OCR Text |
Show ABSTRACT I A STUDY ON FLAME STABILIZATION OF A PERFORATED POROUS PLATE BURNER Masahiro Yahagi and Koji Hase Energy Technology Research Institute Tokyo Gas Co., Ltd. 1-16-25, Shibaura, Minato-ku, Tokyo, 105 JAPAN Lean premixed combustion burners which utilize perforated porous plates containing many flame ports have recently been found to offer high combustion performance. These burners have two types of flames; port flames by burning the premixture from many ports and percolation flames by burning the premixture percolated from the surface of the p0- rous plate. The flame-stabilizing mechanism of this type of burner, however, has yet to be clarified. This paper investigates the flame stabilizing mechanism of perforated porous burners. The combustion range of both of a perforated porous plate burner and a nonporous plate burner perforated in the same way were measured and compared. The flow rate of the percolation from the porous plate and the port flow rate from the ports were also measured. The flames were observed by taking direct photographs and high speed video photographs. The state of the flow above the perforated porous plate was also observed by laser tomography using a tracer of Ti02. INTRODUCTION The necessity for a compact, low NOx gas boiler has been increasing in city areas such as Tokyo. Lean premixed combustion has therefore been applied recently to boilers. Premixed combustion burners, however, have some drawbacks such as back fire and resonance noise and a narrow combustion range. |