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Experimental Study on Electrostatic Hazards of Powder in Fluidized Bed  

Moon, Kyoon-Tae (The Graduate School of Energy and Environment, Seoul National University of Technology)
Chung, Jae-Hee (The Graduate School of Energy and Environment, Seoul National University of Technology)
Choi, Kwang-Seok (Japan National Institute of Occupational Safety and Health)
Publication Information
Journal of the Korean Society of Safety / v.25, no.4, 2010 , pp. 19-24 More about this Journal
Abstract
A large amount of electrostatic charges is often generated on polymer powders in fluidized bed and thereby may lead to electrostatic problems. In this study, to evaluate electrostatic hazards of powder in fluidized bed, the electric field(E[v/m]) and the charge amount(q[c/g]) during fluidizing were monitored. We also investigated the Minimum Ignition Energy(MIE [J]) of sample powder used in fluidized bed with the Hartman vertical-tube apparatus. The batch-type fluidized bed system and 2kg as Polypropylene(PP) resin powders were used in the experiments. The following results were obtained: (1) Even when a safe margin of several times was considered, the values of E obtained with PP powder in this paper did not exceed 3 to 5kV/cm, at which an incendiary electrostatic discharge could occur. (2) the ave. q was -0.26${\mu}$C/g during fluidizing. This value was high enough to cause electrostatic agglomeration and adhesion. (3) the entrained PP powder in upper column due to fluidizing could be ignited by electrostatic discharges of 71mJ.
Keywords
fluidized bed; electrostatic discharge; minimum ignition energy; electric field; electrostatic hazard;
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