Numerical Simulation And Structural Improvement Of Pneumatic Conveying Characteristics Of Rotary Feeder

Rotary feeder pneumatic conveying is a technology that uses air pressure difference to realize continuous conveying of powder materials.Because of its advantages of airtight,clean,simple equipment and easy automation,it is widely used in chemical industry,construction,rubber,biotechnology and other fields.At present,there are relatively few research results on the design of the feeder in pneumatic conveying system,the domestically produced rotary feeder cannot effectively control the air leakage on the basis of ensuring the transport capacity.Many enterprises rely heavily on imports for the demand of rotary feeder,which has been restricting the development of China's powder pneumatic conveying.Therefore,this paper uses numerical simulation technology to study the performance of rotary feeder pneumatic conveying system,which provides simulation technology basis for the following research on rotary feeder pneumatic conveying.First of all,in this paper,the theoretical calculation and the computational fluid dynamics(CFD)method are used to study the variation law of the air leakage of the simple gap model under five different parameters.Based on Fluent software,the air leakage of rotary feeder pneumatic conveying system under air supply condition is numerically simulated,the air leakage law and flow field characteristics of rotary feeder are studied,and the influence law of inlet and outlet pressure difference and blade tip clearance on the air leakage of rotary feeder is analyzed.The results show that the air leakage of rotary valve increases linearly with the pressure difference between inlet and outlet,and nonlinearly with the tip clearance.The experimental results verify the accuracy of the numerical simulation results.Secondly,the CFD-DEM coupling method was used to simulate the filling,feeding and conveying process of rotary feeder from the perspective of gas transport particles.Under the condition of "flood feeding",the filling coefficient,blanking rate and transport flow of rotary feeder pneumatic conveying are calculated.The results show that the transportation pressure of the pipeline has little influence on the filling and feeding of the material particles.The filling coefficient of the rotary feeder can reach above 0.94,and the feeding rate can reach above 0.99.The transportation flow of the rotary feeder fluctuates periodically with time.Finally,this paper improved the rotary feeder of the original structure into a rotary feeder without plough,and compared the air leakage characteristics of the rotary feeder of the two structures under the condition of air supply and the material transport characteristics under the condition of pneumatic conveying wheat particles.The results show that there is a small difference in material conveying characteristic coefficient between the two structures and the transport capacity is basically the same,but the air leakage of the rotary feeder without plough is smaller and the flow field characteristics are more stable.