無塵室內污染物大量溢散之緊急處理-應用空氣簾控制防止汙染物散佈研析

Using Air Curtain to Control Pollutant Spreading for Emergency Management in a Cleanroom

呂張維(Chang-Wei Lu)

指導教授 ： 楊安石 ； 施陽正

國立臺北科技大學/機電學院/能源與冷凍空調工程系碩士班/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00087

摘要

由於生產技術的進步與發展，無塵室被廣泛的應用於不同等級之需求以滿足工業的製程應用。高科技產業製程之生產過程所需的液氣態化學品越趨於複雜，且用量越大，一旦發生大量溢散汙染將對無塵室內工作人員造成莫大的危害。本研究針對一個長21.6m，寬16.7m，高6m的進料品管無塵室，利用實驗以及數值模擬的方式探討當大量氣態污染物(乙醇)揮發散佈時，其汙染物受氣流場影響之散佈情形。本文實驗利用TSI8495 熱線式風速計量測FFU (fan filter unit)的風速量測以探討此無塵室之流場特性。汙染物濃度實驗則以定量氣態酒精持續釋放一分鐘，利用三台VOC（揮發性有機化合物）檢測儀(ppbRAE Plus PGM-7240)同時監測並記錄其汙染物經由釋放源產生的氣態酒精於實驗無塵室內之時間以及空間上的汙染濃度變化。
為了解無塵室流場與汙染物之交互作用，本研究使用計算流體力學軟體ACE+® 建立三維、暫態、等溫、不可壓縮流之k-ε紊流模型無塵室。並將實驗量測數據之風速、隨時間空間變化之濃度與數值方法預測之結果做驗證比對。本研究設計一氣簾裝置以期望能夠產生良好的阻隔效果來阻擋汙染物通過，考慮緊急狀況為氣態酒精因工作機具上蓋的故障而產生大量且持續的汙染逸散，並比較無開啟氣簾以及開啟氣簾後其汙染物受到氣流影響之阻隔效果。其汙染的危害範圍以及到達危險的時間亦因氣簾參數設計可以達到明顯改善。其中空氣簾噴出速度、噴出角度以及高度將影響氣簾對於氣態汙染物阻隔的效果。本文經由數值模擬方法，觀察氣態汙染物散佈狀態與氣簾產生氣流速度場之交互作用，分析流場運動行為，以取得最佳化空氣簾設計參數，取得最佳組汙染物阻隔效果，以保障工作人員之生命安全。

關鍵字

無塵室 ； 氣流分佈 ； 污染物散佈 ； 空氣簾

並列摘要

Cleanrooms have been extensively utilized in various industries to fulfill the cleanliness requirement during the fabrication process. The present research aims to study the dispersion flowfield of gaseous pollutant in a 21.6m×16.7m×6m cleanroom. Experimentally, the airflow velocities issued from the fan filter units (FFUs) were measured using a TSI 8495 hot-wire anemometer to inspect the flow characteristics. Gaseous ethanol with a known concentration was also released for the duration of 1 min. Three ppbRAE Plus PGM-7240 photoionization detectors were used to concurrently measure the spatial and temporal distributions of ethanol concentration from a gas-pollutant leaking source. To probe the interaction of the airflow via the FFUs with the emitted flow from a pollutant leaking source, the computational analysis was based on the unsteady three-dimensional conservation equations of mass, momentum and species concentration for the incompressible isothermal turbulent flow. A k-ε two-equation turbulent model was adopted for turbulence closure. The predicted steady-state velocity and transient ethanol concentration distributions were then compared with the measured data to validate the computer software. To investigate the personnel safety concern in a contaminated cleanroom, a scenario considered a large amount of gaseous ethanol released accidentally and continuously from the top surface of a machine. The airflow and contaminant characteristics were examined to better understand the spreading process for the situations without and with activation of an air curtain device for contamination control purpose. Numerical experiments was then extended to verify if the air curtain can establish an effective shield for constraint of pollutant dispersion and optimize its operational performance by systematically varying the parameters of installation height, blowing velocity and ejected angle.

並列關鍵字

Cleanroom ； Air curtain ； Pollutant dispersion ； Flow recirculation

參考文獻

[1] Rouaud, O., and Havet, M. 2005. "Numerical investigation on the efficiency of transient contaminant removal from a food processing clean room using ventilation effectiveness concepts.” Journal of Food Engineering, 68: 163-174.

[2] Yang, L., and Eng Gan, C. 2007. "Costing small cleanrooms". Building and Environment, 42: 743-751.

[3] Chen, J.-J., Lan, C.-H., Jeng, M.-S., and Xu, T. 2007a. "The development of fan filter unit with flow rate feedback control in a cleanroom. " Building and Environment, 42: 3556-3561.

[4] Phillips, M., Herrera, J., Krishnan, S., Zain, M., Greenberg, J., and Cataneo, R.N. 1999. "Variation in volatile organic compounds in the breath of normal humans. Journal of Chromatography B: Biomedical Sciences and Applications", 729: 75-88.

[5] Na, K., Kim, Y.P., Moon, K.-C., Moon, I., and Fung, K. 2001. "Concentrations of volatile organic compounds in an industrial area of Korea. Atmospheric Environment", 35: 2747-2756.