Abstract: A combustion/evaluation apparatus having a sampling member for sampling light emitted from flame in an internal combustion engine, optical fibers for separating the light sampled by the sampling member into at least two lights, optical filters for selectively transmitting lights having different wavelengths by being provided in optical paths for the separated lights, photoelectric conversion elements for respectively converting optical signals transmitted through the optical filters into electrical signals, and a calculation/evaluation unit for calculating an air ratio and a temperature for evaluation of the combustion condition of the flame by using a ratio of outputs from the photoelectric conversion elements, and for evaluating the combustion condition on the basis of the air ratio and the temperature.

Abstract: A waste flue gas cleaning method and an apparatus for practicing said method, in which a reactant solution is sprayed into a waste flue gas introduced into a spray tower, whereby a toxic component in the flue gas is caused to be absorbed in and react with the droplets of the sprayed reactant solution, and the water contained in the droplets is vaporized and the reaction products are dried into solid particles by the sensible heat of said flue gas. A series of the above operation is accomplished within the spray tower while maintaining the outlet gas temperature always above the dew point of the flue gas, and the solid particles of the reaction products are removed from the flue gas by an after dust collector.

Abstract: A waste flue gas cleaning method and an apparatus for practicing said method, in which a reactant solution is sprayed into a waste flue gas introduced into a spray tower, whereby a toxic component in the flue gas is caused to be absorbed in and react with the droplets of the sprayed reactant solution, and the water contained in the droplets is vaporized and the reaction products are dried into solid particles by the sensible heat of said flue gas. A series of the above operation is accomplished within the spray tower while maintaining the outlet gas temperature always above the dew point of the flue gas, and the solid particles of the reaction products are removed from the flue gas by an after dust collector.