包覆层对含能药粒与器壁间静电相互作用特性

This paper aims to study the electrostatic safety threshold of energetic explosive particles in the production process. A theoretical model of electrostatic interaction between coated energetic explosive particle and conducting wall in the cylindrical coordinate system is established using the re-expansion method. The boundaries of charge density and electric field threshold for electrostatic discharge between coated energetic explosive particle and conducting wall are defined based on the modified Paschenŋ’s law. The influences of particle structure and key electrical properties on electrostatic safety threshold are discussed. The results show that the conducting wall remains electrostatic attraction to particles with arbitrary charge and gap. The maximum electric field is located at the particle-wall gap. The electric field between the conductor particle and the metal conducting wall tends to infinity when they contact with each other. The electrostatic discharge risk of ractive metal particle is much higher than that of single-component explosive particle. The coating layer with small gap can increase the gap electric field of dielectric-core particles, but decrease the gap electric field of conductor-core particles. When the dielectric constant of the coating layer is 7. 5ε₀(ε₀ is the dielectric constant of vacuum),the peak gap electric field of the coated dielectric-core particles with a surface charge density of 40 μC/ m² is increased by 29. 5%,reaching the discharge threshold. However,the peak gap electric field of the coated conductor-core particle with a surface charge density of 1. 0 μC/ m² decreases from infinity to a value below the discharge threshold. Although,the coating layer improves the intrinsic electrostatic safety of active metal conductor particle but reduces the electrostatic safety of single-component dielectric particle,the coated active metal conductor particle possesses less electrostatic safety than that of coated single-component dielectric particle.