Rotary-vane compressors: Some technical aspects of long-life lubricants

Compressors are used all over the world for various individual applications; the current application concerns their use in the ozone process of water treatment. Technical data on different mineral and synthetic lubricants are given. In particular, a new oil was chosen for investigation. Field testing was undertaken over more than 6000 h on two different locations. Used oil monitoring was conducted by sampling during the experiment; analyses of physical and chemical parameters were made and their kinetics are described. Wear, viscometrics and ozone process interaction are discussed in this study.     

催化裂化催化剂铁污染研究进展

介绍近年关于FCC催化剂铁中毒现象的研究进展。平衡剂上铁存在新鲜催化剂自身铁、原油原有铁和过程铁3个来源,其中,高酸原油的过程铁含量已不容忽视。催化裂化过程中,原料油中以环烷酸铁为主的铁物种不断沉积在催化剂的表面,与催化剂中的钠、氧化硅形成低熔点共熔物,形成覆盖平衡剂表面的光滑结构,堵塞催化剂的孔道,导致汽油产率下降,严重影响装置稳定运行。根据铁中毒的机理研究,提出加强人员技术交流与培训、提高分析检测频次、应用抗铁污染催化剂、铁中毒解决方案等预防和应急措施,为加工高铁含量原料油催化裂化装置的长期稳定运行提供技术参考。     

无黏土相盐水储层钻开液体系构建及其抗污染性能评价

采用NaCl/KCl/HCOONa复配欠饱和盐水作为钻开液的基础液相,自研的聚合物VIS-B作为流型调节剂,可酸溶的改性淀粉STA作为体系的降失水剂,Dua及Jqw作为暂堵材料,构建了一套无黏土相钻开液体系.该体系在密度1.10～1.28 g/cm3间稳定可调,抗温可达130℃,具有较高的低剪切速率黏度和较好的润滑性能...     

Catalytic conversion of MTBE to biodegradable chemicals in contaminated water

The behavior of different acid zeolites in the hydrolysis at room temperature of methyl tert-butyl ether (MTBE) was studied with reference to the possibility of its conversion to more biodegradable products in underground water contaminated by MTBE. The effect of the structure of the zeolite and SiO₂/Al₂O₃ ratio was analyzed. The results indicate that acid H-MFI and H-BEA zeolites are effective in both adsorption and hydrolysis of MTBE and may be applied for both in situ underground water remediation and as protection barrier for wells or leaking tanks. However, other zeolites (mordenite and faujasite) result completely inactive. Furthermore, contrary to what was expected, the increase of the Si/Al ratio promotes the reactivity which is determined by the resistance to diffusion of MTBE in the pores of zeolites and the resistance of back-diffusion of the reaction products.     

深度型过滤材料进流面和出流面使用效果差异

滤材料的流体通过性能及过滤性能与过滤材料的结构特性密切相关。所以,在使用过滤材料的时候,要充分考虑其结构特性,使其得到充分合理的利和     

有色金属矿区土壤重金属污染调查与修复研究进展

有色金属矿区是土壤重金属污染的主要地区之一,本文主要基于土壤重金属元素基准值、土壤理化特征、土壤重金属元素空间分布特征、土壤重金属元素形态特征、土壤重金属污染源同位素示踪等方面调查,为生物修复,物理、化学和联合修复的不同修复方法选择及土壤重金属污染监测提供科学依据。     

[可靠性建模及试验技术]重型机床液压元件油液污染退化量分布剖面可靠性建模

针对重型机床液压系统故障频繁且多与油液中的固态颗粒污染物相关的问题,进行了油液污染趋势变化试验。通过时域分析获得了油样颗粒数的有量纲和量纲一参数,通过Q-Q图和K-S检验分析有量纲参数,污染颗粒数是退化量服从正态分布的退化数据。进行了油液污染与环境相关性分析试验,采用相关系数法分析得到,颗粒数变化量与一定范围内的温度、流量、压力的相关性小;将液压元件分为管路、阀、过滤器三类,用直径5 μm左右的颗粒和直径大于15 μm的颗粒分别研究管路及阀件的堵塞和磨损情况,以过滤器过滤精度大小的颗粒研究过滤器的堵塞情况,设定ISO4406标准20/17级对应的颗粒数为阈值,利用退化量分布建立了液压元件单一故障模式的可靠性模型;利用竞争失效模型将上述模型融合为多故障模式下的可靠性模型。     

Assessing the public health risk of microbial intrusion events in distribution systems: conceptual model, available data, and challenges

Low and negative pressure events in drinking water distribution systems have the potential to result in intrusion of pathogenic microorganisms if an external source of contamination is present (e.g., nearby leaking sewer main) and there is a pathway for contaminant entry (e.g., leaks in drinking water main). While the public health risk associated with such events is not well understood, quantitative microbial risk assessment can be used to estimate such risk. A conceptual model is provided and the state of knowledge, current assumptions, and challenges associated with the conceptual model parameters are presented. This review provides a characterization of the causes, magnitudes, durations and frequencies of low/negative pressure events; pathways for pathogen entry; pathogen occurrence in external sources of contamination; volumes of water that may enter through the different pathways; fate and transport of pathogens from the pathways of entry to customer taps; pathogen exposure to populations consuming the drinking water; and risk associated with pathogen exposure.     

放射性重金属污染水体的植物修复技术

分析水体中放射性重金属的来源,探讨影响植物修复放射性重金属污染水体的因素,对用于修复放射性重金属污染水体的植物种类、修复机制和主要技术进行综述,并对研究方向作出展望.     

润滑油污染因素的分析

以柴油机润滑油为例,通过分析其污染的过程,建立了柴油机润滑油污染程度的数学模型,并对润滑油被污染的影响因素进行了分析研究,得出了油池中润滑油污染度的变化规律,即从初始污染开始,按指数规律变化并最终趋向稳定平衡;润滑油污染变化程度随外界污染颗粒侵入率Ri和系统内部磨屑生成率Rp的增加而上升,随过滤比βu1,βu2,βu3的提高而降低,与润滑油的初始污染度C0无关等结论。