Abstract
The electro-static electrification and flowing characteristics of metal powder particles which had fallen through inclined friction pipes made of various materials were studied by the use of a Faraday's cage.
Using pipes having a constant inside diameters under different inclined angles of friction, 100g of 8 kinds of metal powders were examined and converted to values per unit Kg of weight.
The results obtained in this research are summarized as follows:
1) Measuring the time required for those metal powders to flow-out through the pipes, tin powder was found to be shorter than that of any other powder. Depending on the sort of metal powders, the selection of materials of friction pipes has a considerable effect on the flow-out time of powder particles.
2) When friction pipes were inclined at large angles, the lowest values of flow-out time and the highest ones of electrification were obtained under the condition of sliding and rolling motion of metal powder particles.
3) Electro-static electrification values of metal powder particles depend on the electrical characteristics of the materials used as friction pipes. The values obtained between non-metallic pipes and metal powder particles were larger than those obtained between metallic pipes and metal powder particles. It was impossible to measure those values between Al powder particles and non-metallic pipes because of excess electrification.
4) Polarities of metal powder particles electrified under frictional conditions did not have any constant tendencies.
