JPS6438510A - Burner for use in radiant tube - Google Patents

Abstract

PURPOSE:To reduce the quantity of NOx generated upon combustion by providing a secondary air nozzle at the central part of a burner head mounted on the opening end of a cylinder, forming a plurality of through holes in the burner head equidistantly on a concentric circle with the secondary air nozzle, and inserting the opening ends of gas lances into the through holes. CONSTITUTION:Since the inner diameters of a plurality of through holes 31 are equal to each other and the outer diameters of a plurality of gas lances 5 are equal to each other, the opening areas of a plurality of primary air nozzles 39 have a predetermined equal size. A combustion gas ejected through each gas nozzle 7 is efficiently subjected to a primary combustion F1 within a combustion chamber 13 in a state where the combustion gas is encircled within primary air ejected in a torus shape through the primary air nozzles 39. Upon this occasion, primary air is completely burnt and consumed. An unburnt gas is subjected to a secondary combustion F2 together with secondary air supplied through a secondary air nozzle 12 in a secondary combustion zone, whereby the burner 32 completely carries out a two-stage combustion.