Abstract: A method and apparatus for operating a dryer used to reduce the moisture content of sheet material such as a jet veneer dryer. A drying chamber is provided and includes a plurality of individual, juxtaposed drying sections. Each drying section circulates air in a path substantially transverse to the path of movement through the dryer. A single point exhaust system extracts the exhaust from the first drying section. A wet seal section located at the input end of the dryer includes an exhaust passage through which a gas sample is drawn by a sampling fan. Gases within the wet seal section are a combination of ambient air drawn through restricted passages at the entry to the wet seal section and exhaust gas that bleeds into the wet seal section from the drying chamber. A controller monitors the temperature of the sampled gases and ambient air and adjusts the rate of exhaust flow from the main exhaust system as a function of the temperature differential.

Abstract: A dryer for reducing the moisture content of material in sheet form comprising a drying chamber through which material to be dried is conveyed and through which heated air is recirculated being withdrawn from the material exit end thereof at less than atmospheric pressure and returned to the material feed end of the drying chamber by power driven fans. During its return to the material feed end of the drying chamber it is reheated. A supplemental gas chamber is provided at the feed end of the drying chamber for controlling the flow of gas from the material feed end of the drying chamber. A second supplemental gas chamber at the material exit end of the drying chamber has means for limiting the leakage of air at ambient temperature thereinto and is provided with an exhaust fan for withdrawing gas therefrom and in turn from the material exit end of the drying chamber.

Abstract: An elongated generally horizontal stationary housing having generally horizontal, continuous conveyors extending therethrough and including a material drying zone or chamber for reducing the moisture content of material conveyed therethrough and a gas seal zone or chamber having an exhaust fan connected thereto at the material discharge end of the drying chamber. Hot gases are circulated through the drying chamber from the material entrance end to the material exit end of the drying chamber by a fan located in a recirculating duct connected to the opposite ends of the drying chamber and which fan maintains a subatmospheric pressure in the material exit end of the drying chamber. During return of the drying gases to the material entrance end of the drying chamber the temperature of the gases being circulated is increased. Baffles are provided at the material exit end of the seal chamber to restrict the entrance of air into the seal chamber at the material exit end thereof.