| 摘要 |
<p>A gas boiler condensing heat exchanger (1) has a casing (15), in which combustion fumes are conducted to an outlet port (28); a first and second hollow elongated member (1, 2) having respective end portions (6, 8) and wound at least partly about an axis (A) to form a first and second helix (3, 4), which are arranged successively along an axis (A) inside the casing (15; 32), form respective turns (11) separated by respective helical gaps (12); the first and the second helix (3, 4) being configured to define, between the end portions (6, 8) and a turn (11) of the first helix (3) and a turn (11) of the second helix (4) facing each other, a space having a dimension parallel to the axis (A) that is larger than the helical gaps (12).</p> |
