摘要 |
The invention relates to a water heating apparatus and method to passively recirculate flue gas in order to reduce NOx emissions formed during combustion. The apparatus uses a high efficiency burner, a submergible, pressurized, combustion chamber having multiple external heating surfaces, and a flue collector that collects and passively recirculates a portion of the flue gases back into the burner air intake while exhausting the rest. The multiple external heating surfaces are installed within a closed tank and are submerged in water under pressure during use.
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