Method of and apparatus for measuring concentration of harmful gases in flue gases of a heating plant by making use of photo spectrometry

摘要

The present invention relates to a method of and apparatus for measuring, the concentration of harmful gases in the flue gases through a heat-producing plant of the kind that comprises a first space (3) for the combustion of a fuel, a device (5) placed in a second space û gas duct (4) located downstream of the combustion space, said device (5) in the second space comprising tubes through which a medium, such as water, air or steam, may pass in order to be heated by heat transfer from the flue gases formed during the combustion. The invention is characterized in that, in a region near said tube device (5), at least one beam (11) of ultraviolet light is emitted from a light emitter (7') on one side of a flue gas duct (4) to a light receiver (7'') located on the opposite side of said duct (4), which light emitter (7'') is connected to a spectrometer (13) cooperating with a computer unit (14), in which spectrometer the light is divided spectrally. This spectrometer is calibrated for registering the spectral intensity distribution of the light within the wavelength range of 200 to 310 nanometers, in order to substantially continuously detect in situ the concentration of gaseous metals and/or metal chlorides in the flue gases during the operation of the plant.