Gas-fired heat exchanger, especially for absorption refrigerators

摘要

The heat exchanger has a vertically arranged premixing burner (22) constructed like a grate and having an array of holes (86), between the gas-outlet openings (45), to feed secondary air to the flame roots. The respective total cross-section of the holes (86) in relation to a surface element of the burner (22) decreases in the vertical direction of the burner from the top to the bottom such that, in spite of the thermal buoyancy of the combustion gases, a uniform intake of secondary air takes place over the entire height of the burner (22). It can be ensured by a corresponding dimensioning of the holes (86) and arrangement of the plane in which the holes (86) open, in relation to the plane of the gas-outlet openings (45), that the stream pulses of the inflowing secondary air are aligned parallel to the burner flames, so that the furnace efficiency is likewise improved and the pollutant fraction in the combustion gases is reduced. IMAGE