熔融尿液泵出口尿液取样方法的讨论

熔融尿液泵（40I－J）出口尿液浓度高,温度高,容易生成缩二脲,为保证分析40I－J出口尿液缩二脲含量能真正反映尿素生产工艺状况,论证了采40I－J出口尿液样品直接取样是不正确的,提出在容量瓶中先加入一定量的蒸馏水进行取样的方法。     

防止尿液泵进口介质汽化的技术措施

1问题的提出 中石油宁夏石化分公司二化肥尿素主装置采用意大利斯那姆氨汽提工艺,装置从1999年9月试车到2002年5月底,低压预浓缩器尿液出口温度一直≤90℃,远离设计值103℃,预浓缩器出口尿液泵汽化非常频繁,由于打量不稳,又导致熔融尿液泵进口液位和出口打量频繁波动,最终导致造粒喷头易堵,严重时出现死床,成为影响造粒长周期运行的关键因素(造粒运行周期最长为7d,最短为2d),大大增加了清床造成的人、财、物资源浪费.     

熔融尿液泵机械密封失效原因分析及改进

介绍熔融尿液泵结构特点与运行情况,针对使用过程中机械密封损坏频率较高的问题,分析原因为尿液在密封腔内置换不完全、停运后结晶所致。改进机械密封结构,在密封腔部位增加冲洗口,并改进操作。改进后熔融尿液泵运行情况良好。     

IN型熔融尿液泵结构改进

通过对熔融尿液泵泵体结构缺陷的分析,提出并实施了相应的改进措施,保证了熔融尿液泵的正常使用。     

一起熔融尿素致使多人烫伤事故分析

一、事故经过 2009年11月22日9时,豫北一化肥厂尿素车间因造粒系统皮带电机故障,蒸发系统短时停运,85％尿液经尿液熔融泵P106直接送入熔融尿液储槽T101。10时10分造粒系统故障处理完毕,85％尿液由尿液熔融泵P106送入蒸发系统,走大循环提温提真空,10时25分达到造粒条件后送造粒。熔融尿液储槽T101的液位控制室DCS显示,由9时的3．9％上升到10时26分的86．7％。为防止尿液结晶,10时30分当班班长通知蒸发岗位启动尿液回收泵P109A打循环。     

尿液泵入口管道吸瘪事故分析及技改措施

中原大化集团年产30万t尿基复合肥装置采用法国KT尿液喷浆造粒工艺,尿液泵担负向造粒机内输送尿液。投产以来尿液泵运行较为正常,但在某年的一次开车过程中,尿液泵出现流量偏低,     

缩短1620t/dCO2气提尿素工艺熔融尿液泵倒运时间

从日常生产维护出发,通过技术改造解决了装置需停蒸发系统才能倒运熔融尿液泵的难题,通过在线倒运熔融尿液泵,缩短了倒运时间,避免了蒸发长时间打循环,减少成品缩二脲的生成,降低了蒸汽耗量和CO2耗量,提高了产品质量合格率,降低了生产成本。     

硫磺回收装置中夹套管的管道设计

硫磺回收装置中,输送液硫的工艺管道常使用蒸汽夹套管伴热系统。夹套管的管道设计要注意套管伴热的长度,要保证加热介质的流动畅通,还要注意内外管的材料和连接、夹套管的坡度和跨接管等问题。文中论述了夹套管内外管的选用、夹套管管件的选用原则,以及夹套管的连接方式,夹套管设计须注意的问题等。     

一种焦炉斜道口堵塞疏通工具

<正>本实用新型涉及一种焦炉斜道口堵塞疏通工具,该工具包括钎头、套管。钎头位于套管头部,与套管固定连接,套管内设有水夹套结构。所述的套管包括水夹套外管和水夹套内管,水夹套外管套在水夹套内管外侧,进水管通过内管接头与水夹套内管相连接,出水管通过外管接头与水夹套外管相连接;在水夹套内管的头部设有与水夹套外管的连通口。该工具结构简单、使用方便,由于采用了水夹套式结构,使用该工具时,可     

流化床造粒机的典型故障分析及对策

从造粒机流化空气风量、熔融尿液泵汽化、蒸发系统真空度、尿液喷头卡涩4个方面,分析流化床造粒机的典型故障成因,提出解决措施。     

乙烯酮(双乙烯酮)下游产品废水的治理技术

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。     

A study of miscibility of blends of polybutadienes of varying microstructure

The miscibility of various amorphous polybutadienes with mixed microstructures of 1,4 addition units (cis, 1,4 and trans 1,4) and 1,2 addition units have been investigated. The studies here involved optical transparency, differential scanning calorimetry, and small angle light scattering. It was found that a 90 percent (cis) 1, 4 addition polybutadiene was immiscible with high (91 percent) 1,2 addition polybutadiene. Reduction of the 1,2 content to 71 percent induced an upper critical solution temperature (UCST) with the cis 1,4 polymer. Polybutadienes with 50 percent and 10 percent 1,2 contents were miscible above the crystalline melting temperature of the cis 1,4 polybutadiene. Immiscibility of the 91 percent 1,2 addition polymer was also found with a 10 percent 1,2 polybutadiene. The latter polymer also exhibits an UCST with the 71 percent 1,2 polymer. The results are used to interpret the characteristics of blends of polybutadienes of varying microstructure.     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

粉煤灰中烧失量检测的不确定度分析

以F类粉煤灰为例,详细介绍了测定粉煤灰中烧失量的步骤、计算数学模型、影响测量不确定度的因素以及各项测量不确定度分量评定,人员、设备、材料、方法、环境都是影响测量不确定的因素。     

生物油的成分分析及物性测定

以添加FeCl2的ZnCl2-KCl混合熔盐裂解纤维素和秸秆,制得生物油。采用傅立叶变换红外光谱法和气相色谱-质谱法分析生物油的成分。结果表明,生物油中成分复杂,含有氧元素、多种有机化合物,主要包括酮类、醛类、酚类及羧酸类等。测定了20～80℃生物油的密度和粘度,发现生物油的密度与温度呈较好线性关系,而生物油的粘度均大于水的粘度,且不同熔盐体系对秸秆生物油的粘度无较大影响。     

分解炉扩径的技术改造

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     

Process of acceleration of filtration of viscose

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.     

Effect of degree of deacetylation of chitosan on the kinetics of ultrasonic degradation of chitosan

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