Patent ID: 6422179
Filing Date: 2002-07-23
Classification: F23M,F24H,F28F

Abstract:
A water heater comprising:a tank for holding water; a combustion chamber; a flue tube extending through the tank and communicating with the combustion chamber, the flue tube having an inner surface and a longitudinal axis; and a fin structure positioned within the flue tube, the fin structure including at least one fin portion that is V-shaped in cross-section and that has a base extending substantially parallel to the longitudinal axis, the fin portion also having two legs that extend from the base and that are each metallurgically bonded to the inner surface to define a joint between each of the legs and the inner surface, and the fin portion also having at least one slot to reduce the amount of thermal expansion of the fin structure at the joints, the fin structure dividing the flue tube into a plurality of flue chambers extending substantially parallel to the longitudinal axis.