氦气钢瓶抽真空处理方法的探讨

在保证钢瓶处理质量的前提下,如何高效率的进行氦气钢瓶抽真空置换处理,对氦气充装企业来说非常重要。通过实验得知,同一排氦气钢瓶的处理时间主要取决于罗茨泵的启动时间,罗茨泵启动后钢瓶内无论是氦气介质还是氮气介质,抽到相同的真空度数值所用时间相差不大。螺杆泵启动后,通入一定量氩气可以大大缩短氦气钢瓶抽真空时间,提高氦气钢瓶的处理效率,同时对钢瓶处理质量不会造成影响。     

余杭气瓶试压机厂新产品通过技术鉴定

<正>与杭州制氧机厂联合推出,并专业生产氧气瓶试压装置的杭州余杭县气瓶试压机厂,近两年根据市场发展需要,改变单一产品结构,贯彻劳动部“89瓶规”,在氧气钢瓶试压装置的基础上,自行设计开拓了:液化石油气钢瓶瓶阀装卸机、液化石油气钢瓶蒸汽清洗机、液化石油气钢瓶气密性试验机、液化石油气钢瓶瓶阙校验机。在试制过程中得     

钢瓶焚烧技术可行性分析

根据GB8334-1999《液化石油气钢瓶定期检验与评定》的规定要求,钢瓶检验周期为4年,超过有效期的钢瓶应进行检验,以确保钢瓶的使用安全。在检验流程中,首先要对钢瓶内的残液残气进行回收,然后拆卸瓶阀进行瓶内蒸气吹扫,使钢瓶内的残气浓度不大于0.4%(体积比),以确保气密性试验的安全。但是钢瓶采用蒸气吹扫工艺存     

二氧化碳钢瓶破裂爆炸失效分析

某气体公司发生一起充装二氧化碳的37Mn钢无缝钢瓶破裂爆炸事故。通过现场勘察与宏观分析、壁厚测量、化学成分分析、力学性能测试、金相检验、断口分析等方法,分析了钢瓶破裂爆炸的原因。结果表明:该钢瓶瓶体内壁发生了应力腐蚀开裂,在内部压力和搬运过程中的碰撞及振动作用下,钢瓶承压能力不足,最终导致钢瓶发生了物理破裂爆炸。最后,根据失效原因提出了相应的预防措施。     

液氯钢瓶充装改造中的定量控制和联锁控制技术应用

液氯钢瓶的充装有严格规定,在充装过程中严禁过量充装,通过智能定量充装技术的应用,实现了液氯钢瓶定量充装,杜绝生产过程中的超量充装,同时又实现了液氯钢瓶的计算机档案管理,提高钢瓶充装过程的安全可靠性,提高生产效率和安全生产管理水平。     

台湾液化气钢瓶半数无合格

台湾流通的液化气钢瓶近800万只,按台湾行政当局要求每只钢瓶回收时应回检验厂检验,每只钢瓶从消费者手中收取钢瓶折旧维护费0.65元,这样一年消费者支出近8亿元的液比气钢瓶检验费。然而却有400万只钢瓶     

浅谈液化石油气钢瓶定期检验的重要性

一、前言 　　液化石油气作为一种优质高效的燃料,已经被城市和农村的广大用户所接受,发展前景广阔.液化石油气钢瓶作为盛装液化石油气的压力容器,其安全管理工作是十分重要的.国家规定,液化石油气钢瓶应定期检验,但居民、宾馆、饭店等用户使用的钢瓶绝大多数未按国家规定进行检验,有的甚至使用15年之久却从未检修过,液化石油气钢瓶的安全使用已成为一个社会问题,需引起我们的高度重视.下面笔者对液化石油气钢瓶安全问题进行分析,从而说明液化石油气钢瓶定期检验的重要性.……     

