75000 m~3/h制氧空分液氧泵的几次故障案例分析

总结了某钢铁公司一期制氧75000 m~3/h空分运行多年过程中,立式液氧泵出现的几种常见问题,包括:出口逆止阀漏液、泵侧K点温度低、吸入口过滤器堵塞、出口压力波动等情况,通过分析原因,积累经验,提高了设备运行管理水平,提升了设备运行周期及安全性。     

攀钢煤焦油蒸馏二段柱塞泵出口管道工艺改造研究

研究了攀钢焦油蒸馏二段柱塞泵出口管道存在的问题,并通过在二段泵出口管道上增加空气缓冲罐、移位流量调节阀和压力表等改造,有效减轻了泵出口脉冲振动,消除了泵出口管道接管焊口的开裂现象,保证了生产的连续稳定。     

高压循环水泵断轴原因分析与解决措施

针对硫酸车间高压循环水泵泵轴断裂频繁的问题,从泵的轴承、泵出口压力、叶轮等方面出发,对泵轴断裂问题进行全面分析,找出泵轴断裂的主要原因为叶轮失衡。通过重找静平衡,对泵的后续运行进行监测,发现重找静平衡后,泵轴断裂周期增大,泵的使用寿命大大延长。     

液氧活塞泵出口波纹管多次爆裂的处理措施

分析并查找出了往复式液氧活塞泵出口不锈钢波纹软管多次爆管断裂的原因,提出了整改的意见和措施,消除了故障和安全隐患,起到了生产后备保障系统的作用。     

定径机高压水除鳞系统的改进优化

针对钢管表面高压水除鳞系统柱塞泵曲轴进油口机械密封不可靠、柱塞使用寿命短、泵出口阀组故障多、液动除鳞阀易失效等问题,分析了其原因,采取了相应的改进优化措施,取得了较好的效果。     

延长高压除鳞泵使用寿命探讨

阐述了影响除鳞泵使用寿命的因素,详细介绍了除鳞泵在出口压力和流量一定的情况下,选用不同的叶轮级数和泵转速,对除鳞泵使用寿命的影响。     

齿轮泵泄漏原因分析及处理措施

齿轮泵又叫正排量泵,属于容积泵的一种,广泛应用到各类液压设备中,该泵具有体积小、效率高,工作效率能够达到98%,且出口运行平缓等优点。但是齿轮泵长期运行后往往容易发生轴封泄漏等问题,轻则污染设备浪费油脂,重则导致整个齿轮泵效率下降,运行压力波动导致供油不足损坏设备,本文对齿轮泵的泄露原因进行分析并进行处理。     

真空热处理炉炉况对钽粉碳含量影响因素分析

分析了真空热处理炉炉况管理对钽粉碳含量的影响因素,重点分析了不同热处理温度、真空阀加装限位、油扩散泵冷凝壁冷却水连接方式,油扩散泵关闭维持泵后不同管道真空、扩散泵障板冷却方式、油扩散泵壁不同回水温度对钽粉碳含量的影响。研究表明较高的烧结温度能够有效地降低钽粉中的碳含量,可提高真空炉空载烘炉温度;真空炉真空阀未加装限位器较加装限位器生产钽粉碳含量明显偏高,真空炉的真空阀需加装限位器有效实现阀门的连锁开启关闭;油扩散泵冷凝壁冷却水连接方式采用下进上出的方式生产钽粉的碳含量明显偏高,油扩散泵冷凝壁冷却水应采用上进下出的方式;扩散泵前级管道在关闭维持泵6h后的管道压力越大碳含量越高,应保证扩散泵的管道在一定压力范围内;油扩散泵障板处采用氟利昂制冷的碳含量较采用水冷的碳含量明显偏低;扩散泵泵壁出口温度偏高,可在扩散泵泵壁出口端增加增加泵,有效碳解决了出口温度偏高、真空炉生产钽粉的碳含量偏高的问题。     

长距离矿浆输送管道清管实践

长距离矿浆输送管道的及时疏通清理,可有效保障高压管道系统运行安全。针对内径为Φ212.75 mm长距离高压矿浆输送管道,采用Φ205 mm、Φ209 mm软体清管器、Φ205 mm、Φ209 mm软体除垢清管器及Φ212 mm四皮碗清管器3个类型5种定位清管器对管道内部进行除垢清理。矿浆管道在清管前,水流量为230.45 m³/h,主泵出口压力为1 150.7 kPa,清管后,在相同矿浆输出条件下,水流量为303.13 m³/h,主泵出口压力为1 115.2 kPa,管道流量提高31.54%,主泵出口压力降低3.09%。矿浆管道清管在生产现场的成功应用,有效提高了管道输送能力,降低主泵出口压力,对长距离矿浆输送管道的除垢有重要的借鉴作用。     

3号焦炉高压氨水系统的改造

针对高压氨水系统存在的氨水阀门泄漏量较大，泵工作电流偏高，泵出口压力高且不稳定等问题进行了逐一分析和改造，满足了生产要求。     

Effect of a vancomycin restriction policy on ordering practices during an outbreak of vancomycin-resistant Enterococcus faecium

A miniaturized pivot bearing-supported centrifugal blood pump (Gyro PI) has been developed as a long-term biventricular assist system (BiVAS). In this study we determined the anatomical configuration of this system using a bovine model. Under general anesthesia, a left lateral thoracotomy was performed to open the chest. Two Gyro PI-601 pumps for left and right assists were placed in the preperitoneal pocket by a subcostal abdominal incision. The left pump could be placed along the dome of the diaphragm just beneath the apex of the left ventricle. The right pump could be placed next to the left pump. The inlet and outlet ports of both pumps penetrated the diaphragm. The inlet port of the left pump, with a length of 55 mm, was inserted directly into the apex of the left ventricle. A woven Dacron graft (150 mm long, 11 mm inner diameter) was placed between the outlet port of the left pump and the descending aorta. As for the right pump, a 100 mm long and 120 degree angled inflow conduit was placed between the inlet port and the right ventricular infundibulum. The outlet port of the right pump was connected to the main trunk of the pulmonary artery using a 90 mm long, 11 mm inner diameter Dacron graft. We could perform biventricular assistance to confirm the anatomical feasibility of the Gyro implantable centrifugal BiVAS.     

