Patent US3986268A successfully refreshed from Google Patents.
US3986268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for seasoning wood
Assignee: DELANO COMPTON
•
Filing: 1974-11-19
•
Granted: 1976-10-19
•
Expires: 1994-11-19
Abstract
Abstract A process and apparatus for accelerated drying of green lumber employs high voltage dielectric heating at subatmospheric pressure to effect a rapid removal of moisture from the wood without splitting, checking, case hardening, honeycombing or similar damage to the wood structure. The invention combines the advantages of both dielectric and vacuum drying techniques without inefficient and destructive corona, arcing, or ionization effects which have heretofore prevented combining such techniques. When desired, the use of subatmospheric pressures in the drying process also permits injection of suitable chemicals for fireproofing or other specialized treatments of the wood allowing the combination of such treatments with the drying of the wood in a single process.
Inventors
- 👤 Edward Koppelman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:11
CPC Classifications
F; F26; F26B; F26B7/00; F26B3/00; F26B3/32; F26B3/34; F26B5/00; F26B5/04; F26B5/048; B; B27; B27K; B27K3/00; B27K3/02; B27K3/0207; B27K3/0214; F26B2210/00; F26B2210/16
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
103 words
A process for drying unseasoned wood comprising the steps of placing the wood to be dried in an enclosed space, evacuating the gaseous substances from said enclosed space to impose a subatmospheric pressure on said wood, applying a non-discharging alternating electric potential across the wood between electrodes disposed within the enclosed space and maintained in fixed relationship to the wood while the electric potential is applied to effect a dielectric heating of the wood and the moisture entrapped within the interior thereof until the water content of the wood attains the desired level, and thereafter removing the dried wood from the enclosed space.
Claim 2
Dependent Claim
103 words
A process for drying unseasoned wood comprising the steps of placing the wood to be dried in an enclosed space, evacuating the gaseous substances from said enclosed space to impose a subatmospheric pressure on said wood, applying a non-discharging alternating electric potential across the wood between electrodes disposed within the enclosed space and maintained in fixed relationship to the wood while the electric potential is applied to effect a dielectric heating of the wood and the moisture entrapped within the interior thereof until the water content of the wood attains the desired level, and thereafter removing the dried wood from the enclosed space.
Claim 3
Dependent Claim
62 words
The process as defined in claim 1 wherein the non-discharging alternating electric potential is applied by positioning the wood to be dried between parallel plate electrodes disposed within the enclosed space and having means for preventing arcing or other sudden discharges, and applying a high frequency electric potential to the electrodes in a manner to effect a dielectric heating of the wood.
Claim 4
Dependent Claim
58 words
The process as defined in claim 1 wherein the non-discharging alternating electric potential is applied by positioning wood to be dried while confined in the enclosed space between a pair of electrodes and applying a high frequency electrical potential to the electrodes in a manner so as to effect a dielectric heating of the wood to be dried.
Claim 5
Dependent Claim
28 words
The process as defined in claim 1 in which the heating of the wood and the application of subatmospheric pressure to the wood is performed continuously and concurrently.
Claim 6
Dependent Claim
28 words
The process as defined in claim 1 in which the heating of the wood and the application of a subatmospheric pressure thereto is performed in an alternating manner.
Claim 7
Dependent Claim
28 words
The process as defined in claim 1 in which the temperature of the wood during the drying cycle is controlled so as not to exceed about 200° F.
Claim 8
Dependent Claim
29 words
The process as defined in claim 1 in which the temperature of the wood during the drying cycle is controlled so as not to cause plasticization of the wood.
Claim 9
Dependent Claim
25 words
The process as defined in claim 1 in which the subatmospheric pressure present during the drying cycle is less than about 500 mm Hg. absolute.
Claim 10
Dependent Claim
24 words
The process as defined in claim 1 in which the subatmosphere pressure within the enclosed space is less than about 100 mm Hg. absolute.
Claim 11
Dependent Claim
39 words
The process as defined in claim 1 in which the temperature of the wood during the drying cycle is controlled between about 100°F to about 155°F and the pressure is controlled to less than about 500 mm Hg. absolute.
Claim 12
Dependent Claim
31 words
The process of claim 1 including the further step of impregnating the wood with fireproofing chemicals by injecting said chemicals into the enclosed space while the wood is under subatmospheric pressure.
Claim 13
Dependent Claim
31 words
The process of claim 1 including the further step of impregnating the wood with preservative chemicals by injecting said chemicals into the enclosed space while the wood is under subatmospheric pressure.
Claim 14
Dependent Claim
26 words
The process of claim 1 including the further step of applying compressive forces to opposing surfaces of the wood while the wood is under subatmospheric pressure.
Claim 15
Dependent Claim
112 words
A process for drying commercial lumber to a moisture content of 12% or less by weight comprising the steps of placing green lumber having a moisture content above 20% by weight in an enclosed space, imposing a subatmospheric pressure on the green lumber for a period between 2 and 24 hours, applying a non-discharing alternating electric potential across the green lumber between electrodes disposed within the enclosed space and maintained in fixed relationship to the green lumber during application of the potential while the green lumber is under subatmospheric pressure and during the period it is at a moisture content between 12% and 20%, and removing the lumber from the enclosed space.
Claim 16
Dependent Claim
112 words
A process for drying commercial lumber to a moisture content of 12% or less by weight comprising the steps of placing green lumber having a moisture content above 20% by weight in an enclosed space, imposing a subatmospheric pressure on the green lumber for a period between 2 and 24 hours, applying a non-discharing alternating electric potential across the green lumber between electrodes disposed within the enclosed space and maintained in fixed relationship to the green lumber during application of the potential while the green lumber is under subatmospheric pressure and during the period it is at a moisture content between 12% and 20%, and removing the lumber from the enclosed space.
