给水管道腐蚀原因及防护措施探讨

给水管道在使用过程中很容易受到人为外力、管道材质、地下水、周围空气、土壤等因素的影响而腐蚀,影响了管道的使用质量和寿命,也带来较大的安全隐患。本文主要是从给水管道腐蚀原因出发,并探讨防护措施。     

丙烯酸装置循环气压缩机叶片损伤分析与修复

某石化公司丙烯酸装置循环气压缩机在运行过程中,一级叶片突然发生断裂,导致机组停机。采用宏观检查、扫描电子显微镜、能谱分析等方法对断裂叶片进行检验和检测,将断裂叶片的材质、裂纹及断口特征检测结果与疲劳断裂特征和机组运行状况进行对比,确定压缩机叶片的断裂系其达到疲劳寿命所致,提出采用激光熔覆方法对压缩机叶片进行修复,介绍了修复工艺操作程序要点,可为同类故事的处理提供参考。     

浅析混凝土搅拌站的防雷

近年来,我市因雷击而导致搅拌站系统瘫痪停产、影响工程进度的事件时有发生,在针对混凝土搅拌站配料秤的实际检定工作中,也常发现配料秤的称重传感器因雷击损坏而影响计量准确性。因此,对混凝土搅拌站防雷的研究具有重要意义。本文阐述了雷电对混凝土搅拌站的主要危害,分析了混凝土搅拌站常见的雷击原因及其防护措施,旨在引起生产方、安装方以及使用方对混凝土搅拌站防雷的共同重视。     

4140钢弯壳体断裂原因分析和改进措施

某钻具厂生产的一个批次的4140钢螺杆钻具弯壳体出现较多断裂。通过化学成分、力学性能和显微组织分析对失效弯壳体断裂原因进行了研究,并相应优化了热处理工艺。结果表明:弯壳体失效断裂主要原因是由于淬火过程中未淬透,导致显微组织存在大量条状和块状铁素体,未淬透的组织导致材质的强度、硬度和冲击性能较差,从而导致断裂。采用优化的淬火工艺,材料寿命达到了正常水平。     

QC小组活动原因分析要点

在开展问题解决型质量管理小组活动中,原因分析不可或缺。要分析到问题的末端原因,须展示问题的全貌,从人、机、料、法、环、测,从全面到重点,从综合到局部,分析到可以直接采取对策的因素为止。掌握原因分析的技巧和要点,有效采取头脑风暴法、5why分析法、5M1E分析环节,正确使用因果图、系统图、关联图,一定能够达到事半功倍的效果。     

Root cause analysis of the fracture of a sonar window caused by hydrostatic,hydrodynamic, and transient forces around a ship

Sonar systems are installed in naval vessels to inspect objects in the sea. When the system is installed at the bulbous bow of the ship, it can be vulnerable to fractures in rough seas due to hydrostatic and hydrodynamic forces, such as fluid-induced forces, and transient forces, such as slamming and collision with submerged foreign objects. In this paper, root causes analysis (RCA) of the fracture of a sonar window of a typical naval vessel was performed. To identify the root causes of the fracture, a numerical analysis was performed of the stress distribution on a sonar window under various extreme conditions. The results of the analysis, together with hypotheses of the causes of the fracture, are presented. The results of the analysis were verified by measuring the stress on the sonar window under typical sailing conditions of ships. The RCA demonstrated that buckling in response to the hydrostatic forces applied under the typical operating conditions of a water management system (WMS), in addition to excessive slamming, can cause a sonar window to fracture. Based on this RCA, corrective actions to prevent sonar window fractures include changing the material of the window and the operating conditions of the WMS.     

Failure analysis of power transformer for effective maintenance planning in electric utilities

In this paper, power transformer failures are analyzed and their root causes are systematically investigated in Tamil Nadu Transmission Corporation Limited (TANTRANSCO)/Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO) electric utilities, based on 196 failure cases from the year 2009–2013. Failure analysis is conducted in two phases. Initially, voltage level, geographical zone and power transformer components based failure analysis are performed through statistical analysis. Secondly, the most significant factors that cause power transformer failures are identified by using root cause analysis (RCA). Finally, current maintenance practice is reviewed and an effective maintenance planning has been proposed for implementation in order to prevent these failures and to maintain the power transformers in good operating condition during their life cycle. This study provides a practical guidance to help maintenance personnel for the best utilization of the power transformer in electric utilities.     

Root cause analysis of process fault conditions on an industrial concentrator circuit by use of causality maps and extreme learning machines

Model-based fault diagnosis tends to be too expensive or time-consuming to apply in the mineral processing industries, owing to the complexity and variability of operations. In contrast, data-based methods are inexpensive, but do not exploit the availability of first principle knowledge of plant operations. In this investigation, the use of process causality maps in conjunction with data-based fault diagnosis is considered as a hybrid methodology that can leverage the advantages of both approaches. Extreme learning machine algorithms are used to implement the data-based component of the approach. These algorithms can be deployed rapidly on large-scale systems and have the ability to deal with highly nonlinear systems. Two different variants are considered, viz. one used in combination with principal component analysis, as well as one with a bagging algorithm for fault diagnosis and applied to an industrial concentrator circuit in South Africa. The use of process causality maps led to significantly more effective fault diagnosis, while the use of extreme learning machines in combination with principal component analysis likewise allowed markedly better fault detection and diagnosis. In contrast, fault diagnosis with the bagging approach did not perform particularly well, owing to the high degree of correlation between the variables, which made it difficult to isolate individual causal variables.     

苏里格南区气井井筒堵塞原因分析与防治对策

针对苏里格南区气井井筒特别是油管内形成大量堵塞物现状,通过现场调研和室内研究,明确气井井筒堵塞原因,并提出相应的防治对策。     

预防煤矿瓦斯爆炸事故的措施

文章从煤矿瓦斯事故统计分析、事故原因分析、预防措施，对预防煤矿瓦斯事故进行了全面的探讨，得出只要严格按照“一通三防”的各项规定来施，重大事故是可以得到有效控制的。