氣泡床之壓力擾動分析探討

Analysis of Pressure Fluctuations in Bubbling Beds

劉德濱(De-Bin Lau)

指導教授 ： 呂理平

國立臺灣大學/工學院/化學工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.02328

摘要

中文摘要
本實驗使用內徑0.1m、高1.8m的透明壓克力管，以平均粒徑163 、280 、323 及500 的河砂為研究對象，利用不同軸向位置的壓力探針，探討在不同靜床高及量測位置下，量測系統之單點與雙點位置的壓降和壓力擾動偏差值，以決定最小流體化速度。
以壓降對氣速做圖而言，在同一靜床高不同量測位置下，經由
Davidson and Harrison (1963)method，可以得到相同的 Umf。然而雙點位置(plenum-10cm, plenum-20cm…)的壓力擾動偏差利用Puncochar et al. (1985)method同樣可以得到相同之Umf，本實驗中如要求得較為準確之Umf，雙點位置(Plenum-10cm, Plenum-20cm…)為最佳的測量方式。
由主頻分析的結果可知，單點、雙點量測位置的主頻隨著氣速與靜床高增加而下降，而單點位置的主頻不隨測壓接頭軸向高度增加而改變。但是雙點量測位置(plenum-10cm, plenum-20cm…)的主頻在低氣速時隨著測量位置高度增加而下降，高氣速時主頻則不隨測量位置高度增加而有任何改變。由於雙點位置(plenum-10cm, plenum-20cm…)的主頻隨氣速變化的關係，使得 =X 的參數值 “X” 隨主頻的不同而有所變化。

關鍵字

氣泡床壓力擾動

並列摘要

Abstract

The minimum fluidizing velocity was determined by the measurement of pressure drop and pressure fluctuations at various axial positions in a 0.1m i.d., 1.8m high bubbling bed. The sand particles used in this study with mean particle size 163 , 280 , 323 and 500 .
The result showed that there was the same Umf by Davidson and Harrison (1963)method at various probe locations in the same static bed height. And the same result to determined Umf by puncochar et al. (1985) at differential probe locations(plenum-10cm, plenum-20cm…). this is the best way to determine Umf in this study.
The dominant frequency was found to be nearly independent of air velocity and probe locations at absolute pressure fluctuations, but to decrease with increasing static bed height at absolute and differential pressure fluctuations. And the dominant frequency decreased with the increasing probe locations at differential pressure fluctuations for low air velocity, high air velocity didn’t.
The =X ’s parameter “X” was dependent of dominant frequency at differential probe locations (plenum-10cm, plenum-20cm…).

並列關鍵字

Analysis of Pressure Fluctuations in Bubbling Beds

參考文獻

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