| Summary: | 碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程研究所 === 102 === In the transportation of granular materials in the industrial manufacturing process, these materials will rub or hit against the pipes, become charged, and therefore form a potential source of danger. If the charged bodies are not controlled well, the electrostatic discharge may ignite matters like inflammable vapor, combustible gas, or dust and increase the risk of fire and explosive accidents.
Active corona discharge, also called voltage-applied static corona discharge, is a common method of electricity neutralization in the industry; however, not many national reports have yet to work on its application to the materials during piping transportation.
This study utilizes the active-corona-discharge neutralization device, installing it inside plastic piping to remove the electricity of the transported granule materials, so as to discuss whether this method is effective and efficient. Also, by applying discharge needles with different velocity of flows and different numbers of discharge needles, we analyze the efficiency of static-electricity removal of the two materials, ABS and FR-ABS, via the ionizer in the piping. Finally, we conclude the effectiveness and efficiency of ionizer in neutralizing transported granule charged materials. It is the purpose of this study to provide suppliers in the granule transportation industry with these statistics as the references to perform effective static electricity neutralization.
According to this research, for an ionizer whose neutralizing capability is uncertain, we can lower the potential of the charged body, which is still in its initial stage, to 90% within thirty seconds. That way, the neutralizing ability of active corona discharge will become so obvious as to effectively neutralize the static electricity of granular materials carried within the pipes. When the potential of the granular materials in the pipes reaches 640kV, it can be lowered to 170kV through this method. Moreover, the number of discharge needles has a positive correlation with neutralizing efficacy. As suggested by this research, if we hope to achieve better electrostatic neutralization, it is the best to place four discharge needles. When the velocity of flow is too high (20m/s), there is a tendency for the efficiency of electrostatic neutralization to decrease; when the velocity of flows is at 10m/s, the best neutralizing effect can be produced.
Key Words: granule transportation, static electricity, static electricity neutralization in the piping, active corona discharge, neutralization, efficiency of neutralization
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