Janusz Podlinski

Measurements of the velocity field of the flue gas flow in an electrostatic precipitator model using PIV method

Abstract In this paper, results of use of the PIV method to measure the flow field in a wire-plate type ESP model are presented. The results show that the PIV method is well suited to investigate the flow field in ESP models, in particular the characteristics of secondary and reversal flows, which increase the flow turbulence. The PIV investigation of the near-collecting electrode region shows the importance of the secondary flows, the velocity of which is several tens of cm/s. This means that the secondary flows can have a great impact on the motion and precipitation of small particles, mainly those in the submicron range.

Electrohydrodynamic secondary flow and particle collection efficiency in spike-plate multi-electrode electrostatic precipitator

In this work the results of electrohydrodynamic (EHD) secondary flow measurements in a spike-plate type electrostatic precipitator (ESP) are presented. In the investigated ESP two-sided and one-sided spike electrodes were used as a discharge electrodes. The results of 2D PIV measurements showed that flow pattern obtained for a different spike tips positions in respect to the primary flow direction significantly changing the flow structures in the ESP duct. The submicron dust particles collection measurements in this ESP were also performed. The obtained results showed that the collection efficiency of submicron dust particles depends on the generated EHD secondary flow.

Comparison of airflow patterns produced by DBD actuators with smooth or saw-like discharge electrode

In this paper we compare the performance of DBD actuators when either a smooth or saw-like electrode is employed. Two electrode arrangements of DBD actuators are investigated. The first is the classic DBD actuator and the second is a DBD actuator with floating electrode. The usefulness of the saw-like electrode in these two types of DBD actuators is studied.

Electrohydrodynamic secondary flow and particle collection efficiency in a one-sided spike-plate type electrostatic precipitator

In this work, results of electrohydrodynamic secondary flow and particle collection efficiency measurements in an electrostatic precipitator under positive and negative voltage polarity are presented. The electrostatic precipitator had two plate collecting electrodes and a single spike discharge electrode. The spike tips were only on one side of the discharge electrode, therefore called a one-sided spike electrode. The electrohydrodynamic secondary flow pattern and collection efficiency measurements were carried out for two one-sided spike electrode positions: with the spike tips directed either upstream or downstream the primary flow. The results of the flow pattern measurement showed different flow patterns for different spike tips positions in respect to the primary flow direction. The electrostatic precipitator collection efficiency measurements clearly showed difference in the particle collection for both spike tips positions. Since the other electrostatic precipitator working parameters were the same, it can be concluded that the observed change of the electrohydrodynamic secondary flow was the main reason of the difference in the electrostatic precipitator collection efficiency.

Particle image velocimetry measurements of wire-nonparallel plates type electrohydrodynamic gas pump

2D particle image velocimetry (PIV) measurements were performed in a wire nonparallel plates type electrohydrodynamic (EHD) gas pump. Using simultaneously two CCD cameras allowed obtaining high resolution vector maps which illustrate the flow patterns generated inside the EHD gas pump.

Recent progress in experimental studies of electro-hydrodynamic flow in electrostatic precipitators

Many experimental, theoretical and numerical works were devoted to the electrohydrodynamic (EHD) flow generated in electrostatic precipitators (EPSs). The generally accepted conclusion from these studies is that the EHD flow plays an important role in the particle collection in ESPs. However, despite of the recent fast progress in numerical simulation and experimental techniques used in the ESPs studies many problems related to the influence of the EHD flow on the performance of ESPs are unsolved. In particular, the influence of the turbulent EHD on submicron particles transport and deposition in ESPs is ambiguous. This problem and other related to the particle collection in ESPs are objectives of this paper, basing on the recent progress in experimental investigations of the EHD flow in ESPs.

Electrohydrodynamic flow and its effect on ozone transport in corona radical shower reactor

New arguments supporting the supposition that the ozone is transported along a corona discharge radical shower (CDRS) reactor by the electrohydrodynamic (EHD) flow are presented. The arguments are based on the analysis of the corona discharge, which is a precursor of the EHD flow in the CDRS reactor, and on the measurements of velocity field of the EHD flow in the CDRS reactor by the particle image velocimetry (PIV). The obtained velocity flow structures and the possible causes of the ozone transport in the CDRS, i.e., diffusion, additional gas flow, EHD flow, and convection by the main flow, were discussed basing on the conservation equations for the EHD flow. The discussion showed that the EHD flow plays a dominant role in the ozone transport. This is also supported by the results of a simple phenomenological model for one-dimensional description of EHD-induced ozone transport in the CDRS reactor. The results of the computer simulation based on this model explained the main features of the measured ozone distribution in the CDRS reactor, establishing the EHD flow as the main cause of the ozone transport from the discharge region upstream, i.e., against the main flow.

Pumping Effect Measured by PIV Method in a Multilayer Spike Electrode EHD Device for Air Cleaning

Dust particles can be harmful for human health when inhaled. Particularly dangerous are submicrometer dust particles, which can contain traces of toxic elements and can easily penetrate into the human respiratory system. Thus, efficient devices for the air cleaning from submicrometer dust particles are needed. Recently, Katatani and Mizuno have proposed an electrohydrodynamic (EHD) device for air cleaning for submicrometer particles. In this paper, we present the flow velocity field patterns in an EHD device for air cleaning, which is similar to that of Katatani and Mizuno. The presented EHD device had a set of the stressed plate electrodes with spike tips and the grounded electrodes also in the form of plates. The parametric studies of the flow velocity patterns in such an EHD device using particle image velocimetry were made by us for a different electrode arrangement.

Visualization of Dust Collection in DC-Corona-Driven Electrostatic Precipitator

In electrostatic precipitators (ESPs), dc corona discharge is typically used for collecting dust. Occurrence of a corona discharge in the space between electrodes causes strong disturbances of the externally forced flow. Consequently, the secondary flow of dust particles in the ESP assumes complicated structures. In this paper, the particle flow structures and the patterns of particle deposits on a collecting electrode in a spike-plate-type ESP are presented.

Images of electrohydrodynamic flow velocity field in a DC positive polarity needle-to-plate nonthermal plasma reactor

Images showing the flow pattern and velocity field in a positive polarity needle-to-plate nonthermal plasma reactor are reported. The images were obtained using the particle image velocimetry. They showed a strong secondary flow, caused by the electrohydrodynamic forces, which transport the working gas also in the upstream main-flow direction. This may influence operation of the nonthermal plasma reactors and affect their capability of gaseous pollutant remediation.