Abstract
This report describes the formation and their prevention of acid smuts at oil-fired industrial boilers. Results obtained from the field tests were as follows.
1) The acid smuts were mainly formed in the stack and falled out within the limits of 400m from the stack in conditions of light wind.
2) Full load condition and load up period were critical from the point of view of smuts emission, which increased with increasing excess air.
3) Three methods of prevention against acid smuts emission tried were.
a) to retain minimum excess oxygen under 1.0 percent in order, to decrease the acid dew point below flue gas temperatures.
b) to neutralize SO3 by mean of NH3 injection of over 0.04 percent by weight of fuel oil.
c) most steam-power plants in Japan have been operated eliminating completely not only acid smuts but dust in flue gas.
