Experimental and Theoretical Studies on Characterisation and Capture of Single-Wire Square Crossectional Electrostatic Precipitator in Indoor Environment

AISWARYA KUMAR, Prashant Nawale, Y. S. Mayya, Manoranjan Sahu, Indian Institute of Technology Bombay

     Abstract Number: 637
     Working Group: Control and Mitigation Technology

Abstract
Most individuals spend the majority of their working and living hours indoors. As particulate matter (PM) is found to be a health concern, several indoor PM control technologies are available on the market as well as at lab scales, but they have different drawbacks. Electrostatic precipitators (ESP), which are a preferred technology in industries, can achieve similar performance indoors with additional benefits like high removal efficiency even at lower PM concentrations, flexibility of keeping them as standalone/induct, ability to handle high velocity, lesser energy consumption, recovery of being washed, multiple pollutant removal and low maintenance. Compared to other ESP geometries that were well studied in literature as well as considered in different theoretical contributions, single-wire square cross-section geometry has multiple advantages like easier adaptation for design as well as a multiplication for various applications, space-filling characteristics, corona, as well as collection efficiency could be modelled at same time as charging as well as collection happens simultaneously and as approach to modelling is relatively straight forward. As there is a requirement to customise ESP for a particular application, single-wire square cross-section ESP was designed, operated and tested for its performance experimentally. As experimental investigation can be complicated under some circumstances, a model was developed to predict PM capture efficiency theoretically with automatic consideration of the effects of space charge and theory of corona. Results from experimental settings were compared with the developed model in terms of characterization, which is the behaviour of the corona discharge as well as PM capture efficiency of ESP. Good agreement was found between theoretical and experimental data with a corona breakdown voltage of 7.75 kV. Similarly, PM capture efficiency in clean and worst indoor scenarios was found to be following the same trend in theoretical as well as experimental studies, with a total efficiency value above 95% for PM size range of 10 nm to 5 µm. Although not that significant, model underestimated efficiency compared to experimental values, which could be due to non-ideal scenarios in experiment setting or due to the assumptions to which area and other radial parameters were approximated. As results from the study seem promising in terms of PM capture efficiency as well as with secondary effects of air cleaning systems such as by-product emission, energy consumption, and multipollutant removal, there is a possibility of scaling up to various applications like air purifiers and outdoor air cleaning.