comprises the step of superheating at least some of the saturated vapor in a heating surface suspended in front of the evaporator tube system having the lowest discharge enthalpy.
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) | 1975-05-30 | 1975-11-29 | 1976-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-30 | 1979-11-29 | 1980-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-30 | 1983-11-29 | 1984-05-30 | $7700.00 | Window Closed / Lapsed |