摘要 |
A dew point corrosion resistant heat exchanging system having a plurality of hollow heat transferring tubes through which cooler ambient air or hot combustion product gasses flow. The other of the air or gas flows across the outer surfaces of the tubes, and heat is transferred from the hot gasses to the ambient air, thus heating the air. A portion of the tubes includes an inner liner forming an air pocket chamber between the liner and the outer wall of the tube. The air pocket chamber provides heat transfer advantages that maintain the tubes at a temperature above the dew point of the gasses in the system, thus inhibiting corrosion of the tubes. |