上万个“炸药包”在流动：淮阴市瓶装液化气市场亟需规范

通过近期的市场检查，我们发现淮阴市瓶装液化气市场主要存在以下问题。 １．安全隐患。（１）液化气经销单位无资质。无证液化气站不具备残液回收装置，安全保障设施不足。（２）液化气钢瓶未检测。我市近５万只钢瓶至少有一半在超期使用。有的甚至使用１６年未检测一次。已严重腐蚀、变形的钢瓶，相当于上万个炸药包在流动。（３）一些用户安全意识淡薄。为图便宜，购买劣质、假冒钢瓶；一些用户不注重保护钢瓶，摔、砸、滚动，造成瓶体变形；在冬季，一些用户违章火烤钢瓶，造成钢瓶局部受热，钢瓶材质强度降低。所有这些隐患，极易酿成…     

液化石油气钢瓶爆炸及其灭火技术探讨

本文结合液化石油气民用钢瓶的类型及液化石油气钢瓶发生爆炸的条件和原因,分析总结液化石油气钢瓶发生爆炸的时间及爆炸前的特征,并针对不同类型的液化石油气钢瓶火灾,提出具体的灭火战术与技术。     

液化气体钢瓶的容积和充装量

在石油化工生产中,经常使用液化气体钢瓶装原料和产生品,有的钢瓶属于《压力容器安全监察规程》的监察范围。由于钢瓶价格较低,不少厂矿企业没有把它纳入固定资产项目,因此也没有完整的设备档案。在使用中,有人习惯称这种钢瓶为“半吨瓶”和“一吨瓶”等。这种以重量称呼的习惯并不好,因为容积钢瓶忽视了液体比重。充装不同介质,其充装量差异很大。技术资料无人管理,设备带病运输,操作者违章作业的现象普遍存在,致使爆炸事故时有发生。据大量的统计数据判断,液氯、液氨、环氧乙烷等一类液化气体钢瓶,发生事故的主要原因是超量充装。     

Detailed thermodynamic characterization of hermetic reciprocating compressors

The aim of this paper is the detailed analysis of different well-known thermodynamic efficiencies usually used to characterize hermetic compressors. Attention is focussed on the volumetric efficiency, the isentropic efficiency, and the combined mechanical–electrical efficiency. A procedure is presented to detach these efficiencies into their main components (physical sub-processes) to get deeper insight on the overall behavior.The volumetric efficiency is split into partial efficiencies related to pressure drop and heat transfer effects, supercharging effects, superdischarging effects, leakages, etc. The isentropic efficiency is detached using two different points of view: the work associated to the individual sub-processes (compression, discharge, expansion, suction), and the work associated to the underpressures, overpressures, and between the inlet and outlet mean compressor pressures. Finally, the combined mechanical–electrical efficiency is related to the heat transfer losses/gains, and to the exergy transfers and exergy destroyed.Even though some of the concepts introduced in the paper can be applied to different kinds of compressors, the discussion is specially focussed on hermetic reciprocating compressors. An advanced simulation model developed by the authors has been used to generate data to illustrate the possibilities of the detailed thermodynamic characterization proposed. The criteria developed are useful tools for comparison purposes, to characterize compressors, and to assist designers during the optimization process.     

On the Effect of Triaxial State of Stress on Ductility Using Nonlinear CDM Model

Ductility takes into account the material capability to plastically deform. This parameter is not only modified by temperature but it is strongly affected by the stress triaxiality that, in the case of positive hydrostatic stress, reduces the material strain to failure. Due to the importance of this parameter in engineering design many attempts to predict the evolution of ductility with stress triaxiality have been done. Here, a nonlinear continuum damage model, as proposed by the author, is used to obtain the evolution of material ductility with stress triaxiality. The expression found relates the strain to failure in multi-axial state of stress regime only to the uniaxial strain to failure, to the damage strain threshold, to the material Poisson's ratio, and, of course, to stress triaxiality. The proposed model was successfully verified comparing the predicted evolution of material ductility with the experimental data relative to several metals. The procedure for the damage parameters identification is also discussed in details.     

