Experimental study on electrostatic charges and discharges inside storage silo during loading of polypropylene powders

Advances in Materials Science and Engineering

et al. 2020

The pneumatic conveying focusing on gas-solid two-phase flow plays an important role in a conveying system. Previous work has been conducted in the fields of small particles, where the size was less than 5 mm; however, there are few studies regarding large sizes (>5 mm). In order to predict the horizontal pneumatic conveying of large coal particles, the coupling methods based on the Euler–Lagrange approach and discrete phase model (DPM) have been used for the simulated research. Compared with the experimental results under the same working condition, the particle trajectory obtained by simulation is similar to the particle distribution at the same position in the experiment, and it turns out that the simulation method is feasible for the horizontal pneumatic conveying of large particles. Multifactor simulations are also carried out to analyse the effects of particle size, flow field velocity, solid-gas rate, and pipe diameter on the wall abrasion during horizontal pneumatic conveying, which provides simulation reference and design guide for pneumatic conveying of large particles.

Section: Introductionmentioning

confidence: 99%

Prediction of Horizontal Pneumatic Conveying of Large Coal Particles Using Discrete Phase Model

Yang

Advances in Materials Science and Engineering

et al. 2020

“…Previous work in the field has looked at fine particle [19,20], powder [21,22] and seed [23,24], all of which are less than 5 mm in size and are within the range of Geldart A to Geldart C. However, there are a few studies on large sizes (larger than Geldart D) [25,26]. When using the common computational fluid dynamics and discrete element method (CFD-DEM) simulation, due to the coupling method between the discrete element method and the finite element method, the simulation time is long and there is a lot to calculate, so it is difficult to get the results quickly.…”

Section: Introductionmentioning

confidence: 99%

Research on the Pressure Dropin Horizontal Pneumatic Conveying for Large Coal Particles

Yang

Hu³

2020

Processes

As a type of airtight conveying mode, pneumatic conveying has the advantages of environmental friendliness and conveying without dust overflow. The application of the pneumatic conveying system in the field of coal particle conveying can avoid direct contact between coal particles and the atmosphere, which helps to reduce the concentration of air dust and improve environmental quality in coal production and coal consumption enterprises. In order to predict pressure drop in the pipe during the horizontal pneumatic conveying of large coal particles, the Lagrangian coupling method and DPM (discrete particle model) simulation model was used in this paper. Based on the comparison of the experimental results, the feasibility of the simulation was verified and the pressure drop in the pipe was simulated. The simulation results show that when the flow velocity is small, the simulation results of the DPM model are quite different from that of the experiment. When the flow velocity is large, the large particle horizontal pneumatic conveying behavior predicted by the model is feasible, which can provide a simulation reference for the design of the coal pneumatic conveying system.

“…In terms of powder electrostatic characteristics research, Choi et al (2018) found research that the charge-to-mass ratio of polypropylene powder during loading in a cone-shaped silo remained at a constant value of approximately À12 μC/kg. Peltonen et al (2018) found that the adhesion of the powder causes the powder charge to decrease exponentially, and the powder with a higher concentration in the mixed powder leads the charge.…”

mentioning

confidence: 99%

Analysis of static electricity generation and elimination in the process of food powder screw feeding

Shen

J Food Process Engineering

et al. 2022

The static electricity in the powder can easily cause poor packaging accuracy, incomplete heat‐sealing of the packaging bag and certain safety hazards. Therefore, the electrostatic generation and elimination of wheat flour and wheat starch were studied in the process of powder screw feeding. Firstly, taking powder particle size, screw speed and conveying distance as influencing factors, the law of static electricity generation in the process of powder screw conveying is studied. Then, an adjustable DC power supply and an ion fan were used to apply voltage and ion wind during the powder screw feeding process to study the elimination of powder static electricity. The research results show that the electrostatic charge of wheat flour and wheat starch is positive. The greater the screw speed, the more severe the powder collision and friction, and the greater the increase in powder charge‐to‐mass ratio. The larger the conveying distance, the greater the increase in the powder‐to‐mass ratio, and when the conveying distance reaches 5200 mm, the experimental powder‐to‐mass ratio tends to be stable. The gain and loss of the charge of wheat starch with small particle size is obviously greater than that of wheat flour with large particle size. The ability and stability of adding ion wind at the outlet of the screw feeder to eliminate static electricity are obviously stronger than the ability and stability of adding voltage to eliminate static electricity. Practical applications The static electricity generated in the process of screw conveying and feeding causes trouble to the packaging weighing, packaging sealing and safety production of powder. Therefore, this paper studies the electric characteristics of food powder in the process of screw transportation and the influence of various factors on the electrostatic generation law, and also through experiments to compare the two methods of electrostatic elimination. This study provides ideas and references for reducing the generation and elimination of static electricity in the process of screw transportation of food powder, so as to improve the packaging accuracy, packaging quality and reduce safety risks in actual industrial production.