普通导爆索在高温爆破中的应用

本文叙述了导爆索在高温炮孔受热后的感度变化,测定了导爆索受热后的爆速和对防自爆药包的起爆能力,对普通导爆索用于高温爆破进行了论证。     

高温炮孔中乳化炸药升温规律分析?

为了获得高温炮孔中防护前后的乳化炸药内部温度变化规律,采用热电偶测温技术对乳化炸药内部不同位置的温度变化曲线进行测量。结果表明:防护下乳化炸药最高温度不超过水浴温度,其内部不同位置的温度变化曲线可通过指数函数进行较好的描述,最外层的温度变化曲线与水的温度变化曲线变化规律基本一致,而内部温度相对较低,说明乳化炸药的外层受到环境温度影响较大,而油包水结构与硝酸铵溶液吸热作用导致内部升温速率相对较慢,因此有利于防护后的乳化炸药在高温火区中得到应用。     

分布式光纤测温技术在火区爆破中应用

为了满足多点测量、响应时间短、精度高以及测温范围广等要求,将分布式光纤测温技术应用到高温火区炮孔测温中。为了适应高温炮孔中温度高、湿度大等复杂条件,采用镀金光纤作为分布式光纤测温系统的测温段。现场试验表明分布式光纤测温系统能快速获得炮孔温度分布情况,通过比较同一炮孔在注水降温前后的温度,结果表明:炮孔温度在注水降温停止后的较短时间内即可回升至降温前的温度,因此现场装药连线等爆区区域内的工作需要在抽出水管后的较短时间内完成。     

煤矿导爆索试制成功

近年来,矿井的爆破作业推广了深孔光面爆破的新技术。为了提高煤炭生产率,在瓦斯矿井也推广了此项技术,相应地提出了适用于瓦斯煤层用的煤矿导爆索或称“安全导爆索”。煤矿导爆索在深孔光面爆破中有显著的优越性。在较深的炮孔中,装药长度过长,对硝酸铵类的低爆速炸药就不能一次起爆,为了弥补这一缺陷,在较长装药炮孔中采用导爆索连接最为适宜。此外,在光面爆破中,为使周边光滑平直,减少周岩的破坏,通常使用分段装药,     

全孔蓄水法在高温火区爆破中的应用

针对高温炮孔因裂隙多导致蓄不住水的情况,将内层带有不透水材料的套管快速下放到炮孔并在短时间内注满水,在套管中装有模拟药卷并采用热电偶测量套管中的水温变化。结果表明:全孔蓄水可使工业炸药与起爆器材长时间保持在最高温度不超过水浴温度的环境中,因此能大幅延长高温火区装药施工时间。探索出高温火区的全孔蓄水爆破方法,并通过爆区规模试验,效果良好,该方法能保证施工安全,同时基本解决高温火区较大规模爆破的问题。     

露天煤矿高温爆破技术研究

宁煤大峰露天矿岩石炮孔温度有的高达200℃,为确保爆破的装药联网施工安全,必须将炮孔温度降到60℃以下,且需保证炮孔温度维持半小时以上不升温反弹。结合国内现有高温爆破方法,选择了生产成本较低的注水降温方法进行降温,然而注水降温方法有温度回升快的缺点,经过现场生产实验,研发出了水中加CaCl2、MgCl2的炮孔注水降温方法,炮孔温度降到60℃以下后,选用粉状乳化炸药,外缠三层石棉,用导爆索联接齐发起爆,满足了安全生产要求。     

远程控制装置在火区高温爆破中的应用

为了提高煤矿火区高温爆破的安全性,采用远程控制装置进行装药施工。结果表明:远程控制装置可在远程控制一次性完成下放导爆索、装药、堵塞工作(危险时段),装置中的钢管以及容器底部少量的堵塞物能防止雷管爆炸产生的能量与冲击波引爆容器内部的炸药,另外,开关网路可使所有炮孔同时完成下放导爆索、装药、堵塞的工作,使整个炮区中在最短时间内完成装填工作并引爆炸药。远程控制装药施工方法使施工人员远离高温火区,在实际应用中操作简便,克服了传统高温爆破工艺限制炮孔孔数的不足,能够对高温火区进行大规模爆破,从而提高矿山剥离挖运效率,并提高高温爆破的安全性。     

露天煤矿高温火区干冰降温试验研究

通过分析干冰(固态二氧化碳)性质,制定现场试验方案,采用干冰在露天煤矿高温火区内进行了炮孔局部降温试验。试验结果表明,干冰降温效果与孔深、孔温、干冰形状、与水的配合比例及注水顺序有关。高温炮孔注水后再注入干冰进行局部降温,当孔深小于8m时,孔底会形成1m左右的冻结段,能起到有效降温及维持低温效果的作用;当孔深超过8m时,孔底部温度降低,孔中部温度回弹速率较快,降温效果不佳。试验结论对进一步研究干冰降温方案有指导意义。     

关于高温凝结物的爆破实践

详细描述了冶炼炉内高温凝结物爆破拆除施工工艺。提出炉内喷水强制降温,爆破前测量高温炉内炮孔温度,找出炮孔温度随时间的变化规律,采用隔热药包,确保孔内药包在规定时间内温度不大于60℃。通过对宁夏平罗、惠农等地区铁合金冶炼炉400余次炉内高温凝结物的成功爆破清除验证了施工工艺的正确性。     

高温岩石爆破

<正>高温岩石爆破降温应遵守以下规定:每次降温后,应重新测量孔深并监测升温过程,如果炮孔变浅或坍塌,应及时调整该炮孔及其周围炮孔的装药量;对回温较快的炮孔应采取进一步的降温措施,并注意观测温度变化;装药前爆破员要对炮孔的温度、孔深进行测量并做好记录。     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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.     

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