| 摘要 |
In the combustion using air pre-heated by accumulation type direct heat exchange between an exhaust gas and combustion air by using an accumulator as a heat-exchange medium, the present invention provides a low NOx burner which is effective for reducing NOx not only in a high temperature zone but also in a medium temperature zone, in which the NOx reduction has been difficult conventionally, and has high flame stability. In this low NOx burner, a burner tile (22) having a burner tile expanded diameter portion (23) having a diameter greater than that of an outlet of an air throat (2) for passing the full amount of combustion air is disposed at this outlet, and a fuel nozzle (19) injecting a fuel from this burner tile expanded diameter portion (23) is provided. The flow of combustion air jetted from the air throat (24) generates a negative pressure at the portion of a sub-combustion chamber (25) encompassed by the burner tile expanded diameter portion (23), so that strong re-circulation of the exhaust gas occurs inside a furnace, and a flame stabilizing region (X1), a furnace exhaust gas re-circulation/combustion region (X2) and a gentle combustion region (X3) are formed. <IMAGE> |
