技術(shù)交流

1、水及其影響

      Water and its effects.

  在本文中描述的技術(shù)應(yīng)用中使用未經(jīng)處理的水（=自來水）是不可取的，因?yàn)檫@種類型的水在大多數(shù)情況下不具有必要的純度水平。因此，自來水必須經(jīng)過適當(dāng)?shù)奶幚恚员阕鳛榧夹g(shù)系統(tǒng)中消毒室和/或伴隨的蒸汽發(fā)生器的給水。

    The use of untreated water (= tap water) for the technical application described herein is not advisable, since this type of water does not possess the necessary level of purity in most cases. For this reason, tap water must be treated appropriately in order to be used as feed water for the sterilization chamber and/or the accompanying steam generator in technical systems.

     相關(guān)標(biāo)準(zhǔn)中規(guī)定了必要的水質(zhì)，其中DIN EN 285標(biāo)準(zhǔn)目前適用于消毒器的水質(zhì)領(lǐng)域(見表B1)。在實(shí)際應(yīng)用中，自來水通過單一混合床離子交換和/或涉及膜技術(shù)（反滲透）的系統(tǒng)進(jìn)行處理（實(shí)際淡化/脫鹽化）。在某些情況下，還可以使用額外的電化學(xué)脫鹽工藝。在每種情況下，目標(biāo)是以有目標(biāo)和控制的方式降低自來水中的離子或礦物質(zhì)含量，水的特定電導(dǎo)率通常被用作水質(zhì)的重要指標(biāo)。

   The necessary water quality is specified in the relevant standards, with the DIN EN 285 standard being currently applicable to the area of water quality for sterilizers (see Table B1). In practice, tap water is treated (for actual desalination / demineralisation) by means of a single mixed-bed ion exchange and/or in systems involving membrane techniques (reverse osmosis). In some instances, additional electrochemical post-demineralisation processes may also be used. In each case, the goal is to reduce the ion or mineral content of the tap water in a targeted and controlled manner.

1.1水的成分及處理方法

     Water constituents and treatment

  雖然在用于蒸汽生成的技術(shù)性水處理過程中偶爾會遇到引用“去離子水”，但應(yīng)該注意的是，“去離子水”不是一個(gè)定義規(guī)范的術(shù)語。結(jié)合歐洲藥典和美國藥典，“去離子水”被定義為“純凈水”。因此，每個(gè)人都可以自由地解釋“去離子水”或“部分去離子水”一詞的含義。從技術(shù)角度來看，這種情況是非常不令人滿意的，特別是當(dāng)人們認(rèn)為它似乎是非常重要的精確的定義標(biāo)準(zhǔn)化水質(zhì)所需的特定應(yīng)用，也能夠采取適當(dāng)?shù)牟襟E來監(jiān)測符合必要的/定義的質(zhì)量限制。

    Though one will occasionally encounter re- ferences to 'deionised water' in practice in the context of technical water treatment for steam generation, it should be noted that 'deionised water' is not a defined normative term. In the binding Ph. Eur. and USP compendiums, 'deionised water' is defined as 'aqua purificata'. As a result, each individual is free to interpret the meaning of the terms 'deionised water' or 'partially deionised water' for his/her own field of activity. From a technical standpoint, this state of affairs is highly unsatisfactory, especially when one considers that it would appear to be extre- mely important to have on hand at all times a precise definition of the standardised water quality required for specific applications, and also to be able to take the appropriate steps to monitor compliance with the required/defined quality limits for the water constituents.

  特別是當(dāng)在水處理中使用混合床離子交換時(shí)，對除鹽水的特定電導(dǎo)的連續(xù)監(jiān)測和處理水中硅酸含量的測試都很重要，因?yàn)楹笳撸ɑ蛴谜_分析的術(shù)語表示，硅酸鹽含量）不包括在特定電導(dǎo)的典型測量中。

    Particularly where the use of mixed-bed ion exchanges in water treatment is concerned, both a continuous monitoring of the specific electrical conductance of the demineralised water and testing for the silicic acid content in treated water are important, since the latter (or in analytically correct terms, the silicate content) is not covered by the typical measurement for specific electrical con- ductance.

