| 摘要 |
PURPOSE:To improve a temperature distribution of a tube and to reduce noise and NOx by providing an inner tube having a plurality of holes on an outer periphery or a forward space of a burner top provided in a straight outer tube, and supplying a specific amount of secondary air to an annular chamber between both the tubes. CONSTITUTION:This tube burner comprises a burner top 2 provided in a straight outer tube 4. Air mixed gas having an air ratio of primary air to gas of 0.6 or less (about 0.5) is supplied from an air mixed gas passage 11 to the top 2. An inner tube 3 having a plurality of holes is provided on an outer periphery or in a forward space of the top 2. 55-60% of theoretical air amount of the preheated secondary air is supplied from an air passage 5 onto an annular chamber 8 between the tubes 3 and 4, and hence the secondary air in which a total air amount with the primary air set to 1.1 times as large as the theoretical air amount is supplied to the top 2. Combustion gas is expedited to be exhausted by an eductor 11, and exhaust heat is used for preheating supply air by an air preheater 12. |
