從漿料的乾燥來得到粉體的過程中，一般都會面臨顆粒凝聚的問題，此凝聚的現象會因顆粒的奈米化而更趨嚴重；目前業界與學界對奈米陶瓷微粒有不同的乾燥方法，但每種方法都有不同程度的凝聚問題也都各有缺點。基於液體會在真空環境下會瞬間汽化，且膨脹的力量可以抵消粒子間的吸引力，所以本研究利用真空乾燥來避免或減輕粒子之凝聚。
在乾燥實驗中，吾人使用不同的乾燥方式處理奈米θ-Al2O3微粒漿料，並以乾粉回衝於水中的再分散度當作品質好壞的依據；結果顯示，真空乾燥因為可在較低溫度下進行脫水動作，所以品質較常壓下高溫處理的乾粉要好，更值得注意的是在真空環境下使用微波給熱，因為加熱快速且均勻，所以乾粉回衝後幾乎可以回覆到和原始漿料相同的粒徑分佈。
雖然真空乾燥早已被使用，但尚未被用在含水量較多的場合，因為真空腔內水份的汽化會使體積迅速地膨脹，很容易因為壓力的升高失去真空度而終止汽化的連續性，而且使用真空泵浦抽除水汽相當不切實際；因此，本研究依據溴化鋰吸收式冷凍系統的概念建立了一連續性吸濕脫水系統，可連續性地在真空腔內吸收汽化的水汽，並將所吸收之水排出真空腔體來維持低壓真空環境。
為了提升系統的吸濕能力，實驗測試中改變吸收器內不同冷卻水排管形式作為比較；結果顯示，短針鰭型冷卻管因為有效熱傳面積較大，使得整體效能比平滑型冷卻管要好；而在短針鰭型管間加裝平行銅鰭片後，整體效能與未加裝者差異不大。最後則是在溶液中加入少量二乙基己醇進行測試，其可強化之吸濕效果相當地顯著，但因為系統為開放式，二乙基己醇的蒸氣會被排到環境產生惱人的氣味，所以需要尋找其它可用的替代品。實現此真空環境下連續脫除水汽的系統即是本研究最重要的成果，也是對於奈米陶瓷粉體的量產邁向實用化的一大步。

It is well known that drying of liquid-borne powders will create agglomerates and the problem of agglomeration is particularly acute in the range of nano-scale size. There are many kinds of drying process for nano-particles, each one has its advantage and limitation but none of them can be free from particle agglomeration. Since the liquid water will instantaneously flush into steam under the condition where the pressure is below its saturated state, and the outward expansion force during flashing is able to counteract the attracting force among particles, it is thus reasonable to use vacuum dry technique to prevent/mitigate agglomeration.
In the tests of drying θ-Al2O3 colloid (solution of nano-particles and water), we used other drying methods to compare with our proposed vacuum drying. The degree of re-dispersibility obtained from each dried powder was taken as the level of product quality. The results indicated that the quality of powders from vacuum drying were better than that from others. Especially when the vacuum drying added microwave energy heating, the re-dispersed powders can almost return to the state of original colloid.
Although the vacuum dry technology had been used in the fields of drying solid food, timber and medicine powder, this technology has not been used in the situation when the water-content percentage is high. The behind reason may be due to the fact that the flashing process of water will be terminated once the environment pressure rise above saturation state due to the tremendous volume expansion when liquid water converts to vapor. This study proposed the concept of LiBr-H2O absorption cooling system, which can continuously absorb the expanded steam in the vacuum chamber and keep the chamber pressure below the saturated value.
To promote the absorption rate of steam, we changed different kinds of cooling-tube-bundle. The results show that the bundle made by low-fin-tube has a slightly better efficiency than that the one made by smooth-tube, and the enhanced effect of using flat plate connected between the upper and lower tubes was found to be insignificant. By adding a small amount of 2-ethyl-hexanol into LiBr solution was found very effective to improve the ability of absorption. However, the exhausted steam containing 2-ethyl-hexanol would have a strong bad order and may contaminate the nearby environment.
The most important contribution of this study is to demonstrate that our designed device can continuously absorb and expel steam from the vacuum chamber, which indeed is the most important step to achieve applying the vacuum drying device for mass production.

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