Simulation, Optimization And Scale-up Of Stirred Tank Bioreactor

Sepharose is a carrier for preparation of the protein A immunoadsorption column,and its industrial-scale process of activating reaction has been the key issues of batch production for the blood purification material.In the activating reaction process of the sepharose,the optimization and scale-up technology of the stirred tank reactor is a crucial factor to industrial processes.Although there are a number of experimental and theoretical studies for stirred tank reactor,the relative theory and design method is still not perfect.In recent years,researches on flow and mixing characteristics of stirred tank reactor by using Computational Fluid Dynamics method has shown remarkable advantages,and leads the development of mixing techniques.In this paper,the single-phase flow field is simulated with standardκ-εturbulence model and multi-reference frame method of steady-state flow using FLUENT software.To verify the feasibility of the CFD,the results are compared with the experimental data of literature.Then the single-phase flow field of sepharose is simulated.Through the researches of the flow pattern, velocity field and shear force field under the different type impellers conditions,it is found that 45°pitched blade down flow turbines(PBTD45) impeller has higher circulation flowrate and lower shearing effect,its performance is superior to rushton disk turbine(DT).So the PBTD45 impeller is recommended for the activating reaction of sepharose.The suspended characteristics of solid-liquid in stirred tank reactor,as solid catalyst and sepharose,are simulated in this paper.Through the researches of solid phase suspended performance,it is found that PBTD45 is superior to DT and PBTU45.Just-suspended impeller speed of the three impellers is respectively simulated as 948rpm,570rpm and 1152rpm,and the results are compared with the Zwietering correlation.The maximum relative deviation is 13.4%. In conclusion,the optimal operating conditions for activating catalyzed reaction of sepharose in 20L stirred tank reactor are:with PBTD45 impeller,N=570rpm and D=0.10m.Additionally,artificial neural networks(ANN) technology is introduced,with MATLAB as a software platform,to establish a prediction model for sepharose activated reaction,which is a 3-layer BP network structure.The predictions for two experimental conditions,shaked flask and stirred flask,are respectively made using ANN models.Compared to the experimental data,the average absolute relative deviation is less than 6%. Finally,scale-up technology of bioreactor for preparation of blood purification materials is studied.Then the large scale biorcactor is simulated and optimized,which can provide some theoretical basis and design guidance for bioreactor optimization design and scale-up.