Patent ID: 9423176
Filing Date: 2016-08-23
CPC Classification: F26B

Claim Text:
1. A method of operation of a kiln duct system for a system for balancing the return air flow in a direct fired lumber kiln between forward and reverse fan directions that employs a pair of return air ducts, wherein the return duct used for reverse flow operation carries return air within a heated space of the kiln that is located above lumber stacks in the kiln; where this reverse flow return duct carries return air from a low pressure side of the kiln on a distal side of the lumber stacks to a proximal side of the lumber stacks closer to a mixing chamber located outside of the kiln to mix burner exhaust with return air; and the return air flows during both forward and reverse fan cycles leave the heated space of the kiln to enter the mixing chamber through ducts located on the side of the kiln adjacent to the mixing chamber.