Printer Friendly

Field test of sodium bicarbonate and liquid C[O.sub.2] use for accelerating char bed cooling.

Application: Short, high-volume bursts of coolant are apparently more effective than slow, steady application. Bicarbonate and liquid carbon dioxide appear to be worth the costs and the efforts involved in cooling a hot char bad after an ESP.

Both bicarbonate (NaHC[O.sub.3]) and liquid C[O.sub.2] work effectively to quickly cool a char bed, based on results from a simulated emergency shutdown procedure (ESP) was carried out in the No. 4 recovery boiler at Willamette Industries mill in Albany, Oregon, USA.

The results of the full-scale truial revealed no significant problems in applying either coolant to a hot, porous, actively burning bed and no indication that the bed reheated and re-ignited after we stopped the coolant application. These results suggest advantages to begin applying coolants as early as possible, consistent with safety considerations about possible smelt-water contact in an actual ESP.

Although early application of coolants to the hot burning bed is likely to require more coolant, the economics of accelerated bed cooling are such that the cost of using more chemical is usually overshadowed by the savings brought about by shortening the cooling time. The test results showed that short bursts of coolant at higher rates appeared to be more effective than slow, steady application. Proper technique is important. This includes identification and assessment of furnace access points, lance construction to allow easier handling and manipulation, capability to maneuver lances to the desired locations on the bed, and means for using the lances and coolant discharge to penetrate the bed surface.

Grace is adjunct professor, Tran and Kawaji are professors, Pulp & Paper Centre and Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada; email Tran at
COPYRIGHT 2003 Paper Industry Management Association
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2003, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Recovery Boilers
Author:Kawaji, Masahiro
Publication:Solutions - for People, Processes and Paper
Date:Jan 1, 2003
Previous Article:Mill manager Larry Newell: a team-based philosophy helped make Larry Newell PIMA's 2002 Mill Manager of the Year.
Next Article:Economic benefits achieved from an odor reduction project.

Related Articles
Maintaining Coreless Induction Furance Water Systems.
Sinus irrigation kit. (Product Marketplace).
Fireside behavior of black liquors containing boron.
Dust and flue gas chemistry during rapid changes in the operation of black liquor recovery boilers: Part 1--dust formation.
Dust and flue gas chemistry during rapid changes in the operation of black liquor recovery boilers part II--dust composition.
Partial autocausticizing of kraft smelt with sodium borates--Part I: effects on recovery boiler performance.
Dust and flue gas chemistry during rapid changes in the operation of black liquor recovery boilers--Part 3: gaseous emissions.
New or revised Technical Information Papers (TIPS) and test methods.

Terms of use | Privacy policy | Copyright © 2020 Farlex, Inc. | Feedback | For webmasters