| Budget Amount *help |
¥6,900,000 (Direct Cost: ¥6,900,000)
Fiscal Year 1997: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1996: ¥6,100,000 (Direct Cost: ¥6,100,000)
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| Research Abstract |
In a gas-solids pipe flow, particles are charged as a result of particle collision with the pipe wall. On the basis of the static electrification, a method for measuring the powder-flow rate was proposed. The electrical method takes advantage of high-responsibility without obstructing a pipe-flow, however, the method has fundamental problems ; the charge transfer between a particle and a wall depends both on the initial charge of the particle and on the electrostatic properties. To resolve the problems, we proposed a new electrical method by analyzing the electric currents generated from two detecting pipes in series, which were made of different materials such as titanium nitride and nickel. From the experiments using mineral powders, it was found that the dual-detecting system had high-performance on the measurement of mass-flow rate. The relative error in the measurements was within 10%. Furthermore, the particle charge could be obtained simultaneously in this measuring system.
Polymer powders as well as mineral powders are generally used in industry. Polymer powders formed a stiff coationg layr on a wall surface due to particle collision in a gas-solids pipe flow. This phenomenon is especially remarkable if a pipe wall is made of hard material like metal. Therefore, several polymer materials were examined as the detecting pipes, and the performance of the current detection was evaluated by changing the powder flow rate. It was found that electrically conductive polymers containing carbon had superior stability on the current detection. It was also found that the mass-flow rate of polymer powder could be measured by use of two different conductive polymers, e.g., conductive polytetrafluoroetylene and conductive nylon, for the detecting pipes.
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