US3739490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Orifice pattern for jet dryers
Assignee: Weyerhaeuser Co
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Filing: 1971-06-01
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Granted: 1973-06-19
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Expires: 1991-06-01
Abstract
Abstract An impinging jet air dryer generally utilizes a plurality of opposed jet dryer boxes having a plurality of spaced orifices therein. Suitable formulas are disclosed which offers a method of selecting the optimum orifice pattern for repeating row units which result in a uniform heat transfer over the entire surface of the sheet material as well as maximuzing the overall rate of heat transfer to the sheet material. A means for providing a uniform moisture profile across the sheet material is disclosed which allows more air to be supplied to the sheet material toward the cooler end of the jet dryer boxes. This can be done by varying either orifice spacing or orifice size. The combination of the above-mentioned orifice placement methods gives a jet dryer box which provides the fastest most uniform drying for an impinging jet air dryer.
Inventors
- 👤 G Comstock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:05
CPC Classifications
F; F26; F26B; F26B13/00; F26B13/10; F26B13/101; F26B13/103; F26B15/00; F26B2210/00; F26B2210/16
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
216 words
In a dryer box unit for drying moving sheet materials by impinging streams of warm air, the dryer box comprising an elongated duct having a closed end and an open end in communication with a source of air under a positive static pressure, one surface of the duct being a face defining a plane lying substantially parallel to and facing the sheet material being dried, said surface having a pattern of at least five rows of orifices directed toward the sheet material and extending parallel to the long dimension of the duct, said orifices in any given row being spaced from each other, and said rows being spaced from each other with respect to a perpendicular line through a given row a distance that is the average spacing between orifices in a given row, the improvement comprising: laterally displacing the orifices of one row from those of its adjacent rows by a spacing determined by the formula LDF times the spacing between the corresponding adjacent orifices in any given row; where, LDF n + OR - 1/2 /n when n is an odd integer, and LDF n + OR - 2/2 /n when n is an even integer, and where LDF is the lateral displacement fraction and n is the number of rows in the pattern.
Claim 2
Dependent Claim
216 words
In a dryer box unit for drying moving sheet materials by impinging streams of warm air, the dryer box comprising an elongated duct having a closed end and an open end in communication with a source of air under a positive static pressure, one surface of the duct being a face defining a plane lying substantially parallel to and facing the sheet material being dried, said surface having a pattern of at least five rows of orifices directed toward the sheet material and extending parallel to the long dimension of the duct, said orifices in any given row being spaced from each other, and said rows being spaced from each other with respect to a perpendicular line through a given row a distance that is the average spacing between orifices in a given row, the improvement comprising: laterally displacing the orifices of one row from those of its adjacent rows by a spacing determined by the formula LDF times the spacing between the corresponding adjacent orifices in any given row; where, LDF n + OR - 1/2 /n when n is an odd integer, and LDF n + OR - 2/2 /n when n is an even integer, and where LDF is the lateral displacement fraction and n is the number of rows in the pattern.
Claim 3
Dependent Claim
45 words
The dryer box unit of claim 1 in which the orifice area per square unit of face is increased from the inlet end of the box to the closed end in order to maintain a uniform delivery of energy across the width of the sheet.
Claim 4
Dependent Claim
25 words
The dryer box unit of claim 2 in which the orifice area per square unit is increased by providing orifices of larger cross sectional area.
Claim 5
Dependent Claim
50 words
The dryer box unit of claim 2 in which the length of the spacing between the orifices of a given row is decreased from the inlet end to the closed end in order to provide a larger number of orifices per square unit of face area toward the closed end.
Claim 6
Dependent Claim
32 words
The dryer box unit of claim 2 in which the total orifice area toward the closed end is on the order of 1.4 times the total orifice area toward the inlet end.
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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) | 1976-06-18 | 1976-12-18 | 1977-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-18 | 1980-12-18 | 1981-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-18 | 1984-12-18 | 1985-06-19 | $7700.00 | Window Closed / Lapsed |