The Effects of Electric Double Layer on Freezing and dehydration in Fine Packed Beds with Liquid Content
| Project/Area Number |
17560177
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Thermal engineering
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
AOKI Kazuo Nagaoka University of Technology, Department of Mechanical Engineering, Professor (60115095)
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| Co-Investigator(Kenkyū-buntansha) |
AKAHORI Masatoshi Nagaoka University of Technology, Department of Mechanical Engineering, Assistant (10303182)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2005: ¥1,900,000 (Direct Cost: ¥1,900,000)
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| Keywords | Electric double layer force / Fine particles / Surface electric charge / Electro-osmosis / Electromagnetic field / Freezing / Dehydration / Colloid / 電気泳動 / 誘電泳動 / 乾燥 / 電場付与 |
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| Research Abstract |
We have investigated two different phenomena in heat transfer problems relating to electric double layer ; (1) the trapped and swept phenomenon of foreign particles due to freezing of liquid and (2) the dehydration in fine packed beds using the electro-osmotic flow.
(1) When water solution involving fine particles freeze, the freezing process can be divided into two cases whether particles are trapped in the freezing layer or particles are swept out from the freezing layer. The trapped and swept phenomenon of particles due to freezing is widely an important problem related to the freezing process of sludge, the concentration technology and the solidification of metal including foreign particles. We have investigated this phenomenon due to freezing for two cases of independent particles and large number of particles existing in water solution. The trapped and swept phenomenon largely depends on the freezing rate, the size of particle and the surface electric charge of particle. Especially, we focused on the effect of the surface electric charge of particle, on this phenomenon using various particles and water solutions. The calculated results for the critical freezing rate were in agreement with the experimental results using various particles.
(2) In packed bed composed of fine particles, an electro-osmotic flow is caused by the addition of external electric fields for the effect of the electric double layer formed near the surface of particles. This phenomenon is an important problem related to the dehydration of contaminated sludge, the electro-osmotic pump in microchannel and the drying in packed beds. The electro-osmotic flow in saturated packed bed has been investigated experimentally. It was found that the flow rate depended on the surface charge of particles, the structure of packed bed and the electrical conductivity. The dehydration of the packed bed using the electro-osmotic flow has been investigated experimentally.
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Report
(3 results)
Research Products
(10 results)
