Heating device for corrugated paperboard production

A heating device for a traveling paper web comprising:

• a thin outer metal plate having a smooth web-supporting outer surface;
• a series of spaced generally parallel open-ended heating tubes positioned in operative heat-conducting contact with an inner surface of said outer plate;
• a pair of heating fluid supply manifolds each connecting the open ends of the tubes along one of a pair of opposite edges of said outer plate;
• a source of steam operatively connected to said heating fluid supply manifolds for transfer of the steam through said tubes between the manifolds;
• a series of cooling water supply tubes of a diameter smaller than said heating tubes, said water supply tubes mounted generally coaxially within said heating tubes;
• said cooling water supply tubes having an open end and perforated walls providing open communication from each of the supply tube interior to the interiors of the respective heating tubes;
• a cooling water supply manifold mounted along one edge of the outer metal plate adjacent one of said heating manifolds and connecting the open ends of the water supply tubes at said one edge;
• and,
• a pressurized source of cooling water operatively connected to said cooling water supply manifold.