A KDS Windsor CDK system has a reverse flow double track design that incorporates preheating, drying, cooling, equalizing and conditioning phases all in one extended chamber. In addition to new CDK systems we have also converted existing double track batch kilns to CDKs. The lumber stacks traverse through the kiln in opposite directions on the two tracks. The lumber is automatically advanced, based on the moisture content (an exclusive to KDS Windsor) of the lumber in the central heating zone by hydraulic advancer units. The CDK system control is via our Dryspec kiln management program integrated with our DryTrack® Echo in-kiln moisture measurement system.
A CDK process has three distinct phases which occurs in three distinct zones in the overall chamber:
As green wet lumber enters the CDK it travels down the first ER (Energy Recovery) section where it is preheated by hot moist vapor from the central MD (Main Drying) section and the adjacent hot dry lumber. The ER sections include overhead fans and a series of dividers with side and overhead baffles.
The lumber then moves through the MD section and is effectively dried to the target MC. This section includes fans, baffles, hot air ducts, and a system for wet bulb control as well as, our DryTrack in kiln moisture measuring system
The dried lumber then moves through the 2nd ER sections where it is equalized, conditioned and cooled by the adjacent cold wet stack and overhead fans prior to exiting the CDK. The lumber on the other track travels in the opposite direction hence you always have a mix of dry and wet lumber in all zones interacting together.