Research On Performance Regulation Of Acrylonitrile Two-stage Cyclone Separator

Cyclone separators are widely applied in various fields to realize gas-solid separation by centrifugal force.In the industrial application of a fluidized bed reactor,the operating period extends,leading to the fine particles and storage of the catalyst in the reactor exceeding the self-adjusting range,resulting in a decrease in the yield of the product.In this paper,the performance regulation method of a cyclone separator is proposed to solve this problem,which can realize the regulation of catalyst storage and catalyst particle size distribution in the reactor.In this paper,a new inlet pipe is added to the interstage channel of the two-stage series cyclone separator,and a control component is added.A part of the gas-solid flow is distributed through the interstage inlet pipe and separated only by the secondary cyclone separator.The ratio of the flowrate q of the interstage inlet pipe to the total flowrate Q is defined as the split ratio U.The effects of split ratio,total flowrate,and the diameter of interstage inlet pipe on the performance of acrylonitrile two-stage series cyclone separator were studied by industrial size cold mold experiment.(1)The experimental results show that when the split ratio U increases,the primary separation efficiency and total separation efficiency decrease,and the secondary separation efficiency increases.When the total flowrate Q increases,the total separation efficiency and the separation efficiency of each stage show an increasing trend.When the interstage inlet diameter d changes and other conditions remain unchanged,the separation efficiency of each stage is almost unchanged.(2)The results of fractional efficiency show that with the increase of split ratio or the decrease of interstage inlet diameter,the separation efficiency of the two-stage series cyclone separator for small particles decreases,but there is no noticeable change for large particles.As the total flowrate increases,the separation efficiency of smaller particles remains unchanged,and the separation efficiency of larger particles increases.(3)The numerical simulation results show that the interstage inlet pipe significantly influences the secondary cyclone separator’s internal flow field.With the increase of split ratio U or the decrease of interstage inlet diameter d,the axial velocity stagnation decreases,increasing small particle loss.(4)The similarity criterion related to the separation efficiency is selected based on the experimental results.A mathematical model for predicting the separation efficiency of acrylonitrile two-stage series cyclone separator is established.The error is less than2%,which can be applied for engineering design reference.