To eliminate a water leakage accident, if any, at a heat transfer tube placed in a severe corrosion environment exposed with a dry corrosion due to an exhaust gas acid component and a wet corrosion due to an acid drain in a combustion equipment having a latent heat recovery heat exchanger.
A combustion equipment having the latent heat recovery heat exchanger uses a stainless steel having excellent corrosion resistance as a manufacturing material instead of a heat transfer tube 11 heretofore made of aluminum, and covers an inner surface of the tube 11 with a coating 14 of a film of a water insoluble polymer material having a thermal expansion coefficient near that of the stainless steel on an inner surface of the tube 11. Thus, even if a pinhole or a hair crack exists or takes place, this can be sealed by the coating 14, thereby entirely eliminating an anxiety of a water leakage.
SHINTANI YOSHIHIRO
KOSHIMIZU DAISUKE
Next Patent: CIRCULATING CONNECTING IMPLEMENT FOR BATHTUB