真空粉末绝热

良好的绝热是提高低温设备经济性的有效措施。目前国内外低温工程的迅速发展,大大促进了对各种绝热形式的研究。在我国,原有基础较为薄弱,液化气体的贮存与运输设备的设计与制造甚为迫切。因此     

浅谈煤矿机电运输设备安全管理存在问题及对策

煤矿机电运输设备设备的运行任务繁重，工作环境恶劣，且移动频繁，常常得不到应有的及时维护，从而造成机电运输设备故障。我近几年不断到各个煤矿下井，并对煤矿机电运输设备完好情况等进行检查，总结一些机电运输设备安全管理中存在的问题及认识，并针对这些问题提出了完善煤矿机电运输设备安全管理的具体对策。     

浅析煤矿机电运输设备管理

作为煤矿生产环节的重要部分,煤矿机电运输发挥的作用举足轻重。基于这一点,使得煤矿机电运输设备所涵盖的面积广、范围大并涉及大量高端技术。对于煤矿机电运输设备来说,设备如果管理不好,则有可能影响矿井安全。论文结合笔者研究,首先分析了煤矿机电运输设备运行的特点,其次分析了导致煤矿机电运输设备问题的原因,最后则分析了如何优化管理,保障煤矿机电运输设备的安全性。     

蓄冷板冷藏车

当前,易腐货物运输工具的冷源主要还是采用水冰和机械制冷。但这两种冷源都并不十分理想。使用水冰时,车内达不到适于运送冻结货物的低温,运输途中又需要补冰,不但增加了辅助的运输设备,还滞延了车辆周转和货物的送达;机械制冷对温度的调节幅度大,采用机械制冷的运输工具在全年任     

如何在冷库内进行有效火灾探测？

很多人理所当然的认为在低温情况下火灾的发生率很低，这是错误的假设。事实恰恰相反，低温下的干燥空气反而会有助于火势蔓延。所以关键在于提前采取预防措施，特别是食品仓储等，即使是少量的烟雾也会污染整个仓库，从而使所有库存毁于一旦。由此不仅导致直接经济损失，而且也造成不能及时履行供货义务，从而导致客户及市场份额损失，甚至会影响公司运转。冷库中易燃风险不仅来源于食物中富含的油脂，更多是由于塑料和纸制的包装以及运输设备，像传输带、叉车和高架货物装卸设备等。此外，大量密集的电缆也增加了火灾风险。如果由于技术故障发生火灾，火灾初期的烟雾在冷库里产生的速度远比在普通条件下缓慢，原因在于冷库中的低温。     

辅助运输设备在煤矿井下应用

为了加快我国煤矿辅助运输机械化现代化的步伐，搞好煤矿辅助运输工作，本文重点介绍了煤矿辅助运输设备：臣煤矿井下应注意的几个问题，并提出了选用煤矿辅助运输设备的建议和方法。     

煤矿机电运输设备安全运行技术保障措施

随着我国工业生产技术的不断提升,在当前的煤矿生产过程中,应用机电运输设备成了企业提高生产效率的重要手段。为了进一步强化这方面的工作内容,强化工作人员的认识,这里就煤矿机电运输设备安全运行的技术保障措施展开探究,希望能够起到积极的参考作用。     

底顶多支点起重运输设备的机械设计与研究

对于这一类型起重运输设备的设计而言,当前在国内外并没有经验可参考,因此,为了满足生产线间平移工作之需,需要以相关起重机设备的设计方法为参考,结合实际场地之需,在明确相应设计参数的基础上,实现相应架构的设计,然后通过试验来明确设计中所存在的不完善之处,并针对问题进行解决,并实现设备维修与管理工作的有效落实,以确保该类型起重运输设备能够满足实际应用之需。本文针对底顶多支点起重运输设备的机械设计进行了研究,以供参考。     

露天矿开采半连续卸料系统研发

近30余年来,露天矿开采运输设备主要依靠矿用汽车。为了降低露天矿山的运输成本,在现有运输设备的基础上,开发出运用经济高效、能够适应大规模矿山开采的工艺,半连续卸料系统应运而生。本文对露天矿开采半连续卸料系统的组成、工艺、工作方式、控制系统网络及系统技术难点等方面做了简要介绍。     

电梯制动器性能检测方法研究

电梯是我们日常生活中常见的基础生活运输设备之一,随着现代高层建筑的逐渐增多,商场、办公楼、住宅楼等建筑中,电梯随处可见,也成为了人们生活中不可缺少的生活运输设备。电梯的安全既关系到电梯的使用,更关系到人们的生命安全,为了保证电梯的足够安全,本文对电梯制动器性能的检测方法进行简要的研究和分析。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.