Burner-heated water heater with heat-exchanger - has damper in flue after exchanger comprising metal plates with apertures sliding in relation to each other

摘要

The heater has a heat-exchanger in the top of the combustion chamber and through which the exhaust gases flow. This is followed by a flue containing a damper(6). The latter comprises two or more metal plates(7,8) with apertures(9,10) and sliding in relation to each other, so as to give stepless variation of the free cross-sectional area. The apertures can be formed by parallel slots of the same width and/or pitch. The slot length can be equal to the respective chord length of the flue cross-section. Alternatively the apertures can be overlapping round or square holes. ADVANTAGE - Simple damping.