| 摘要 |
PURPOSE:To permit to maintain the heat transfer performance of high degree for a long period of time by a method wherein protuberances for preventing errosion are provided at the downstream side of the internal surface ribs in the heat transfer tube through which a fluid containing corrosive factors is flowed. CONSTITUTION:The heat transfer tube 6' is arranged in the enclosed vessel 3a of a condenser 3 and cooling water, including corrosive factors, flows therethrough into the direction of arrow signs. The rib 10, provided with spiral small protuberance, not parallel to the flow direction of the cooling water, is formed on the internal surface of the heat transfer tube 6'. The sectional configuration of the rib 10 is formed so as to have a gentle slope 11a at the downstream side of the protuberance 11 with respect to the flow of cooling water as shown by the non-symmetrical protuberance 11 in the diagram. In the heat transfer tube 6' formed with the rib 10, the cooling water flows along the gentle slope 11a after passing the apex of the protuberance 11 of the rib 10 when the cooling water flows into the direction of the arrow sign, therefore, a local turbulent flow will never be generated and there is few passibility to generate the corrosion of the inner wall of the tube due to water corrosion effect or so-called errosion. According to this method, reliability as the heat transfer tube for the condenser 3 becomes high and the heat exchanging performance of high degree may be maintained for a long period of time. |
