| Project/Area Number |
02555137
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
金属精錬・金属化学
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
NAKAZAWA Shigeatsu Tohoku Univ., Faculty of Engng., Assoc.Prof., 工学部, 助教授 (70006055)
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| Co-Investigator(Kenkyū-buntansha) |
HINO Mitsuhisa Tohoku Univ., Faculty of Engng., Instructor, 工学部, 助手 (40005335)
AZAKAMI Takeshi Tohoku Univ., Faculty of Engng., Prof., 工学部, 教授 (50006029)
伊藤 聰 東北大学, 工学部, 助手 (70133048)
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| Project Period (FY) |
1990 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥5,200,000)
Fiscal Year 1992: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1991: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1990: ¥4,400,000 (Direct Cost: ¥4,400,000)
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| Keywords | Vapor Pressure Measurement / Knudsen Effusion Method / Torsion Effusion Method / Metalloid Element / Poly-atomic Vapor / クヌ-セン流出法 / 解離会合平衡 |
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| Research Abstract |
A new apparatus has been designed and assembled to measure the equilibrium constants between poly-atomic vapors of metalloid elements such as arsenic, antimony, selenium, tellurium, etc. at the temperature range of 1000-1500K.
A torsion-effusion cell bearing a pure element or some alloy is hung on a weighing balance with a fire wire and heated under high vacuum. The decreasing rate of sample mass and the torque around the suspension wire, both caused by the effusion of vapors, are simultaneously measured. A set of two equations is solved to determine the equilibrium pressures of predominant species and the equilibrium constant for the dissociation/association reaction among species is derived.
An electronic balance was assembled in a big bell jar of an ultra high vacuum pumping system. The controlling and indicating circuits were separated to the outside of the vacuum chamber. The torsional force on the cell is determined from the twisting angle of the suspension wire, which is 195mm long in this study.
Torsion effusion cell of graphite has two orifices with 1mm diameters and a separation of 16mm. The total mass of the cell with a sample weighs around 20g. A heating device of 75mm high and 60mm diameter is located inside the chamber. The cell is heated by radiation.
Experimental errors were analyzed for various conditions of measurements. A systematic error by neglecting any third species if exists was also discussed.
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