作業場所通風特性評估方法之研究

Study of Methods for Evaluating Ventilation Characteristics in Work Places

劉德齡(De-Ling Liu) ； 王秋森(Chiu-Sen Wang)

《中華公共衛生雜誌》 16卷3期 (1997/06) Pp. 244-257

https://doi.org/10.6288/CJPH1997-16-03-06

摘要

本研究主要目的在於以追蹤氣體技術建立一簡易、實用之通風測量方法，以期適用於使用整體換氣之作業場所其通風特性之測定與評估。通風為工業衛生中危害控制之一環，通風功能之良窳對現場工作人員之健康有相當重要的影響。本研究分別選擇在三種不同類型之作業場所：半導體業之清淨室、大樓辦公室與印刷廠中進行。利用脈衝注射法或濃度衰減法，在待測空間之空調入口內釋放追蹤氣體六氟化硫或二氧化碳，由擺設在作業場所中位於呼吸區高度、不同位置的紅外光吸收光譜儀－MIRAN或B&K IR，記錄該測量地點之追蹤氣體濃度變化與時間之關係。由此計算出局部通風率、平均空氣年齡等通風參數。
由現場測量之結果顯示：作業環境空調出、回風口的位置與形式，空氣之再循環情況、與熱源分別為影響上述測量地點通風特性之關鍵。氣流型態為置換式氣流的清淨室，在空間的不同位置測得之平均空氣年齡差異可達4倍之多，並有氣流短路現象。在空氣總供應率8.5hr^(-1)之大樓辦公室經濃度衰減法求得其有效通風率僅0.7hr^(-1)；室內空氣主要為再循環使用。在印刷廠中，當其重要熱源－印刷機組開始運轉後，使原接近空氣完全混合之氣流型態變為不均勻混合，其中一測點之局部通風率約降為印刷機組完全未啟動時1/7，顯示熱源所在之位置與強度對通風帶來負面作用。

關鍵字

追蹤氣體技術 ； 平均空氣年齡 ； 通風特性

並列摘要

The primary objective of this study is to develop a practical method for evaluating ventilation parameters and investigating ventilation characteristics in work places equipped with a general ventilation system. Designed and operated properly, a ventilation system can be effective for hazards control. Three work places were selected for this study: a cleanroom, an office, and a printing factory. After a tracer gas (sulfur hexafluoride or carbon dioxide) was released into the air supply, its concentrations were measured at various locations by non-dispersive infrared photometers. The ventilation parameters, such as local ventilation rate and average age of air, were then calculated from the results obtained by tracer gas concentration decay method or pulse injection method.
The results of field measurements indicate that the position and type of air inlets and outlets, the air recirculation rate, and the heat sources were the key factors influencing the ventilation characteristics. In the cleanroom studied, the air was found to be short-circuiting and the average age of air at one of the air outlets was about one-fourth of the highest value measured in the cleanroom, In the office studied, the total supply air rate was 8.5 hr^(-1), but the effective ventilation rate was only 0.7 hr^(-1) because most of the air was recirculated. In the printing factory studied, the airflow pattern was found to be incomplete mixing when the printing machines (which act as heat sources) were in operation. Furthermore, one local ventilation rate was reduced to one-seventh of the rate when there were no significant heat sources. Clearly, the heat sources have negative effects on ventilation performance.

並列關鍵字

average age of air ； tracer gas techniques ； ventilation characteristics