Structural Design And Optimization Of Cyclone Separation Device For Rapeseed Dryer

As the first major oilseed crop in China,rapeseed is of strategic importance in ensuring the safety of China’s edible vegetable oil supply.Just harvested rapeseed has a high moisture content,high moisture absorption and not easy to dissipate heat,if not dried in time,rapeseed is very easy to sprout,mold,affecting the quality of rapeseed.In this paper,according to the agronomic requirements of rapeseed drying,the structural design and optimization study of the cyclone separation device of rapeseed dryer,and the experimental study of the cyclone separation device.The main research contents are as follows.（1）The water content W₁of rapeseed at the inlet of the cyclone separation unit was measured and W₁=12.38%was measured.The required air volume U_1kof the cyclone separation device was calculated and U_1k=236.82 m³/h was obtained.Design the settling chamber with inverted cone-shaped structure to realize automatic separation and settling of rapeseed from hot air in the settling chamber.（2）ANSYS Fluent software was used to model,mesh and set boundary conditions for the cyclone separator,and the Reynolds stress model was selected as the turbulence model.The airflow field simulation was carried out for cyclones with different worm shell cladding angles and different diameters,and the optimal worm shell cladding angle for the cyclone was 180°and the optimal diameter was 250 mm.（3）A single-factor test on rapeseed drying was carried out.The test results showed that the moisture content of rapeseed could reach below the safe storage moisture content and had a low crushing rate when the feeding rate was 2.5 kg/min-3.5 kg/min,the hot air speed was 19 m/s-21 m/s and the aperture ratio was 0.5-0.6.（4）A multi-factor test was conducted with feeding rate,hot air speed and aperture ratio as test factors and rapeseed moisture content and crushing rate as evaluation indexes.The optimal process parameters of the cyclone separation device were obtained through optimization analysis by Design-Expert software:feeding rate was 2.7 kg/min,hot air speed of 21 m/s,and pore size ratio of 0.6.And carry out verification test,the test results show that the rapeseed dryer cyclone separation device drying effect is good and meet the design requirements.