Sources of Error in UV Radiation Measurements

Increasing commercial, scientific, and technical applications involving ultraviolet (UV) radiation have led to the demand for improved understanding of the performance of instrumentation used to measure this radiation. There has been an effort by manufacturers of UV measuring devices (meters) to produce simple, optically filtered sensor systems to accomplish the varied measurement needs. We address common sources of measurement errors using these meters. The uncertainty in the calibration of the instrument depends on the response of the UV meter to the spectrum of the sources used and its similarity to the spectrum of the quantity to be measured. In addition, large errors can occur due to out-of-band, non-linear, and non-ideal geometric or spatial response of the UV meters. Finally, in many applications, how well the response of the UV meter approximates the presumed action spectrum needs to be understood for optimal use of the meters.     

Temperatureinfluss auf den Adhäsionsverschleiß beim Umformen von Aluminiumblechen

Influence of temperature on adhesive wear at deep drawing of aluminium alloys Deep drawing processes, used to manufacture aluminium components, are often sensitive to adhesive wear. Thus, the process stability as well as the quality of the formed parts may not fulfil the required specifications. Approaches, developed to reduce this wear phenomenon, still neglect the influence of temperature inside the forming area. Hence, this parameter is analysed by numerical and experimental tests. The tests are conducted by using a strip drawing device, enabling the experimenter to accomplish parameter variations. Subsequently analysis with tempered tools were done to show correlation between adhesion and temperature. The temperature supplied to the model tool corresponds to the temperature occurring in real forming process. In contrast to strip drawing test without external heat source, during the experiments with tempered tools adhesive wear could be shown. Thus, approaches to reduce adhesion wear should account for the influence of temperature.     

Viscosity Measurements on Gaseous Argon, Krypton, and Propane1

A new vibrating-wire viscometer was designed to perform quasi-absolute measurements of very high precision on gases. It was applied to determine the viscosity of argon at temperatures of 298.15, 348.15, and 423.15 K and pressures up to 20 MPa, and the viscosity of krypton at 298.15 and 348.15 ,K and pressures up to 16 MPa. Furthermore, several isothermal series of viscosity measurements on gaseous propane were carried out. The subcritical isotherms at 298.15, 323.15, 348.15, and 366.15 K were restricted to 95% of the saturated vapor pressure, the supercritical isotherms at 373.15, 398.15, and 423.15 K to 20 MPa. In general, the measurements are characterized by a reproducibility of ±0.05% and an accuracy of ±0.2%. However, close to the critical point an accuracy of ±3% has to be accepted, mainly due to the uncertainty of the density. In this context the influence of the equation of state used for propane is discussed.     

基于 SDAE 的受损 QR 码恢复算法

目的针对包装产品外壳上黑白QR码易受到污渍侵蚀损坏,长期磨损易模糊,以及图像采集过程易出现失焦模糊、运动模糊,导致无法完成识别需求,提出一种基于栈式降噪自编码器的受损QR码恢复的预处理方法,达到显著修复包装产品上受损的QR码图像并提高其识别率的目的。方法通过深度学习模型栈式降噪自编码器,可以将受到噪声干扰的像素点根据受损像素数据映射到以标准数据为参照的高概率数值点,实现整个受损QR码基于像素点的重构恢复,从而提高识别率。结果通过对实验QR码进行高斯模糊、随机污渍侵蚀等多种方式的损坏,能够将识别率较低或完全不能识别的测试图像集恢复出高质量的QR码图像,显著地提高了识别率,并且速度快、可重复性好。结论采用基于栈式降噪自编码器的受损QR码恢复的预处理方法,能够重建受损的QR码,并可以广泛应用于包装产品QR码识别前的预处理,以提高识别率。     

