Application of pulping models to investigate the performance of commercial continuous digesters.Application: Modeling allows mills to efficiently and economically simulate and modify digester di·gest·er n. 1. One that makes a digest. 2. Chemistry A vessel in which substances are softened or decomposed, usually for further processing. Noun 1. operations. Continuous digesters are complex plug flow reactors with long residence times. One relatively simple method to study digester performance is to develop a simulation of the reactor and then exercise that simulation through various operating scenarios. The results can provide a meaningful picture of the digester operation and insight into possible digester operation modifications to improve performance. In this study, we developed a pulping model to look at the operation of a continuous commercial digester operated in EMCC EMCC See Emerging Markets Clearing Corporation (EMCC). [TM] and Losolids[TM] cook modes. The pulping model is assembled as a WinGEMS[TM] simulation with the University of Washington kraft pulping blocks serving to simulate the reaction-diffusion mechanisms occurring within the chips during pulping. The model was tested against commercial digester operating data with good results. The model accurately predicted pulp kappa Kappa Used in regression analysis, Kappa represents the ratio of the dollar price change in the price of an option to a 1% change in the expected price volatility. Notes: Remember, the price of the option increases simultaneously with the volatility. , liquor temperatures and flows, and black liquor Black liquor is a byproduct of the Kraft process, (also known as Kraft pulping or sulfate process) during the production of paper pulp. Wood is decomposed into cellulose fibers (from which paper is made), hemicellulose and lignin fragments. solids concentrations of various digester streams. The standard kinetics kinetics: see dynamics. Kinetics (classical mechanics) That part of classical mechanics which deals with the relation between the motions of material bodies and the forces acting upon them. incorporated in the pulping model could be used without further tuning. We used the model to investigate digester operational issues such as white liquor splitting scenarios on pulping performance, the relationship of residual alkali alkali (ăl`kəlī) [Arab., al-gili=ashes of saltwort], hydroxide of an alkali metal. Alkalies are readily soluble in water and form strongly basic solutions with a characteristic acrid taste. concentration in spent wash liquor (cold blow) on the final pulp kappa, and the effect of chip thickness screening on pulp uniformity. This paper reports some of the results. In general, the model was found to work well when applied to a continuous digester The challenge of the modeling was to get an accurate picture of the actual operating conditions. The model provided considerable insight into the digester operation that would not be brought to light without its use. Walkush and Gustafson are with the University of Washington, College of Forest Resources, Seattle, Washington  This page is protected from moves until disputes have been resolved on the .The reason for its protection is listed on the protection policy page. , USA; contact Gustafson by email at pulp@u.washington.edu. |
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