US3757428A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for drying lumber
Assignee: Individual
•
Filing: 1972-06-28
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Granted: 1973-09-11
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Expires: 1992-06-28
Abstract
Abstract A method and apparatus for drying stacked lumber by solvent extraction, said apparatus including an elongate chamber through which stacked batches of lumber to be dried are moved. The elongate chamber includes a first compartment in which a stacked batch of lumber is steamed. A second longitudinally adjacent compartment wherein a liquid mixture of a solvent and water near its boiling point wets the stacked lumber in the presence of a vapor mixture of steam and solvent such that the solvent in the liquid phase replaces water within the lumber. As the stacked lumber is moved through this second compartment both the liquid and vapor phases in contact with the lumber have progressively greater solvent contents. The wetting liquid flows progressively through a series of weirs counter the direction of lumber movement, while the vapor moves between the stacked lumber in the direction opposite liquid flow and in this manner, the solvent drying the lumber is itself distilled within the chamber. A condenser adjacent the exit end of the second compartment withdraws vapor having a high solvent content from the compartment and returns solvent condensed therefrom to the dry wood end of the compartment where it is again used to wet the lumber. A third compartment is provided longitudinally adjacent the second compartment wherein the stacked lumber is subjected to steam or a steam and air combination to remove a desired percentage of solvent in the wood to produde substantially dry lumber. A method of drying lumber by solvent extraction including the steps of steam conditioning wood for drying; wetting the lumber to be dried with a substantially closed chamber with a watersolvent liquid mixture maintained at or near its boiling point; increasing the solvent content of the liquid mixture such that solvent replaces substantially all of the moisture in said lumber; simultaneously distilling the solvent within the substantially close chamber; and raising the temperature of the lumber to drive off the solvent therein to produce substantially dry lumber.
Inventors
- 👤 D Runciman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:04
CPC Classifications
F; F26; F26B; F26B5/00; F26B5/005; F26B25/00; F26B25/06; F26B25/14; F26B25/18; F26B25/185; F26B2210/00; F26B2210/16
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
17 words
The method of claim 1 including the step of simultenaeously distilling said solvent within said closed chamber.
Claim 2
Independent Claim
134 words
A method of drying wet lumber by solvent extraction comprising the steps of: steaming said lumber to raise its temperature to near the boiling point of water; wetting said lumber with a boiling liquid mixture of water and a minor amount of solvent in the presence of a vapor mixture of water and solvent to cause said solvent to replace a minor portion of the water in said lumber; progressively increasing the amount of solvent in said liquid and vapor mixtures till said solvent comprises a major portion of said mixtures while maintaining said liquid mixture at its boiling point to cause said solvent to replace a major portion of the water in said lumber; and heating said lumber to raise its temperature above the boiling point of said solvent to clean said lumber.
Claim 3
Independent Claim
213 words
A method of drying stacked wet lumber in a methanol distillation column having a relatively cold end wherein liquid methanol at its boiling temperature enters said column and a hot end wherein steam enters said column, including the steps of: conveying said stacked lumber into the hot end of said distillation column such that said lumber substantially fills the cross sectional area of said column and acts as the packing therefor; steaming said lumber; wetting the surface areas of said stacked lumber with a boiling liquid mixture of water and a small amount of methanoL in the presence of said steam to replace a small portion of the water in said wood with methanol; moving said stacked lumber progressively from said hot end toward said cold end of said distillation column while continually wetting said lumber with a boiling liquid mixture of water and methanol in the presence of a steam and methanol vapor mixture; increasing the methanol content of said lumber wetting mixtures as said lumber moves toward said cold end of said column to replace substantially all of the water in said wood with methanol; and removing said stacked lumber from the relatively solc end of said distillation column and stripping the methanol from said lumber to produce substantially dry lumber.
Claim 4
Dependent Claim
28 words
The method of claim 4 including the step of distilling said methanol within said column as said stacked lumber moves toward the relatively cold end of said column.
Claim 5
Dependent Claim
27 words
The method of claim 4 including the step of withdrawing and condensing the vapor mixture from the cold end of said column to produce substantially pure methanol.
Claim 6
Independent Claim
139 words
A method of drying wet lumber by solvent extraction comprising the steps of: moving said wet lumber into a first end of a sealable longitudinal chamber and sealing said chamber; directing steam into said chamber at its first end such that said stem surrounds said lumber and migrates toward the second end of said chamber; directing a boiling liquid solvent having a boiling point below 212*F. into said chamber at its second end in a manner such that said solvent wets said lumber and is prgressively distilled by contact with said steam as it flows toward said first end; progressively moving said lumber from said first end toward said second end to allow said solvent to replace the water within said lumber; and steaming said lumber to strip substantially all of said solvent therefrom to produce substantially dry lumber.
