US3780261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic control for electrode boilers
Assignee: Eaton Williams Group Ltd
•
Filing: 1972-05-19
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Granted: 1973-12-18
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Expires: 1992-05-19
Abstract
Abstract An electronic controller for an electrode boiler in which the heating current passing through an electrode depends upon the water level in the boiler, in which circuitry controls feed and drain valves to carry out an automatic repetitive cycle to feed water into the boiler to a predetermined level, to sense when boiling has reduced the level to another predetermined point, to open the drain valve to allow a quantity of water to drain out to remove solid matter precipitated during boiling, then to re-open the feed valve to restore the original level so that boiling may recommence. An alternative feed, boil, feed, drain cycle is provided.
Inventors
- 👤 Williams R Eaton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:17
CPC Classifications
F; F22; F22B; F22B1/00; F22B1/28; F22B1/30; F22D; F22D5/00; F22D5/24; Y; Y10; Y10T; Y10T137/00; Y10T137/7287; Y10T137/7306
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
An electronic controller for controlling, in accordance with a repetitive cycle, an electrode boiler in which the heating current passing through an electrode depends upon the depth of immersion of the electrode and hence upon the water level in the boiler, the controller comprising circuitry for initially operating an electrically controlled feed valve to allow feed water to enter the boiler, first sensing means in the circuitry to detect when the electrode current has risen to a level corresponding to a desired normal water level, means responsive to the first sensing means to cause the feed valve to be closed, whereupon the water is allowed to boil, second sensing means to detect when the electrode current falls to a level corresponding to a water level lower than the said normal water level due to loss of water boiled away, and means responsive to the second sensing means to initiate a desired sequence of steps including the opening of a drain valve to allow a quantity of water to drain from the boiler and the subsequent closure of the drain valve and the re-opening of the feed valve to allow the boiler to re-fill to the said normal level.
Claim 2
Dependent Claim
198 words
An electronic controller for controlling, in accordance with a repetitive cycle, an electrode boiler in which the heating current passing through an electrode depends upon the depth of immersion of the electrode and hence upon the water level in the boiler, the controller comprising circuitry for initially operating an electrically controlled feed valve to allow feed water to enter the boiler, first sensing means in the circuitry to detect when the electrode current has risen to a level corresponding to a desired normal water level, means responsive to the first sensing means to cause the feed valve to be closed, whereupon the water is allowed to boil, second sensing means to detect when the electrode current falls to a level corresponding to a water level lower than the said normal water level due to loss of water boiled away, and means responsive to the second sensing means to initiate a desired sequence of steps including the opening of a drain valve to allow a quantity of water to drain from the boiler and the subsequent closure of the drain valve and the re-opening of the feed valve to allow the boiler to re-fill to the said normal level.
Claim 3
Dependent Claim
153 words
A controller as claimed in claim 1 in which the means responsive to the second sensing means comprises means to cause an electrically controlled drain valve to be opened whereupon water is allowed to drain from the boiler, the circuitry also comprising third sensing means to detect when the electrode current falls to a level corresponding to another water level due to loss of water drained from the boiler, and means responsive to the third sensing means to cause the drain valve to be closed and the feed valve to be opened, whereupon feed water is again allowed to enter the boiler, the first sEnsing means and the means responsive thereto causing the feed valve to be closed when the electrode current has again risen to a level corresponding to the said normal water level so that boiling may recommence, the circuitry being arranged to carry out the feed, boil, drain cycle repetitively.
Claim 4
Dependent Claim
163 words
A controller as claimed in claim 1 in which the means responsive to the second sensing means comprises means to re-open the feed valve, the circuitry comprising also further means responsive to the first sensing means to cause the feed valve to be closed and an electrically controlled drain valve to be opened when the electrode current has again reached a level corresponding to the said normal water level, third sensing means to detect when the electrode current has fallen to a level corresponding to a further water level, and means responsive to the third sensing means to cause the drain valve to be closed and the feed valve to be re-opened, the first sensing means and the means responsive thereto causing the feed valve to be closed when the electrode current has again risen to a level corresponding to the said normal water level so that boiling may recommence, the circuitry being arranged to carry out the feed-boil, feed, drain cycle repetitively.
Claim 5
Dependent Claim
58 words
A controller as claimed in claim 1 comprising additional sensing means to sense when the electrode current has risen to a level corresponding to a maximum water level, and means responsive to the additional sensing means to cause the drain valve to open, thereby draining water from the boiler and bringing about a reduction in the electrode current.
Claim 6
Dependent Claim
27 words
A controller as claimed in claim 1 in which the circuitry comprises means to prevent the opening of the drain valve while the feed valve is open.
Claim 7
Dependent Claim
42 words
A controller as claimed in claim 1 comprising a current transformer having a primary winding for connection in series with a boiler heating electrode, and a secondary winding, the controller including means to sense the voltage developed in the transformer secondary winding.
Claim 8
Dependent Claim
29 words
A controller as claimed in claim 6 in which the sensing means comprise two-state circuits which change state when the voltage of the transformer secondary winding reaches predetermined levels.
Claim 9
Dependent Claim
42 words
A controller as claimed in claim 1 a ''''boiler full'''' electrode for insertion in the boiler, the controller including circuit elements which cause the feed valve to be closed when the boiler full electrode becomes immersed, to prevent overfilling of the boiler.
Claim 10
Dependent Claim
20 words
A controller as claimed in claim 8 comprising circuitry to activate warning means when the boiler full electrode becomes immersed.
Claim 11
Dependent Claim
33 words
A controller as claimed in claim 1 in which the circuitry comprises means to vary the amount of water drained from the boiler in relation to the amount boiled away during each cycle.
Claim 12
Dependent Claim
26 words
A controller as claimed in claim 1 comprising means to enable the drain valve to be opened and kept open in order to drain the boiler.
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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) | 1976-12-17 | 1977-06-18 | 1977-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-17 | 1981-06-18 | 1981-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-17 | 1985-06-18 | 1985-12-18 | $7700.00 | Window Closed / Lapsed |