Comparison of methods for evaluating particle charges in the electrostatic precipitation of fly-ash from small-scale solid fuel combustion

Small-scale heating units with solid fuels combustion cause a global atmospheric pollution by fine particles. Electrostatic precipitation is suggested as a method of controlling fine particle emissions. The correctness of modelling for precipitation efficiency is defined by the accuracy of the evaluation of particle charges. This work focuses on reviewing the existing particle charging theories in terms of their suitability for practical engineering for the electrostatic precipitation of fly ash particles from the flue gases of small-scale boilers. Charging calculation methods were rated as a function of the particle sizes, external discharge electric field strength, and ion density-time product and compared to published experimental data. Two particle charge rating methods were identified to be suitable for the electrostatic precipitation of such particles.