| 摘要 |
A condensing heat exchanger for a gas boiler has a casing (3) for conducting combustion fumes; a hollow elongated member (4) for conducting a liquid, and which is coiled about an axis (A) to form a helix (5) which is housed inside the casing (3) and has a number of adjacent turns (12) and a helical gap (13); and a first combustion fume feed region (11) for feeding combustion fumes into the helix (5); the casing (3) having a first wall (6) extending about the axis (A) and the helix (5) and equipped with a first outlet (23) for the combustion fumes; and a second wall (7) extending about the first wall (6) and spaced apart from the first wall to form an annular gap (22) between the first wall (6) and the second wall (7), which has a second outlet (24) offset with respect to the first outlet (23). |
