Fluid flow pattern and solids circulation rate in a liquid phase spout‐fluid bed with draft tube

Abstract

The fluid flow pattern and solids circulation rate in a liquid phase spout‐fluid bed with a draft tube were studied in a semi‐circular column 196 mm in diameter equipped with a semi‐circular draft tube 34.5 mm in diameter using water and spherical glass particles 1.20, 1.94 and 2.98 mm in diameter. Both the solids circulation rate and fluid distribution between the draft tube and the annulus are influenced by the location of the draft tube, the relative magnitude of the inlet spouting and annulus flowrates, and the total fluid flowrate entering the bed. A one‐dimensional steady state model of vertical non‐accelerating liquid‐solids flow predicts the solids mass flux in the draft tube with a mean deviation of 12.3% when experimental values of the axial pressure gradients in the draft tube and annulus are specified. A simple correlation for the fountain height is also presented.

Hydrodynamic simulations of gas–solid spouted bed with a draft tube

“…Kalwar and Raghavan (1992) investigated the spout pressure drop and minimum spouting superficial velocity in a two-dimensional gas-spouted bed. The feature of the spouted bed with a draft tube is reported by Grbavcic et al (1992).…”

Minimum spouting velocity in a spout‐fluid bed with a draft tube

“…Comparing with conventional spouted bed with or without a draft tube, and spout‐fluid bed without a draft tube, there is relatively very limited information available on the hydrodynamic behaviour of DTSFB (Yang and Keairns, 1983; Berruti et al, 1988; Muir et al, 1990; Grbavcic et al, 1992; Xiao et al, 2002; Osorio‐Revilla et al, 2004). Minimum spouting velocity is one of the most important flow characteristics for proper design and operation of the spouted bed reactors.…”

Globally Optimal Design and Operation of a Continuous Photocatalytic Advanced Oxidation Process Featuring Moving Bed Adsorption and Draft-Tube Transport

“…The upper limit for jet flow rate is determined by eq 27, solving for the maximum particle mass flowrate with the minimum fluidization voidage, and then using (eqs [8][9][10][11] to determine the maximum jet flowrate at a voidage equal to vc .…”

“…10 In operating these systems, a ideal photocatalyst should be mechanically robust, readily separated from the reaction stream, rapidly regenerated, and capable of maintaining its activity until the oxidizer can react with the contaminant species. Many of the studies performed on photocatalytic advanced oxidation systems employ fine particles of TiO 2 on the order of 1-10 µm.…”