基于AMESim的水压单体液压支柱建模与仿真

为研究水压单体液压支柱在负载作用下的特性,建立了单体支柱的物理模型和元件级仿真键合模型,通过模拟支柱工作过程分析了不同参数对支柱升降特性及水压三用阀的压力流量特性的影响。分析结果表明:增大进液口与排液孔直径、减小阀口重叠量与等效阻尼可提高系统响应速度、增大溢流流量和支柱回缩量,但过大进液口直径会影响阀口的关闭性能,同时减小等效阻尼会使安全阀阀芯的稳定性降低。     

煤矿液压提升机的安全功能与安全隐患分析

液压提升机是较为复杂的机电液一体化产品 ,是煤矿井下作业提升物料和运送人员的关键设备 ,素有矿井咽喉之称。液压提升机的防爆、提升过程中的超速、过卷保护、液压系统的高、低压保护及升降与制动工作协同性是其安全性设计的核心与关键。笔者概要介绍了液压提升机的主要安全保护功能 ,分析并探讨了液压提升机存在的安全隐患与对策     

工业锅炉安全阀的选择、安装与调试

安全阀是保障锅炉安全运行的最重要的安全附件,必须灵敏,可靠。没有安全阀或者安全阀失灵的锅炉是禁止运行的。工业锅炉安全阀,常见的有重锤杠杆式和弹簧式两类。一、重锤杠杆式安全阀重锤杠杆式安全阀的作用原理是利用重锤的重量,通过杠杆作用,将阀芯紧紧地压在阀座上,使锅炉内的压力保持在允许压力之内,当锅炉压力超过允许值时,阀芯被顶     

中国能建安徽电建一公司拧紧春季作业“安全阀”

4月19日,中国能源建设集团有限公司安徽电建一公司机械化大修厂的钳工师傅,在组装筒吊液压泵站前,先在吊装物件上系上防风溜绳,组装一结束便立即夹紧龙门吊的夹轨钳,并用4根手指粗细的钢丝绳抛锚固定。据了解,这是大修厂春季安全作业防范措施之一,该厂在强化安全意识,提升安全素养,细化作业方案策划与编制的同时,结合机修作业特点、作业环境,开展拧紧“安全阀”,夯实春季安全基础活动,即强化起重作业前备好防风溜绳、易燃材料及时回收等六项安全防范措施的执行落实。     

安全阀的安装、校验和试验

工业锅炉安全阀主要有杠杆式、弹簧式和静重式三种。以杠杆式和弹簧式最为常见。安全阀的正确安装、校验和试验,对锅炉的安全运行起着很重要的作用。 《蒸汽锅炉安全监察规程》第90条规定;安全阀应铅直地安装(即垂直于水平面安装),主要是由安全阀的结构特点所决定的。不论那种安全阀,它的密封都是用适当的垂直力作用到阀芯与阀座的接触面上,使其阀芯、阀座接触严密。如果安全阀不铅直地安装,作用到接触面上的力将分为垂直于接触面的压紧力和平行于接触面的滑移力。当安全阀动作以后复位时,垂直于接触面的压紧力使阀芯复位,而平行于接触面的…     

液压起升机构二次提升防滑装置研制成功

液压起升机构二次提升时的下滑现象是当前这一设备在安全生产中的一个难题。为了解决这一难题,大连市劳动保护教育中心与大连理工大学经过两年多努力,于最近研制成功液压起升机构二次提升防止下滑装置。并通过国家劳动部职业安全卫生监察局组织的专家鉴定 这种装置通过改善液压起升机构的微动性能,从而保证作业的安全可靠,有效地避免人身伤亡事故和设备事故,还提高了作业效率。 该装置安装使用方便,同时具有称重功能。把它用于各种起升或卷扬机构的液压系统,既不改变原有系统其他部分的组成及性能,亦不增加功耗,无需专门操作。现已在一百多…     

要重视安全阀

为了确保锅炉安全运行,必须保证锅炉的三大安全附件准确、灵敏、可靠。压力表是指示锅炉内压力的仪表;水位表是指示锅筒中水位的装置;安全阀则是避免锅炉因超压而造成事故的一个安全保险装置。 司炉人员操作时,往往重视压力表、水位表是否正常,却常常忽视安全阀。但是,不少锅炉事故,往往由于没有按要求对安全阀进行定期的手动或自动排汽试验,安全阀的阀芯和阀座粘住,锅炉超压时发挥不了作用而造成的。也有些事故是由于安装和维修人员没按规定调整安全阀的开启压力造成的。可见,必须重视安全阀的作用。 锅炉常使用的安全阀有杠杆式和弹簧式两…     

