在過去的研究中可以得知若要在逆流型多行程薄膜萃取系統中計算出質量傳送速率，因為計算式中包含了未知的出口濃度，所以計算上必須要使用繁雜的疊代法來求得。 然而在本研究中所提出的改良型修正因子圖表，在計算上已將未知出口濃度消除，我們只需要查表便可求得修正因子，再佐以簡單的運算便可以求得我們所需之質量傳送速率，也同時間比較了行程數對於質量傳送速率與能量損耗的影響。本研究並採用了雙行程逆流型薄膜萃取系統的實驗來佐證我們的研究結果。 A modified correction-factor analysis is introduced in present study to develop equations for estimating the mass-transfer rate in multipass backward-flow membrane extractors, in which the unknown solute outlet concentrations are neither in the estimating equation nor in the modified correction-factor charts, and thus the calculation is easy and direct without using the try-and-error method that should be employed in the conventional correction-factor analysis. Experimental results confirm the prediction values for the extraction of acetic acid from aqueous solution by methyl isobutyl ketone in a double-pass device.
