Optimising parameters for improved electrostatic precipitation of fly ash from small-scale biomass combustion

The main technical characteristics of the electrostatic precipitation process, which can be applied to ESPs of any type, are the electric field strength and the Nt-product (the product of ion concentration and the residence time of the particle in the electric field). The present study investigates the impact of these characteristics on the efficiency of ESP in suppressing particulate matter (PM) emissions from a 160-kW boiler with wood pellet combustion. PM concentration was reduced to 2 mg/m3, representing a removal efficiency of ∼95%. The SMPS continuously recorded changes in the particle concentration. The growth of removal efficiency was not uniform with enhancing ESP parameters. The study shows that Nt-product demonstrated a prior effect on removal efficiency until growing up to the value of 4.5 × 1014 s/m3. Exceeding this value of Nt-product had no significant impact on the cleaning efficiency, but the electric field became prior. The results of the present research can help to optimise the ESP dimension parameters, therefore they can be used in the practical engineering of any new ESP to collect ultrafine particles and promote the implementation of ESPs for small-scale boilers for global pollution.