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31.
阐述了中央空调制冷机结垢的类型及其产生的原因和危害,分析了中央空调制冷机的冷媒水系统、冷却水系统的化学清洗技术和操作方法. 相似文献
32.
叙述了洞庭氮肥厂合成氨装置高压蒸汽发生系统以碱洗、酸洗、钝化为主要环节的首次化学清洗工艺,阐述了清洗机理,总结了清洗处理要点。 相似文献
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This study determines the influences of siloxane flow agents’ migration on the outermost surface composition of clearcoats, before and after ethanol cleaning. This evaluation is undertaken to improve adhesion of pressure-sensitive adhesives (PSAs) on automotive paint systems. Most of the siloxane flow agents segregate from the bulk to the clearcoat outermost surface during curing. These additives can cover until 50% of the surface area but X-ray photoelectron spectroscopy (XPS) and time of flight-secondary ion mass spectrometry (ToF-SIMS) analyses indicate that they can be removed by ethanol cleaning. Composition of the cleaned clearcoats surfaces are similar as the composition of clearcoat formulated without siloxane additives: the polyester-(melamine)-polyurethane network is more detected than before cleaning. However, outermost surface analyses show that several aging weeks increase the siloxane additives segregation. This post-cleaning migration modifies the clearcoat surface composition and cancels the chemical modifications due to the ethanol cleaning. XPS analyses show that silicon concentrations after cleaning and aging are inversely proportional to the initial silicon concentrations measured after curing. It highlights that aging has to be controlled to improve adhesion of PSAs on clearcoats. A second ethanol cleaning on aged clearcoats is not effective to remove these new siloxane additives. Their formulation should be different from the flow agents and it could modify their solubility in ethanol. This result could also indicate that these new siloxane additives are not located on the last molecular layer of surface and they would not be soluble in ethanol. 相似文献
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中国加入WTO后,中国洗涤用品行业面临着新的机遇与挑战,中国洗涤用品市场将面临更加激烈的竞争。由于环保的呼声越来越高,中国已开始在部分地区禁磷。中国洗涤用品工业将如何发展,其前景如何,专家的看法又如何,就这些问题本刊专访了有关人士。 相似文献
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分析了影响热媒炉热效率的主要因素 ,介绍了通过对热媒炉盘管干冰除灰和改进风油比控制方式来提高热效率的方法 ,指出提高热媒炉热效率的主要途径是 :降低排烟温度和空气过剩系数。 相似文献
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Chateau Marie-Elise Galet Laurence Soudais Yannick Fages Jacques 《Journal of surfactants and detergents》2004,7(4):355-362
A new test was developed to assess the efficiency of no-wiping hard-surface cleaning. The test allows cleaner comparisons
according to their ability to remove greasy soils. The chosen approach minimizes the mechanical forces applied while cleaning
so that the interactions between a detergent solution and the soil to be removed can be characterized. For this, immersion
cleaning was chosen, with coated stainless steel as substrate and pigmented oils as the model soil. Several parameters were
studied in defined ranges using the Experimental Design method and systematic comparisons. The test shows high reliability
on degreasing assessments and is there-fore especially suited to optimization of nonionic surfactant mixes. The originality
of the test lies in the possibility of keeping a visual trace of the cleaned substrate appearance by imprinting it on a piece
of paper. The validation of the test leads to corroboration of several practical observations. Temperature and agitation play
a major role in cleaning efficiency. Detergent solution concentration is a more relevant parameter than pH. Sodium carbonate
is shown to have a higher buffering effect than pentahydrated sodium metasilicate. The test is easy to set up, highly sensitive,
and can be adapted to solve the problems encountered by formulators of detergent cleaners, such as screening the best ethoxylated
fatty alcohol mix for better degreasing properties. 相似文献