Claim 7
Dependent Claim
40 words
The method of drying wet lumber of claim 7 including the steps of: withdrawing liquid from the first end of said longitudinal chamber; reboiling said liquid to produce steam; and directing said steam into said first end of said chamber.
Claim 8
Dependent Claim
44 words
The method of drying wet lumber of claim 7 including the steps of: withdrawing vapor from the second end of said longitudinal chamber; condensing said vapor to produce substantially pure, boiling solvent; and directing said boiling solvent into the second end of said chamber.
Claim 9
Dependent Claim
28 words
The method of drying lumber of claim 9 including the step of adding additional solvent to said boiling solvent leaving said condenser to make up for solvent losses.
Claim 10
Dependent Claim
24 words
The method of claim 7 including the steps of periodically monitoring the water content of said lumber as it moves through said longitudinal chamber.
Claim 11
Dependent Claim
131 words
Apparatus for drying stacked pieces of wet lumber by solvent extraction including: a sealable elongate chamber having a first wet lumber entrance end and a second dry lumber exit end; means conveying lumber through said chamber from said entrance end to said exit end; boiler means directing steam into said chamber at said entrance end such that it moves toward said exit end; means directing solvent into said chamber at its exit end such that it flows toward said entrance end; means spaced along said elongate chamber wetting said lumber with said solvent in the presence of said steam such that said solvent replaces water within said lumber as said lumber moves toward said exit end; and means stripping said lumber to remove said solvent therefrom to produce substantially dry lumber.
Claim 12
Dependent Claim
38 words
The apparatus of claim 12 wherein said elongate chamber includes baffle means spaced therealong to snugly surround said lumber such that said steam moves from said entrance end toward said exit end between said stacked pieces of lumber.
Claim 13
Dependent Claim
34 words
The apparatus of claim 13 including spacer means inserted between said pieces of stacked lumber to form passageways through which said steam travels from said entrance end to said exit end of said chamber.
Claim 14
Dependent Claim
41 words
The apparatus of claim 12 wherein said elongate chamber includes substantially airtight outer doors at said entrance and exit ends and substantially airtight inner doors spaced from said outer doors to define heating compartments at each longitudinal end of said chamber.
Claim 15
Dependent Claim
67 words
The apparatus of claim 12 wherein said means wetting said lumber with solvent include solvent distribution means spacedly mounted along the top of said elongate chamber, a sump associated with each of said solvent distribution means and positioned therebelow to catch solvent running off said lumber; and, pump means associated with each of said sumps to recirculate solvent from said sump to said solvent distribution means thereabove.
Claim 16
Dependent Claim
38 words
The apparatus of claim 12 wherein the means directing solvent into the exit end of said chamber includes condenser means withdrawing solvent vapor from said chamber, condensing it to liquid and returning said liquid solvent to said chamber.
Claim 17
Dependent Claim
145 words
Apparatus for drying stacked lumber by solvent extraction including: an elongate sealable chamber having a cross-section sized to closely surround stacked lumber positioned therein; stacked lumber conveying means within said elongate chamber moving said lumber from the entrance end of said chamber to its exit end; a first compartment within said elongate chamber positioned adjacent said entrance end; means steaming said stacked lumber within said first compartment; a second compartment within said elongate chamber adjacent said first compartment wherein said stacked lumber is wet by progressively stronger boiling liquid mixtures of solvent and water in the presence of like proportioned vapor mixtures of solvent and water such that said solvent replaces water within said lumber; and a third compartment adjacent said exit end of said chamber wherein said stacked lumber is heated to drive off the solvent within said lumber to produce substantially dry lumber.
Claim 18
Dependent Claim
41 words
The apparatus of claim 18 including means holding said stacked pieces of lumber at a spaced distance from each other such that steam from first compartment flows between said pieces of stacked lumber through said second compartment toward said third compartment.
Claim 19
Dependent Claim
25 words
The apparatus of claim 18 including door means positioned at each end of said compartments such that each of said compartments may be separately sealed.
Claim 20
Dependent Claim
61 words
The apparatus of claim 18 wherein the means wetting said stacked lumber within said second compartment includes a plurality of weir trough distributors spacedly mounted along the top of said compartment; sump means positioned below each of said weir trough distributors to catch solvent runoff from said lumber; and pump means recirculating solvent from said sumps to said weir trough distributors.
Claim 21
Dependent Claim
42 words
The apparatus of claim 21 including baffle means surrounding said stacked lumber between each of said weir trough distributor means such that steam from said first compartment means flows toward the exit end of said second compartment means between said stacked lumber.
Claim 22
Dependent Claim
34 words
The apparatus of claim 22 including condenser means withdrawing vapor from adjacent the exit end of said second compartment and returning condensed liquid solvent to said weir trough distributor means adjacent said exit 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) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |