| 摘要 |
Heat exchanger for central heating boilers of the forced draught, sealed type. The heat exchanger comprises a bundle of tubes (4) having a substantially trapezoidal cross-section disposed according to a cylinder generatrix for forming an internal combustion chamber. The side faces (11) of the tubes have a length which is substantially three times the average thickness of the tube and form an angle of 4` to 6`. The angle between the side faces of two neighbouring tubes, seen from the axis of revolution of the exchanger, is between 0.5` and 1`. |
