| 摘要 |
The present invention relates to a radiant tube having protective pipes, which are doubly embedded in connection points of pipes to prevent damage to a welded part due to heat when the connection point is welded to continuously connect straight pipe members with U-shaped bent pipe members, and red heat means included in the protective pipes to allow unburned gas to be completely burned in a process where the unburned gas comes in contact with the red heat means. The radiant tube includes the straight pipe members formed in a multi-stage. The straight pipe members form one continuous radiation tube by welding both ends of each straight member with the bent pipes. A plurality of convex parts are continuously included on the outer circumferential surfaces of the straight members, the convex parts having a semi-arc shape protruding upward. The protective pipes are embedded in the welded parts of the straight pipe members and the bent pipe members in such a manner that the protective pipes are in close contact with the inner circumferential surfaces of the straight pipe members and the bent pipe members, thereby protecting the welded parts from flame. |
