Author :
Publisher :
ISBN 13 :
Total Pages : 162 pages
Book Rating : 4.:/5 (16 download)
Book Synopsis Confined Zone Dispersion Flue Gas Desulfurization Demonstration. Quarterly Report No. 7, May 1, 1992--August 16, 1992 by :
Download or read book Confined Zone Dispersion Flue Gas Desulfurization Demonstration. Quarterly Report No. 7, May 1, 1992--August 16, 1992 written by and published by . This book was released on 1993 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: The CZD process involves injecting a finely atomized slurry of reactive lime into the flue gas duct work of a coal-fired utility boiler. The principle of the confined zone is to form a wet zone of slurry droplets in the middle of the duct confined in an envelope of hot gas between the wet zone and the duct walls. The lime slurry reacts with part of the SO2 in the gas, and the reaction products dry to form solid particles. A solids collector, typically an electrostatic precipitator (ESP) downstream from the point of injection, captures the reaction products along with the fly ash entrained in the flue gas. The features that distinguish the CZD process from other similar injection processes are: (1) Injection of an alkaline slurry directly into the duct, instead of injection of dry solids into the duct ahead of a fabric filter. (2) Use of an ultrafine calcium/magnesium hydroxide, type S pressure-hydrated dolomitic lime. This commercial product is made from plentiful, naturally occurring dolomite. (3) Low residence time, made possible by the high effective surface area of the Type S lime. (4) Localized dispersion of the reagent. (5) Improved electrostatic precipitator performance via gas conditioning from the increased water vapor content, and lower temperatures. The waste product is composed of magnesium and calcium sulfite and sulfate, with some excess lime. This product mixed with fly ash is self-stabilizing because of the excess lime values, and thus tends to retain heavy metals in insoluble forms within the fly ash.