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《化学工程》2013,(10)
为研究板式换热器碳酸钙的污垢特性,以BR0.015F型板式换热器为实验平台,研究了2种配制碳酸钙溶液方法(碳酸钠与氯化钙和碳酸氢钠与氯化钙)在板式换热器下的污垢特性,并用扫描电镜观察结垢表面的晶体类型。结果表明:在相同的实验条件下,碳酸钠法在板片表面结垢薄、易于清除,污垢没有凝结成块状,板式换热器速度场和温度场对污垢分布的影响不明显,扫描电镜观察污垢粉末多为六面体晶型,单个分布未粘结在一起。碳酸氢钠法在板片表面结垢相对致密、难于清除,污垢凝结成块状,板式换热器温度场的分布对污垢分布的影响明显,结垢量的分布与板式换热器数值模拟的温度场分布基本一致,扫描电镜观察污垢发现污垢晶体紧密的粘结在一起。 相似文献
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基于水处理技术抑垢及缓蚀效果在线监测实验台,进行了换热器表面污垢在电磁处理下生长特性的半工业性实验研究。通过污垢热阻的在线监测跟踪换热器表面碳酸钙的结垢过程。利用Quanta 200扫描电子显微镜及X'Pert Pro X射线衍射仪对污垢样本的晶型、晶貌进行了定性和定量分析,表述了电磁场对碳酸钙晶型及晶貌的影响。实验结果表明:电磁场能降低换热器表面的结垢速率,垢样中方解石质量分数由100%降低为40.55%,文石质量分数增加为59.45%。 相似文献
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结垢是油田采出水集输过程中遇到的最严重的问题之一,为了避免由于结垢而造成的不良影响,应对结垢类型及趋势进行科学而准确的预测,现场可以根据预测结果采取相应的防垢和除垢措施。大庆油田集输及污水系统出现结垢问题,对系统中各节点的水质指标以及特征垢样的外貌特征和组成成分进行分析,结果表明集输及污水系统水质有碳酸盐和硅酸盐结垢趋势,现场垢样是碳酸盐、有机物、硅酸盐和氢氧化铁等的混合垢,主要成分是碳酸钙。使用稳定指数法(SAI)对大庆油田集输及污水系统碳酸钙结垢趋势及最大结垢量进行预测。预测结果:稳定指数4.0SAI5.0,最大结垢量100PTB250,严重结垢。 相似文献
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某电厂在生产过程中用循环水作为主机油换热器的冷却水,设备运行一段时间后频繁出现结垢问题,对循环水水质、垢样化学成分分别进行检测,结果显示循环水的硬度值偏高,垢样中主要成分为碳酸钙、硅酸钙和二氧化硅。另外在换热过程中循环水易产生有机物颗粒,加上主机油对油温的要求,循环水流量不能过高,导致板式换热器板间通道更容易堵塞,进而导致结垢。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses. 相似文献
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