First Edition, 2012 ISBN 978-81-323-3760-7 © All rights reserved. Published by: University Publications 4735/22 Prakashdeep Bldg, Ansari Road, Darya Ganj, Delhi - 110002 Email:
[email protected] Table of Contents Chapter 1 - Electrostatic Precipitator Chapter 2 - Dust Collector Chapter 3 - Wet Scrubber Chapter 4 - Scrubber Chapter 5 - Types of Scrubbers Chapter 6 - Catalytic Converter Chapter 7 - Thermal Oxidizers and Biofilters Chapter 8 - Flue-Gas Desulfurization Chapter 9 - Gas Flare Chapter 10 - Venturi Scrubber Chapter- 1 Electrostatic Precipitator An electrostatic precipitator (ESP), or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic precipitators are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream. In contrast to wet scrubbers which apply energy directly to the flowing fluid medium, an ESP applies energy only to the particulate matter being collected and therefore is very efficient in its consumption of energy (in the form of electricity). Invention of the electrostatic precipitator The first use of corona to remove particles from an aerosol was by Hohlfeld in 1824. However, it was not commercialized until almost a century later. In 1907 Dr. Frederick G. Cottrell applied for a patent on a device for charging particles and then collecting them through electrostatic attraction — the first electrostatic precipitator. He was then a professor of chemistry at the University of California, Berkeley. Cottrell first applied the device to the collection of sulfuric acid mist and lead oxide fume emitted from various acid-making and smelting activities.