| 摘要 |
PURPOSE:To remarkably reduce the size of an air preheater by forming the sectional shape of a heat transfer tube in a flat state, bringing the long diameter direction of the flat section in coincidence with the passing direction of the outer fluid of the tube, thereby mounting many tubes in the same area without decreasing the capacity. CONSTITUTION:The long diameter of a flat heat transfer tube 7 coincides with the direction of an arrow C passing the outer fluid of the tube. The shape of the tube 7 is, for example, in a flat shape by pressing the circular steel pipe having 45mm. of diameter so that the short diameter (g) is 14mm., the long diameter (f) is 62.65mm., and the peripheral length is 141.3mm.. The number of the tubes is 14 rows per one tube group and 28 rows of two groups, 38 rows of the direction perpendicular to the 28 rows, totally to 1,064. The size of the gap between the tubes 7 is 20mm. in the long diameter direction, and 15mm. in the short diameter direction (n). The total value of the size (n) is 15mm.X39=585mm., thereby maintaining the exhaust gas side pressure loss to the prescribed value or lower. |
