Experimental study on electrostatic charging of polymer powders in mixing processes
| Autor: | Kwang Seok Choi, Muammar Omar, Xiaotao Bi, John R. Grace |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
chemistry.chemical_classification
Materials science General Chemical Engineering Brush discharge Analytical chemistry Mixing (process engineering) Energy Engineering and Power Technology Faraday cup Polymer Management Science and Operations Research Electric charge Industrial and Manufacturing Engineering symbols.namesake Chemical engineering chemistry Control and Systems Engineering Electrical resistivity and conductivity Electric field symbols Particle size Safety Risk Reliability and Quality Food Science |
| Zdroj: | Journal of Loss Prevention in the Process Industries. 23:594-600 |
| ISSN: | 0950-4230 |
| DOI: | 10.1016/j.jlp.2010.05.007 |
| Popis: | Powder mixing is often carried out in the chemical and pharmaceutical industries. Electrostatic charges generated on polymer powders during mixing may lead to electrostatic problems due to the poor conductivity of those powders. In this study, we investigated the electrostatic charges, surface potential, and apparent volume resistivity of sample powders using a simple mixing device utilizing the Faraday cup method. To neutralize the charged powders, we also applied an AC-type ionizer in the mixing study. A commercial polyethylene powder with a mean particle size of 585 μm was tested in this experiment. The charge-to-mass ratios at the end of 600 s of mixing were −0.075 nC/g at 295 rpm agitation speed, −0.21 nC/g at 495 rpm, and −0.31 nC/g at 660 rpm, high enough to cause electrostatic agglomeration and adhesion. The electric fields based on the surface potential on the powders were several hundreds of V/cm, too small to give rise to brush discharge. The apparent volume resistivity of powders estimated by a simple measurement system is 1.0 × 1016 Ωm, in reasonable agreement with that acquired by the conventional test cell method (5.9 × 1015 Ωm). The charging level on the polymer powders was reduced with an AC-ionizer. |
| Databáze: | OpenAIRE |
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