Study On Residence Time Distribution Of Five-stage In Series Fluidized-bed Bioreactor With External Circulation

Multistage fluidized-bed bioreactor with external circulation has been in use in the production of fuel alcohol by immobilized yeast cells technique.As a new-style reactor.it has the advantage of high conversion,complete reaction and little damage to immobilized yeast cells.Flow properties is the foundation of reactor's physical transmission process.and it is the key factor of deciding whether the auxiliary material conversion is high or low.At present,the study on flow properties of multistage fluidized-bed bioreactor with external circulation at a pilot scale is rarely reported.In this paper.flow properties of multistage fluidized-bed bioreactor with external circulation at a pilot scale is studied.According to characteristic analysis,the model of completely mixing reactor in series is introduced to characterize real reactor as a theoretical model.On the basis of analog computing analysis and discussion of theoretical model.by means of pulse tracer method,experiments on residence time distribution (RTD) have been done in different conditions including the change of tracer level,feeding flow rate and circulation flow rate.The result shows when the ratio of circulation flow rate and feeding flow rate amounts to at least 4,the flow properties of multistage fluidized-bed bioreactor with external circulation at a pilot scale is very close to the model of completely mixing reactor in series.An amendatory model has been established by the regression method.The study on flow properties of multistage fluidized-bed bioreactor with external circulation at a pilot scale will offer instructions of theoretical parameters in actual fermentation,and it can also provide very important theoretical basis in the course of engineering amplification for future commercial process.