應用六標準差方法於沸石轉輪焚化系統之操作最佳化研究

Abstract

近年來，高科技產業之空氣污染防制已不斷地導入新穎處理設備，表示企業對環境保護要求已非只符合空污法規門檻，而是追求企業責任與綠色的零污染工業。於既存之空污防制設備上，也被要求持續提升去除效率，以有機廢氣處理之沸石轉輪焚化處理設備為例，往往在效率與運轉成本呈現衝突狀況，若要提高效率，就可能需要犧牲運轉成本。本研究以六標準差之D-M-A-I-C (Define-Measure-Analyze-Improve-Control) 改善步驟手法，以特性要因圖、柏拉圖、效果圖及SPC等品質管制圖表，並套用Minitab軟體工具，逐一探討分析有機廢氣之沸石轉輪直燃處理系統，以便了解如何在提升處理效率下，也可同時降低運轉成本。 經研究結果顯示，影響處理效率及燃料用量共有15個因子，利用品質分析圖表及回歸分析，可將其收斂至3個主要因子，分別為脫附風量、脫附溫度及燃燒溫度，此3因子對處理效率之影響貢獻度達92.2%；對燃料用量則為75.8%。透過實驗設計法(DOE)，發現脫附風車頻率及燃燒溫度偏高操作、而脫附溫度偏低操作，可同時提升效率及節省燃料用量。實際運用於VOCs處理設備之案例研究結果顯示，其最佳化組合為脫附風車頻率45 Hz、燃燒溫度710 ℃及脫附溫度200 ℃。依其最佳化參數，所得之出口有機排放量由0.28 kg/hr降低至0.24 kg/hr，減少14 %；去除效率由95.9 %提升至96.9 %，提升約1 %。另針對衍生指標的瓦斯耗量，由25 m3/hr降低至23.9 m3/hr，減少4.4 %。

The zeolite rotor/oxidizer system for organic waste gas emission reduction is an advanced air pollution control device (APCD) which is widely applied in many high-tech. industry plants. However it is often under the conflict situation between operation efficiency and the operating costs. In this study, the six standard deviations method which uses the D-M-A-I-C (Define-Measure-Analyze-Improve-Control) approach to improve the system operation is employed. It has incorporated the characteristic figure、Plato figure、effect figure、SPC and other quality control charts as well as Minitab software as tools for understanding, optimizing and improving the operation condition. This would help in improving the process efficiency of a zeolite rotor/oxidizer while reducing the operating cost at the same time. Research results show that there are a total of 15 factors influencing the operation efficiency and fuel consumption. By using quality analysis charts and regression analysis, it converges to 3 major factors, inverter frequency of desorption fan, desorption temperature and combustion temperature. The 3 factors have a major effect on the operation efficiency with contribution of as high as 92.2%; while it is 75.8% on the fuel consumption. And through the Design of Experiment (DOE), it is found that by increasing the frequency of desorption fan and the combustion temperature as well as by decreasing the desorption temperature, both the operation efficiency can be enhanced and the fuel consumption can be reduced. As a result, the optimization condition for the case study shows that desorption fan inverter frequency is 45 Hz, the combustion temperature is 710℃ and the desorption temperature is 200℃. This yields that the organic emission is reduced by 14% from 0.28 kg/hr to 0.24 kg/hr; the operation efficiency was enhanced by 1% from 95.9% to 96.9%. The Fuel consumption was cut by 4.4% from 25 m3/hr to 23.9 m3/hr.