| 摘要 |
PURPOSE:To lower the temperatures of primary combustion flame and secondary combustion flame thereby to reduce the production of nitrogen monoxide, and nitrogen oxide by providing a burner head having a plurality of primary burner ports, also providing a primary combustion chamber covering said burner head and having at its upper part secondary burner ports, and forming a heat insulating member of a heat insulating cylinder at the side walls of said primary combustion chamber. CONSTITUTION:Primary air and a fuel ejected through a blast pipe 9 and a fuel nozzle 12 is supplied as a premixed gas to primary burner ports 16 via a premixed gas passage 13 so as to form a primary combustion flame 21. The primary combustion formed within a primary combustion chamber is conducted at limits of inflammability or higher based on primary air and less than theoretical air amount. Further, unburned components not completely burned and remain within the primary chamber 18 receive the supply of secondary air at secondary burner ports 19 thereby to form a secondary combustion flame 22. Upon this occasion, since the combustion is divided into two stages, that is, primary combustion and secondary combustion, the combustion load is lowered and a slow combustion is carried out. Hence, the amount of nitrogen monoxide generated is remarkably reduced.
|
