| 摘要 |
1,267,139. Heat exchanger tubes. UNIVERSAL OIL PRODUCTS CO. 3 Nov., 1970 [12 Jan., 1970], No. 52202/70. Heading F4S. The wall of a heat exchange tube is corrugated with annular or helical (single or multistart) corrugations, and the outer surface of the tube has a coating thereon of a porous metallic material (e.g. a sintering of powdered metal) to improve heat transfer. Examples of preferred tube dimensions are given. |
