流體化床中水平噴嘴分佈器對氣體徑向混合之研究

A STUDY OF RADIAL GAS MIXING IN A FLUIDIZED BED EQUIPPED WITH A MULTI-HORIZONTAL NOZZLE DISTRIBUTOR

邱華逸(Hua-Yi Chiou)

指導教授 ： 錢建嵩

中原大學/工學院/化學工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200292

摘要

本研究之目的是在流體化床中，研究其徑向氣體混合的效果。實驗利用回應曲面法進行實驗設計，回應曲面法是數學迴歸和統計方法的集合，對於問題的建模和分析有明顯的效果。實驗係於直徑0.29公尺的圓形床中進行，以二十二個三層同心圓順時鐘排列的水平噴嘴構成水平噴嘴分佈器作為分配板。吾人注入二氧化碳到床內作為追蹤氣體，同時在床的下游處採樣，以氣相層析儀進行分析。追蹤氣體注入的位置有二，一在床中心位置，一在環形區位置，藉以比較床中內循環對氣體徑向混和之影響，同時亦改變靜床高、空床氣速、分佈器的開孔比進行研究，以提供流體化床反應器設計之參考。
實驗結果顯示採用回應曲面的實驗設計，可以更有效的進行實驗。同時能辨認出對結果有顯著影響的變數。床中心位置注入的追蹤氣體，在床內有較良好的分散情形；而環形區位置注入的追蹤氣體受到操作條件的影響較劇烈。空床氣速是影響床內徑向氣體混合最主要的因素，隨著空床氣速的增加，整個床內的氣體混合的程度會提升。床中心的氣體分散主要受到氣速和開孔比的影響。環形區的氣體分散則同時受到氣速和靜床高和開孔比的影響。追蹤氣體注入水平噴嘴流體化床床內時，並不是以垂直的方式上昇，有左右漂移的情形出現。

關鍵字

流體化床 ； 回應曲面法 ； 氣體混合

並列摘要

The purpose of the present work is to study radial gas mixing in a multi-horizontal nozzle distributor fluidized bed. The experiments were studied using response surface methodology (RSM), which is a collection of mathematical and statistical techniques that are useful for the modeling and analysis of experiments. The experiments were carried out in a circular fluidized bed of 0.29 m inside diameter. The distributor is placed by 22 horizontal nozzles which are arranged in three concentric circles with all discharge exists directed clockwise. The carbon dioxide is discharged into the bed as the tracer. It was sampled by sampling tube in the downstream of the fluidized bed. The analysis is made by the Gas Chromatograph (MTI M200). In order to compare the internal circulation, the tracer can be discharged in the center area or annular area of the bed. At the same time, static bed height, superficial velocity and open area ratio of the distributor are chosen as the research variable. This can be used as the reference of the design of the fluidized bed reactor.
The results of experiment show that the experiment design by RSM, the experiment can be performed more efficiently. We also can tell the most significant influence variable. The tracer gas injected to the center position have a better dispersion; the operation condition influences the gas dispersion in the annular area violently. The superficial velocity has the most significant influence on radial gas mixing in fluidized bed. The radial gas mixing in fluidized bed is better as the superficial velocity increasing. The radial gas mixing in the center part of fluidized bed is influenced by the superficial velocity and the open ratio of distributor. The radial gas mixing in the annular part of fluidized bed is influenced by the superficial velocity and the static bed height and the open ratio of distributor. The tracer injected into bed is not raise directly; it meanders unpredictably in the multi-horizontal nozzle distributor fluidized bed

並列關鍵字

response surface methodology ； gas mixing ； fluidized bed

參考文獻

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