超高温旋转夹紧油缸优化设计与应用研究

金属冶炼技术及高端装备技术的飞速发展,对高温环境下夹具起升与旋转夹紧锁定等的要求更高,对其安全性、可靠性、准确性、耐高温等提出了更高的要求。传统旋转夹紧机构有采用电气控制、两套液压缸完成夹具的提升和旋转锁定,也有采用机械机构进行旋转夹紧锁定,具有渗漏、寿命短、起降不同步等特点。通过对以上特点的分析,研制出一种组合夹具,采用液压与机械相结合技术,将提升与旋转锁定在一起,实现了工装在高温环境下的规定动作,符合当今节能、环保、安全的理念。该夹具已获3个专利。     

反力控制式EHPS的仿真与试验

介绍了反力控制式EHPS的基本结构和工作原理,建立了基于转阀的主油路的数学模型和以及基于电液比例阀的旁通油路的数学模型,并进行了仿真分析,在此基础上,对反力控制式EHPS进行了台架试验,并对仿真结果进行验证。结果表明:仿真结果与试验结果吻合,验证了模型的正确性。     

一种新型旋转直线组合式液压缸设计

随着制造业自动化的快速发展,市场对液压传动产品的要求也越来越高,而现有液压缸产品性能单一、运动模式少,日益不能满足市场的需求。针对此问题,设计了一种新型旋转直线组合式液压缸,该液压缸利用滚珠花键既能传递扭矩又能实现直线运动的特点,将双螺旋摆动液压缸与传统往复直线运动液压缸有机结合,不仅可以实现单一的往复直线运动和旋转运动,也可以实现复杂的旋转直线复合运动,技术功能完善,结构紧凑,输出载荷大,传动效率高,传动平稳,安装方便,能够满足市场对液压传动产品性能多样化的需求。     

Recovery of Polycyclic Aromatic Hydrocarbons During Solvent Evaporation with a Rotary Evaporator

Analytical behavior of dichloromethane solutions containing polycyclic aromatic hydrocarbons (PAHs) was systematically studied through evaporation in a rotary evaporator. Starting sample concentration levels for each PAH were 0.167 w g/mL (concentrated) and 0.0167 w g/mL (diluted). Solvent reductions from 300 mL to final volumes of 30, 10, 3, and 1 mL (concentrated) and from 300 mL to 3 and 1 mL (diluted) were evaluated and each sample analyzed using gas chromatography-flame ionization detection (GC-FID). Factors affecting the percentage of analyte recovery include boiling point of analyte, the final sample volume, and starting sample concentration. When concentrated solutions were reduced from 300 mL to 1 mL, PAH recoveries were nearly all higher than 90%, except for naphthalene, acenaphthylene, and acenaphthene. However, when diluted solutions were evaporated to 1 mL, recoveries of all analytes dropped to 64.5% (naphthalene) ～ 89.2% (benzo[ ghi ]perylene). For evaporation to a final volume of 3 mL, recovery of PAHs in both concentrated and diluted solutions was higher than 90%. This implies that no significant losses of semivolatile analytes were found during evaporation of methylene chloride by rotary evaporation, regardless of boiling point or concentration level, until or unless the final volume was below 3 mL. Results of comparison of rotary evaporation and nitrogen blowdown showed that both concentration techniques provide qualitative recovery but rotary evaporation was more time effective.     

An Evaluation of Starting-Load Capacity and Static Friction in Babbitt-Lined,Hydrodynamic Journal Bearings

A recent application called for starting 127-mm (5-in) diameter, babbitt-lined hydrodynamic journal bearings under unit loads of about 10.34 MPa (1500 psi). In this application, the load was imposed only a few seconds before rotation could be started and hydrostatic jacking was not permitted. This paper presents the results of a test effort in which one full-size bearing was subjected to several hundred starts under unit loads ranging from 3.4 to 15.5 MPa (500 to 2250 psi). The dwell time between load application and start of rotation was varied in the test from less than one second to more than one hour. The paper also provides a review of the relevant literature, as well as calculations of the contact zone temperature during starts under boundary lubrication conditions.     

双摆台五坐标铣削后置处理软件Star-Fpost研究

针对MIRON UCP800双摆台立式五坐标加工中心,研究其五坐标加工的数学模型.推导出刀心和刀轴矢量六坐标转换成AC双摆台式五坐标的算法公式.利用坐标矩阵转换的方法实现直线圆弧插补刀轨源文件到机床代码的后置处理过程.使用面向对象程序,采取逐行读取刀轨文件关键字触发的方式,开发了专用的五坐标铣削后置处理软件Star-Fpost,在VERICUT仿真环境中完成五坐标机床的建模,在UGNX通过三元整体轴径流式叶轮的仿真加工,仿真结果验证了后置处理软件的功能,可以为MIKRON UCP800五坐标机床实际加工提供参考.     

四风道煤粉燃烧器常见问题分析及解决措施

介绍了水泥回转窑用四风道煤粉燃烧器的结构及其原理,以及四风道煤粉燃烧器在水泥厂实际使用过程中常见的一些问题,并针对这些问题提出了解决或改进的方法和措施。     

Static research of flow in rotor channels of the regenerator

One demonstrates here the results of static experiments which suggest the pulsating flow in rotating channels of the rotor of heat regenerators occurs. Electrolytic technique was used to measure distribution of the mass transfer coefficient for one of many straight, round, radial ducts of the rotor for different angle positions at mean Reynolds number as a parameter. The use of the Chilton–Colburn analogy made it possible to state the angle-distribution of flow-velocity. The Reynolds number deviation was about ±30% in comparison with its mean value which suggests that the phenomenon should be taken into account in formulating the models of rotary heat exchangers. An equality – approximately – of the mean velocity of an out-gassed electrolyte in the opposite ducts of the rotor of the model, working in a closed hydraulic system, was stated which was justified theoretically for one-dimensional flow.     

Development of a new rotary demister

The collection efficiency of a new helicoidal rotary demister, a novel technology for removing persistent fine droplets from gases, was evaluated using a tracer-based method. The demister uses a helicoidal element, which consists of a metal sheet wound as a spiral, designed to rotate at high speed within a cyclone body. Larger droplets are separated as they enter the cyclone housing, while the smaller droplets are carried by the gas into the helicoidal path of the rotating element, where they are centrifuged towards the outer collecting walls and, due to a baffle, flow counter-currently to the gas and are drained out from the bottom of the helicoidal element. The mist-free gas leaves through a channel located at the center of the spiral. The droplets collection efficiency and the pressure drop of the demister were measured under various conditions, to determine the impact of rotation speed and of gas flow rate.     

回转焙烧炉在催化裂化催化剂行业的应用及其结构优化

介绍了回转焙烧炉在催化裂化（FCC）催化剂行业的应用，根据实际应用情况进行了设备结构优化，实现节能降耗，提高产品收率。