The hydrodynamic behavior of the liquid–solid circulating fluidized bed ion exchange system for cesium removal

Studies on Regime Transition, Operating Range and System Stability in a Liquid‐Solid Circulating Fluidized Bed

“…However, when the effect of the particle properties for different liquid velocities is eliminated by dividing the particle terminal velocities, the development from region 1 to region 2 in the LSCFB becomes similar for all particles. The variation in the solids velocity and solids holdup analysis and the results observed in the present study agree quantitatively with the observations reported in the literature [4,8]. The experimental data of the present study and the literature data in the LSCFB regime are studied and the cross-point (critical liquid velocity) velocity from region 1 to region 2 is determined for the first time.…”

“…From the above discussion, it is noted that the particles experience two regions in the regime of LSCFB, as described by [4,8] for a given auxiliary liquid velocity: region 1 in which the solids velocity increases and the solids holdup decreases quickly with increase in total liquid velocity, and region 2 in which the solids velocity and solids holdup vary insignificantly with increasing liquid velocity. Zheng et al [8] termed the region of rapid rise in solid velocity and rapid decrease in solid holdup with total liquid velocity as the initial circulating fluidization zone, and distinguished the same from the fully developed circulating fluidization zone.…”

“…The authors called the region of rapid increase in the circulation rate as the initial circulation fluidization zone in which the solids circulation rate increases quickly with increasing liquid flow rate, and the plateau region as the fully developed circulation fluidization zone where the solids circulation rate increases insignificantly with increasing liquid flow rate. Feng et al [4] have recently shown the existence of two zones in the regime of LSCFB. However, the boundary between the initial zone and the fully developed zone is still not well defined.…”

Effect of various parameters on the solid circulation rate in a liquid–solid circulating fluidized bed

“…E-mail: natoviya@yahoo.com from benzene and l-dodecene using zeolite catalysts, [2] continuous protein recovery from unclarified fermentation broth through adsorption followed by desorption using anion-exchange resins [3,4] and removal of cesium using potassium titanium hexacyanoferrate from highly radioactive liquid waste. [5] It has been recognized that LSCFB has several advantages, such as highly efficient liquid-solid contact, favourable mass and heat transfer, integrated reactor and regenerator design and considerable reduction of back-mixing of the liquid phase. Therefore, several investigations have been carried out to study LSCFBs, such as in Refs 4-16.…”

Effect of Liquid Viscosity and Solid Inventory on Hydrodynamics in a Liquid - solid Circulating Fluidized Bed

“…In applications where quick reactivation of catalysts is important, such as in the production of linear alkyl benzene, the LSCFB becomes an obvious candidate (Liang et al, 1995). Also, the LSCFB has proved a reliable technology for Biological Nutrient Removal (BNR) from landfill leachate (Eldyasti et al, 2010), for removal of Cesium from highly radioactive waste (Feng et al, 2003), in simultaneous enzyme catalyzed reaction and regeneration using Soybean Peroxidase (SBP) enzyme (Trivedi et al, 2005(Trivedi et al, , 2006, for continuous protein recovery from whey (Lan et al, 2002), in the elimination of organic carbon and nitrogen using a Circulatory Fluidized Biological Bed Reactor (CFBBR) (Cui et al, 2004;Patel et al, 2006), in treatment of aniline polluted water (Zheng et al, 2016) etc. Natarajan et al, (2007) developed a general expression which is useful for predicting radial distribution or for analyzing and interpreting experimental data, derived for an LSCFB.…”