(21c) Scaling Analysis of Rectangular Spouted Bed Dynamics

2017 AIChE 8th World Congress on Particle Technology

Topic/Group: Fluidization & Multiphase Flow

Tentative Session:  Fundamentals of Fluidization

Title: Scaling Analysis of Rectangular Spouted Bed Dynamics

Authors:

Steven L. Rowan:       Steven.Rowan@netl.doe.gov

Jingsi Yang:                Jingsi.Yang@netl.doe.gov

Ronald W. Breault:     Ronald.Breault@netl.doe.gov

Key Words: Spouted Beds, Scaling, Cold Flow, Energy

Abstract:

Spouted bed reactors are used
extensively in the chemical and food industries for the processing and drying
of large, coarse particles that are not suitable for use in other multiphase
flow systems such as fluidized beds. A thorough understanding of the dynamic performance
of these units is critical when scaling up from small bench-scale units to
larger production scale systems.  An experimental study has been conducted to
examine the hydrodynamic characteristics of rectangular spouted beds of
geometric scales. 

For this study, experimental data
has been obtained using a small scale 4-inch x 1-inch rectangular spouted bed,
as well as a larger 12-inch x 3-inch bed, using a variety of bed material,
including 707 µm glass beads, 860 µm high density polyethylene, and 750 µm
hollow alumina spheres.  Hydrodynamic similarity between the two spouted bed
reactors is explored via a statistical (skewness and kurtosis), frequency
(power spectral density), and autocorrelation analysis of differential pressure
data. In addition to analysis of differential pressure measurements, high speed
video was recorded and used to determine the bed expansion ratio and the fountain
height as a function of gas velocity.  From the data obtained, correlations for
various spouting regime transition velocities are proposed.