Wood Products Online Expo Temperature Control Zones X Moisture Content / Lumber Shrinkage X Dry Kiln Structure X Loading The Kiln X Temperature Control Zones X Fans and Fan Deck X Venting X Dry Kilns - Double Track Dry Kiln Overview:
 Moisture Content / Lumber Shrinkage Free water is held within the cell cavity. Bound water is held within the cell walls. The fiber saturation point is the moisture content at which moisture is saturated within the cell walls od wood and the cell cavities are free of water. This is normally at 30% moisture content. Lumber shrinkage starts when lumber is dried lower than the fiber saturation point.  Dry Kiln Structure A typical dry kiln is constructed of steel, aluminum or a combination of both. The panels are grade 1100 aluminum skins with Thermax or fiberglass insulation. There are I-beam monorail door carrier s which can be heated to prevent freezing.  Loading The Kiln Dry kilns can be loaded from one end or both ends. The loads are typically on carts or trains. The rails can have heating installed to prevent the cart wheels from freezing to the track  Temperature Control Zones There are horizontal overhead and vertical center reheat coils in the dry kiln to provide uniformly reheated air before each pass through the load. The kilns are zoned from side to side and along the length for uniform heat control.  Fans and Fan Deck The fans can be 72 inch to 84 inch diameter with anywhere from 6 to 12 blades. The fans can be fixed or variable pitch. The drives can be mounted in the kiln or external. Motors can be direct coupled or line shaft connected. The vents open momentarily to prevent implosion when the fans reverse.  Venting The vents open to allow moisture to be removed from the dry kiln. Removing moisture lowers the relative humidity in the kiln | ||
