(3.231.229.89) 您好!臺灣時間:2019/12/15 21:27
字體大小: 字級放大   字級縮小   預設字形  
回查詢結果

詳目顯示:::

我願授權國圖
本論文永久網址: 
line
研究生:陳春萬
研究生(外文):Chun-Wan Chen
論文名稱:防塵濾罐過濾品質探討
論文名稱(外文):The Filter Quality of Dust Cartridge
指導教授:陳志傑陳志傑引用關係
學位類別:博士
校院名稱:國立臺灣大學
系所名稱:職業醫學與工業衛生研究所
學門:醫藥衛生學門
學類:公共衛生學類
論文出版年:2008
畢業學年度:96
語文別:中文
論文頁數:53
中文關鍵詞:防塵濾罐呼吸防護具穿透率通氣阻力摺疊濾材最佳摺疊數
外文關鍵詞:Dust cartridgeRespiratorPleated filterFilter qualityPenetrationFlow resistanceOptimal pleat count
相關次數:
  • 被引用被引用:4
  • 點閱點閱:255
  • 評分評分:系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔系統版面圖檔
  • 下載下載:0
  • 收藏至我的研究室書目清單書目收藏:0
研究就過濾品質觀點,探討職業衛生常見之防塵濾罐影響因素,研究透過單一纖維理論模擬計算濾材表面風速、濾材靜電密度、濾材纖維直徑、填充密度、厚度、濾材積重、濾材不均勻度等對濾材過濾品質、穿透率、與最易穿透粒徑之影響。研究也設計實驗,測試防塵濾罐常採用之摺疊方式對過濾品質之影響。
研究各項濾材影響因素帶入單一纖維理論,計算各項過濾幾制,求得不同微粒粒徑下之濾材性質,每次計算只更改一個變項,評估各項因素對濾材性質之影響。研究發現影響濾材過濾品質最大影響因素為過濾風速,要增加濾材過濾品質應該降低濾材表面風速及填充密度,而應該增加及濾材靜電密度及濾材纖維直徑。濾材穿透率隨著過濾風速及纖維直徑增加而增加,而隨著填充密度、厚度、靜電密度增加而降低,此影響趨勢與濾材過濾品質部份不相同,若不考慮通氣阻力,濾材製造商可降低纖維直徑及增加填充密度,來達到濾材低穿透率,但所增加之通氣阻力,使得濾材過濾品質下降。研究也發現,最易穿透粒徑(MPS)也會受到這些因素之影響,現階段各國測試規範都是設定特定粒徑微粒進行測試,就模擬中最易穿透粒徑變化情形來看,特定微粒粒徑測試結果並不能代表所有粒徑微粒之捕集效率。規劃未來呼吸防護具防塵濾罐測試規範時,應該更慎選測試微粒粒徑,也應該考慮未來可能發展之低濾材表面風速與高靜電密度濾材,如何進行測試與負載及儲存之管理,另也應考慮設定更嚴格的通氣阻力要求,讓呼吸防護具廠商更重視濾材過濾品質。
對於摺疊濾材研究採用單一一摺之摺疊濾材進行實際穿透率及通氣阻力量測,研究透過浸泡異丙醇方式及挑選相同通氣阻力之方式,降低濾材本身(含靜電密度)之的差異。實際測試結果顯示,通氣阻力量測部份證實與文獻之趨勢符合,摺疊濾材之穿透率及過濾品質與測試微粒粒徑及摺疊數都有關係,就現有研究對於過濾品質考慮之最佳摺疊數,約較最低通氣阻力之最佳摺疊數增加每公分0.5摺。研究中推測摺疊濾材中濾材表面風速並不均勻分布,因此造成摺疊濾材穿透率降低,特別是高摺疊數濾材。
研究已掌握濾材品質之各項影響因素之影響趨勢,可供防塵濾罐測試規範修訂之方向,也可提供濾材生產廠商努力方向之參考,但對於實際之影響係數與生產技術,則須更多實驗設計才能更精確掌握實際影響因素,例如濾材表面風速降低與濾材靜電密度增加是否有一定限制,而對於應用於防塵濾罐上,是否有其使用上限制與管理之要求,而防塵濾罐測試規範如何研擬,以及濾材廠商如何設計生產更高品質之防塵濾罐,都需更多研究或更多測試數據補強。
The filter quality of dust cartridge depends both on the collection efficiency of the filter material and the pressure drop across the filter, and is affected by the face velocity, fiber diameter, packing density, filter thickness, charge density, and homogeneous of the filter. The study used theoretical model to examine the filtration factors effect the penetration and filter quality. The study also used the experiment to measure the collection efficiency and the pressure drop of pleated dust cartridge.
The study used theoretical model to measure the penetration and filter quality on each aerosol sizes depend on one filtration factors. The results showed the filter quality effects more significant with face velocity than the other mechanisms, the filter quality increase with face velocity decrease and charge density increase. The penetration increases with face velocity, fiber diameter increase, and packing density, thickness, charge density decrease. The most penetrating size increases with face velocity, fiber diameter increase, and packing density, thickness, charge density decrease. But for filter with no charge, the most penetrating size increases with face velocity decrease and doesn’t effect by thickness.
The study of pleat filter fabricated six sizes of filter holders to hold just one pleat of filter, simulating six different pleat counts, ranging from 0.5 to 3.33 pleats per centimeter. The possible electrostatic charges on the filter were removed by dipped in isopropyl alcohol (IPA), and the air velocity is fixed at 100 centimeter per second. Liquid dicotylphthalate (DOP) particles generated by a constant output atomizer were used as challenge aerosols to minimize particle loading effects. A scanning mobility particle sizer (SMPS) was used to measure the challenge aerosol number concentrations and size distributions upstream and downstream of the pleated filter. The pressure drop across the filter was monitored by using a calibrated pressure transducer.
The results showed that the performance of pleated filters depend on not only the size of particle but also the pleat count of the pleated filter. Based on filter quality factor, the Optimal pleat count (OPC) is always higher than that based on pressure drop by about 0.5 pleats per centimeter. From the aspect of filter quality factor, this study suggests that the respirator manufacturers should add about 0.5 pleats per centimeter to the OPC derived from the generalized correlation curve for pleated filter design based on minimum pressure drop.
口試委員會審定書 II
摘 要 III
ABSTRACT V
目錄 VII
表目錄 IX
圖目錄 X
第一章 前言 1
第一節 濾材之過濾機制及影響因素 2
第二節 摺疊濾材 9
第二章 研究方法 13
第一節 各項因素影響過濾品質情形 13
第二節 摺疊濾材之穿透率與過濾品質 14
第三章 結果與討論 17
第一節 各項因素影響過濾品質情形 17
第二節 摺疊濾材 24
第四章 結論 28
參考文獻 30
1.Barrett, L.W., 1998; “ Aerosol Loading Performance of Electret Filter Media” Am. Ind. Hyg. Assoc. J. 59(8): 532-539
2.Brown, R.C., 1993; “Air filtration: an integrated approach to the theory and applications of fibrous filters”, Pergamon, Oxford, U.K.
3.Chen, C.C., M. Lehtimaki, and K. Willeke, 1993; “ Loading and Filtration Characteristics of Filtering Facepieces” Am. Ind. Hyg. Assoc. J. 54(2):51-60.
4.Chen, C.C. and S.H. Huang, 1998; “The Effect of Particle Charge on the Performance of an Electret Filtering Facepiece” American Industrial Hygiene Association Journal, 59(4): 227-233
5.Chen, D.R., D.Y.H. Pui, B.Y.H. Liu, 1995; “Optimization of pleated filter designs using a finite- element numerical method” Aerosol Sci. and Tech. 23:579-590
6.Cho, S.-J., Y. Otani, H. Emi, K. Oshima, 1994; “Characteristics of flow and pressure drop in a separator type filter”, 4th International aerosol conference, Los Angeles; CA, Aug.:976-977
7.Dhaniyala S. and B. Y. H. Liu, 2001; “Theoretical Modeling of Filtration by Nonuniform Fibrous Filters”, Aerosol Science and Technology 34: 170–178
8.Emi, H., C. Kanaoka, Y Otani, and T. Ishiguro, 1987; “ Collection Mechanisms of Electret Filter”, Particulate Sci. and Technol. 5:161-171
9.Fabbro, L. D., J. C. Laborde, P. Merlin, L. Ricciardi, 2002; “Air flow and pressure drop modeling for different pleated industrial filters”, Filtration+Separation January/February:34-40
10.Hinds, R.C., 1999; “Aerosol Technology, 2nd Edition”, John Wiley & Sons, Inc.
11.Lathrache, R., and H.J. Fissan, 1987; “Enhancement of Particle Deposition in Filters due to Electrostatic Effects” Proc. of the Filtration Society 418- 422
12.Lee, K.W. and B.Y.H. Liu, 1982; “Theoretical Study of Aerosol Filtration by Fibrous filter.” Aerosol Sci Technol. 1:147-161
13.Lucke, T., Fissan, H., 1996; “The prediction of filtration performance of high efficiency gas filter elements”, Chemical engineering science, 51(8):1199-1208
14.Moyer, E.S. and G.A. Stevens: “Worst Case”Aerosol Testing Parameters:II. Efficiency Dependence of Commercial Respirator Filters on humidity Pretreatment. Am. Ind. Hyg. Assoc. J.50 (5):265-270, 1989.
15.Moyer, E.S. and G.A. Stevens: “Worst Case”Aerosol Testing Parameters: III. Initial Penetration of Charged and Neutralized Lead Fume and Silica Dust Aerosols through Clean, Unloaded Respirator Filters. Am. Ind. Hyg. Assoc. J.50(5):271-274, 1989.
16.NIOSH, 1995; “42 CFR Part 84 Respiratory protection devices; Final Rules and Noice.” Federal Register 60:110(8 June 1995)
17.Plog, B. A., 1988; “Fundamentals of Industrial Hygiene” 3rd. National Safety Council.
18.Pui, D.Y.H., Chen, D.R., Liu, B.Y.H., 1994; “Optimization of pleated filter design using a finite element numerical method” J. Aerosol Sci. 24, Suppl. 1,39-40
19.Shapiro, M., 1996; “An Analytical Model for Aerosol Filtration by Nonuniform Filter Media” J. Aerosol Sci. 27, 263-280
20.Spurny, K.R., 1998; “Advances in aerosol filtration”, CRC/Lewis, Boca Raton, FL.
21.Subrenat, A., J. Bellettre, P. Le Cloirec, 2003; “3-D numerical simulations of flows in a cylindrical pleated filter packed with activated carbon cloth” Chemical Engineering Science 58, 4965 – 4973
22.Walsh, D.C., J.I.T. Stenhouse, 1997; “The effect of particle size, charge, and composition on the loading characteristics of an electrically active fibrous filter material”, J. Aerosol Sci., 28(2): 307-321
23.Wu, H.S., M.C. Yen, H. Chiang, B.C. Yang, 2002; “Study of the pressure drop of pleated filters upon some influential parameters” 6th International Aerosol Conference, Taipei, Taiwan, September 9-13
24.黃盛修, 1997﹔”低填充密度纖維性濾材過濾與負載特性研究”,國立台灣大學公共衛生學院碩士論文
QRCODE
 
 
 
 
 
                                                                                                                                                                                                                                                                                                                                                                                                               
第一頁 上一頁 下一頁 最後一頁 top
系統版面圖檔 系統版面圖檔