| 摘要 |
<p>1. A gas-fired water heater including a vertical shaft (2) in which the hot gases circulate in an ascending current, the wall (2) of this shaft defining a peripheral water jacket (7) constituting a portion of a water circulation circuit of a first exchanger surrounding the vertical shaft and at least a second exchanger element (3) constituted by an axial tube (5) and a peripheral jacket (18), mounted vertically inside said shaft (2), characterized in that each second exchanger element (3) forms an overheater for the water already heated in the first exchanger, the inflow of the water to this or these second exchanger elements being effected, from the top of the peripheral water jacket (7) of the first exchanger in contact with the shaft (2), via the descending current axial tube (5) of this second exchanger element and the outflow, from the top of the peripheral jacket (18) of this second exchanger element toward an intermediate point (19) of the inner water circulation circuit of the heater, and in which the water flows while being channelled from the periphery to the center, the water to be heated coming in this peripheral jacket (7) in direct contact with the wall (2) of the jacket at the bottom point (14) in order to be discharged at the top point of said jacket.</p> |
