Numerical Simulation And Structural Optimization Of Rotating Flow Field Ceramics Dry Granulation Process

Rotating flow field dry granulation of ceramics can thoroughly solve a series of problems existing in the original wet granulation technology of ceramics production,such as high consumption,high pollution,low energy efficiency and so on.However,due to the existence of solid rotation zone and low axial motion strength of powders in the rotating flow field ceramics dry granulation process,the problems cause low fluidity index,single size distribution and uneven composition of the prepared particles,which make the products cracking and pore in the compaction process.Therefore,in view of the problems existing in the process of rotating flow field ceramics dry granulation,the flow field characteristics and morphology in the rotating flow field are analyzed,the mechanism of rotating flow field ceramics dry granulation is revealed,the powder homogenization structure is designed and optimized,which provides scientific and theoretical guidance for the further improvement of rotating flow field ceramics dry granulation process.This topic originated from the national natural science foundation of china "Research on the mechanism and key technology of dry granulation of new energy-saving ceramics"(Project No.51365018).The powder homogenization mechanism of rotating flow field ceramic dry granulation is analyzed by numerical solution and experimental detection,and the homogenization structure effects and flow field characteristics are explored.The main contents are as follows:⑴ The powder mixing process of rotating flow ceramic dry granulation was combined to construct a practical Euler-Euler powder mixing process mathematical model.The turbulence phenomenon of flow field in the rotating room of powder mixing process is analyzed by modified RNG k-? model.The pressure field,volume distribution and velocity field of powder and gas in the rotating room are solved by numerical methods.⑵ Based on the phenomenon of powder whirlpool in the process of rotating flow field ceramics dry granulation.the cross structure,single wall structure and single bottom structure can optimize the problem to a certain extent.At the same time,the single wall structure and single bottom structure can improve the axial movement of powders better than the cross structure.⑶ Optimizing the structure parameters of single wall structure and single bottom structure in rotating chamber.the single sector bottom structure has a great influence on the axial motion of the powder.The single semicircular bottom structure can not change the circular motion of powder in the radial plane.⑷ The influence of multi-body wall structure on rotating flow field is analyzed.The rectangular multi-wall structure improves the flow field obviously,but the excessive number of rectangular wall structure would reduce the movement velocity of powder.The results show that when the number of rectangular wall structure is 2,the powder accumulation degree is the lowest and the flow field state is optimal.⑸ Based on the experimental analysis,the rectangular wall structure in the rotating room can improve the effect of rotating flow field ceramics dry granulation,the qualified rate of granulation is increased by 7.5%,and the sphericity of particles is improved to a certain extent.The results of this research have certain scientific reference value for the promotion of rotating flow field ceramic dry granulation in the preparation of raw materials for the ceramic industry.