循环水系统存在的水锤问题及对策

通过对自备电厂循环水系统水锤造成设备损坏的原因进行分析，发现是循环水泵出口碟阀关闭时间和关闭特性存在问题。通过试验调整关阀时间和关阀特性，彻底地解决了所存在的问题。     

水泵优化运行新方法的研究

介绍了水泵吸水阀门与出水阀门联合调节技术,该技术实现了水泵优化运行。     

粉末冶金零件在摩托车上的应用

综述了粉末冶金零件在我国摩托车业中的应用现状和发展状况 ,介绍了金城集团公司摩托车上应用的齿轮、进排气门座、油泵转子等 2 0余种粉末冶金零件     

液压系统噪音产生的原因与降噪技术

本文通过对广钢双膛石灰窑液压系统在生产运行过程中的噪音和振动原因进行了分析，认为柱塞泵的噪音是液压系统噪音产生的主要原因，而柱塞泵出口的流量脉动和压力脉动则是造成次级噪音的原因。并提出解决问题的途径之一是采用具有P—Q控制降噪新技术的柱塞泵，认为这种柱塞泵能够更有效地减少柱塞泵泵体产生的噪音量以及柱塞泵出口流量脉动和压力脉动引起的次级噪音量。     

国产JYJ-22-6000滤油机的改造

分析国产滤油机在结构和功能存在的缺陷，介绍对真空泵、水冷却系统、进出口油泵、主电源电缆和开关所实施的具体改造方案，提高了滤油机的性能。     

Native valve staphylococcal endocarditis: etiology, risk factors and outcome in 53 cases

Pump manufacturers recommend setting roller pump occlusion such that the level of a 100 cm column of crystalloid drops 2.5 cm/min (Sarns, 8000 Modular Perfusion System, operator's manual, roller pump software version 2.3L. May 1993; 2.1-2.14). Though this almost occlusive setting ensures accurate pump flow, it has been shown to cause more hemolysis than nonocclusive pumps (Noon GP, Kane LE, Feldman L et al. Reduction of blood trauma in roller pumps for long-term perfusion. World J Surg 1985; 9: 65-71). We conducted a clinical study (n = 19) to compare the standard occlusion method with the dynamic method and to determine the accuracy of flow for the nonocclusive pump. Standard occlusion was set by clamping the pump tubing distal to the arterial line filter and timing the drop in pump outlet pressure as indicated by a pressure transducer connected to the filter. The occlusion setting, expressed in mmHg/s, was recorded for each roller at two specific points along the raceway. The pump was then set nonocclusively with the dynamic method using the Better Header (BH) (Circulatory Technology, Oyster Bay, NY, USA). Readings of the change in pressure in the same two selected points on the raceway were taken. The latter was repeated after discontinuation of bypass. Flow was recorded throughout the procedure from both roller pump output display and a flow meter (Model #109 Transonic, Ithaca, NY, USA). The average drop in pump outlet pressure for the standard method was 1.3 +/- 4.0 (range 0-18 mmHg/s), and for the dynamic method was 38 +/- 28 (range 1.2-89 mmHg/s). Off bypass, the average reading was 44 +/- 38 (range 2.0-103 mmHg/s). Regression analysis indicates that patient flow, when corrected for retrograde flow by the dynamic method, equals 1.003 x revolutions per minute + 40 ml/min (r2 = 0.964). The average error between indicated pump flow, corrected for retrograde flow, was -1% (range from -6.7 to 6.6%). We conclude that the BH allows nonocclusive setting (30 times less than our standard method) without sacrificing pump flow accuracy.     

Three-dimensional numerical prediction of stress loading of blood particles in a centrifugal pump

The successful use of centrifugal pumps as temporary cardiac assist devices strongly depends on their degree of blood trauma. The mechanical stress loading experienced by cellular components on their passage through the pump is a major cause of blood trauma. Prediction of the mechanical stresses will assist optimization of pump design to minimize hemolysis and platelet activation. As a theoretical approach to this task., the determination of the complete three-dimensional (3D) flow field including all regions of high shear stress is therefore required. A computational fluid dynamics (CFD) software package, TASCflow, was used to model flow within a commercially available pump, the Aries Medical Isoflow Pump. This pump was selected in order to demonstrate the ability of the CFD software to handle complex impeller geometries. A turbulence model was included, and the Newtonian as well as the Reynolds stress tensor calculated for each nodal point. A novel aspect was the assignment of scalar stress values to streaklines representing particle paths through the pump. Scalar stress values were obtained by formulating a theory that enables the comparison of a three-dimensional state of stress with a uniaxial stress as applied in all mechanical blood damage tests. Stress loading-time functions for fluid particles passing inlet, impeller, and outlet domains of the pump were obtained. These showed that particles undergo a complex, irregularly fluctuating stress loading. Future blood damage theories would have to consider an unsteady stress loading regime that realistically reflects the flow conditions occurring within the pump.(ABSTRACT TRUNCATED AT 250 WORDS)