| Project/Area Number |
62550685
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
化学工学
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| Research Institution | Institute of lndustrial Science, University of Tokyo |
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Principal Investigator |
YAMAMOTO Hideo Institute of lndustrial Science, University of Tokyo, 生産技術研究所, 講師 (50107554)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1988: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1987: ¥1,400,000 (Direct Cost: ¥1,400,000)
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| Keywords | Electrostatic Sepanation / High Temperature / CVD / Ultra Fine Particle / Corona Discbarge / 粒径制御 / DMA / ボクサーチャージャー / 鉄超微粒子 / 静電捕集 / 窒化珪素超微粒子 |
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| Research Abstract |
The feasibility of the high temperature electrostatic precipitation method was demonstrated for separation of the ultra-fine particles synthesized by thermally activated CVD (Chemical Vapor Deposition) technique from a reaction gas stream. Silicon nitride particles were produced in a tubular flow reactor by using the NH_3/SiCl_4 reaction system at 1200゜C and atmospheric pressure. The reaction system produces the NH_4Cl by-product that is in solid state at room temperature. Separation under room temperature presents, therefore, a mixture of silicon nitride and ammonium chloride particles. Using the electrostatic precipitation technique above about 340゜C, the sublimation temperature of NH_4Cl, it is expected that Si_3N_4 particles as the product may be directly collected from the reaction gas stream, without particles of the NH_4Cl by-product.
The new electrode system using Ac-corona surface discharge was developed to charge the particles efficiently because Dc-corona discharge did not stably occur in complex gas composition of the reaction system and at high temperature. A high AC-voltage with peak voltage above 10KV and frequency of 10KHz was applied for the electrodes system to generate a high frequency SC-corona surface discharge. Negative high voltage about 1KV was used as a grid voltage to take out monopolar ions from the AC-corona in order to charge the particles monopolar and as DC-field voltage to migrate the charged particles to a collection zone.
The silicon nitride particles prepared at 1200゜C by the CVD method were under submicron size and completely collected by the electrostatic separation system. The X-ray diffraction analysis indicated that the particles collected under high temperature condition of 500゜C contains no particle the NH_4Cl by-product.
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