Study of Fluidization of Cohesive Powder by Mechanical Vibration

机械振动流化粘性粉体的研究

• 批准号: 11650180
• 负责人: TOMITA Yuji
• 金额: $ 0.7万
• 依托单位: Kyushu Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650180/
• 关键词: Powder; Fluidization; Jet; Vibrated Bed; Percolation; Pressure Fluctuation; 付着性微粉末; 縦振動; 空気圧変動; フラッシング; 振動強度; 密閉容器; 開放容器

Experimental and numerical studies of spouting of powder from vertically vibrated bed are performed. The powder, especially fine and cohesive one, spouts out vigorously through a side orifice of the vertically vibrated vessel in which the powder is contained, provided that the vibration intensity is greater than unity. We examine the mechanism of this phenomenon and the relationship between the efflux rate and the vibration condition. The interstitial air pressure in the bed that periodically fluctuates is measured and is compared to the results of the numerical analysis considering the relative motion of the powder bed to the vibrated vessel and percolation air flow. The outflow behavior of powder is observed by using a high-speed video camera. The experimental and the numerical results indicate that the powder spouts out with periodic air outflow, which is generated in response to the change of the gap between the bed and the vessel base. Furthermore, it is found that the efflux rate of powder is in proportion to the generated air pressure and in inverse proportion to the vibration frequency.

对垂直振动床中粉体喷动过程进行了实验研究和数值模拟。如果振动强度大于1，则粉末，特别是细的和有粘性的粉末，通过容纳粉末的垂直振动容器的侧孔有力地喷出。我们研究了这种现象的机制和流出率和振动条件之间的关系。测量了周期性波动的床层中的间隙空气压力，并将其与考虑粉末床与振动容器和渗滤空气流的相对运动的数值分析结果进行了比较。用高速摄像机观察了粉末的流出行为。实验和数值计算结果表明，粉末喷出时存在周期性的气流流出，气流流出是响应于流化床与容器底部之间的差距变化而产生的。此外，还发现粉末的流出率与产生的空气压力成正比，与振动频率成反比。