  先前要求并達(dá)到的特定電導(dǎo)值為5μS/cm，并不自動等于允許的硅酸鹽含量（小于1mg/l）。硅酸鹽或硅酸的量只能用化學(xué)方法來確定，而不能通過測量電導(dǎo)率來確定。特別是在使用標(biāo)準(zhǔn)化的混合床離子交換時(shí)，人們會遇到反復(fù)發(fā)生的硅酸/硅酸鹽突破離子交換的問題。這就是為什么最終存在于處理過的水中的硅酸/硅酸鹽濃度經(jīng)常被認(rèn)為是在不銹鋼表面形成黃褐色到紫藍(lán)變色的（部分）原因。

    A required—and achieved—specific elect- rical conductance value of 5 μS/cm therefore does not automatically equal a permissible silicate content (of less than 1 mg/l). The amount of silicate or silicic acid can only be determined using chemical me- thods, not by measuring electrical conductance. Specifically where standardised mixed-bed ion exchanges are used, one encounters the reoccurring problem of the silicic acid / silicates breaking through the ion exchanges. This is why the silicic acid / silicate concentrations which are ultimately present in the treated water are frequently cited as being the (partial) cause of the formation of yellowish-brown to violet-blue discolourations found on stainless steel surfaces.

  其他信息可從德國儀器再處理工作組AKI（“儀器再處理，儀器再處理以保持價(jià)值”）在www.a-k-i-.org上出版的紅色手冊上獲得。

    Additional information is available from the Red Brochure published by the German Instrument Reprocessing Workgroup AKI ('Instrument Reprocessing, Reprocessing of Instruments to Retain Value') at www.a-k-i- .org.

  另一種有些情況下發(fā)現(xiàn)于經(jīng)過不完整或不恰當(dāng)?shù)奶幚磉^程的處理過的水中有不可接受的高濃度的元素，是氯離子。即使在滅菌過程后不銹鋼表面干燥時(shí)存在ppm量級的少量物質(zhì)，這也足在表面上的產(chǎn)生一個(gè)關(guān)鍵的聚積。在低氯化物濃度下，低耐點(diǎn)蝕等效數(shù)量的奧氏體不銹鋼合金，如1.401、1.440301、1.4404、1.4571或其他類似合金，表現(xiàn)出對氯化物引導(dǎo)（局部）點(diǎn)蝕和應(yīng)力腐蝕裂紋的敏感性。

    Another element that can in some cases be found in inadmissibly high concentrations in treated water following an incomplete or improper water treatment process (e.g. during water softening) are chloride ions. Even where small amounts on the ppm scale are present as the stainless steel surface dries following thesterilization process, this is enough to cause a critical accumulation on the surfaces. At low chloride concentrations, austenitic stainless steel alloys with low pitting resistance equivalent numbers in particular, such as 1.4301, 1.4404, 1.4571 or other similar alloys, exhibit a susceptibility to what is known as chloride-induced (local) pitting and to stress corrosion cracking.

Figure 3: Chloride-induced pitting

圖3：氯化物誘導(dǎo)的點(diǎn)蝕

    水處理的另一個(gè)重要因素是水中的實(shí)際氧含量。在室溫下，天然水總是含有一定數(shù)量的大氣溶解氧。這種氧含量可以通過在水處理過程中大大降低，特別是通過加熱。

    Another important factor for water treatment is the actual oxygen content in the water. At room temperature, natural water will always contain a certain amount of dissolved atmospheric oxygen. This oxygen content can be greatly reduced by the processes applied during water treatment – in particular, through heating.

    然而，由于氧—除了其他條件外—對鈍化層的形成至關(guān)重要，對在不銹鋼表面上保持這些層也相關(guān)，氧氣的使用方面對于任何其他考慮都是極其重要的。（也請參見第2章）   富含氧化鉻的鈍化層的破裂，不可避免地導(dǎo)致材料失去其化學(xué)惰性的表面性質(zhì)，并直接導(dǎo)致在關(guān)鍵的環(huán)境條件下可能出現(xiàn)腐蝕效應(yīng)。

    However, because oxygen—in addition to other conditions—is critical to the formation of passive layers and also in regard to maintaining these layers on stainless steel surfaces, the aspect of oxygen availability is extremely important for any other considerations. (see also Chapter 2)   Disruptions in the passive layer, which is rich in chromium oxide, inevitably cause the material to lose its chemically inert surfac e properties and, as a direct result, lead to the possible appearance of corrosion effects under critical environmental conditions.

來自：德國的錢伯斯工作組(德語縮寫：AKK)的手冊