生产工艺条件对菌粉爆炸特征参数的影响

利用扫描电镜及激光粒度分析仪,探究了不同生产工艺条件下医药中间体菌粉A和菌粉B的表面形状及粒径分布,并进行了热解分析,证实上述特征参数存在一定差别。在此基础上进行了爆炸特性参数研究。研究结果表明,上述两种菌粉爆炸下限处于70~90 g/m3,最大爆炸压力峰值0.4~0.5 MPa之间,爆炸性相对较弱,但也必须引起足够的重视。与菌粉B相比,菌粉A相对安全,因此条件许可时优先采用菌粉A生产工艺流程。     

Explosion behaviour of metallic nano powders

This paper describes experiences and results of experiments with several metallic dusts within the nanometer range. The nano dusts (aluminium, iron, zinc, titanium and copper) were tested in a modified experimental setup for the test apparatus 20 L-sphere (also known as 20-L Siwek Chamber), that enables the test samples to be kept under inert atmospheric conditions nearly until ignition. This setup was already introduced in earlier papers by the authors. It was designed to allow the determination of safety characteristics of nano powders under most critical circumstances (e.g. minimisation of the influence of oxidation before the test itself). Furthermore the influence of passivation on explosion behaviour is investigated and additional tests with deposited dust were carried out to describe the burning behaviour of all dusts. For a better characterisation all samples were tested with a simultaneous thermal analysis (STA). To minimise the influence of oxidation all samples were handled at inert conditions until shortly before ignition or start of the test respectively.     

脱硫石粉贮存库气化装置改造

对火电厂脱硫石粉贮存库运行过程中散装机出料口下料缓慢,进气母管及气化槽体中进粉等问题进行了分析,提出了改造对策,石粉贮存库气,石粉贮存气化装置改造后运行效果良好,以60t罐车为例,石粉的装车为例,石粉的装车时间同原来的30min减少到15min.     

由硫酸亚铁（绿矾）制取还原铁粉的工艺研究

提出了一种新的绿矾综合利用的途径,即绿矾经碳酸盐转化,然后采用无烟煤作还原剂,CaCO3为添加剂,进行高温还原焙烧制取还原铁粉.先将绿矾用水溶解,用理论量1.2倍的（NH4）2CO3将FeSO4转化为FeCO3,FeCO3焙烧的最佳条件是FeCO3∶无烟煤∶CaCO3为100∶60∶8,焙烧温度为1000℃,焙烧时间为4.5 h.粗还原铁粉化学成分除C含量较高外,符合国家有关标准,900℃左右经氢气精还原1 h所得精还原铁粉化学成分的各项指标,均达到或优于国家有关标准的要求.     

基于磁场理论的矿岩加载损伤破坏表征研究

充填体与围岩的相互力学作用,除了接触带表壁附近可以通过贴置电阻应变片的方式进行应变值测量外,接触面及接触带附近的损伤破坏情况不易监测。基于此,应用磁场理论,将磁粉加入到配比试样中,充磁之后进行加载试验。通过特斯拉计测量试样表壁在加载过程中的磁感应强度变化,建立由表及里的损伤破坏联系规律。试验结果表明:加了磁粉的配比试样,在加载过程中各监测点处的磁感应强度值变化明显,特别是在内部裂纹扩展至临空面处的磁感应强度几乎减小至0.2 mT以下;而试样在加载过程中,各监测点的磁感应强度值随着压密破坏而变化;在未破坏时,不同区域有较一致的随试样内部压密相应磁感应强度增大的变化规律,而在试样加载破坏后,不同监测点磁感应强度变化起伏较大。     

活性粉末混凝土(RPC)槽形梁模型破坏试验研究

活性粉末混凝土 (RPC)具有高强、高耐久性以及高延展性等特点 ,因此 ,RPC在桥梁中有很好的应用前景。但是当前对RPC桥梁的设计研究很少 ,笔者根据自行研制的RPC ,设计了预应力拼装结构的槽形梁模型 ;并进行了RPC槽形梁模型的破坏试验研究 ,以验证槽形梁模型的承载力及发现设计上存在的问题。通过对模型拼装、预应力张拉及模型加载的试验现象的介绍和对试验结果的分析可知 ,破坏时主梁底部的拉应力远没有达到RPC的抗拉极限强度 ,而主梁腹板和下翼缘连接处的局部承载力不足才是主梁破坏的真正原因。最后 ,在总结裂缝发展和模型破坏的原因的基础上 ,对进一步的模型设计提出了修改意见。     

Utilisation of high volumes of limestone quarry wastes in concrete industry (self-compacting concrete case)

In limestone quarries, considerable amounts of limestone powders are being produced as by-products of stone crushers. High amounts of powders are being collected and utilisation of this by-product is a big problem from the aspects of disposal, environmental pollution and health hazards. In conventional concrete, the introduction of high volumes of limestone quarry dust to concrete mixes is limited due to its negative effects on water demand and strength of concrete. However, these fines can be efficiently utilised as viscosity enhancer particularly in special concrete (like self-compacting concrete—SCC) applications. Thus, the successful utilisation of this quarry dust in SCC could turn this material into a valuable resource.In this paper the usability of a quarry dust limestone powder in self-compacting paste and concrete applications was investigated. In the first part, the physical and mechanical properties of cement pastes incorporating quarry waste limestone powder (QLP) and a powder produced by direct grinding of limestone (PLP) were compared. In the second part, the performance of quarry waste limestone powder in SCC applications were tested and discussed. Results showed that, it is possible to successfully utilise high amounts of quarry waste limestone powder in producing normal-strength SCCs. Among its observed mechanical advantages, employment of quarry waste limestone powders improved the economical feasibility of SCC production.     

针刺滤料过滤筒技术及应用探讨

本文分析了针刺滤料过滤简的技术特点、过滤原理及特性，并介绍了其在烟气除尘领域中的应用及实例。     

细化粉基介质抑制熄灭油池火的模拟实验研究

利用行星式球磨机细化加工普通BC干粉灭火材料,并通过扫描电子显微镜对细化前后粉体颗粒的粒径分布和表面形态进行了比较分析;随后在小型粉体灭火装置内,比较了普通BC干粉和细化后粉体的灭火效率。实验发现:细化粉体的灭火效果好于同等实验条件下的普通BC干粉,侧面施加粉体的灭火方式好于底部施加;粉体熄灭煤油火较熄灭酒精火容易。最后,简要讨论了粉体的灭火机制以及细化后粉体灭火性能得到提高的原因。     

利用粉煤灰处理采油废水的研究

利用电厂粉煤灰及灰场氧化塘对现河首站采油废水中的污染物进行吸附和生化处理试验。试验结果表明:粉煤灰具有类似活性炭的结构和比表面积,对废水中的石油类、COD、氨氮、挥发酚等污染物具有较强的吸附、沉降和过滤作用。