移动脚手架升降作业的FMECA分析

利用FMECA(故障模式,影响及危险度分析)方法回顾了升降作业的典型事故,阐述了架体结构和升降作业流程,对移动脚手架升降作业进行了故障类型、影响及危险度分析,认为保障移动脚手架升降施工作业安全的重点是:保证防坠装置的有效可靠性、维护防护装置的功能完整性、确保提升机构和架体结构的整体稳定性。     

对一起违章作业造成的事故的分析

1996年3月17日,某型钢厂南线精轧机的大罩发生故障。为维持生产,该厂决定用行车起吊的方法升降大罩。为确保起吊作业安全,设备厂长组织起重工商讨起吊方案,决定采用两根5m长的钢丝绳捆束大罩两头,再穿一根3m长钢丝绳作“人字”型挂钩,并在大罩基架两侧板上开孔,大罩吊起时插入保护销,防止大罩意外坠落。 用行车起吊大罩连续作业4个班次后,在第5个班,因成品不合格,当班调整工卢某用行车起吊大罩时少用一根3m的钢丝绳,只用2根5m长的钢丝绳,采用“八字”型方法挂钩,钢丝绳2次滑出均未挂上,第3次在另一个调整工的帮助下强行挂钩,大罩吊起时两侧的安全销只插了一个。卢某进入罩内     

油田特种车辆的安全管理

特种车辆是油田作业中不可缺少的配套设备,特种车辆安全管理的效果会直接影响井下作业的效率,甚至井下作业的安全。因此,加强对特种车辆的安全管理,才能确保井下作业安全平稳运行。用于油田的特种车辆主要有井下作业系统和测井系统特种车辆2大类:     

Safety studies on hydraulic proportional valves with electrical position feedback.

The authors analysed a proportional valve with electrical position feedback for its failure behaviour. Several failures were introduced into the feedback loop, especially into the 2 solenoids and the inductive position transducer. The behaviour of the valve for square and ramp reference signals was recorded and systematically analysed. It was shown that failures could be detected by monitoring the residual signal from the equipment under control or the residual signal from the sensor. It was possible to achieve the safe position within twice the normal response time of the valve by switching off the current of both solenoids. The application of these results for a new generation of safe proportional valves is discussed. The use of the results of these investigations obviates the need for redundancy of the electrical position monitoring arrangement in a safe proportional valve.     

Safety Studies on Hydraulic Proportional Valves With Electrical Position Feedback

The authors analysed a proportional valve with electrical position feedback for its failure behaviour. Severalfailures were introduced into the feedback loop, especially into the 2 solenoids and the inductive positiontransducer. The behaviour of the valve for square and ramp reference signals was recorded and systematicallyanalysed. It was shown that failures could be detected by monitoring the residual signal from the equipmentunder control or the residual signal from the sensor. It was possible to achieve the safe position within twice thenormal response time of the valve by switching off the current of both solenoids. The application of these resultsfor a new generation of safe proportional valves is discussed. The use of the results of these investigationsobviates the need for redundancy of the electrical position monitoring arrangement in a safe proportionalvalve.     

液体危化品罐车卸货防喷技术研究

液体危化品大量地通过罐车运输,目前液体危化品罐车卸货完成后从通用卸货管道上拔掉卸货软管时,发生软管内残余液体危化品外喷伤人现象,其原因是液体危化品罐车卸货完毕,关闭罐车上的卸货阀门后,软管内压力大于管口大气压,在从通用卸货管道上拔掉卸货软管时,造成管内残余液体危化品从管口外喷,拔管时出现的外喷现象的动力,就是来自于这种压差.提出解决该问题的方法是对罐车的卸货装置进行简单改造,增加一个调节装置来平衡卸货软管内与外界大气压,消除液体外喷的动力.并在一家危险化学品经营企业的浓硝酸运输罐车上进行了实践应用,证明了该方法安全可行,提高了浓硝酸卸货时的安全性.     

