US3836689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric glass furnace with zone temperature control
Assignee: Owens Corning
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Filing: 1973-04-19
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Granted: 1974-09-17
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Expires: 1993-04-19
Abstract
Abstract An improved furnace for electrically heating material such as molten glass. At least one and, preferably, a plurality of controlled thermal zones are established transverse to the direction of glass flow through the furnace. For each thermal zone, at least two electrical circuits supply power to at least three submerged electrodes for heating the glass. A control circuit is provided to maintain substantially constant the square of the average current in each circuit. If a predetermined permissible temperature variation is exceeded in the molten glass in any thermal zone, power to all electrodes for such thermal zone is either reduced or interrupted. The thermal zones may also be interdependent for maintaining a desired temperature profile in the material flow direction.
Inventors
- 👤 R Holler
- 👤 R Rothrock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:57
CPC Classifications
G; G05; G05D; G05D23/00; G05D23/19; G05D23/1927; G05D23/193; G05D23/1932; G05D23/1934; C; C03; C03B; C03B5/00; C03B5/02; C03B5/027; C03B5/03; G05D23/20; G05D23/22; Y; Y10; Y10S; Y10S65/00; Y10S65/04
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
136 words
An electric furnace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, at least one thermal zone extending within the material in the container in a direction transverse to the material flow direction, means comprising at least two electric circuit means for said one zone including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in said one zone with said electrodes spaced in a direction transverse to the material flow direction, and means responsive to a predetermined temperature difference in a direction transverse to the material flow direction in said one thermal zone for controlling power in all of said circuit means which supply power to all of said electrodes in said one thermal zone.
Claim 2
Dependent Claim
136 words
An electric furnace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, at least one thermal zone extending within the material in the container in a direction transverse to the material flow direction, means comprising at least two electric circuit means for said one zone including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in said one zone with said electrodes spaced in a direction transverse to the material flow direction, and means responsive to a predetermined temperature difference in a direction transverse to the material flow direction in said one thermal zone for controlling power in all of said circuit means which supply power to all of said electrodes in said one thermal zone.
Claim 3
Dependent Claim
41 words
An electric furnace for heating a molten material, as set forth in claim 1, wherein said power controlling means interrupts power to all electrodes in said on thermal zone in response to the predetermined temperature difference in said one thermal zone.
Claim 4
Dependent Claim
45 words
An electric furnace for heating a molten material, as set forth in claim 1, wherein each of said electric circuit means includes control means for maintaining substantially constant the value of the root mean square of the current supplied to the material through said electrodes.
Claim 5
Dependent Claim
55 words
An electric furnace for heating a molten material, as set forth in claim 3, wherein said at least two circuit means each includes a pair of said electrodes for supplying power to the molten material, a power source, and means connecting said power source, said pair of electrodes and said circuit control means in series.
Claim 6
Dependent Claim
36 words
An electric furnace for heaTing a molten material, as set forth in claim 3, wherein each of said circuit control means includes switch means for periodically interrupting power flow from said power source to said electrodes.
Claim 7
Dependent Claim
68 words
An electric furnace for heating a molten material as set forth in claim 5, wherein said power controlling means includes a plurality of temperature sensors, means positioning said temperature sensors to measure the relative temperature of the molten material at a plurality of points sapced within said one thermal zone downstream of said electrodes and transverse to the material flow direction, and means for comparing such sensed temperatures.
Claim 8
Dependent Claim
62 words
An electric furnace for heating a molten material, as set forth in claim 3, wherein said power controlling means includes means for measuring the average powers supplied to the molten material through each of said circuit means, such powers being a function of the temperature of the molten material being heated by said circuit means, and means for comparing such measured powers.
Claim 9
Dependent Claim
133 words
An electric furnace for heating molten glass by the Joule effect and in which the molten glass flows in a direction transverse to a plurality of thermal zones within the molten glass comprising, in combination, a container for holding the molten glass during heating, at least three electrodes for one of the thermal zones, means mounting said electrodes for electrical contact with the molten glass in said one thermal zone with said electrodes spaced transversely to the glass flow direction, a plurality of power supply circuits, at least two for supplying power to said at least three electrodes, and means responsive to a predetermined temperature difference in a direction transverse to the glass flow direction in said one thermal zone for controlling power to all of said electrodes in said one thermal zone.
