A Study of Flow Properties of Paper Stock Suspension

Abstract

The authors examined the effects of plug stoppage of high consistency pulp suspensions by the flow tests of nozzles using groundwood pulp suspensions which have comparatively stable flow properties, and observed that the suspensions of consistency more than 6% indicate flow patterns of brittle solid. Moreover, we measured the pipe friction losses up to high consistency of about 6%, using brass pipes with diameters 23.3, 36.6 and 48.8 mm, and galvanized gas pipes with diameters 1", 1 1/2" and 2". As the results of plotting the pipe friction coefficients vs. a new dimensionless number : N=8 (ρυ2)/(τω) (N is flow number, ρ : density, υ : mean velocity in pipe and τω : shear stress at pipe wall) which corresponds to Reynolds number in the case of water, the experimental values coincided well on the line of λ=64/N (λ being the coefficients of pipe friction losses). At last, the authors gave the calculation formulas of pipe friction losses which are more accurate than previous ones.