| 摘要 |
A thremal insulator which is applied to a wall subjected to hot fluid comprises a number of sealed tubes arranged parallel to each other and to the wall and extending along the whole length of the wall. The tubes may be partially evacuated or filled with the heating fluid and are held in bundles, e.g. by straps. The bundles may have trapezoidal or T-shaped cross-section, so that only alternate bundles need be fixed to the wall. Individual layers of tubes within a bundle may be separated by thin sheets, e.g. of aluminium, to reduce convection and the bundles may be partially covered, e.g. by a perforated plate on the outward facing side. Circular walls may be protected by toroidal tubes having a non-rigid connecting member joining the two ends into a closed loop. |
