Patent US3787985A successfully refreshed from Google Patents.
US3787985A
Expired / Lapsed
US
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Dryer control system and method
Assignee: Industrial Nucleonics Corp
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Filing: 1972-08-14
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Granted: 1974-01-29
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Expires: 1992-08-14
Abstract
Abstract Moisture in tobacco flowing through a dryer is controlled so that it is maintained substantially at a desired amount during start up and shut down trasitional periods of the tobacco flow through the dryer. Trajectories for the dryer drying rate during the start up and shut down periods are provided in a computer memory. During start up, an indication of the moisture and flow rate of the tobacco flowing into the dryer is derived to enable the amount of moisture expected to be removed by the dryer (dryer duty) to be calculated. When shut down commences the temperature of the dryer is derived and stored in the memory. During start up, the trajectory and dryer duty are time weighted so that a weighting factor for the trajectory decreases as the transitional period progresses and a weighting factor for the dryer duty increases as the period progresses and the two time weighted indications are combined to control the dryer drying rate. During shut down, the shut down trajectory and stored drying rate indication are time weighted so that a weighting factor for the trajectory increases as the period progresses and a weighting factor for the drying rate indication decreases as the period progresses and the two time weighted indications are combined to control the drying rate of the dryer.
Inventors
- 👤 R Fowler
- 👤 E Freeh
- 👤 D Koenig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:11
CPC Classifications
A; A24; A24B; A24B3/00; A24B3/04; F; F26; F26B; F26B21/00; F26B21/30; F26B21/35; F26B25/00; F26B25/22
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
109 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during a transitional period, means for providing a predetermined trajectory for the dryer drying rate during the transitional period, means for deriving an indication of the dryer performance during at least a portion of said transitional period, means for time weighting said trajectory and indication in opposite directions during said transitional period, and means for combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 2
Dependent Claim
109 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during a transitional period, means for providing a predetermined trajectory for the dryer drying rate during the transitional period, means for deriving an indication of the dryer performance during at least a portion of said transitional period, means for time weighting said trajectory and indication in opposite directions during said transitional period, and means for combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 3
Independent Claim
105 words
A method for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during a transitional period comprising the steps of in a computer: storing a predetermined trajectory for the dryer drying rate during the transitional period, deriving an indication of said transitional dryer performance during at least a portion of the period, time weighting said trajectory and indication in opposite directions during the period; and controlling the dryer in response to concomitantly derived time weighted values of the trajectory and indication.
Claim 4
Independent Claim
105 words
A method for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during a transitional period comprising the steps of in a computer: storing a predetermined trajectory for the dryer drying rate during the transitional period, deriving an indication of said transitional dryer performance during at least a portion of the period, time weighting said trajectory and indication in opposite directions during the period; and controlling the dryer in response to concomitantly derived time weighted values of the trajectory and indication.
Claim 5
Independent Claim
122 words
A method of controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a signficant change in the dryer load during a transitional period including the steps of providing a predetermined trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the dryer characteristics and the expected dryer load change during said transitional period, deriving an indication of the dryer performance during at least a portion of said transitional period, time weighting said trajectory and indication in opposite directions during said transitional period, and combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 6
Independent Claim
122 words
A method of controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a signficant change in the dryer load during a transitional period including the steps of providing a predetermined trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the dryer characteristics and the expected dryer load change during said transitional period, deriving an indication of the dryer performance during at least a portion of said transitional period, time weighting said trajectory and indication in opposite directions during said transitional period, and combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 7
Dependent Claim
144 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up or shut down transitional period of flow the material through the dryer, means for providing a time weight trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during the period and the change in the amount of material during said transitional period, means for deriving a time indication of the dryer performance during at least a portion of said transitional period, said trajectory and indication being time weighted in opposite directions during the period, and means for combining said transitional time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 8
Dependent Claim
144 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up or shut down transitional period of flow the material through the dryer, means for providing a time weight trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during the period and the change in the amount of material during said transitional period, means for deriving a time indication of the dryer performance during at least a portion of said transitional period, said trajectory and indication being time weighted in opposite directions during the period, and means for combining said transitional time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 9
Independent Claim
160 words
A method of controlling a dryer for mateRial that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up or shut down transitional period of flow of the material through the dryer, comprising in a computer storing a predetermined trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, deriving an indication of the dryer performance during at least a portion of said transitional period, time weighting said trajectory and indication in opposite directions during said transitional period so that as the period progresses the effects of the weighting factors on said indication and said trajectory change in opposite directions; and concomitantly controlling the dryer in response to the time weighted trajectory and time weighted indication.
