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Journal articles
Commissioning Brownstock Washing Controls for an Evaporator Limited Mill
An automated shower water control system has been implemented to reduce the volume and vari-ability of weak black liquor being sent from the pulp mill to the evaporators. The washing controls attempt to bal-ance the need for consistent and low soda carryover to the bleach plant with consistently high weak black liquor solids being sent to the evaporators. The washer controls were implemented on two bleachable grade hardwood lines (one with oxygen delignification, one without oxygen delignification) and one pine line. Â Implementation of the con-trol program resulted in an increase in black liquor solids of 0.6 percentage points for the hardwood lines. Significant foam reduction was realized on the pine line since the pine black liquor solids were able to be consistently maintained just below the soap separation point. Low black liquor solids excursions to the evaporators were eliminated. Bleach plant carryover was stabilized and no negative impact on chemical consumption was noticed when control-ling weak black liquor solids to recovery.
Journal articles
Corrosion Monitoring and Root Cause Identification in High Solids Concentrators
Black liquor high solids (about 80%) concentrators have often been found to suffer from aggressive corrosion. In particular, the first and second effect bodies are susceptible to corrosion attacks resulting in tube leaks and wall thinning, which limit the availability and lifetime of evaporator lines. Corrosion dynamics and construction materials have been studied extensively within the pulp and paper industry to understand the corrosion process. However, it has been challenging to identify root causes for corrosion, which has limited proactive measures to minimize corrosion damage. Corrosion of the first phase concentrator was studied by defining the potential regions for passive area, stress corrosion cracking, pitting corrosion, and general corrosion. This was achieved by using a technique called polarization scan that reveals ranges for the passive area in which the equipment is naturally protected against corrosion. The open circuit potential, also known as corrosion potential, and linear polarization resistance of the metal were monitored online, which allowed for definition of corrosion risks for stainless steel 304L and duplex stainless steels 2205 and SAF 2906. An online temperature measurement added insight to the analysis. A process diagnostics tool was used to identify root causes of the corrosion attacks. Many of the root causes were related to process conditions triggering corrosion. Once the metal surface was activated, it was difficult to repassivate the metal naturally unless a sufficient potential range was reached.
Journal articles
Bleaching optimization at WestRock mill in Covington, Virgi
Bleaching optimization at WestRock mill in Covington, Virginia, TAPPI JOURNAL September 2016
Journal articles
Using white liquor as the alkali source in oxygen delignific
Using white liquor as the alkali source in oxygen delignification, TAPPI JOURNAL September 2016
Journal articles
Preparation and characterization of cellulose nanofibers from bleached pulp using a mechanical treatment method, TAPPI JOURNAL May 2014
Preparation and characterization of cellulose nanofibers from bleached pulp using a mechanical treatment method, TAPPI JOURNAL May 2014
Journal articles
Editorial: Innovative oxygen delignification: Conversations with the TAPPI Journal 2012 Best Research Paper Award-winning authors, TAPPI JOURNAL June 2013
Editorial: Innovative oxygen delignification: Conversations with the TAPPI Journal 2012 Best Research Paper Award-winning authors, TAPPI JOURNAL June 2013
Journal articles
Extended usage of xylanase enzyme to enhance the bleaching of softwood kraft pulp, TAPPI JOURNAL, January 2006
Extended usage of xylanase enzyme to enhance the bleaching of softwood kraft pulp, TAPPI JOURNAL, January 2006, Vol. 5(1) (164 KB)
Journal articles
Comparative annual cost efficiency between thermal and chemical oxidation of TRS in kraft mills, TAPPI JOURNAL, July 2005, Vol. 4(7) (200 KB)
Comparative annual cost efficiency between thermal and chemical oxidation of TRS in kraft mills, TAPPI JOURNAL, July 2005, Vol. 4(7) (200 KB)
Journal articles
Choosing the right refiner plate bolts: a practical guide, TAPPI JOURNAL, February 2000, Vol. 83(2)
Choosing the right refiner plate bolts: a practical guide, TAPPI JOURNAL, February 2000, Vol. 83(2)
Journal articles
Good gravy, davy, TAPPI JOURNAL, February 2000, Vol. 83(2)
Good gravy, davy, TAPPI JOURNAL, February 2000, Vol. 83(2)