| 摘要 |
<p>PURPOSE:To provide a burner in which a part of a combustion gas is supplied to a suction port of a blower to reduce the amount of NOx, the turn-down ratio is high, the size is miniaturized, noise is reduced and reliability is high by forming a burner port body, providing upright a plurality of tubular flame holding members, and connecting a recirculation pipe to a part of the suction port of the blower. CONSTITUTION:A part of an exhaust gas emitted from swirling blue flame zones, tending to spread outward is mixed into a total primary premixed gas swirling and ejecting through air holes 32 between free gaps 33', formed between the inner peripheral wall of a burner port body 28 and swirling blue flame zones 35 at the time of combus tion state. As a result, the rise in the temperature of the total primary premixed gas ejecting is promoted and a recirculating operation of making a more dilute mixed gas is generated. Particularly, since a part of a high-temperature combustion gas is sucked up through the upper opening 34' of a flame holding body 34 and the combus tion gas is supplied to a blast chamber 42, the surface of the flame holding body 34 has a further higher and uniform temperature distribution, the flame holding effect is improved, and moreover a high-temperature gas is supplied to a part of the total primary premixed gas, which is heated to improve the combustion characteristic.</p> |