Claim 17
Dependent Claim
19 words
The process of claim 14 in which the green lumber has an initial moisture content above 25% by weight.
Claim 18
Dependent Claim
19 words
The process of claim 15 in which the green lumber has an initial moisture content above 30% by weight.
Claim 19
Dependent Claim
11 words
The process of claim 1 where the green lumber is tanoak.
Claim 20
Dependent Claim
107 words
A process for drying commercial lumber to a moisture content of 8% or less by weight comprising the steps of placing green lumber having a moisture content above 20% by weight in an enclosed space, imposing a subatmospheric pressure on the green lumber for a period between 2 and 24 hours, applying a non-discharging alternating electric potential across the green lumber by charging electrodes disposed within the enclosed space and maintained in fixed relationship to the green lumber during application of the potential while the green lumber is between 8% and 20% in moisture content and under subatmospheric pressure, and removing the lumber from the enclosed space.
Claim 21
Dependent Claim
107 words
A process for drying commercial lumber to a moisture content of 8% or less by weight comprising the steps of placing green lumber having a moisture content above 20% by weight in an enclosed space, imposing a subatmospheric pressure on the green lumber for a period between 2 and 24 hours, applying a non-discharging alternating electric potential across the green lumber by charging electrodes disposed within the enclosed space and maintained in fixed relationship to the green lumber during application of the potential while the green lumber is between 8% and 20% in moisture content and under subatmospheric pressure, and removing the lumber from the enclosed space.
Claim 22
Independent Claim
107 words
An apparatus for drying unseasoned wood comprising means defining a chamber, means for supporting wood to be dried within said chamber, means in communication with the interior of said chamber for evacuating the gaseous substances therefrom, means disposed within the chamber and adapted to be maintained in fixed relationship to the wood during the drying thereof for applying an alternating electric potential across the wood within the chamber to effect a heating of the interior thereof to the volatilization temperature of the water in the wood at the prevailing subatmospheric pressure present in the chamber, and means for preventing arcing and sudden discharge of the electric potential.
Claim 23
Independent Claim
107 words
An apparatus for drying unseasoned wood comprising means defining a chamber, means for supporting wood to be dried within said chamber, means in communication with the interior of said chamber for evacuating the gaseous substances therefrom, means disposed within the chamber and adapted to be maintained in fixed relationship to the wood during the drying thereof for applying an alternating electric potential across the wood within the chamber to effect a heating of the interior thereof to the volatilization temperature of the water in the wood at the prevailing subatmospheric pressure present in the chamber, and means for preventing arcing and sudden discharge of the electric potential.
Claim 24
Dependent Claim
38 words
The apparatus as defined in claim 19 in which said means for applying an alternating electric potential across the wood comprises a pair of spaced electrodes between which the wood is disposed for applying a dielectric field thereto.
Claim 25
Dependent Claim
30 words
The apparatus as defined in claim 20 wherein the means for preventing discharge of the alternating electric potential comprises a coating of dielectric material on the surface of the electrodes.
Claim 26
Dependent Claim
64 words
The apparatus as defined in claim 19 in which said means for applying an alternating electric potential across the wood comprises a plurality of electrodes disposed in spaced superimposed relationship and wherein alternate ones of said electrodes are electrically charged with a plurality opposite to that of the adjacent electrodes so as to apply a dielectric field to the wood interposed between adjacent electrodes.
Claim 27
Dependent Claim
40 words
The apparatus as defined in claim 22 further including means for moving the electrodes to and from a closed position in close proximity to opposed faces of the wood and an open position disposed in clearance relationship to the wood.
Claim 28
Dependent Claim
33 words
The process as defined in claim 1 in which the temperature and the subatmospheric pressure within the enclosed space are sufficiently low that unvaporized moisture is extracted from the wood without damage thereto.
Claim 29
Dependent Claim
21 words
The process of claim 1 in which the frequency of the non-discharging alternating electric potential is between 1 and 20 megacycles.
Claim 30
Dependent Claim
21 words
The process of claim 1 in which the frequency of the non-discharging alternating electric potential is between 3 and 5 megacycles.
Claim 31
Dependent Claim
19 words
The apparatus of claim 21 further including cooling means for condensing moisture on the interior surface of the chamber.
Claim 32
Dependent Claim
21 words
The apparatus as defined in claim 21 wherein the spaced electrodes are parallel plate electrodes, each having a substantially planar configuration.
Claim 33
Dependent Claim
29 words
The apparatus of claim 28 wherein the parallel plate electrodes are adapted to be positioned adjacent to opposing surfaces of the wood during the heating of the interior thereof.
Claim 34
Dependent Claim
60 words
The apparatus of claim 19 wherein the means for applying an alternating electric potential across the wood comprises two pairs of parallel plate electrodes between which wood is disposed, each electrode having a substantially planar configuration, and wherein the means for preventing discharge of the alternating electric potential comprises a coating of dielectric material on the surface of the electrodes.
Claim 35
Dependent Claim
31 words
The apparatus of claim 30 wherein the parallel plate electrodes are oriented in vertical planes and adapted to be positioned adjacent to opposing surfaces of the wood during the heating thereof.
Claim 36
Dependent Claim
48 words
The apparatus of claim 31 further including flexible bags affixed to the surfaces of the electrodes opposite to the surfaces facing the wood and means in communication with the interior of said bags for supplying air thereto at a pressure above the prevailing subatmospheric pressure in the chamber.
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) | 1979-10-19 | 1980-04-19 | 1980-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-10-19 | 1984-04-19 | 1984-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-10-19 | 1988-04-19 | 1988-10-19 | $7700.00 | Window Closed / Lapsed |