| 摘要 |
PROBLEM TO BE SOLVED: To reduce a pressure loss during the exhaustion while enabling use of a regenerative body in a wider range. SOLUTION: An injection hole forming means 6 which separates an air throat 2 internally equipped with a regenerative body 4 and a combustion space 8 in a radiant tube is provided with an injection hole 3 which has the surface 7 thereof made spherical facing the side of the combustion space 8 on the side of the radiant tube and the surface 9 thereof made hemispherical facing the side of the air throat 2 as plane orthogonal to the inner circumferential surface 1a of the radiant tube 1 while arranged so biased to inscribe or in proximity to the inner circumferential surface 1a of the radiant tube 1 and a clearance 10 is made between the hole and the inner circumferential surface 1a of the radiant tube 1. During the combustion period with a burner, air for combustion is injected mainly through the injection hole 3 and during the stoppage of the combustion, an exhaust gas is made to flow into the air throat 2 not only from the injection hole 3 but also from the clearance 10 between the hole and the radiant tube 1 on the perimeter of the injection hole forming means 6. |
