Apparatus for gaseous treatment of materials

Claim 1

IN APPARATUS FOR THERMALLY TREATING SHEET MATERIAL, SUCH AS PAPER, IN CONTINUOUS LENGTHS WHEREIN STREAMS OF GASEOUS MEDIUM ARE DIRECTED ON TO BOTH SIDES OF THE MATERIAL FOR THE EXCHANGE OF HEAT WITH THE MATERIAL AND TO PROVIDE GUIDING SUPPORT FOR THE MATERIAL AND WHEREIN THE SPENT GASEOUS MEDIUM FLOWS LATERALLY OF THE MATERIAL: THE COMBINATION COMPRISING OPPOSED PRESSURE CHAMBERS, MEANS FOR SUPPLYING GASEOUS MEDIUM TO SAID PRESSURE CHAMBERS, FRONT WALLS ON SAID PRESSURE CHAMBERS FACING ONE ANOTHER, SAID FRONT WALLS HAVING A PLURALITY OF ROWS OF OPENINGS FOR DIRECTING STREAMS OF GASEOUS MEDIUM TOWARDS SHEET MATERIAL BETWEEN SAID PRESSURE CHAMBERS AND ARCUATE FACING MEANS POSITIONED BETWEEN SAID ROWS OF OPENINGS ON SAID PRESSURE CHAMBER FRONT WALLS, WHEREBY THE ARCUATE FACING MEANS IN COMBINATION WITH SAID OPENINGS MAINTAINS THE STATIC PRESSURE OF SPENT GASEOUS MEDIUM FLOWING LATERALLY OF THE SHEET MATERIAL AFTER SAID DIRECTING AT LEAST AS GREAT AT THE LATERAL EDGES OF THE MATERIAL AS AT THE CENTRAL REGION OF THE MATERIAL.