Claim 10
Dependent Claim
133 words
An electric furnace for heating molten glass by the Joule effect and in which the molten glass flows in a direction transverse to a plurality of thermal zones within the molten glass comprising, in combination, a container for holding the molten glass during heating, at least three electrodes for one of the thermal zones, means mounting said electrodes for electrical contact with the molten glass in said one thermal zone with said electrodes spaced transversely to the glass flow direction, a plurality of power supply circuits, at least two for supplying power to said at least three electrodes, and means responsive to a predetermined temperature difference in a direction transverse to the glass flow direction in said one thermal zone for controlling power to all of said electrodes in said one thermal zone.
Claim 11
Dependent Claim
41 words
An electric furnace for heating molten glass, as set forth in claim 8, wherein said power controlling means simultaneously interrupts power to all electrodes in said one thermal zone in response to the predetermined temperature difference in said one thermal zone.
Claim 12
Dependent Claim
44 words
An electric furnace for heating molten glass, as set forth in claim 9, and including second control means for maintaining substantially constant the value of the root mean square of the current supplied through said electrodes to the glass in said one thermal zone.
Claim 13
Dependent Claim
67 words
An electric furnace for heating molten glass, as set forth in claim 10, wherein said power controlling means includes a plurality of temperature sensors, means positioning said temperature sensors to measure the relative temperature of the molten glass at a plurality of points spaced within said one thermal zone downstream of said electrodes and transverse to the material flow direction, and means for comparing such sensed temperature.
Claim 14
Dependent Claim
60 words
An electric furnace for heating molten glass, as set forth in claim 10, wherein said power controlling means includes means for measuring the average power supplied to the molten glass by said power supply circuits, such powers being a function of the temperature of the molten glass to which the power is supplied, and means for comparing such measured powers.
Claim 15
Dependent Claim
126 words
An electric furnace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, a plurality of thermal zones each extending within the material in a direction transverse to the direction of material flow, means comprising at least two electric circuit means for each of said thermal zones and including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in each of said zones with said electrodes spaced in a direction transverse to the material flow direction, and means for each thermal zone for interdependently controlling power in all of said circuit means for such thermal zone separately of the control of the other of said thermal zones.
Claim 16
Dependent Claim
126 words
An electric furnace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, a plurality of thermal zones each extending within the material in a direction transverse to the direction of material flow, means comprising at least two electric circuit means for each of said thermal zones and including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in each of said zones with said electrodes spaced in a direction transverse to the material flow direction, and means for each thermal zone for interdependently controlling power in all of said circuit means for such thermal zone separately of the control of the other of said thermal zones.
Claim 17
Dependent Claim
129 words
An electric furNace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, a plurality of thermal zones each extending within the material in a direction transverse to the direction of material flow, means comprising electric circuit means for each of said thermal zones and including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in each of said zones with said electrodes spaced in a direction transverse to the material flow direction, and means connected for controlling power in all of said circuit means for each one of said thermal zones in an interdependent relation to establish a predetermined temperature profile in the molten material in the flow direction.
Claim 18
Dependent Claim
129 words
An electric furNace for heating a flowing molten material by the Joule effect comprising, in combination, a container for the molten material, a plurality of thermal zones each extending within the material in a direction transverse to the direction of material flow, means comprising electric circuit means for each of said thermal zones and including electrodes for supplying electric power to the molten material, means mounting said electrodes for electrical contact with the material in each of said zones with said electrodes spaced in a direction transverse to the material flow direction, and means connected for controlling power in all of said circuit means for each one of said thermal zones in an interdependent relation to establish a predetermined temperature profile in the molten material in the flow direction.
Claim 19
Dependent Claim
41 words
An electric furnace for heating a flowing molten material, as set forth in claim 14, and including means for each thermal zone for controlling power in said circuit means for such thermal zone separately of the other of said thermal zones.
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) | 1977-09-16 | 1978-03-18 | 1978-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-16 | 1982-03-18 | 1982-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-16 | 1986-03-18 | 1986-09-17 | $7700.00 | Window Closed / Lapsed |