Particle Flow Modelling in Slurry‐Fed Stirred Vessels

Abstract

Despite its importance, experimental information on the Residence Time Distribution (RTD) of solid particles in continuousflow stirred vessels is still scant. In this work, experimental data on particle RTD in a high-aspect-ratio vessel stirred by three equally-spaced Rushton turbines, obtained by means of Twin Systems Approach (TSA), are employed to assess the suitability of the well known Axial-Dispersion Model to describe particle behavior in the investigated system. The data analysis and model parameter assessment are preceded by a discussion on the utility of self-recirculated systems in carrying out experiments concerning continuous slurry-fed apparatuses. In particular, the suitability of single recirculated systems is discussed and a way to extract numerical RTD data from the relevant experiments is proposed. The advantages and disadvantages of employing instead a couple of twin systems, as it was actually done to obtain the experimental data employed in this work, is shortly discussed.

Various applications of the dispersion model for flow systems with Danckwerts’ boundary conditions

“…The first reactor was filled by a tracer and the tracer response was measured at an outlet of the second reactor. The whole of system works in regime of the total recycle (Scargiali et al, 2004). The tracer concentration c(t) behind the second mixer is given by the sum of tracer wash-out from an initial tracer distribution and circulation flow…”