| 摘要 |
PURPOSE:To provide a smooth sliding at spacer members, reduce an accumulation of heat, decrease a load applied to the radiant tube and at the same time reduce a time required for a repair work by a method wherein a concave spacer member abutting against a convex surface of a convex spacer member fixed to one side is fixed to the other side. CONSTITUTION:A spacer 3 is composed of a convex spacer member 3a having a convex surface and a concave spacer member 3b having a concave surface abutting against the convex surface with a lower rate of curvature than that of the convex surface of the convex spacer member 3a. The convex spacer member 3a forms a hollow part at an outer circumference of the bottom surface of a hot temperature lower end part 2a, welded and fixed thereto, and further the concave spacer member 3b forms a hollow part in the same manner as above, welded and fixed in such a way as the convex surface of the convex spacer member 3a may be abutted against the concave surface of the concave spacer member 3b. The hot-temperature U-shaped pipe 1a is slidably supported at the low-temperature U-shaped pipe 1b through the spacer 3 with a proper spacing held therebetween. |
