Effect of flue gas conditioning on the cohesive forces in fly ash layers in electrostatic precipitation

Flue gas conditioning (FGC) systems are an effective option for improving the performance of electrostatic precipitators (ESP). The effect of FGC on the cohesive forces in ash layers during electrostatic precipitation has been studied for a complete range of ash compositions. Cohesive forces have been determined by means of a laboratory apparatus specifically developed within this research work. SO₃ and NH₃ have been tested as conditioning agents. It is concluded that the effect of injecting NH₃ on the cohesive properties is variable, and depends on the type of ash. The mechanism of NH₃ adsorption, influenced by the carbon content in ash, appears to play an important role. On the other hand, SO₃ addition involves the reduction of the cohesive forces in all the cases tested.