The effect of pressure pulsing on the mechanical dewatering of nanofiber suspensions

TL;DR

This study combines CFD simulations and analytical modeling to optimize nanofiber suspension dewatering, demonstrating that pressure pulsing improves efficiency and predicting optimal pulsing parameters.

Contribution

It introduces a combined CFD and analytical approach to model and optimize pressure pulsing in nanofiber suspension dewatering processes.

Findings

Pressure pulsing enhances dewatering efficiency.

Analytical model accurately predicts optimal pulsing parameters.

CFD simulations match experimental dewatering flow profiles.

Abstract

Dewatering processes are invariably encountered in the chemical manufacturing and processing of various bioproducts. In this study, Computational Fluid Mechanics (CFD) simulations and theory are utilized to model and optimize the dewatering of commercial nanofiber suspensions. The CFD simulations are based on the volume-averaged Navier-Stokes equations while the analytical model is deduced from the empirical Darcy's law for dewatering flows. The results are then successfully compared to experimental data on commercial cellulose suspensions obtained with a Dynamic Drainage Analyzer (DDA). Both the CFD simulations and the analytical model capture the dewatering flow profiles of the commercial suspensions in an experiment utilizing a constant pressure profile. However, a temporally varying pressure profile offers a superior dewatering performance, as indicated by both the simulations and the analytical model. Finally, the analytical model also predicts an optimized number of pressure pulses, minimizing the time required to completely dewater the suspension.