Multiphase flow characteristics of a novel internal-loop airlift reactor

Gas Sparger Orifice Sizes and Solid Particle Characteristics in a Bubble Column – Relative Effect on Hydrodynamics and Mass Transfer

“…Normally, the addition of solid phase has three major impacts on bubble geometry and flow behaviors: it increases the breaking rate, accelerates the coalescence rate, and slows down the bubbles . With different solid concentrations and bubble sizes, the solids would have diverse effects.…”

“…In contrast to the case with the small‐orifice sparger, very large bubbles were rarely formed. The presence of solids may have lowered the liquid velocity and reduced the rising velocity of the bubbles by obstructing them. The increase in solids concentration may have enhanced this effect especially with the ring particles, which had the highest projected surface area, leading to the highest drag force.…”

Profiles of solid fraction and heterogeneous phase structure in a gas–solid airlift loop reactor

“…At present, ALR is mainly running in gas-liquid (Kemblowski et al, 1993), liquid-solid (Wang et al, 2003) or gasliquid-solid systems (Hwang and Cheng, 1997). According to literature reviews, experimental and numerical simulation studies on ALR are mainly focused on three aspects: (1) hydrodynamics, including gas holdup, liquid circulation velocity, mass transfer (Korpijarvi et al, 1999;Chia and Lii, 2001;Guo et al, 1997;Blažej et al, 2004a;Cockx et al, 1997Cockx et al, , 2001Oey et al, 2001), and residence time distribution of gas or liquid phase (PrmHamo et al, 2001;Pareek et al, 2001;Gavrilescu and Tudose, 1999;Sivashanmugam and Sundaram, 2000;Sahle-Demessie et al, 2003); (2) mathematical models to predict gas holdup and liquid circulation velocity based on several principles, such as energy conservation (Kundakovic and Vunjak-Novakovic, 1995;Heijnen et al, 1997;Garcia-Calvo et al, 1999;Lu et al, 1995 ), and drift flux (Zuber and Findlay, 1965); (3) structural development and optimization, mainly focusing on the square or rectangular ALRs (Couvert et al, 1999;Lu et al, 2000), the dimension optimizations including configuration of draft tube (Blažej et al, 2004b;Bado, 1990;Fu et al, 2004;Du et al, 1994), gas distributor and bottom structure Luan et al,1994;Mudde and Van Den Akker, 2001), and configuration of the gas-liquid separation region (Freitas and Teixeira, 1997;Zhang et al, 2005).…”

Mixing parameters for an airlift bioreactor considering constant cross sectional area of riser to downcomer: Effect of sparging gas location

“…An analytical solution in the Laplace domain can be obtained for the mathematical model as follows: (10) This function was transformed back to the time domain by inverse Laplace transformation in Matlab 7.1. The calculated output function was then compared with the experimental output function to determine the stage numbers, which appear in the transfer function.…”

“…These parameters are sensitive to superficial gas velocity and physical properties of the fluids, gas flow rate and bioreactor geometry and have been extensively studied because of their influence on mass transfer phenomena [10]. Muthukumar et al [7], Freitas et al [11] and Fadavi et al [12] investigated the hydrodynamic behavior of concentric draft-tube type airlift bioreactors.…”