Vertical progressive lumber dryer
AssigneeWeyerhaeuser Company
InventorFrank C. Beall
Life of this patent
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Abstract
A vertical progressive lumber dryer has a plurality of vertically spaced functional zones through which lumber formed into units pass. Each unit rests atop a base and each layer of boards in the stack is separated by sticker means. Predetermined appropriate operating conditions are selected for the drying medium as well as other parts of the process. After a car has completed the last step within the dryer, it is removed and the dryed lumber sent for further processing.
Claims19
The method of drying wet wood in a vertical progressive dryer having a plurality of drying stations comprising the steps of:
- forming a plurality of units of wet wood in which each unit is comprised of a plurality of vertically stacked layers of wet wood extending upwardly from a closed base and with each layer separated by separating means,
- successively feeding so formed units of wood to an infeed station which is vertically spaced upwardly from a plurality of vertically stacked drying stations each of which holds one unit of wet wood and through which each unit of wood passes in its downward flow through the dryer with the unit above a lower unit having its base resting atop the upper surface of the lower unit when the dryer is filled with units of wood thereby providing restraining forces to reduce warpage,
- drying the units of wood to a predetermined level within the drying stations while each unit of wood is substantially vertically sealed by the closed base when the unit is in its respective drying station, and
- successively removing a dried unit of wood from the lowermost drying station after it has reached the predetermined level of dryness.
A vertical progressive dryer open at the top and bottom for drying vertically stacked units of wood as they are transported progressively through a plurality of vertically spaced drying stations and out of the dryer, comprising:
- means for substantially vertically sealing each unit in its respective drying station,
- an infeed station spaced upwardly above the drying stations having means for accepting and aligning an incoming unit of wet wood with the first station below the infeed station,
- means for filling the plurality of vertically spaced drying stations with units of wet wood,
- means for progressively drying the units of wood as they progress downwardly through successive drying stations, and
- means for removing the unit of wood from the lowermost station by moving the units of wood downwardly, each into the next lower station, releasing the unit moved downward past the open bottom and then holding the remaining units in the dryer for some predetermined time.
Dependencies are inferred from the claim text.