Prediction of particle charging in a dilute pneumatic conveying system

Abstract

When particles are transported in pipelines, they acquire electrostatic charges as they come into contact with the pipe wall. Charged particles can cause problems such as particle agglomeration, blockage, and explosion. Understanding the particle charge can help to prevent these issues. This study investigates a technique for predicting the particle charge in a straight pipe of any given length, as well as the pipe length at which electrostatic equilibrium occurs, through experimentation in a short 1m pipe section.Experimentation with five different types of particles and four pipe wall materials at longer pipe lengths were used to validate the technique. This predictive technique is applicable to a range of particle shapes and sizes under the restriction that charge transfer is due to impact charging. Heading:Particle technology and fluidization

Advanced characterization of particles triboelectrically charged by a two-stage system with vibrations and external electric fields

“…For example, particles have been charged by repeated contact on a vibrating feeder [28] or in a shaker [29,30]. Otherwise, particles have been charged in gas-solid pipe flows without using vibration [31], and the frequency of particle-wall contacts may be increased by applying a centrifugal force to the particles in a rotational flow [32][33][34]. Furthermore, because particle tribocharging is affected not only by the material property but also by the electric field [35], the charges on the particles can be altered by changing the electric field.…”

Effect of charge transfer on electrostatic adhesive force under different conditions of particle charge and external electric field

“…where E0 is the transferred charge density in the absence of the externally applied electric field Eext and kE is a coefficient representing the effect of the field Eext on the charge transfer. This concept results from the previous studies [26,28,29].…”

Adhesive strength distribution of charged particles on metal substrate in external electric field

“…14 shows a charge-transfer model based on the total potential difference in which the contact potential difference, Vc, was assumed to be negative. The charge transfer depends on the particle charge and the external electric field [22,23]. For example, when the external electric field, Eex, is applied negatively in this system, the total potential difference, V, becomes largely negative and the transferred charge, Δq, from the substrate to the particle is also negative.…”

“…In an electric field, charged particles experience electrostatic forces, making the particles useful in applications such as electrostatic precipitation [15], particle separation [16], powder coating [17], and electrophotography [18]. To achieve an optimum performance in each application, accurate measurement and control of the charge on the particles is crucial [19][20][21][22][23]. In addition, the electrostatic forces acting on the particles need to be measured and analyzed.…”