危化品罐车自封堵式安全截断阀设计与分析

为解决危化品罐车的储罐阀门管线等关键部件易损坏造成危化品泄漏的问题，基于系统本质安全原理设计1种内置自封堵式安全截断阀并对其关键部件强度进行校核计算，建立实现阀芯阀座有效密封的三维实体模型并完成有限元分析。结果表明:在阀座密封面与球形阀芯接触处出现最大应力，阀座承受的最大应力小于材料的最大屈服应力，内置自封堵式安全截断阀具有较高的可靠性，可为危化品储运相关安全装置设计提供理论参考。     

Reducing commercial fishing deck hazards with engineering solutions for winch design

INTRODUCTION: The majority (67%) of hospitalized injuries among Alaska commercial fishermen are associated with deck machinery. This paper describes the "Prevention Through Design" process to mitigate one serious machinery entanglement hazard posed by a capstan deck winch. METHODS: After observing that the capstan winch provides no entanglement protection and the hydraulic controls are usually out of reach of the entangled person, NIOSH personnel met with fishermen and winch manufacturers to discuss various design solutions to mitigate these hazards. RESULTS: An emergency-stop ("e-stop") system was developed that incorporated a momentary contact button that when pushed, switches a safety-relay that de-energizes the solenoid of an electro-hydraulic valve stopping the rotating winch. The vessel owners that had the e-stop installed enthusiastically recommend it to other fishermen. NIOSH entered into a Proprietary Technology Licensing Agreement with a company to develop the system for commercial use. CONCLUSIONS: This is an example of a practical engineering control that effectively protects workers from a hazardous piece of equipment by preventing injuries due to entanglement. This solution could reduce these types of debilitating injuries and fatalities in this industry.     

流水作业工人神经行为功能的研究

采用ＮＣＴＢ测验对１８７名流水线作业工人测试，结果表明工人的情绪状态变得更焦虑、愤怒、抑郁、易疲劳。反映记忆力、感知／运动速度、心理运动稳定性、视反应速度对神经行为功能与劳动强度与工龄呈负相关。这与工人反映的头痛、头昏、多梦、记忆力下降等症状增多一致     

Self-Rated Physical Loads of Work Tasks Among Firefighters

Objectives. The present study sought to identify firefighters’ rated physical demands for the most frequently occurring work tasks and to determine if the ratings differed between full-time and part-time firefighters to help create a basis for the development of physical employment tests for firefighters. Methods. An extensive questionnaire was completed by 125 and 68 firefighters in 2000 and 2010, respectively. The data were analysed with the Mann-Whitney U test and binominal test and ranked on the basis of the responses in each category. Results. Significant differences were seen between the full- and part-time firefighters. The work tasks rated as the most physically strenuous in terms of aerobic fitness, muscle strength, work posture and body control by most respondents were smoke diving upstairs (carrying a hose), victim rescue in different ways, carrying a stretcher over terrain and pulling a hose. Conclusions. Physically strenuous work tasks should be included in the end-point performance variables used to select physical performance tests for firefighters. The part-time firefighters with no experience in several of the work tasks suggests that work-related exercises are important if both groups of firefighters are expected to do similar work.     

大型石化装置安全阀安全保障综合管理体系应用研究

本文研究采用基于风险的完整性综合管理方法解决大型石化企业安A-N管理中存在的问题。阐述了建立安全阀数据库的基本原则，提出根据失效可能性和风险等级制定安全阀分类管理策略，实现分类管理，进行检验组织优化，制定安全阀失效紧急处置指南，以期形成安全阀安全保障综合管理体系，并建立包括网上报检、备阀备件统计管理、风险定量计算等功能的安全阀管理信息系统，在保障安全阀安全运行的同时，提高管理效能，降低管理成本。     

高炉旋流除尘器煤气泄漏火灾爆炸安全分析

高炉旋流除尘器在检修时,打开顶部眼镜阀,煤气可能外泄.分析了高炉煤气的性质、特点.距离眼镜阀40 m处的煤气放散塔对除尘器的安全使用影响极大.     

含硫天然气井口笼套式节流阀硫沉积数值模拟研究

为分析含硫天然气气田井口笼套式节流阀的硫沉积问题,基于雷诺应力模型、组分输运模型及离散相模型,建立硫沉积数值模拟模型,分析笼套式节流阀的硫沉积规律及影响因素.研究结果表明:硫沉积主要出现在正对来流的节流孔外侧下缘、阀套边缘以及阀芯内侧,其中节流孔外侧下缘的沉积最严重,对于该位置,随着气流进口速度的增大,硫沉积速率先增大...