摘要 |
<p>The invention is for heat radiation tubes for furnaces and the like heating devices, mainly for industrial processes. Heating can be obtained by electrical heating elements or by combustion for example of gas. The radiation tube is a circular tube having end walls, flanges etc. as required. Thereby that a radation tube according to the invention is a seam-less tube made from iron-chromium-aluminium essential advantages are obtained in respect of oxide spalling which is greatly reduced and shape strength at high temperatures of use. Preferably the tubes are made by extrusion whereby conditions are chosen to give a rough surface with grooves and ridges which further improves the adhesion of the oxide layer.</p> |