NC State
BioResources
Zeng, J.-S., Chen, K.-F., and Li, J. (2011). "Study of the bulk density of high consistency pulp and engineering application in the bleaching tower," BioRes. 6(1), 594-605.

Abstract

From experimental simulation of the process of high consistency pulp moving in a bleaching tower, the aerated bulk density and packed bulk density were measured and studied by using a self-made experimental system. The scattered experimental data – pressure p, and bulk density difference, which was between packed bulk density and aerated bulk density (ρ-ρ0) – were fitted by using Matlab software, and some good-fitting regression curves and equations were obtained. The results showed there was a break point W in the regression curves; within the range 0 £ p £ W the relationship between (ρ-ρ0) and p was a linear function, while for W £ p £ 70000 the relationship was a power function. To effectively meet with the bleaching response for the different kinds and different consistencies of pulp in the tower, by using the fitting regression equations combined with the expressions of average bulk density and pressure in the tower caused by gravity-driven pulp, two equations for average packed density ρa were deduced with the aim of deciding the maximum volume value of the tower, in agreement with the sizes of the towers presently used by major companies.
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