利用水滴破碎產生空氣負離子之研究

The Study of Negative Air Ion Produced By Water Droplet Breakup

顏麗凰(Li-Huang Yen)

指導教授 ： 李慧梅

國立臺灣大學/工學院/環境工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00837

摘要

近年來空氣中存在的離子被認為與生命的活動息息相關，而且在現代的生活環境中，空氣離子的濃度更直接顯示出環境中空氣污染的程度。一般市面上有釵h種不同處理機制之空氣清淨機，其中空氣負離子清淨機為無二次污染物生成主要訴求，且文獻指出空氣負離子對人體健康具有正面效益，然而空氣負離子產生器主要可利用電暈放電與水滴破碎兩方式生成空氣負離子，因此本研究欲以水滴破碎的方式產生空氣負離子，並探討各種環境因子與空氣負離子濃度之關係。另一方面，由於國內缺乏空氣負離子濃度相關的背景資料，因此本研究還進行野外採樣的部分，包括不同林相的森林區、瀑布區以及都市中室內與室外環境等之正負離子濃度的偵測，以建立本土資訊。
野外森林區中共有六個偵測地區，包括五種不同的林相與一處觀瀑亭休息區(位於瀑布與森林之間)，負離子平均濃度在2,800-22,000 ions/cm3之間。五種不同林相偵測的結果顯示不同林相之空氣負離子濃度不同，其中檜木林的空氣正負離子濃度為最高。都市區的偵測地點共有四處，偵測結果顯示都市區的正負離子濃度遠低於野外森林區，且室內環境中的正負離子濃度均較室外環境小。負離子平均濃度為130-970 ions/cm3之間。瀑布區的負離子濃度遠高於野外森林區與都市區，負離子平均濃度在9,430-44,130 ions/cm3之間，顯示瀑布區附近可能因水滴破碎機制的影響，增加負離子產生量。
室內架設噴霧箱利用噴嘴霧化模擬水滴破碎產生空氣負離子之機制，並分為三種不同噴嘴孔徑與五個不同距離點的實驗條件，研究結果最高負離子平均濃度為10,670 ions/cm3、最低830 ions/cm3。噴嘴以串聯的方式產生空氣負離子之濃度比單顆噴嘴所產生的負離子量多，其中又以三顆噴嘴串聯所產生的離子濃度最高，三顆串聯比單一噴嘴的產生量大2-3倍。兩顆噴嘴串聯不同孔徑的配對結果差異不大，較單一噴嘴約多出2,000-4,000 ions/cm3。

關鍵字

室內空氣品質 ； 瀑布 ； 噴嘴 ； 空氣負離子 ； 水滴破碎

並列摘要

Many investigators have studied the relationships between air ions and the living body, and show that a certain amount of negative air ions (NAI) in inhaled air is necessary for normal vital activity. The concentrations of air ions are dependent on the level of air pollution. Many kinds of air cleaners are used to improve indoor air quality. Recently, the negative air ion cleaners are emphasized without by-products produced. Thus, this kind air cleaner becomes more and more popular for indoor air preventing. There are two types of generating methods: one is by corona discharge, and the other is by droplet breakup. In this work, we would like to use the droplet breakup to generate NAI and also investigate the characteristics of air ions in the environments regarding forest, waterfall and city zones.
There are six sampling places in the forests including five kinds of the woods and one pavilion, which is between waterfall and forest. The results showed that the average NAI concentration of this six places were between 2,800-22,000 ions/cm3. The NAI of five kind woods showed the different concentration, which the NAI concentration of Chinese juniper was the highest. Furthermore, this study also contains four zones in the downtown city. The results showed that the air ions concentration of the downtown city were lower than the forest zones, as well as the air ions concentration of the outdoors were lower than the indoors. The average NAI concentration of the downtown city is in the range of 130-970 ions/cm3 and that of the waterfall zones were between 9,430-44,130 ions/cm3. Comparison of these data, the NAI concentration of the waterfall zones was much higher than that of forest zones and the downtown city.

In this study, we use three kinds of orifice diameter of nozzles and five distances to simulate the mechanism of droplet breakup by atomization in the spray system. The experimental results showed that the maximum and minimum average-NAI concentration were 10,670 ions/cm3 and 830 ions/cm3, respectively. In contrast with single-nozzle, the connection of nozzles were produced much lager amount of NAI. The type of three nozzles connected could produce the highest NAI concentration. The results also indicated that the NAI concentrations produced by the connection of any two nozzles were nearly the same.

並列關鍵字

negative air ion ； waterfall ； Indoor air quality ； droplet breakup ； nozzle

參考文獻

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