| 摘要 |
PURPOSE:To improve the heat exchange efficiency and enable to save energy by a structure wherein the length of the fin toward the direction of draft is rendered to be gradually larger as the fin locates nearer to the center of a blast fan. CONSTITUTION:The forms of the fins 12 are set in such a manner that the front surface A of the heat exchanger 4, which is formed by the envelope of the leading edges of the fins 12, turns to be a convexly curved surface toward the front grill near the central part of the heat exchanger 4 and the rear surface B of the heat exchanger 4, which is formed by the envelope of the trailing edges of the fins 12, turns to be a concavely curved surface toward a fan (not shown) about the vertical center line of the heat eachanger 4. Furthermore, the length of the fin 12 toward the direction of draft is formed to be gradually larger as the fin 12 locates nearer to the center of the fan and as well as heat exchange pipes 13 are so formed as to have proper curvatures and intervals corresponding to each fin 12. Consequently, the surface area of the fin located at higher passing air speed zone turns to be larger and that of the fin located at lower passing air speed zone turns to be smaller, resulting in enabling to improve the heat exchange efficiency. |
