Abstract
In order to obtain the accurate contact parameters in the simulation process of powder screw conveying, this paper took wheat flour as an example, based on the discrete element JKR (Johnson-Kendall-Roberts) contact model, and directly calibrated the simulation contact parameters in the process of screw conveying in response to the mass flow rate of wheat flour. Firstly, the simulation density of wheat flour particles was calibrated, and the simulation density of wheat flour particles was 1320 kg/m. Then, Plackett-Burman experiment was used to screen out the parameters that had significant influence on the mass flow rate: surface energy JKR, coefficient of static friction between wheat flour and wheat flour, and the coefficient of static friction between wheat flour and stainless steel. The second-order regression model of mass flow rate and significance parameters was established and optimized based on Box-Behnken experiment, and the optimal combination of significance parameters: JKR was obtained to be 0.364; the static friction coefficient of wheat flour to wheat flour was 0.437; and the static friction coefficient of wheat flour to stainless steel was 0.609. Finally, the calibration parameters were used for simulation. By comparing the mass flow rate of simulation and experiment, the relative error of the two was 1.37%. The simulation and experiment flow rate values at different rotating speeds (60 r/min, 80 r/min, 100 r/min, 120 r/min, and 140 r/min) were further compared, and the errors were all within 3%. The method of directly calibrating the simulation contact parameters through the screw conveying process can improve the accuracy of screw conveying simulation, and providing a method and basis for powder contact parameters calibration and screw conveying simulation of wheat flour.
Highlights
With small particle size and large specific surface area, the powder has good solubility, dispersibility, adsorbability, and chemical reactivity, etc
Because the movement of powder particles in the screw conveyor is extremely complicated, it is difficult to describe the force and movement of powder particles through experimental research and theoretical analysis. e numerical simulation can make up for the deficiency of experimental research and theoretical analysis and can analyze the force and movement of powder in the process of screw conveying in detail
The simulation density of wheat flour particles was calibrated by experiment and numerical simulation firstly, and the discrete element simulation contact parameters of wheat flour particles were calibrated by Plackett-Burman, steepest climb, and BoxBehnken experiments to obtain the optimal parameter combination
Summary
With small particle size and large specific surface area, the powder has good solubility, dispersibility, adsorbability, and chemical reactivity, etc. E numerical simulation can make up for the deficiency of experimental research and theoretical analysis and can analyze the force and movement of powder in the process of screw conveying in detail. It can determine the effect of specific parameters on performance through sensitivity analysis and experimental detail reproduction. Wheat flour is used as the transport material; considering the cohesion between wheat flour particles, JKR contact model is adopted On this basis, the simulation density of wheat flour particles was calibrated by experiment and numerical simulation firstly, and the discrete element simulation contact parameters of wheat flour particles were calibrated by Plackett-Burman, steepest climb, and BoxBehnken experiments to obtain the optimal parameter combination. The optimal parameter combination is used to conduct the numerical simulation of the screw conveying at different speeds, and the mass flow rate of the numerical simulation is compared with the mass flow rate of the experiment, and the error is analyzed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
