| 摘要 |
<p>A heat exchanger for a condensing boiler has several upright tubes (1) disposed around a central combustion chamber in which a burner (10) is disposed, the tubes extending between upper and lower headers (4,5) for conducting water to and from the tubes. The tubes are fitted with fins which are provided with means, such as rods (12), wicks (13) and/or downwardly deflected tabs (15;16;115;145) defining drainage paths for condensate formed on the fins. The upper surface of the lower header (5) is arranged to collect the condensate and direct it to drainage holes formed in the header and through which the condensate passes into a collection chamber defined below the header by a sump (25). The sump chamber is connected by an overflow channel (32) to an overflow chamber (30) defined around the burner by a burner mounting plate (28) and the lower header (5), and a flame detector (31) which projects up through the overflow chamber is adapted to detect condensate in the overflow chamber.</p> |
