水霧及細水霧對醋酸的吸收效率探討

Abstract

在環保法令中，將氯歸屬第三類毒性化學物質【1】，其對呼吸系統有強烈刺激性且具有毒性與腐蝕特性，在製程上如有操作或管理不當，經暴露將立即危害人體健康或生物生命，並且對生態環境造成影響。本研究以醋酸模擬洩漏氯氣施以水霧、細水霧及灑水系統實施不同噴灑壓力、流量等實驗探討其吸收效率之優劣。本研究發現各系統皆呈現隨著噴灑時間增長或噴灑壓力提高會使吸收效率提升的趨勢。在不考慮自然通風換氣時，理論推估水霧系統末端噴灑壓力2.5kg/cm2 以上、持續噴灑40 分鐘以上才能達到91.66%吸收效率。消防自動灑水系統即使噴灑時的流量較水霧及細水霧系統噴灑流量高很多，但並未呈現出良好的吸收效率。細水霧系統在噴灑壓力為20-50kg/cm2 的實驗結果顯示，以最大壓力時的50kg/cm2，滴的粒徑最小吸收效率表現最好，在不考慮自然通風換氣時，理論推估只要持續噴灑30 分鐘即可達90.62%吸收效率，60 分鐘更可達99.12%的吸收效率。

In environmental laws, chlorine gas is classified as the third type toxic chemical substance1. It is a strong stimulant to the respiratory system, and has toxic and corrosive characteristics. Upon exposure due to improper operation or management,human health will be threatened and ecological environment will be affected. This study investigated the absorption efficiency of acetic gas to simulate the leaking chlorine gas by using water mist, fine water mist and water sprinkler systems at different spray pressures and flow rates. It was found that for all systems, the absorption efficiency increased with increasing spraying time. The theoretical calculation shows that the spraying pressure of the water mist system must be over 2.5kg /cm2 and lasts for over 40 minutes for the absorption efficiency to reach 91.66 %.The absorption efficiency for the fire sprinkler system is low even if the flow rate is much higher than that in the water mist and fine water mist systems. For theexperiments of the fine water mist system using the spraying pressure from 20 to 50kg/cm2, the best absorption efficiency was obtained at the maximum spraying pressure of 50 kg /cm2 which had the smallest droplet size. At this pressure, the predicted absorption efficiency without considering air exchange due to natural ventilation is 90.62 % for 30-min spraying time, and 99.12 % for 60-min spraying time.