چكيده به لاتين
The potential difference between polymer particles and metal surfaces in powder transfer systems causes problems such as high pressure drop, increased energy consumption, blockage of the transfer path, and reduced product quality. Many researchers have investigated various aspects of gas-particle (polymer) systems and have investigated the effects of various factors such as collision velocity, particle material, tube material, particle diameter, and other effective parameters on the amount of charge produced. Using CFD-DEM simulation to investigate the behavior of two-phase gas-polymer particle flow can improve our understanding of the effects of various parameters on the behavior of the compensation in different operating conditions. In this project, the LIGGGHTS software code was initially developed to investigate the behavior of a single particle and the effects of various parameters such as collision velocity, particle diameter, particle material, and contact area by adding condenser equations. Then, in DEM simulation, the behavior of a single particle in different operating conditions and its effect on determining the K and C parameters of the condenser model are investigated. In the next step, a gas-particle flow in a powder transfer system is simulated using the CFD-DEM method and the parameters affecting the electrostatic charge generation rate are investigated. Based on the obtained results, the flow pattern is analyzed under different operating conditions. In the final section, the relationship between the particle mass flow rate and the charge generated rate is investigated based on the simulation results. The simulation results show that effective factors such as impact velocity, particle diameter, and number of particles have a significant effect on the charge transfer rate of particles after impacting the pipe surface. Also, changing the parameter K with the impact velocity compared to the case where it is considered constant for all velocities leads to a significant reduction in the calculation error. Changing the particle diameter only affects the determination of the parameter C of the condenser model, and by increasing it, a smaller value for the parameter C should be selected. In addition, the simulation results show that the system reaches an equilibrium state in the electrostatic charge rate after a few specific time steps have passed since the particles enter the pipe. Increasing the number of particles does not significantly affect the time it takes for the system to reach equilibrium in terms of electrostatic charge, but it does increase its amount. This information has led to the presentation of a relationship for determining the mass flow rate of particles based on the amount of electrostatic charge measured in the transfer system.
