Abstract: Fans circulate heated air which is introduced from nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. The fans operate in first and second modes to respectively force flow in opposite first and second directions. Heated air is introduced from the nozzles at the high-pressure sides of the fans.

Abstract: Fans circulate heated air which is introduced from nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. The fans operate in first and second modes to respectively force flow in opposite first and second directions. Heated air is introduced from the nozzles at the high-pressure sides of the fans.

Abstract: A duct system includes an upper duct that supplies heated air to an upper plenum and a lower duct that supplies heated air to a lower plenum, and the upper and lower plenums provide the heated air to a kiln chamber. An intermediate plenum is between the upper and lower plenums and has outlets through which heated air supplied to the upper and lower plenums is discharged. A plurality of circulation passages extend generally laterally through the intermediate plenum. Fans positioned in the circulation passages circulate heated air that is external to the plenums. The outlets are nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. Tips of the fans' blades extend into boundary layers adjacent the interior surfaces of the circulation passages. The fans operate in first and second modes to respectively force flow in opposite first and second directions.

Abstract: A duct system includes an upper duct that supplies heated air to an upper plenum and a lower duct that supplies heated air to a lower plenum, and the upper and lower plenums provide the heated air to a kiln chamber. An intermediate plenum is between the upper and lower plenums and has outlets through which heated air supplied to the upper and lower plenums is discharged. A plurality of circulation passages extend generally laterally through the intermediate plenum. Fans positioned in the circulation passages circulate heated air that is external to the plenums. The outlets are nozzles defining discharge axes that are respectively directed generally parallel to, yet slightly toward, the rotational axes of the fans. Tips of the fans' blades extend into boundary layers adjacent the interior surfaces of the circulation passages. The fans operate in first and second modes to respectively force flow in opposite first and second directions.

Abstract: A kiln chamber has an air moving device for circulating air in the chamber interior space along a flow path, and pipe banks positioned in the chamber interior space. Each pipe bank includes finned pipes for having a heated medium flow interiorly therethrough, and each pipe bank is positioned in the flow path so that air circulated by the air moving device flows exteriorly across the finned pipes. Each finned pipe has an elongate portion having opposite ends and extending in a longitudinal direction between the opposite ends, with the longitudinal direction being at least generally perpendicular to the portion of the flow path that is proximate the finned pipe. The pipe banks are spaced apart from one another and arranged side by side with respect to one another so that a portion of the flow path extends between adjacent ones of the pipe banks.

Abstract: A kiln system includes a kiln chamber defining a chamber interior space, a furnace capable of providing heated air, one or more air moving devices capable of circulating air in the chamber interior space along a recirculating flow path, and a plenum positioned in the kiln chamber and generally separating the chamber interior space into an upper portion and a lower portion. The upper portion of the chamber interior space that is positioned above the plenum, and the lower portion of the chamber interior space is positioned below the plenum and is capable of receiving the charge of lumber for drying. The plenum defines a plenum cavity that is in communication with and capable of receiving the heated air from the furnace. The kiln system further includes one or more upright passageways. Each upright passageway is mounted to the plenum and in communication with the plenum cavity so that the upright passageway is capable of receiving heated air from the plenum cavity.

Abstract: A stack of lumber that can be efficiently dried includes a plurality of layers of lumber that are arranged one above the other and extend longitudinally and laterally. Each layer of lumber includes a first edge that extends in the longitudinal direction and at least partially defines a side of the stack of lumber. Many of the first edges of adjacent layers of lumber are laterally spaced apart by at least a predetermined separation distance so that the first edges define a staggered arrangement. Also, the layers of lumber that are adjacent are vertically spaced apart from one another so that each of the adjacent layers of lumber define a laterally extending passage therebetween. Each of the passages includes an inlet and an opposed outlet defined between two of the adjacent first edges that are vertically and laterally spaced apart from one another. The flow of air through the stack of lumber is distributed through the passages such that within each passage oppositely oriented boundary layers are formed.

Abstract: Elliptically shaped reheater conduits extend downward into a portion of a flow path that extends through a lower chamber interior space of a kiln chamber. Each of the reheater conduits has opposite ends, defines a length that extends between the opposite ends and is perpendicular to the portion of the flow path that extends through the lower chamber interior space, defines a first cross-dimension that is perpendicular to the length and parallel to the portion of the flow path, and defines a second cross-dimension that is perpendicular to both the length and the portion of the flow path. The second cross-dimension is less than the first cross-dimension. Each of the reheater conduits defines outlets positioned along the length of the reheater conduit. Each reheater conduit defines a pair of vertices between which its second cross-dimension is defined, and the outlets are proximate the vertices.

Abstract: The kiln system for drying green lumber to a predetermined moisture content according to the present invention includes a kiln chamber for enclosing a charge of lumber, a fan in upper portions of the kiln chamber above the stacks of lumber to circulate air through the kiln chamber and through the lumber in the kiln chamber and an elongate splitter plate extending laterally from a leading edge in upper portions of the kiln chamber downwardly toward a sidewall of the kiln chamber to a trailing edge. The splitter plate includes a curved portion between the leading edge and the trailing edge for directing the circulating air along the splitter plate and then downward about a rectangular stack of lumber in the kiln chamber. The splitter plate further includes a number of projections extending outwardly from the leading edge for creating vortices in the air circulated by the fan.