US4599808A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drying method and apparatus for fibrous material
Assignee: Schneider Electric Systems USA Inc
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Filing: 1984-03-20
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Granted: 1986-07-15
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Expires: 2004-03-20
Abstract
Abstract Drying material such as lumber by controlling the difference between inlet drying air dry bulb temperature and outlet drying air dry bulb temperature while maintaining wet bulb temperature constant, so that drying is characterized by a constant rate of evaporation.
Inventors
- 👤 Frederick D. Gelineau
- 👤 Thomas B. Kinney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:51
CPC Classifications
F; F26; F26B; F26B21/00; F26B21/30; F26B3/00; F26B3/02; F26B3/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
73 words
The method of drying a fibrous material which comprises the steps of circulating air past said material, sensing the wet bulb temperature of air circulating past said material, maintaining the wet bulb temperature of said air constant, sensing the dry bulb temperature of said air before and after circulating past said material, maintaining the dry bulb temperature drop in said air constant, thereby maintaining the evaporation from said material at a constant rate.
Claim 2
Independent Claim
73 words
The method of drying a fibrous material which comprises the steps of circulating air past said material, sensing the wet bulb temperature of air circulating past said material, maintaining the wet bulb temperature of said air constant, sensing the dry bulb temperature of said air before and after circulating past said material, maintaining the dry bulb temperature drop in said air constant, thereby maintaining the evaporation from said material at a constant rate.
Claim 3
Dependent Claim
11 words
The method of claim 1 in which said material is lumber.
Claim 4
Dependent Claim
48 words
The method of claim 1, wherein said maintaining the dry bulb temperature drop is carried out during a first period and then ended, and further comprising, in a subsequent second period, further drying while controlling inlet dry bulb temperature and still sensing and maintaining said wet bulb temperature.
Claim 5
Dependent Claim
92 words
Drying apparatus which comprises a housing, means for introducing drying air into said housing, a support portion for supporting thereon fibrous material for being dried, means for moving said air past said material, means for sensing the wet bulb temperature of said air moving past said material, means for maintaining said wet bulb temperature constant, means for sensing the dry bulb temperature of said air before and after moving past said material, and means for maintaining the dry bulb temperature drop in said air constant, thereby maintaining drying rate at a constant.
Claim 6
Dependent Claim
92 words
Drying apparatus which comprises a housing, means for introducing drying air into said housing, a support portion for supporting thereon fibrous material for being dried, means for moving said air past said material, means for sensing the wet bulb temperature of said air moving past said material, means for maintaining said wet bulb temperature constant, means for sensing the dry bulb temperature of said air before and after moving past said material, and means for maintaining the dry bulb temperature drop in said air constant, thereby maintaining drying rate at a constant.
Claim 7
Dependent Claim
31 words
The apparatus of claim 4 which includes means for reversing the direction of flow of said air and means for shifting the dry bulb sensor sensed to control dry bulb temperature.
Claim 8
Dependent Claim
26 words
The apparatus of claim 4 which includes means for controlling the difference in temperature between said inlet dry bulb temperature and said outlet dry bulb temperature.
Claim 9
Dependent Claim
24 words
The apparatus of claim 6 which includes means to shift control of inlet air temperature from said difference to said inlet dry bulb temperature.
Claim 10
Independent Claim
84 words
The method of drying a material which will be negatively affected if evaporation therefrom exceeds a safe rate which comprises the steps of circulating air past said material, sensing the wet bulb temperature of air circulating past said material, maintaining the wet bulb temperature of said air constant, sensing the dry bulb temperature of said air before and after circulating past said material, maintaining the dry bulb temperature drop in said air constant, thereby maintaining the evaporation from said material at a constant rate.
Claim 11
Independent Claim
84 words
The method of drying a material which will be negatively affected if evaporation therefrom exceeds a safe rate which comprises the steps of circulating air past said material, sensing the wet bulb temperature of air circulating past said material, maintaining the wet bulb temperature of said air constant, sensing the dry bulb temperature of said air before and after circulating past said material, maintaining the dry bulb temperature drop in said air constant, thereby maintaining the evaporation from said material at a constant rate.
Claim 12
Dependent Claim
100 words
Drying apparatus which comprises a housing, means for introducing drying air into said housing, a support portion for supporting thereon material which will be negatively affected if evaporation therefrom exceeds a safe rate, means for moving said air past said material, means for sensing the wet bulb temperature of said air moving past said material, means for maintaining said wet bulb temperature constant, means for sensing the dry bulb temperature of said air before and after moving past said material, and means for maintaining the dry bulb temperature drop in said air constant, thereby maintaining drying rate at a constant.
Claim 13
Dependent Claim
100 words
Drying apparatus which comprises a housing, means for introducing drying air into said housing, a support portion for supporting thereon material which will be negatively affected if evaporation therefrom exceeds a safe rate, means for moving said air past said material, means for sensing the wet bulb temperature of said air moving past said material, means for maintaining said wet bulb temperature constant, means for sensing the dry bulb temperature of said air before and after moving past said material, and means for maintaining the dry bulb temperature drop in said air constant, thereby maintaining drying rate at a constant.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-07-14 | 1990-01-13 | 1990-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-07-14 | 1994-01-13 | 1994-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-07-14 | 1998-01-13 | 1998-07-15 | $7700.00 | Window Closed / Lapsed |