Claim 10
Independent Claim
160 words
A method of controlling a dryer for mateRial that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up or shut down transitional period of flow of the material through the dryer, comprising in a computer storing a predetermined trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, deriving an indication of the dryer performance during at least a portion of said transitional period, time weighting said trajectory and indication in opposite directions during said transitional period so that as the period progresses the effects of the weighting factors on said indication and said trajectory change in opposite directions; and concomitantly controlling the dryer in response to the time weighted trajectory and time weighted indication.
Claim 11
Dependent Claim
170 words
In a system or controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up transitional period of flow of the material through the dryer, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, means for deriving a time weighted indication of the moisture of the material flowing into the dryer during said transitional the period, said trajectory and indication being time weighted during said transitional period so that a weighting factor for the trajectory decreases as said transitional the period progresses and a weighting factor for the indication increases as said transitional period progresses, and means for deriving a control signal for the dryer in response to the time weighted trajectory and indication.
Claim 12
Dependent Claim
170 words
In a system or controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a start up transitional period of flow of the material through the dryer, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, means for deriving a time weighted indication of the moisture of the material flowing into the dryer during said transitional the period, said trajectory and indication being time weighted during said transitional period so that a weighting factor for the trajectory decreases as said transitional the period progresses and a weighting factor for the indication increases as said transitional period progresses, and means for deriving a control signal for the dryer in response to the time weighted trajectory and indication.
Claim 13
Dependent Claim
36 words
The system of claim 6 further including means for storing a prior indication of a moisture feedback error, and wherein the control signal deriving means is responsive to the stored indication of a moisture feedback error.
Claim 14
Dependent Claim
39 words
The system of claim 6 wherein said moisture indicating deriving means includes means for deriving the indication as a function of the amount of water to be removed from the material while the material is resident in the dryer.
Claim 15
Dependent Claim
171 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a shut down transitional period of flow of the material through the dryer, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, means for deriving a time weighted indication of a drying characteristic of the dryer at the beginning of said transitional period, said trajectory and indication being time weighted during said transitional period so that a weighting factor given to the trajectory increases as said transitional period progresses and a weighting factor given to the indication decreases as the said transitional the period progresses, and means for combining the time weighted trajectory and indication to derive a control signal for the dryer.
Claim 16
Dependent Claim
171 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained during a shut down transitional period of flow of the material through the dryer, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, said trajectory being determined by the drying characteristics of the dryer, the change of the material flow rate during said transitional period and the change in the amount of material during said transitional period, means for deriving a time weighted indication of a drying characteristic of the dryer at the beginning of said transitional period, said trajectory and indication being time weighted during said transitional period so that a weighting factor given to the trajectory increases as said transitional period progresses and a weighting factor given to the indication decreases as the said transitional the period progresses, and means for combining the time weighted trajectory and indication to derive a control signal for the dryer.
Claim 17
Dependent Claim
25 words
The system of claim 9 wherein said drying characteristic deriving means includes means for deriving the indication in response to the temperature of the dryer.
Claim 18
Dependent Claim
111 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during A transitional period, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, means for deriving a time weighted indication of the dryer performance during at least a portion of said transitional period, said trajectory and indication being time weighted in opposite directions during said transitional period, and means for combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
Claim 19
Dependent Claim
111 words
In a system for controlling a dryer for material that flows through the dryer so that a desired moisture content of the material is approximately maintained even though there is a significant change in the dryer load during A transitional period, means for providing a time weighted trajectory for the dryer drying rate during the transitional period, means for deriving a time weighted indication of the dryer performance during at least a portion of said transitional period, said trajectory and indication being time weighted in opposite directions during said transitional period, and means for combining the time weighted trajectory and time weighted indication to derive a control signal for the dryer.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |