US3658309A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature control of ore in multiple hearth furnace
Assignee: Viridian Inc Canada
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Filing: 1970-08-03
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Granted: 1972-04-25
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Expires: 1990-08-03
Abstract
Abstract The temperature of ore on the hearth of a multiple hearth furnace is continuously monitored by means of a thermometer positioned in the undisturbed dead bed of the ore beneath the live bed which is being continuously raked. The temperature readings are used to control the roasting temperature in the live bed within a preselected range.
Inventors
- 👤 William James Lavender
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:42
CPC Classifications
G; G01; G01K; G01K1/00; G01K1/14
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
114 words
In the method of heating an ore disposed on a hearth of a multi-hearth furnace wherein the temperature is controlled within a preselected range to effect roasting of said ore, said ore being disposed in two beds having a common interface and comprising a lower dead bed and an upper live bed, said dead bed remaining relatively undisturbed and said upper bed being continuously raked, the improved procedure for continuously determining the temperature of the ore in said live bed characterized in that a thermometer is placed in the dead bed and said temperature determination is utilized to control the roasting temperature of the ore in said live bed within said preselected temperature range.
Claim 2
Dependent Claim
114 words
In the method of heating an ore disposed on a hearth of a multi-hearth furnace wherein the temperature is controlled within a preselected range to effect roasting of said ore, said ore being disposed in two beds having a common interface and comprising a lower dead bed and an upper live bed, said dead bed remaining relatively undisturbed and said upper bed being continuously raked, the improved procedure for continuously determining the temperature of the ore in said live bed characterized in that a thermometer is placed in the dead bed and said temperature determination is utilized to control the roasting temperature of the ore in said live bed within said preselected temperature range.
Claim 3
Dependent Claim
19 words
The method as claimed in claim 1 wherein said thermometer is placed in the dead bed adjacent said interface.
Claim 4
Independent Claim
16 words
The method as claimed in claims 1 or 2 wherein said ore is a lateritic ore.
Claim 5
Dependent Claim
67 words
In a furnace having a hearth disposed within said furnace for supporting an ore, a rabble arm disposed immediately above said hearth having a plurality of downwardly extending teeth for raking said ore the improvement comprising: a thermometer having a temperature detecting element and being connected to said hearth such that said detecting element is disposed above said hearth but beneath the teeth of said rabble arm.
Claim 6
Dependent Claim
67 words
In a furnace having a hearth disposed within said furnace for supporting an ore, a rabble arm disposed immediately above said hearth having a plurality of downwardly extending teeth for raking said ore the improvement comprising: a thermometer having a temperature detecting element and being connected to said hearth such that said detecting element is disposed above said hearth but beneath the teeth of said rabble arm.
Claim 7
Dependent Claim
106 words
In a furnace having a hearth disposed within said furnace for supporting an ore, a rabble arm disposed immediately above said hearth having a plurality of downwardly extending teeth for raking said ore, said ore when supported by said hearth being disposed in two beds, a lower dead bed and an upper live bed, said beds having a common interface and being at substantially the same temperature, said dead bed remaining relatively undisturbed and said live bed being raked by means of said teeth, the improvement comprising a thermometer having a temperature sensing element, said sensing element being maintained within said dead bed adjacent said interface.
Claim 8
Dependent Claim
106 words
In a furnace having a hearth disposed within said furnace for supporting an ore, a rabble arm disposed immediately above said hearth having a plurality of downwardly extending teeth for raking said ore, said ore when supported by said hearth being disposed in two beds, a lower dead bed and an upper live bed, said beds having a common interface and being at substantially the same temperature, said dead bed remaining relatively undisturbed and said live bed being raked by means of said teeth, the improvement comprising a thermometer having a temperature sensing element, said sensing element being maintained within said dead bed adjacent said interface.
Claim 9
Dependent Claim
41 words
The combination as claimed in claim 5 wherein said thermometer is a thermocouple composed of two dissimilar metals, one said metal being platinum and the other said metal being an alloy composed of about 87 percent platinum and the balance rhodium.
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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |