OCR Text |
Show 2 1. Introduction ()ver the past decades spray combustion and evaporation combustion have contributed several noteworthy progresses and improvements in liquid fuel combustion methods. Indeed, the spray combustion enrolls a significant portion from small size heaters to industrial furnaces because of convenience and availabirity in liquid phase. In some special cases, mixing of fuel and air can be separated from combustion, but most often combustion of the spray proceeds concurrently with mixing, which makes it difficult to prevent the formation of pollutants such as soot, unburnt hydrocarbon, N()x,and C() as using the broad turn-down range. ()n the other hand, in the evaporation combustion, liquid fuel is evaporated before reaching by the heated solid, so wide range turn-down is achieved wi thout the formation of pollutants. However it usually takes long time to prepare for evaporation and steady combustion state because of the low evaporation rate of liquid phase fuel. f(ecently these combustion methods can not answer the growing demand such as energy efficiency, quick response, and low pollutant emissioQ lJnder the circumstance authors investigated very unique combustion method, called "foam combustion". In the foam combustion, liquid fuel forms foa~ numerous fine air bubbles wrapped with very thin liquid fuel fil~ and it evaporates easily as well as injected liquid fuel. J\s the result, the foam combustion attains outstanding performanc~ for exampl~ high energy efficiency, quick respons~ clean exhaust. llhe present work report about basic mechanism of the foam combustion, foaming characteristics, development of the foam combustion burner, and applicatioQ |