Thixotropic Flow Behaviour in Chemical Pulp Fibre Suspensions

Sounding out Paper Pulp: Ultrasound Spectroscopy of Dilute Viscoelastic Fibre Suspensions

A model of attenuation of ultrasound in fibre suspensions is compared to a model of backscattering pressure from submersed cylinders subjected to a sound wave. This analysis is carried out in the region where the wavelength is of the same order as that of the diameter of the fibre. In addition we assume the cylinder scatterer to have no intrinsic attenuation and the longitudinal axis of the sca...

Fractionation of Fibre Pulp in a Hydrodynamic Fractionation Device Fractionation of Fibre Pulp in a Hydrodynamic..

Thixotropic behaviour of thickened sewage sludge

The aim of the work is a description of the rheological behaviour of thickened sewage sludge. The sample of thickened sludge was collected from the wastewater treatment plant, where pressure flotation unit is used for a process of thickening. The value of dry matter of collected sample was 3.52%. Subsequently the sample was diluted and the rheological properties of individual samples were obtai...

The rheology of fibre suspensions

We review theoretical work on the rheology of fibre suspensions. We seek to clarify one or two confusions in published work and also give a small improvement to Batchelor’s formula for extensional viscosity of suspensions of long fibres between the dilute and semi-dilute régimes.

Influence of shear stress applied during flow stoppage and rest period on the mechanical properties of thixotropic suspensions.

We study the solid mechanical properties of several thixotropic suspensions as a function of the shear stress history applied during their flow stoppage and their aging in their solid state. We show that their elastic modulus and yield stress depend strongly on the shear stress applied during their solid-liquid transition (i.e., during flow stoppage) while applying the same stress only before o...