Fire tube boiler

Abstract

A fire tube boiler having a combustion chamber equipped with a burner, and a group of fire tubes provided adjacent to the combustion chamber. The fire tube boiler further includes a heat exchanger disposed in the combustion chamber and serving for heat exchange with combustion flame from the burner. The combustion chamber is divided into a first combustion chamber and a second combustion chamber by the disposition of the heat exchanger. Furthermore, the heat exchanger is disposed in proximity to the burner so that the combustion flame in the first chamber is less than 1500.degree. C. and the combustion flame in the second chamber is between 1100.degree. and 1400.degree. C. Thus, the fire tube boiler allows further reduction in harmful exhausts such as NOx and CO.

Dependencies are inferred from the claim text.