Sheet dryer apparatus using deflectors for steam drying

Abstract

A dryer apparatus is disclosed for drying sheet materials by contact with a drying fluid which is deflected towards the opposite surfaces of the sheet by deflector members spaced longitudinally along such sheet. A major portion of the drying fluid consists of internally generated superheated drying steam above 212.degree. F, to vaporize the water in the sheet material and remove it to produce the steam used for drying. A minor portion of steam is removed from the drying fluid and discarded to maintain pressure equilibrium. The drying steam is produced within the drying chamber from water evaporating from the material being dryed and is either heated to form the superheated steam within the drying zone where it is in contact with the sheet material or is removed from the drying zone, heated to form superheated steam and returned to the drying zone for contact with the sheet material during drying. A wood veneer dryer employing the invention is described including two drying chambers having their drying fluids flowing in opposite directions through the drying zones within such chambers. A crossover section is provided between the two chambers to cause the drying fluids to cross from one drying zone to another. The drying zones provided with the veneer dryer have at least along the major portions of their lengths a negative internal pressure which is below that of the ambient external atmosphere outside the dryer to prevent pollutants from leaking out of the dryer and ambient air is prevented from entering the dryer into such drying zones.

Dependencies are inferred from the claim text.