Biocompatibility Pathways in Tissue-Engineering Templates

Tissue engineering, which involves the creation of new tissue by the deliberate and controlled stimulation of selected target cells through a systematic combination of molecular and mechanical signals, usually involves the assistance of biomaterials-based structures to deliver these signals and to give shape to the resulting tissue mass. The specifications for these structures, which used to be described as scaffolds but are now more correctly termed templates, have rarely been defined, mainly because this is difficult to do. Primarily, however, these specifications must relate to the need to develop the right microenvironment for the cells to create new tissue and to the need for the interactions between the cells and the template material to be consistent with the demands of the new viable tissues. These features are encompassed by the phenomena that are collectively called biocompatibility. However, the theories and putative mechanisms of conventional biocompatibility (mostly conceived through experiences with implantable medical devices) are inadequate to describe phenomena in tissue-engineering processes. The present author has recently redefined biocompatibility in terms of specific materials- and biology-based pathways; this opinion paper places tissue-engineering biocompatibility mechanisms in the context of these pathways.     

蒙古族女性头饰文化研究

目的民族服饰是我国传统文化的重要组成部分,蒙古族女性头饰是其中的重要一支。自20世纪80年代以来,已有大量研究成果出现。对近三十余年蒙古族头饰的相关研究进行综合性梳理,可以掌握其发展进程及研究重点,进而提炼核心内容,构建较为完善的理论体系,为相关研究提供方法论及材料内容的参考。方法一是类型比较研究,从地域邻近文化的趋同性所致头饰造型的相似性角度勾勒出部落头饰的类型样貌。二是整体解读研究,实现由点及面的研究过程,保证研究的精准性与全面性。结论对于蒙古族女性头饰外观、材料及审美的研究已告一段落。下一步需要展开更为深入的研究,一方面需要进行田野资料的搜集,作为文献研究的重要补充,以提高研究的现实价值;另一方面需要透过头饰等物质文化的研究来聚焦与之相关的人群,由物及人,实现技艺文化的在地化研究。     

Risk assessment of chemicals in foundries: the International Chemical Toolkit pilot-project

In Brazil, problems regarding protection from hazardous substances in small-sized enterprises are similar to those observed in many other countries. Looking for a simple tool to assess and control such exposures, FUNDACENTRO has started in 2005 a pilot-project to implement the International Chemical Control Toolkit. During the series of visits to foundries, it was observed that although many changes have occurred in foundry technology, occupational exposures to silica dust and metal fumes continue to occur, due to a lack of perception of occupational exposure in the work environment. After introducing the Chemical Toolkit concept to the foundry work group, it was possible to show that the activities undertaken to improve the management of chemicals, according to its concept, will support companies in fulfilling government legislations related to chemical management, occupational health and safety, and environmental impact. In the following meetings, the foundry work group and FUNDACENTRO research team will identify "inadequate work situations". Based on the Chemical Toolkit, improvement measures will be proposed. Afterwards, a survey will verify the efficiency of those measures in the control of hazards and consequently on the management of chemicals. This step is now in course.     

以问题为导向的老旧小区火灾救援产品设计

目的 老旧小区因建筑规划不完善,物业管理不规范,容易成为火灾高发地,且不便于组织施救,对当地居民生命财产安全形成了巨大威胁,基于此,进一步探索适应于这一特殊环境的火灾救援解决方案。方法 以问题为导向,分析老旧小区环境混乱、配套设施不足,以及现有救援产品针对性、适应性不强等原因,并引入基础条件、核心功能和附属功能等影响因素,分别从通过性、水源、行进、作业、工效和美学等方面进行定义,并分解成若干问题微单元,最后精确锁定、逐一破解。结论 以问题为导向的设计思维,能将设计对象的本质清晰地呈现出来,在应用于老旧小区火灾救援产品设计过程中,将问题划分为适应配套缺陷的基本问题、保证功能实施的核心问题、促使方案完善的延伸问题等3个层次,系统地解决各类难题,最终获得切实可行、符合实际需求的产品方案。