Method and apparatus for controlling cooling temperature and pressure in wood veneer jet dryers

A wood veneer dryer, comprising:

• a) an elongate drying chamber having an input end and an output end and defining a path of movement between said ends;
• b) a conveyor for conveying product to be dried along said path of movement through said drying chamber;
• c) said chamber including a plurality of juxtaposed heating units, each heating unit defining a circulation path for heated air, said path being substantially transverse to said path of movement of said product to be dried;
• d) nozzles forming part of each of said heating units for directing heated air into an impinging relationship with said path of movement;
• e) an exhaust system for extracting gases from adjacent heating units;
• f) a first pressure sensor for sensing a pressure in said output end of said drying chamber;
• g) a cooling section for cooling said veneer leaving said output end of said drying chamber, said cooling section including pressure controlling means for maintaining a pressure in said cooling section that is higher than pressure in said drying chamber while maintaining a near-zero pressure differential between said drying chamber and said cooling section;
• h) a second pressure sensor for sensing a pressure in said cooling section downstream of and adjacent to said output end;
• i) flow controller for adjusting the rate of said exhaust flow as a function of the difference in pressure sensed by said first and second pressure sensors.