| 摘要 |
PURPOSE:To reduce a creep, a crack, etc., at the time of heating to a high temperature due to increase in rigidity by providing a rib between adjacent tubes of a zigzag part of a heating tube and to improve a life to improve a thermal efficiency by further providing a rib to increase heat radiating areas. CONSTITUTION:A radiant tube body 12 is formed of heat resistant cast steel, and bent in a W shape to form a radiant tube 10a. Adjacent tubes 12 in a zigzag manner are coupled with a rib 13 made of stainless steel plates having heat insulation. The rib 13 is divided into a plurality, its width is set to about 200mm, and welded to the body 12 at a gap of about 2mm. The tube 10a is used in a longitudinal direction. In this case, it is coupled with the ribs 13 to largely increase geometrical moment of inertia and a sectional modulus. Accordingly, creep resistance at the time of heating to a high temperature can be increased. Further, overall heat transfer coefficient can be also increased, thereby improving a thermal efficiency. |
