利用振動增加濾材之捕捉效率之理論研究

Abstract

本文之目的為探討同時考慮對流場分佈與過濾材收集效率的理論方法，使研發人員能在設計過濾器時同時考慮對流場之影響，有效地提高無塵室之潔淨度。本文將利用多孔性介質模擬過濾材，並利用葛拉金有限元素法(Galerkin FEM)計算過濾管道內部之流場分佈，且利用軌跡理論(Trajectory Theory)模擬汙染顆粒在流場中之行徑過程，以及利用分子碰撞理論(Molecular collision theory)結合前人所推導出的單一吸附粒子收集效率，模擬污染物質在過濾系統中的捕集過程以及收集效率之計算並利用有限元素法與Arbitrary Lagrangian–Eulerian (ALE)方法計算移動邊界的流場分佈與過濾材收集效率理論結合，計算微粒子在振動過濾材流場的捕捉情形，並對照Kim[20]等人對振動流場所作的微粒子實驗值，比較數值模擬流場的準確性。

The aim of this study is investigate effect of filter structure and fluid velocity on collection efficiency of filter numerically. A finite element method is adopted to solve the above problem. Parameters of porosity, equivalent diameter and thickness of the filter and fluid velocity flowing through the filter are token into consideration, and the contributions of the factors of diffusion, inertia, and interception to collection efficiency are examined in detail. In order to improve the collection efficiency, a vibrational motion is added to the filter. The result show that the enhancement of collection efficiency increase accompanying with the increment of the vibrational velocity.