US3720002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drying sheet material
Assignee: Arjo Wiggins Ltd
•
Filing: 1971-03-03
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Granted: 1973-03-13
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Expires: 1991-03-03
Abstract
Abstract Sheet material to be dried is conveyed through a drying region where a combination of radiant heat and heated gas is directed towards the material. The proportion of radiant heat relative to the amount of heated gas is adjusted through the drying region so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Inventors
- 👤 P Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:27
CPC Classifications
F; F26; F26B; F26B13/00; F26B13/10; D; D06; D06C; D06C7/00; F26B3/00; F26B3/28; F26B3/283; D06C2700/00; D06C2700/09
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
80 words
A method of drying sheet material comprising transporting the material to be dried along a path through a drying region, directing a combination of radiant heat and heated gas towards the material in the drying region and adjusting the proportion of radiant heat relative to the amount of heated gas along the path through the drying region so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 2
Independent Claim
80 words
A method of drying sheet material comprising transporting the material to be dried along a path through a drying region, directing a combination of radiant heat and heated gas towards the material in the drying region and adjusting the proportion of radiant heat relative to the amount of heated gas along the path through the drying region so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 3
Independent Claim
80 words
A method of drying sheet material comprising transporting the material to be dried along a path through a drying region, directing a combination of radiant heat and heated gas towards the material in the drying region and adjusting the proportion of radiant heat relative to the amount of heated gas along the path through the drying region so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 4
Independent Claim
80 words
A method of drying sheet material comprising transporting the material to be dried along a path through a drying region, directing a combination of radiant heat and heated gas towards the material in the drying region and adjusting the proportion of radiant heat relative to the amount of heated gas along the path through the drying region so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 5
Dependent Claim
29 words
A method of drying sheet material according to claim 1 in which the amount of heated gas directed towards the material is reduced towards the end of the path.
Claim 6
Dependent Claim
44 words
A method of drying sheet material according to claim 1 in which a combination of radiant heat and heated gas is directed towards the material from only one side of the path and radiant heat is directed towards the other side of the material.
Claim 7
Dependent Claim
44 words
A method according to claim 1 in which the heated gas comprises air heated to a temperature of at least 200* F and the air is directed at high velocity towards the material through a number of inlet openings spaced apart along the path.
Claim 8
Dependent Claim
24 words
A method according to claim 1 in which the radiant heat comprises infra red radiation in the range of 3 microns to 5 microns.
Claim 9
Independent Claim
326 words
A method of drying a web of sheet material having a coating on one side whicH comprises the steps of: a. passing the web through an elongate drying zone at a speed such that a predetermined time is consumed by the passage of any prescribed point on the web from the entrance to the exit of said zone and adjusting the prescribed time such that as the web passes through the drying zone the drying rate initially increases rapidly followed by a period of drying when the rate of evaporation is substantially constant and finally reaches a falling rate region of drying during which the evaporation rate decreases continuously before reaching the exit of the drying zone; b. directing heated gas against the coated side of said web at a plurality of transverse regions spaced between the entrance and exit of said drying zone while simultaneously withdrawing gas from the drying zone at either side of each such region; c. directing radiant heat energy against said coated side of the web at a plurality of second transverse regions spaced between the first transverse regions whereby the coated side of the web is subjected throughout said drying zone to a combination of radiant heat drying and heated gas drying; d. adjusting the heated gas drying and radiant heat drying adjacent said entrance of the drying zone to provide a selected ratio of radiant heat drying to heated gas drying; and e. progressively reducing the quantity of heated gas directed against the coated side of the web in the first transverse regions of step (b) from the entrance to the exit end of said drying zone while maintaining the radiant heat energy directed against the coated side of the web in the second transverse regions of step (c) such that the ratio of radiant heat drying to heated gas drying is greater within said falling rate region adjacent said exit of the drying zone than said selected ratio.
Claim 10
Independent Claim
326 words
A method of drying a web of sheet material having a coating on one side whicH comprises the steps of: a. passing the web through an elongate drying zone at a speed such that a predetermined time is consumed by the passage of any prescribed point on the web from the entrance to the exit of said zone and adjusting the prescribed time such that as the web passes through the drying zone the drying rate initially increases rapidly followed by a period of drying when the rate of evaporation is substantially constant and finally reaches a falling rate region of drying during which the evaporation rate decreases continuously before reaching the exit of the drying zone; b. directing heated gas against the coated side of said web at a plurality of transverse regions spaced between the entrance and exit of said drying zone while simultaneously withdrawing gas from the drying zone at either side of each such region; c. directing radiant heat energy against said coated side of the web at a plurality of second transverse regions spaced between the first transverse regions whereby the coated side of the web is subjected throughout said drying zone to a combination of radiant heat drying and heated gas drying; d. adjusting the heated gas drying and radiant heat drying adjacent said entrance of the drying zone to provide a selected ratio of radiant heat drying to heated gas drying; and e. progressively reducing the quantity of heated gas directed against the coated side of the web in the first transverse regions of step (b) from the entrance to the exit end of said drying zone while maintaining the radiant heat energy directed against the coated side of the web in the second transverse regions of step (c) such that the ratio of radiant heat drying to heated gas drying is greater within said falling rate region adjacent said exit of the drying zone than said selected ratio.
Claim 11
Dependent Claim
45 words
A method as defined in claim 6 including the step of directing radiant heat energy against the uncoated side of said web at least within said falling rate region of drying to attenuate migration of moisture from the underside of the coating into said web.
Claim 12
Dependent Claim
100 words
Drying apparatus comprising conveying means for transporting material to be dried along a path through a drying region, a plurality of hot gas inlets spaced along the path for directing a flow of hot gas towards the path, a plurality of radiant heating devices spaced along the path for directing radiant heat towards the path, and heat control means for controlling the proportion of radiant heat relative to the amount of heated gas directed towards the path so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 13
Dependent Claim
100 words
Drying apparatus comprising conveying means for transporting material to be dried along a path through a drying region, a plurality of hot gas inlets spaced along the path for directing a flow of hot gas towards the path, a plurality of radiant heating devices spaced along the path for directing radiant heat towards the path, and heat control means for controlling the proportion of radiant heat relative to the amount of heated gas directed towards the path so that a higher radiant heat/heated gas ratio is provided at the end of the path than at the beginning of the path.
Claim 14
Dependent Claim
43 words
Drying apparatus according to claim 8 in which a combination of radiant heating devices and hot gas inlets is provided along one side of the path and a plurality of radiant heating devices alone are provided along the other side of the path.
Claim 15
Dependent Claim
34 words
Drying apparatus according to claim 8 in which some of the sources of radiant heat comprise a plurality of separately operable elements which may be selectively operated to vary the amount of radiant heat.
Claim 16
Dependent Claim
41 words
Drying apparatus according to claim 8 in which the hot gas inlets are spaced from the radiant heating devices so that substantially all the incoming hot gas may reach the material to be dried without flowing over the radiant heating devices.
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) | 1976-03-12 | 1976-09-11 | 1977-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-12 | 1980-09-11 | 1981-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-12 | 1984-09-11 | 1985-03-13 | $7700.00 | Window Closed / Lapsed |