Efficient thyristor controller for ESP [power plant emissions control]

The thermal power station, in which coal is burnt not only produces heat energy but also produces ash. The ash content of coal used at thermal power plants ranges from 35%; to 55%. Ash handling consists of a bottom ash system and a fly ash system. The fly ash system makes use of electrostatic precipitators (ESP) for collecting fly ash. Existing systems use the fly ash concentration as a reference to activate the controller to limit pollution due to fly ash. The system dealt in the paper uses the technique of keeping the supply voltage near the flashover level between electrodes of the ESP in accordance with the furnace load and concentration of dust and gases in the coal. The overall controller design includes data acquisition, data processing, thyristorised control, display, annunciator etc. which provides efficient, reliable and maintenance free control with maximum efficiency and optimal energy consumption