Collection Efficiency of Nano Particles by Electrostatic Precipitator using Dielectric Barrier Discharge

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^*· ^* · ^** · ^†

Jung-Hoon Byeon , Jun-Ho Ji, Suk-Hoon Kang, Jung-Ho Hwang

Key Words : Dielectric Barrier Discharge(DBD), Nano Particle( ), Electrostatic Precipitator ( ), Collection Efficiency( ).

Abstract

Although Dielectric Barrier Discharge (DBD) in air has been applied to a wider range of aftertreatment processes for HAPs(Hazardous Air Pollutants), due to its high electron density and energy, its potential use as precharging dust particles is not well known. In this work, we measured size distributions of bimodal aerosol particles and estimated collection efficiency of the particles by electrostatic precipitator(ESP) using DBD as particle charger. To examine the particle collection with DBD charger, nano size particles of NaCl(20 100 nm) and DOS(50 800 nm) were generated by tube furnace and atomizer, respectively. For experimental conditions of 60 Hz, 11 kV, and 60 lpm, the particle collection efficiency for the hybrid system comprising DBD charger and ESP was over 85 %, based on the number of particles captured.

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E-mail : [email protected]

TEL : (02)2123-2821 FAX : (02)312-2159

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Tube Furnace NaCl

Rotameter

Dry Clean Air Supply System

DMA CPC

Atomizer (DOS)

Rotameter ExcessFlow

Excess Flow

210Po Laminar

Flowmeter

AC Power Supply

DC High Voltage Power Supply

2nd Diluter 1st Diluter

DBD Reactor

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Function Generator

ESP

SMPS system

ExcessFlow

Compressed Air

Fig. 1 Schematics of experimental set-up

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10 100 1000

Particle diameter (nm)

Concentration (particles/cm3 ) 0 Nacl

DOS Bimodal Particle

/ / / / / /Fig. 2 Particle size distribution

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0 5 10 15

Applie d voltage (kV)

Current (mA)

60Hz 80Hz 100Hz 120Hz

DBD

Streamer onset

Arc Generation Frequency (Hz)

0 0.5 1 1.5 2 2.5 3 3.5 4

0 5 10 15

Applie d voltage (kV)

Current (mA)

60Hz 80Hz 100Hz 120Hz

DBD

Streamer onset

Arc Generation Frequency (Hz)

Fig. 3 I-V characteristics under DBD

NaCl

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0 10 20 30 40 50 60 70 80 90 100

10 100 1000

Particle diameter(nm)

Collection efficiency (%)

9 kV, 0.7 mA 10 kV, 1.2 mA 11 kV, 1.4 mA

Fig. 4 Collection efficiency for DBD on and ESP off (60 Hz, 60 L/min)

60 65 70 75 80 85 90 95 100

10 100 1000

9 kV, 0.7 mA 10 kV, 1.2 mA 11 kV, 1.4 mA

Fig. 5 Collection efficiency for DBD on and ESP on (60 Hz, 60 L/min)

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Test Aerosol NaCl DOS

Geometric mean

diameter(nm) 31 213 Geometric

standard

deviation 1.47 1.88 Concentration

(#/cm³) 8×10⁵ 3.5×10⁵

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Frequency(Hz)

0 10 20 30 40 50 60 70 80 90 100

10 100 1000

60 80 100 120

Fig. 6 Collection efficiency for DBD on and ESP off (15.4 W, 60 L/min)

Frequency(Hz)

60 65 70 75 80 85 90 95 100

10 100 1000

60 80 100 120

/ / / / /Fig. 7 Collection efficiency for DBD on and ESP on (15.4 W, 60 L/min)

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Flow rate(L/min)

0 10 20 30 40 50 60 70 80 90 100

10 100 1000

Collection efficiency (%) ⁶⁰

120 180

Fig. 8 Collection efficiency for DBD on and ESP off (60 Hz, 10 kV)

Flow rate(L/min)

0 10 20 30 40 50 60 70 80 90 100

10 100 1000

Collection efficiency (%)0

60 120 180

Fig. 9 Collection efficiency for DBD on and ESP on (60 Hz, 10 kV)

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