Patent ID: 8161918
Filing Date: 2012-04-24
Classification: F24H,Y02B

Abstract:
1. A storage-type water heater comprising: a water storage tank having a generally vertical center axis and having upper and lower ends; a combustion chamber adjacent the lower end of the tank; a burner generating products of combustion in the combustion chamber; a substantially straight flue tube extending within the tank generally along the axis, the flue tube having a closed lower end and having an open upper end; and a helical tube heat exchanger within the tank, the helical tube being generally centered on the axis, the helical tube having an upper end communicating with the flue tube at a point between the upper and lower ends of the flue tube, and the helical tube having a lower end communicating with the combustion chamber such that the products of combustion flow from the combustion chamber into the helical tube, then into the flue tube and then out of the upper end of the flue tube; a portion of the flue tube extending downward from the point at which the helical tube communicates with the flue tube so as to form a condensing water trap in the closed lower end of the flue tube.