Particle Collection Characteristics of a Prototype Electrostatic Precipitator (ESP) for a Differential TEOM System

Abstract

A differential tapered element oscillating microbalance (TEOM) system that includes an electrostatic precipitator (ESP) that is alternately switched on and off has been developed to improve the measurement of airborne particulate matter mass. Preliminary results showed that it has the potential to overcome the difficulties inherent in PM mass measurement and holds the promise of the measurement of PM mass as it exists in ambient air at ambient temperature. A critical aspect of this device is that the ESP totally removes particles from the air stream. In this study a prototype ESP developed by Rupprecht and Patashnick (R&P) Co., Inc. was evaluated for particulate removal efficiency. Laboratory tests were conducted to determine the removal efficiencies for different-sized particles by generating ultrafine (<0.1 µm) and fine (>0.1 µm) particles. The ultrafine particles were generated using a 5% solution of sodium chloride, while the fine particles were generated with the different sizes (0.5 µm and 1 µm) of polystyrene latex particles. The discrete size intervals of generated ultrafine particles were obtained from an electrical differential mobility analyzer (DMA). The transmitted ultrafine and fine particles passing through the ESP were then detected using a condensation particle counter (CPC) and a LAS-X, respectively. The overall particle collection efficiency of the ESP was calculated from the differential particle collection efficiencies and the specific particle size distributions of the test aerosols. The results showed that the collection efficiencies of the ESP were essentially constant over the range of corona current levels tested, indicating that those were not strong functions of the applied potential if the field strength was sufficiently high.

Field evaluation of a new particle concentrator- electrostatic precipitator system for measuring chemical and toxicological properties of particulate matter

“…At all flow rates the lowest ESP collection efficiency was observed for particles between 100 nm and 300 nm in mobility diameter. Similar results were also observed in many experimental studies as reported in literature [ 19 - 21 ]. The electrostatic velocity of particles in any ESP is a combination of the number of charges acquired by the particles and the particle mobility.…”

Separation Characteristics of Submicron Particles in an Electrostatic Precipitator with Alternating Electric Field Corona Charger

“…The results show the particles of submicron size had higher penetration than that of nanometer size. These results were similar to that reported by Yi et al (2004) and , who indicated that the most penetrating size was about 0.2 µm. It is likely that the electrical mobility was not enough to remove particles as low charging efficiency ).…”

Measurement of Both Nonvolatile and Semi-Volatile Fractions of Fine Particulate Matter in Fresno, CA

“…An electrostatic precipitator (Meyer et al 2002;Yi et al 2004) is used in place of the chilled filter (R&P FDMS) to remove particles during the 6 minute reference purge cycle. Similar to the FDMS, during the purge cycle SVM is lost from the TX40 collection filter and measured as a negative mass.…”