Study Of The Structures Of Liquid Chromatographic Column To Flow Proess

The heterogeneity of chromatographic columns have a big impact on the profile of chromatographic peak.Therefore,how to decrease the influence of the heterogeneity of the velocity of the mobile phase attracted much attention.In this paper,the flow process of chromatographic band was simulated by Fluent software.According to the simulation results,we designed two structures which called ring frit and peak regulation outlet end-fitting to optimize the shape of the chromatographic band.The detailed researches are listed as following.1.Building the models.According to the results,to the columns(?20 X 300mm),the appropriate mesh number is 75000,and the time step should be 0.005s.2.The effects of the heterogeneity of chromatographic columns was studied by numerical simulation.According to the previous exploration,we build the model of chromatographic column,at the same time,we setup different loading quality.The results showed that the heterogeneity of loading makes the theoretical plate number is no longer increased with column lengthproportionally.At the condition of loading unevenly,the longer the column length,the less the theoretical plate number increase with the same column length increase.4.The study of ring frit.According to the research,ring frit can improve column efficiency of radially heterogeneous beds.For the short columns with smaller values of the Fw/Fc,the ring frit should have smaller central impervious area.For the long columns with bigger,the ring frit should have bigger central impervious area.5.The effect of peak regulation outlet end-fitting was investigated by numerical simulation and experiment.The results showed that the column(? 20 × 300mm)which Fw/Fc=1.04,join the cone height of 20mm,the number of theoretical plate increases at most.