PURPOSE: To enhance the heating efficiency of a hot water boiler by heating a secondary circulation type heat exchanger provided under a tank with exhaust gas from the primary heat exchanger installed in the tank.
CONSTITUTION: The primary heat exchanger 10 having a burner 7 at one end and a combustion cylinder 8 provided with a baffle therein is laterally passed through a tank 1, a circulation pipe 11 provided with fins 15 at an oblique tube 14 communicating with an inlet tube 12 and an outlet tube 13 under the tank is contained in a cover 16, a partition plate 17 is provided to form the secondary heat exchanger 18, the inlet 21 is connected to the exhaust port 20 of the primary heat exchanger 10 via a connecting pipe 19, and an exhaust tube 22 having a fan 24 is connected to the outlet 23.
FUJISHITA KAZUO
SUGANO TADAO
KANEKO HIDEKI
MIZUTANI GOROU
