Process Parameters Optimization And Research Of Turbo Air Flow Classifier

At present,the ultra-fine powder material is permeating the whole industrial sector and the high technology field,and is regarded as the origin of modern high technology.It has been applied in the fields of chemical industry,light industry,metallurgy,electronics,high technology ceramics,biomedicine and advanced technology.It is difficult to achieve the required particle size directly by the pulverization method and it is necessary to separate the product with the classifier to meet the requirements.And it is of great significance for ultrafine classification if the size of particles can be controlled and the classification accuracy can be improved.As a typical dry powder classification device,turbine air classifier is widely used in the ultrafine powder industry owing to its wide range of classification and high classification accuracy.But so far,there are still some shortcomings in the study of the process parameters of the turbine air classifier.In this paper,the theory and structure of the turbine air classifier were introduced,and the existing airflow classifier at home and abroad was classified and explained.The existing performance evaluation index of the grading machine was reviewed and a kind of performance evaluation index which was suitable for the engineering field on the basis of the existing indexes was put forward.The experiment on secondary air cleaning parameters of classifier was carried out,and the influence law of secondary air and secondary air rising velocity on the grading accuracy of the classifier was obtained.The results showed that the optimal secondary air LNJ-36 A air classifier was 150m3/h,the optimal secondary air rising velocity was 3.91 to 4.73m/s under the optimal secondary air volume and the optimum clearance for the adjustable gap cone was 12.5 to 15 mm.At the same time,the flow field law of the secondary air cleaning area of the classifier was analyzed through the numerical simulation,the optimal secondary air effective cleaning area was 0 to 110 mm and the distribution of the flow field in the secondary air cleaning area was obtained.Through the experiment on the seal parameters of classifier,the influence rules of seal clearance and air sealing pressure to relative precision were drawn.The experimental results showed that the suitable seal clearance for LNJ-36 A air classifier was 3mm,the optimal air pressure was 0.15 MPa.At the same time,through the numerical simulation of the flow field of the sealing surface of the grading machine,the result showed that airflow seal failure pressure was 0.05 MPa,the flow field of the gas seal were obtained,and the experimental results were further explained.