US3578299A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for cement kiln control
Assignee: General Electric Co
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Filing: 1969-09-26
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Granted: 1971-05-11
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Expires: 1989-09-26
Abstract
Abstract A method and apparatus for controlling the operation of a rotary cement kiln which is fed with an incoming slurry. The fuel rate set point and the exit gas rate set point are controlled. The control of fuel rate set point is based upon kiln drive motor torque measurements in conjunction with feedback signals generated by a dynamic kiln model which stores a record of past control actions and a calculated effect of the slurry drying characteristics in the kiln. Control of the exit gas rate set point is based upon measurements of gas temperature at the feed end of the kiln. Oxygen content of the exit gas is monitored and employed to exercise overriding control to insure that no combustibles which might cause an explosion appear in the exit gas.
Inventors
- 👤 Myron R Hurlbut
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:50
CPC Classifications
F; F27; F27B; F27B7/00; F27B7/20; F27B7/42
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
48 words
A rotary cement wet kiln control system as recited in claim 1 wherein said feed temperature determining means comprises means for measuring conditions at the chain means and means for performing a heat balance for the chain means to thereby indicate the temperature of feed leaving the chains.
Claim 2
Dependent Claim
105 words
A rotary cement wet kiln control system as recited in claim 2 wherein said means for measuring conditions at the chain means comprises second and third sensing means for measuring gas temperature entering the chain means and leaving the chain means, respectively, fourth sensing means for measuring the rate of material feed into the kiln, fifth sensing means for measuring the rate dust is introduced into the kiln and sixth sensing means for measuring the rate of flow gas through the kiln and wherein said feed temperature determining means additionally comprises means responsive to said second through sixth sensing means for determining the feed temperatUre.
Claim 3
Dependent Claim
98 words
A rotary cement wet kiln as recited in claim 3 wherein said control system additionally comprises means for storing information concerning past control actions initiated by said control means for inhibiting variations of heat input to the kiln by said control means in response to variations in the torque developed by the drive means directly caused by such past control actions, said information storage means also being responsive to said means for indicating chain means torque changes to directly and immediately inhibit variations of heat input in response to variations in the torque developed by the drive means.
Claim 4
Dependent Claim
76 words
A rotary cement wet kiln as recited in claim 4 wherein said means for indicating chain means torque includes means responsive to successive feed temperatures from said feed temperature determining means for generating a trended feed temperature, means responsive to said feed temperature determining means and said trended feed temperature generating means for generating a feed temperature error and filter means responsive to said feed temperature error generating means for generating the chain means torque indication.
Claim 5
Independent Claim
134 words
A method for controlling a rotary cement wet kiln including chain means for contacting wet feed entering the kiln and driving moisture therefrom, drive means for rotating the kiln at a constant speed and heating means for causing a material transformation in the kiln at a burning zone including the steps of measuring the total torque developed by the drive means to rotate the kiln, said total torque measurement representing, in part, conditions in the chain means, determining the temperature of feed leaving the chain means, generating a signal variable in accordance with torque changes resulting from conditions in the chain means in response to said determination of feed temperature and controlling the heat input to the kiln so as to maintain the total torque minus the chain means torque at a constant value.
Claim 6
Dependent Claim
49 words
A method for controlling a rotary cement wet kiln as recited in claim 6 wherein said determination of feed temperature is made by measuring conditions at the chain means and performing a heat balance for the chain means based upon those measured conditions to thereby obtain the feed temperature.
Claim 7
Dependent Claim
65 words
A method for controlling a rotary cement wet kiln as recited in claim 7 wherein said chain means condition measurement includes measuring the gas temperature entering the chain means, the temperature of gas leaving the chain means, the rate of material fed into the kiln, the rate at which dust is introduced into the kiln, and in response to said measurements determining the feed temperature.
Claim 8
Dependent Claim
98 words
A method for controlling a rotary cement kiln as recited in claim 8 additionally comprising the step of storing information concerning past control actions initiated by said control method for inhibiting variations of heat input to the kiln by said control method in response to said measured torque variations developed by the drive means directly caused by past actions of said control method, said information storage step additionally including step of directly and immediately inhibiting variations of input in response to variations of the torque developed by the drive means in response to said chain means torque determination.
Claim 9
Dependent Claim
67 words
A method for controlling a rotary cement wet kiln as recited in claim 9 wherein said determination of chain means torque includes the steps of generating a trended feed temperature based on said feed temperature determination, generating an error function based on said feed temperature determination and said trended feed temperature determination and filtering the error from said error generation to obtain the chain means torque indication.
References Cited (Backward Citations)
US3300196A
Cited
US3469828A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-10 | 1974-11-09 | 1975-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-10 | 1978-11-09 | 1979-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-10 | 1982-11-09 | 1983-05-11 | $7700.00 | Window Closed / Lapsed |