Study On Micromixing Of Viscous Fluid In Rotating Packed Bed

Rotating packed bed is a novel reactor that does intensify chemicalprocess, tiny liquid droplet or thin liquid film can be generated when thefeed liquid collide with high speed rotational packing, thus enhancingliquid interfacial area and decreasing mass transfer resistance whichresult in intensifying the process of gas-liquid mass transfer andliquid-liquid mixing.The crystallization, polymerization, sulphonationand biological chemical reaction process such as DNA purification,enzyme solution process, protein folding, that fast reaction often involveviscous fluid mixed reaction process, there is a potential and broadprospect for applying Rotating packed bed for intensifying these viscousfluid mixing and reaction process while there is no report about this yet.Some major works are as following: using water-glycerin system toimitate viscous fluid and characterizing the rotating packed bed and teemixing reactors micromixing performance through the iodate-iodide testsystem; the micromixing characteristic time tmof the two kinds of reactors is calculated with incorporation model; first to present thecalculation expression of energy dissipation rate that suit for rotatingpacked bed through dimension analytic method and simulating themicromixing efficiency of viscous liquid in rotating packed bed throughSlab model. Some findings are as following:(1) Problem of the uneven macromxing can be eliminated by usingpremixed liquid distributor, the shorter premixed time and the more smallsize with the high specific surface of packing the better micromixingefficiency.(2) Segregation index decreases that implying better micromixingefficiency with increasing rotational speed and feeding volume flow anddecreasing liquid viscosity and hydrogen ion concentration and feedingflow ratio.(3) There are slight differences between the micromixing efficiency inthe two different reactors while the system viscosity is not so high, whenviscosity increases to higher level especially the rotation speed is highenough, rotating packed bed does obviously intensify micromixingefficiency than tee mixer reactor; there is a suboptimal rotation speedaccoding to various viscous solution system.(4) The characteristic micromixing time tmof rotating packed bed andtee mixing reactors are5.310^-5s to610^-4s and2.310^-4s to9.110^-3swhile the viscosity is in the range of1.01to219.18mPa s. (5) The calculation expression of energy dissipation rate that suit forrotating packed bed through dimensional analytic method isThe simulation results through Slab modelwith the help of calculated energy dissipation rate ε is well agreementwith experimental results which implies the Slab model can well predictthe micromixing efficiency of viscous liquid in rotating packed bed.