PSI - Issue 77

Nikola Čajová Kantová et al. / Procedia Structural Integrity 77 (2026) 170 – 176 Čajová Kantová et al./ St ructur al Integrity Procedia 00 (2026) 000 – 000

171

2

1. Introduction Particulate matter (PM) constitutes a significant emission component of air pollution (Jandačka and Holubčík, 2020). Elevated PM concentrations adversely affect human health, causing respiratory and other diseases that substantially reduce both quality of life and life expectancy (Elbl et al., 2022; Singh et al., 2021). Electrostatic precipitators are widely used in industrial settings and play a crucial role in environmental protection. An electrostatic precipitator (ESP) can operate with high collection efficiency while maintaining low pressure drop (Holubčík et al., 2024; Mizuno, 2000) . However, particulate matter from domestic heating appliances remains unresolved (Jandacka et al., 2024). Various labyrinthine or obstructive configurations within flue gas ducts are utilized to facilitate the capture of particulate matter via inertial separation. Nevertheless, this technique proves inadequate for submicron and nanoparticle retention. Consequently, electrostatic precipitators are advised for the collection of micro and submicron particles, while heat exchangers are recommended for the thermophoretic removal of ultrafine particles (Jaworek et al., 2021; Lim et al., 2015). The efficiency of ESP is fundamentally determined by a combination of its design and operational parameters. Among these design elements, the specific collecting area of the ESP defined as the ratio of the total collecting area to the flue gas flow rate plays a critical role in its performance. On the operational side, the effective particle drift velocity stands out as a key parameter. This velocity is influenced by various factors, including the characteristics of the particles, such as their size and material composition, as well as the operational conditions of the ESP, which encompass the applied high voltage and electric current. Furthermore, the composition and temperature of the flue gas significantly affect this parameter. The assessment of particle drift velocity may not adequately account for complex real-world phenomena occurring within ESPs, such as electric wind effects and gas turbulence. Additionally, it is crucial to consider the interactions between particles and the gaseous medium, as these dynamics can substantially influence the overall performance of the ESP (Høgh Petersen, 1988; Molchanov et al., 2020). Computational fluid dynamics (CFD) models have been used by researchers like Arif et al.; Drga et al.; Guo et al.; Li et al. to study electric field distribution, trajectories of particles, numbers of trapped particles, pressure and velocit y distribution, predicting particle collection efficiency and so on (Arif et al., 2016; Drga et al., 2022; Guo et al., 2015; Li et al., 2019). Kantová et al. optimized the flue gas tract by employing separation baffles in the previous research. This design enables the capture of particulate matter through the utilization of three baffles, thereby preventing its release into the atmosphere within the flue gas. The influence of the baffles on the flue gas flow was initially observed via CFD simulations and subsequently validated by particle imaging velocimetry (PIV) measurements. According to stoichiometric calculations, it is feasible to capture up to 62.3% of the particles in configuration 1. The velocity comparisons derived from CFD and PIV corroborated the anticipated turbulent flow nature, characterized by the presence of vortices within the flue gas tract (Kantová et al., 2021) . This article employs CFD simulations to investigate the velocity distribution in an electrostatic precipitator with four tubes, both with and without a screw construction to direct the flow. It represents novel approach to improve the efficiency of electrostatic precipitation by expanding tubes from one to four and incorporating a screw construction into a four-tubular precipitator. CFD simulations were used for flow visualization of flue gases and particles contained in flue gases. The numerically obtained average velocities of individual tubes without and with a screw construction were also compared. Moreover, ensuring the structural integrity of the screw construction and the precipitator framework is essential for maintaining long-term performance and reliability under thermal and mechanical stresses.

Nomenclature CFD

computational fluid dynamics electrostatic precipitator particle imaging velocimetry

ESP PIV PM SST

particulate matter shear stress transport