| 摘要 |
PURPOSE:To obtain a heat exchanger tube of vertical type for a heat exchanger, etc. of which removal of condensed liquid is performed smoothly of which area to condense steam and to exchange heat is wide, and of which cnduction of condensed heat is high, by providing slant, spiral grooves on the heat exchanging surface. CONSTITUTION:The spiral grooves 2 are formed on the surface of heat exchanger tube by extrusion molding. The angle theta of inclination of the groove is designed to be 20 deg.-30 deg.. The steam is condensed on the flat surface 1 of the tube, and the condensed liquid being formed is dropped into the grooves 2. A part of condensed liquid dropping down and circling the inside of the spiral grooves 2 is sprayed into the air from the grooves by changing direction at each corner of the groove, and by centrifugal force. With regard to the cross section of the groove, the upper wall d is slanted so that the condensed liquid formed on the flat surface 1 of the tube is easy to be flowed into the grooves, while the lower wall e is designed to be nearly horizontal so that the condensed liquid is hard to overflow from the grooves 2 downwards. |
