Improvement in Efficiency of High Temperature Treatment of Waste by Sound Wave Application
| Project/Area Number |
12650731
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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 |
Metal making engineering
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| Research Institution | Tohoku University |
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Principal Investigator |
KOMAROV Sergei V Tohoku University, Institute of Multidisciplinary Research for Advanced Materials, Associate Professor, 多元物質科学研究所, 助教授 (20252257)
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| Co-Investigator(Kenkyū-buntansha) |
KUWABARA Mamoru Nagoya University, Department of Materials Processing Engineering, Associate Professor, 大学院・工学研究科, 助教授 (70023273)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2000: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | High temperature exhaust gas / Sonoprocessing / Agglomeration efficiency of dust particles / Enhancement of NO reduction / Control of interface heat transfer / Effect of frequency / Effect of sound pressure / Effect of temperature / 音波 / 廃棄物 / 高音処理 / 燃焼 / 気相中熱伝達 / 気相中物質移動 / 音波周波数 / 音波強度 / 高温処理 |
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| Research Abstract |
1. Behavior of Dust Particles in High Temperature Exhaust Gas during Sound Wave Application
A sample of Zn (10 g) was evaporated inside a crucible of vertically arranged experimental set-up, then the vapor was transferred into the set-up working space by Ar carrier gas. Cooling of vapor-containing gas resulted in formation of Zn droplets and/or particles (size 1〜100 μm) which were exposed to powerful sound waves. The particle samples were taken at places of different temperatures. The results revealed that the sound waves forces particles to collide and to form agglomerates between each other. In the low frequency range (35〜992 Hz), the agglomeration efficiency is controlled by sound pressure and independently of frequency. In the high frequency range (6.9〜17.2 kHz), both the frequency and sound pressure govern the agglomeration efficiency. For the both frequency ranges, the higher the temperature, the better is the agglomeration efficiency.
2. Improvement in NO Reduction Efficiency by A
… More
coustic Oscillations
Sound waves (frequency 6.9〜17.2 kHz) that were produced by the Hartmann sound generators mounted on the top part of a vertical reaction tube. A graphite disc was positioned in the tube bottom part preheated up to certain temperatures (873〜1173 K). An Ar-NO mixture (NO 911〜934 ppm) was blown onto the disc surface to perform reactions between C and NO. Without sound wave application, NO content in flue gas was reduced to a level of 200 〜 600 ppm. Exposing the disc surface to sound waves resulted in the further decrease in NO content to 50 〜 250 ppm. The NO reduction efficiency was found to be dependent on the sound frequency, intensity, gas flow rate and temperature.
3. Enhancement of Gas Phase Heat Transfer by Acoustic Field Application
Experiments are carried out by using preheated Pt wires (length 0.1〜0.15 m, diameter 50 and 100 μm) positioned at velocity antinode of a standing wave (frequency 216〜1031 Hz) or in the path of a traveling wave (frequency 6.9〜17.2 kHz). Air was blown to the wire surface. Effects of sound frequency, sound strength, blowing gas velocity and wire preheating temperature on augmentation of Nusselt number relative to the natural convection conditions are examined. The gas phase heat transfer rate is enhanced with acoustic field strength. Higher temperatures result in a vigorous radiation from the wire surface and attenuate effect of sound. The large the velocity of blowing gas, the smaller is the effect of sound wave on heat transfer enhancement. Less
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Report
(3 results)
Research Products
(12 results)
