Uninterrupted alternating air circulation for continuous drying lumber kilns

摘要

A continuous drying kiln (CDK) design, in which two sets of carriages carrying spaced stacks of lumber travel in opposite directions through a sequence of chambers in which green lumber is exposed to heated air to dry the lumber to desired conditions. The continuous drying kiln using fans in each chamber to circulate air across the stacked lumber on the two sets of carriages, orthogonal to the direction of carriage travel, in either a first circulation direction or in a second circulation direction. As a carriage moves from chamber to chamber, the circulation direction is reversed.

主权项

1. A structure for curing lumber, the structure comprising:
a first pathway for carriages holding lumber to be dried; a second pathway for carriages holding lumber to be dried, the second pathway set parallel to the first pathway; a first end of the structure for ingress of carriages on the first pathway and egress of carriages on the second pathway; a second end of the structure for ingress of carriages on the second pathway and egress of carriages on the first pathway; a main drying section separated from the first end by a first end energy recovery section and separated from the second end by a second end energy recovery section; the main drying section differing from the first end energy recovery section and the second end energy recovery section in that heat energy is added to the main drying section but in the first and second end energy recovery section, heat is only transferred from lumber that has passed through the main drying section to lumber on carriages that have not passed into the main drying section; a set of partition baffles to subdivide the structure into subsections, the partition baffles operating to allow passage of carriages towards the first end or the second end but interfere with a longitudinal flow of air from the first end towards the second end or from the second end towards the first end; a set of at least two subsections in the main drying section; a set of at least two subsections in the first end energy recovery section; a set of at least two subsections in the second end energy recovery section; and fans and the set of partition baffles to cause air flow to move in one direction within a subsection but alternate directions to switch from a first circulation direction to a second circulation direction each time a carriage moves into a new subsection so that the air flow alternates between traveling from the lumber on the carriages on the first pathway towards the lumber on the carriages on the second pathway to the opposite direction that travels from the lumber on the carriages on the second pathway towards the lumber on carriages on the first pathway.