振動篩網霧化器模擬分析與高黏滯液體霧化量改善

Abstract

由於霧滴的接觸面積較大，噴射、霧化裝置在國計民生諸多領域具有廣泛應用，像是燃油嘴噴霧，機電製程方面所需的霧化、航空航天、醫療衛生、綠色環保、安全節能諸領域皆有許多新型的應用。壓電陶瓷超聲霧化器是一種結構簡單、低能耗、高效率的壓電霧化裝置，在霧化領域有著廣泛的應用，一般普遍可見民生和醫療用的空氣加濕器及吸入治療儀便是其典型的應用實例。 然而針對主動式振動篩網霧化器，國內外均缺乏對霧化液體特性做特別的考慮。由於霧化液體的不同，通常只有改變驅動電壓以補償其霧化效率的不足。除了導致能量的耗損，更可能因驅動裝置的過熱而破壞霧化液體性質。因此本研究將利用模擬分析主動式振動篩網霧化器的霧化方式，再找出可以提高黏滯性液體霧化量的參數配置。 本研究主要工作可以分為三部分，首先是分析主動式振動篩網的霧化器的霧化方式，利用模擬軟體建立振動模型，再利用阻抗分析儀，量測霧化器的阻抗、振動模態與模擬做對照，以驗證並了解霧化時霧化器的作動方式。第二部分是從建立的模型中，藉由改變機構或者其他的方法，找出可以提高霧化器在不同黏滯液體下之霧化量的方法，最後部分嘗試了數種方法後，在相同的驅動條件下，與原本的結果相比霧化量提升了1.7倍。

Due to the large contact area of the droplet, the jetting and atomizing device are widely used in many areas of national economy and daily use. There are many new applica-tions in the fields of atomization, such as nozzle spray, electromechanical process re-quired atomization, aerospace, medical and health, environmental protection, safety and energy saving. Piezoelectric ceramic atomizer is a kind of piezoelectric atomizer with simple structure, low energy consumption and high efficiency. It is often used in atomization sphere. In general, air humidifier and inhalation therapy device in daily and medical use are two typical applications. However, the lack of specific consideration to the atomized liquid properties (such as the viscosity), the loss of efficiency of the active vibrating mesh nebulizer is usually compensated by increasing the driving voltage. It not only causes extra energy consumption, more importantly, the atomized liquid/medicine will be damaged by device overheating. The task of this project is therefore to investigate the dynamic responses of the vibrating mesh of the nebulizer and find out the optimal structural parameters that can enhance the atomization efficiency for liquid with high viscosity. Three steps are taken in this project. Firstly, the vibration modes of the atomization mesh will be analyzed by simulation software and compared with an impedance measurement of real samples. Secondly, several improving approaches are proposed and real samples are manufactured. Finally, the atomization rate under the same driving power are measured and the efficiency can be increased as high as 1.7 times the original samples.