| 摘要 |
PURPOSE:To enhance heat-transmitting efficiency on the air side and draining property for condensed water, by a method wherein rugged stringers each of which extends in the stage direction of a group of heat-transmitting pipes and bypasses each of the pipes on the downstream side with respect to an airflow are provided in each of a group of fins at intermediate parts between adjacent ones of the pipes in the stage direction. CONSTITUTION:A flat plate fin 1a is provided with fin collar parts 1b by burring at regular intervals, and the heat-transmitting pipes 2 are passed respectively through the collar parts 1b. The fin 1a is provided with the rugged stringers 5 by a press working means or the like. Each of the stringers 5 consists of a straight part 5a extending along a straight line connecting adjacent one of the pipes 2 in the stage direction of the pipes 2, that is, in the direction orthogonal to the direction of the airflow (indicated by arrows) and a bypassing part 5b which bypasses each of the pipes 2 on the downstream side with respect to the airflow. Accordingly, the flow of air entering between the adjacent fins 1a is disturbed by the straight parts 5a, whereby growth of temperature boundary layers is restricted, and air is caused to flow along the bypassing parts 5b, whereby burble region is reduced. |
