US3908897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Off-line integration of bridge and boiler controls
Assignee: Shell USA Inc
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Filing: 1973-12-26
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Granted: 1975-09-30
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Expires: 1993-12-26
Abstract
Abstract An apparatus and method for controlling a steam generator operating under rapidly varying load conditions. The method measures steam flow and pressure and combines the measurements with a signal that is proportional to the rate of change of steam flow and utilizes the resulting signal to control the fuel and air flow to the steam generator.
Inventors
- 👤 Holtz Leopold C Van
- 👤 Adrianus G Hop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 21:37
CPC Classifications
F; F22; F22B; F22B35/00
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
109 words
A process for the automatic control of a steam generator operating under varying load conditions, said process comprising: measuring the exit steam pressure from the generator; comparing the measured steam pressure with the desired steam pressure and generating a correcting signal P; measuring the steam flow from the generator and generating a signal A related thereto; measuring the change in steam flow and generating a signal B related to the rate of chang in the steam flow; algebraically adding the signals P, A and B to obtain a control signal; and using the control signal to control the fuel and air flow to the combustion process of said generator.
Claim 2
Dependent Claim
109 words
A process for the automatic control of a steam generator operating under varying load conditions, said process comprising: measuring the exit steam pressure from the generator; comparing the measured steam pressure with the desired steam pressure and generating a correcting signal P; measuring the steam flow from the generator and generating a signal A related thereto; measuring the change in steam flow and generating a signal B related to the rate of chang in the steam flow; algebraically adding the signals P, A and B to obtain a control signal; and using the control signal to control the fuel and air flow to the combustion process of said generator.
Claim 3
Dependent Claim
34 words
A process according to claim 1, in which process the signal B is proportional to the expected rate of change of the steam flow, the signal B being derived from an independent signal source.
Claim 4
Dependent Claim
51 words
A process according to claim 1 where the rate of change of the steam flow is confined to extreme limits, in which the signal B has a fixed positive and a fixed negative value, with the signal being the same as the sign of the change of the quantity of steam.
Claim 5
Independent Claim
208 words
An apparatus for the control of a steam generator operating under varying load condition, in particular a steam generator on board a ship, said apparatus comprising: a flow meter disposed to measure steam flow from the generator and provide a flow signal related to the measured flow; a pressure measuring means disposed to measure the pressure of the steam flow from the generator and supply a pressure signal related to the measured pressure; a controller having a set point, said pressure measuring means being coupled to said controller said controller supplying a control signal in response to the difference between the pressure signal and said set point; a signal generator responsive to the flow signal to supply a rate of change signal related to the rate of change in said flow; an adding circuit, said flow, control and rate of change signals being supplied to said adding circuit, said adding circuit algebraically adding said flow, control and rate of change signals and supplying a fuel-air control signal and; control means disposed to separately control the fuel and air supplied to the combustion chamber of said generator, said adder being coupled to said control means whereby said control means controls the air and fuel supplied to the combustion chamber.
Claim 6
Independent Claim
208 words
An apparatus for the control of a steam generator operating under varying load condition, in particular a steam generator on board a ship, said apparatus comprising: a flow meter disposed to measure steam flow from the generator and provide a flow signal related to the measured flow; a pressure measuring means disposed to measure the pressure of the steam flow from the generator and supply a pressure signal related to the measured pressure; a controller having a set point, said pressure measuring means being coupled to said controller said controller supplying a control signal in response to the difference between the pressure signal and said set point; a signal generator responsive to the flow signal to supply a rate of change signal related to the rate of change in said flow; an adding circuit, said flow, control and rate of change signals being supplied to said adding circuit, said adding circuit algebraically adding said flow, control and rate of change signals and supplying a fuel-air control signal and; control means disposed to separately control the fuel and air supplied to the combustion chamber of said generator, said adder being coupled to said control means whereby said control means controls the air and fuel supplied to the combustion chamber.
Claim 7
Dependent Claim
46 words
An apparatus according to claim 4, in which apparatus the signal generator consists of a computing element having an input connected to the signal output of the flow meter measuring the quantity of steam supplied and an output connected to that input of the adding circuit.
Claim 8
Dependent Claim
50 words
An apparatus according to claim 4, in which apparatus the signal generator is an independent circuit capable of supplying a signal that is proportional to the expected rate of change of the quantity of steam supplied, said signal generator having an output connected to the input of the adding circuit.
Claim 9
Dependent Claim
72 words
An apparatus according to claim 6 in which said signal generator comprises an independent circuit capable of supplying a signal of a fixed positive and fixed negative value the sign of the signal being adapted to the sign of the change in the quantity of steam supplied, said signal generator being connected to a switch element for connecting the signal of the desired sign to the appropriate input of the adding ciRcuit.
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) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |