<track id="l3lpn"></track>

    <menuitem id="l3lpn"><dfn id="l3lpn"></dfn></menuitem>
    <big id="l3lpn"><sub id="l3lpn"></sub></big>

        <address id="l3lpn"></address>

            
            

                <ins id="l3lpn"><track id="l3lpn"></track></ins>

                <track id="l3lpn"></track>

                  德州川和空調設備有限公司為您免費提供恒溫恒濕機組,直膨式空調機組,高效過濾器等相關信息發布和資訊展示,敬請關注!

                  全國咨詢熱線

                  13792948766

                  德州川和空調設備有限公司

                  高效過濾器泄漏率測試:≤0.01%是否必須?

                  來源:http://www.arnikafence.com/news694029.html 發布時間:2021-10-5 3:00:00

                  What is the Acceptance Criteria of HEPA?


                  什么是高效過濾器的接受標準?


                   


                  The approach most test standards take regarding acceptance criteria isthat the acceptable leak size limitsare ultimately determined by the customerand supplier. However, a scan test leak size limit of greater than or equal to0.01% has generally been adopted for many applications utilizing HEPA flters orclean areas of varying classifcations. Although the 0.01% leak size has beenused historically and has its origins linked to early generation analog photometertest equipment, establishing a leak size limit of 0.01% as an acceptancecriteria without performing a science and risk-based assessment can result inissues relating to leak testing and can contribute to signifcant operationalcosts if an out of tolerance or failed condition is identifed in a low riskarea. As previouslynoted in Section 6.5, flters are not 100% efcient and areexpected to have some natural or integral penetration of particles near theMPPS. Test acceptance limits become more controversial or problematic whenutilizing lower-rated HEPA flters where the acceptable factory penetration ator near MPPS can be comparable to or larger than the feldtest leak sizeacceptance criteria. This is especially true where the bleed through e?ectcan occur (see Section 6.9).When purchasing a flter, it is thereforeimportant to consider a flter’s rating as well as how it will be tested after installationin order to avoid unnecessary feld test failures.


                  大多數測試標準關于高效過濾器泄漏率的接受標準是,可接受的泄漏限度最終由客戶和供應商共同確定。但是,對于使用HEPA過濾器或不同級別潔凈區的許多應用,大多數采用≤0.01%的掃描測試泄漏標準。盡管0.01%的泄漏率在歷史上已經使用過,并且其起源與早期的模擬光度計測試設備相關聯,但在沒有進行科學和基于風險的評估的情況下,將0.01%的泄漏率標準作為可接受標準將導致與泄漏測試有關的問題,并且如果在低風險區域發現超限或失敗情況,將可能會帶來巨大的運營成本。過濾器不是100%截留的,并且預計MPPS附近的粒子在過濾器局部或整體可以穿透。當使用較低級別的HEPA過濾器時,工廠進行的MPPS或MPPS附近粒子的可接受泄漏率標準可能等于或大于現場泄漏率測試的接受標準,測試接受標準會變得更具爭議和困難。在可能發生泄漏的地方尤其如此。因此,在購買過濾器時,考慮過濾器的等級以及安裝后如何進行測試非常重要,以避免不必要的現場測試失敗。


                   


                  ISO 14644-3 [33] gives guidance on how alternative leak acceptancecriteria can be implemented. In a risk-based approach, it may be ideal to haveacceptance criteria that trends with the eficiency of the flters being used orthecleanliness of the room being tested. ISO 14644-3 uses the factory flter efciency rating as the basis of acceptancecriteria negotiation. The leak acceptancecriteria for a photometer leak test and a particle counter based leaktestshould be the same, as the theory and methodology behind leak sizing isidentical for both methods. If performedproperly, a leak test with a photometerand a particle counter will result in the same leak size (Meek, et al., 2011[121]).


                  ISO 14644-3 [33]提供了有關如何實施泄漏替代標準的指南。 在基于風險的方法中,理想的接受標準是,該接受標準可以反映所使用過濾器的效率或所測試房間的潔凈度。 ISO 14644-3使用工廠過濾效率等級作為接受標準協商的基礎。光度計泄漏測試和基于粒子計數器的泄漏測試的泄漏接受標準應該相同,因為兩種方法背后的理論和方法是相同的。如果執行得當,使用光度計和粒子計數器進行的泄漏測試將得到相同的泄漏率結果(Meek等,2011 [121])。

                  A leak detected in excess of 0,01 % of the upstream massconcentration is deemed to exceed themaximum allowable penetration. However,for filter systems of an integral efficiency at MPPS ≥ 99,95 %and less than99,995 %, the acceptance criterion is 0,1 %.


                  如果檢測到的泄漏量超過上游濃度的0.01%,一般認為該泄漏率超過最大允許標準。但是,對于整體效率MPPS≥99.95%且小于99,995%的過濾器系統(如H13過濾器),接受標準為0.1%。


                   


                  If filter systems of an integral efficiency lower than 99,95 %at MPPS are to be tested, a different acceptance criterion are necessary, basedon agreement between customer and supplier.


                  如果要測試 MPPS 整體效率低于 99.95% 的過濾系統,則根據客戶和供應商之間的協議,需要不一樣的接受標準。






                  The flters for depyrogenation tunnel


                  用于去熱原隧道的高效過濾器




                  The flters ftted to a depyrogenation tunnel are subject toprolonged periods of high temperature operation, so standard flters are notsuitable. Special flters rated to 350°C are available with a manufacturerguaranteed efciency of 99.99% for 0.3 μm particles (note that the FDA defnitionof a HEPA is > 99.97% at 0.3 μm) at a temperature of 350°C) with a ceramicmaterial used for the media to frame seal. Recently there have been advances inthe materials available and ?exible sealants are being introduced that canreduce the heat up time and reduce the risk of sealant cracking. Traditionalflters need to have a controlled heat up and cool down time (typically not toexceed 1°C per minute; the rate should be confrmed with the flter supplier) toprevent heat stress damage to the seals. Often the systems are maintained hotduring periods of non-use to reduce the heat cycling on the flter.


                  安裝到去熱原隧道中的過濾器需要經受長時間的高溫操作,因此不適用標準過濾器。廠家使用陶瓷材料用于濾材與邊框的密封可提供耐受350℃的對0.3 μm顆粒的效率為99.99%的特殊過濾器(注,FDA對HEPA的定義為> 99.97%@0.3 μm)。最近,可用的材料有了進步,并且引入了柔性密封劑,可以減少加熱時間并降低密封劑開裂的風險。傳統的過濾器需要具有受控的加熱和冷卻速度(通常不超過1℃/分鐘;應與過濾器供應商確認該速率),以防止熱應力損壞密封件。通常,在不使用期間,系統會保持高溫,以減少過濾器的加熱循環。


                   


                  Filters used for depyrogenation tunnel are generally H14. Theseflters can be full face scan leak tested on installation, but after the initialheating cycle (burning in the flter, which usually results in the flter gradebecoming equivalent to H13) traditional testing is not recommended. The oilaerosol (if it is Polyalphaolefn (PAO)) will load onto the flter and burn o?,giving o?unhealthy fumes, and may load the flter media; this is usually more fragileafter burn in as the binder holding the media together has o?-gassed.DEHS (Diethylhexyl Sebacate) is an alternative oil that may evaporatefaster.


                  用于去熱原隧道的過濾器通常是H14。這些過濾器可以在安裝時進行全面掃描泄漏測試,但是在首次加熱循環之后(過濾器會燃燒,通常會導致該過濾器等級與H13相當),不建議再進行傳統測試。因為氣溶膠油(如聚α烯烴(PAO))將被截留到過濾器上并燃燒,從而產生不健康的煙霧,并可能堵塞過濾介質。由于將過濾器介質粘合在一起的粘合劑在燃燒會放氣,通常導致過濾器變脆。DEHS(癸二酸二乙基己酯)是一種可能會更快蒸發的替代油。

                  相關標簽:高效過濾器,過濾器,高效過濾器廠家,德州高效過濾器,

                  查看更多>>

                  相關新聞

                  查看更多>>

                  相關產品

                    <track id="l3lpn"></track>

                    <menuitem id="l3lpn"><dfn id="l3lpn"></dfn></menuitem>
                    <big id="l3lpn"><sub id="l3lpn"></sub></big>

                        <address id="l3lpn"></address>

                            
                            

                                <ins id="l3lpn"><track id="l3lpn"></track></ins>

                                <track id="l3lpn"></track>

                                  2012年中文在线看免费观看_久久天堂综合亚洲伊人hd_又色又爽又黄的视频网站_一本大道一卡二卡三卡 视