| 摘要 |
<p>PURPOSE:To decrease the generation rate of NOx during the primary combustion, as well as the secondary combustion, by lowering the temperature of primary combustion gas, by converting sensible heat of the primary combustion gas into radiant heat, by permeating the gas through a gas-permeable inner tube, provided in a combustion tube. CONSTITUTION:The primary combustion gas is fed into an inner tube 6 from a primary combustion chamber 8, permeating through the wall of an inner tube 6 as shown by arrow signs X. During this time, the inner tube 6, of which substantial surface area is large, is efficiently heated up to high temperature, which is as close as to the temperature of the primary combustion gas, by convection heat transfer. Then, the primary combustion gas is fed into a secondary combustion chamber 14, passing through the inner tube 6, being lowered its temperature by being deprived the sensible heat of the gas by a tube 4 by heat radiation. With such an arrangement, generation of NOx is suppressed during the primary combustion, because the resident time of the primary combustion gas in high temperature zone is shortened. Besides, the temperature of the gas is lowered by the secondary air, being fed from the secondary air feeding tube 15, during the secondary combustion, so that the rate of generation of NOx in the secondary combustion is made low, as well.</p> |
