| 摘要 |
PROBLEM TO BE SOLVED: To enhance a thermal efficiency and to enhance a strength of a cylindrical heat exchange cylinder, by forming the heat exchange cylinder in an integral structure of an aluminum material having a plurality of holes penetrating from one end to the other end and arranged in section between an outer wall and an inner wall of the exchange cylinder. SOLUTION: The heat exchanger comprises a cylindrical heat exchange cylinder 2 made of an aluminum extruded material, and a heat exchange pipe made of a copper tube spirally wound on an outer periphery of the cylinder 2. A fluid to be heated is forcibly circulated and heated in the pipe. The cylinder 2 is integrally formed of an aluminum extruded material of a double tube structure having a plurality of substantially rectangular holes 8 annularly arranged to become a combustion exhaust gas channel penetrating from one end to the other end axially in section between an outer wall and an inner wall of the thick cylinder. A large hole 9 at a center shuts off flowing by a blocking plate to distribute combustion exhaust gas all through the holes 8 from a burner unit. |
