烧结电除尘器气流分布板表面喷涂材料的选择

对普通低碳钢气流分布板进行表面喷涂处理,达到增强分布板耐磨性,进而提高分布板使用寿命的目的.通过化学成分、硬度、耐磨性、结合强度等方面的分析比较,最终确定用铁基喷涂粉作为烧结电除尘器气流分布板的表面喷涂材料.     

大型电除尘器气流分布数值计算的研究和应用

用计算流体动力学(CFD)方法对大型电除尘器进口管道流量分配和电场进口断面气流分布进行了数值计算,根据计算结果得到管道导流板和气流分布板上导流片的布置方案。利用模型试验验证了数值计算的结果,吻合较好,满足《电除尘器》标准的考核性能要求。     

斜气流技术的模拟试验研究

针对宝钢二烧机头450m2电除尘器提效改造这一研究课题,采用斜气流技术进行了模拟试验,通过导流及折流措施的实施,把气流调整到预定的斜气流廓线模式,并分析了气流调节对流速分布的影响,确定了本试验所需的斜气流实施方案.     

谈谈电除尘器三项均匀性要求

通常认为电除尘器内气流分布均匀、板电流密度均匀即可获得高的除尘效率;极板极线上振打加速度分布均匀可实现有效清灰。但实际上电除尘器电场断面上粉尘并非均一分布,极板极线上的结灰也不均匀。本文分析认为:气流分布、板电流密度应当是有条件的均匀,振打加速度无需均匀,也根本无法实现均匀。     

电改袋技术在烧结机除尘系统改造中的应用

本文分析了烧结机机尾电除尘器改造为袋式除尘器过程中的关键技术问题,采用数值模拟方法研究除尘器内部气流组织,为合理布置气流分布装置提供参考依据.并结合具体工程实例验证了此方法的可行性.     

金属喷涂、堆焊与修复/金属喷涂工艺与设备

对普通低碳钢气流分布板进行表面喷涂处理，达到增强分布板耐磨性，进而提高分布板使用寿命的目的。通过化学成分、硬度、耐磨性、结合强度等方面的分析比较，最终确定用铁基喷涂粉作为烧结电除尘器气流分布板的表面喷涂材料。[第一段]     

钢铁工业烧结烟尘电除尘技术的特点及应用

针对钢铁工业烧结机机头、机尾烟气的不同特点,结合烧结烟尘排放标准,从电除尘电场特性、气流分布以及振打等方面,讨论了烧结机电除尘器选型设计和技术改造中应考虑的几个问题,并给出应用实例。     

大型烧结机机尾电除尘器改造

介绍了宝钢一期烧结机机尾214 m2电除尘器的改造项目及结果,为今后大型电除尘器的改造提供了范例.     

气流再压缩等离子弧焊接电弧行为

电弧等离子体行为对焊接接头组织结构和性能具有决定性作用,开展气流再压缩等离子弧特性研究对于指导先进材料的气流再压缩等离子弧焊接工艺和提高焊接接头质量具有重要意义. 针对气流再压缩等离子弧焊接新工艺,基于流体动力学和电磁理论,建立气流再压缩等离子弧数值分析模型,采用ANYSYS Fluent软件,通过C语言进行二次开发,定量计算等离子弧温度分布、流场分布、电势分布,分析压缩气对等离子弧温度场、流场、电弧电压的影响规律. 模拟结果表明,压缩气对喷嘴内的等离子弧温度分布基本没有影响,压缩气对喷嘴外的等离子弧具有拘束压缩作用;压缩气对等离子弧流场分布基本没有影响;压缩气能够提高电弧电压. 相同电流条件下,与常规等离子弧焊接相比,气流再压缩等离子弧焊接电弧穿透能力有望提高.     

电除尘器电晕电流密度分布微机测试处理系统的研制

在电除尘器中,电晕电流密度分布的均匀性是影响除尘效率的因素之一。由于电晕线的种类繁多,且形状复杂,很难靠理论计算得出结果。我们将计算机技术与测试技术相结合,研制成功一套“电除尘器电晕电流密度分布微机测试处理系统”。本文较详细地叙述了该系统的组成、测试方法及工作原理,介绍了系统的功能、作用及主要特点,该系统具有能够自动完成测试处理全过程,自动生成数据表格,自动绘制“电晕电流密度分布状态模拟图”和“电晕电流密度分布状态直方图”数据长期存储,数据重现,故障自动检测报警等功能。     

高速燃气喷涂枪用燃油雾化喷嘴结构参数优化

为开发出以航空煤油为燃料的新型高速燃气喷涂枪,需设计出高效的煤油雾化喷嘴.文中提出了一种双气流空气助力雾化喷嘴,并运用计算流体动力学（CFD）模拟技术计算了该喷嘴的气流场,分析了喷嘴主、辅气出口截面积比对雾化气流场分布的影响规律,发现主、辅气出口截面积比增大,气流的喷射锥角相应增大,最大速度减小.综合考虑喷射锥角和气流速度对雾化效果的影响,确定主、辅气出口截面积比在1.01~1.34范围内喷嘴雾化效果较好.利用高速摄像系统对优化喷嘴的喷雾形态进行了试验分析,发现拍摄到的喷雾形态和计算机模拟结果一致,具有良好的雾化效果.     

单晶铜线材在潮湿环境中的表面氧化规律研究

采用氧化增重实验,通过改变温度、水蒸汽流量两个参数,对单晶铜线材的表面氧化行为进行了研究.结果表明:单晶铜线材在潮湿环境中的氧化由三个阶段构成;温度与水蒸汽流量两个因素对单晶铜线材的表面氧化均有显著影响,温度越高、水蒸汽流量越大,氧化速率越快;单晶铜线材在潮湿环境下的氧化产物是Cu2O,其氧化速度由Cu2O的生长速度控制,氧化膜对线材的后期氧化起阻碍作用.     

高速电弧喷涂枪结构优化的试验

试验优化了一种高速电弧喷涂枪的结构.用SprayWatch-2i热喷涂监测系统测试了喷枪的雾化熔滴速度,并研究了Al涂层和3Cr13涂层的组织和性能.结果表明,丝材和导电嘴的存在,严重扰动了雾化气流流态,两丝夹角和丝交点离喷管出口距离也显著影响了喷管气流场的分布特征;改进设计喷枪的雾化熔滴速度显著提高,其3Cr13雾化熔滴的最高速度达到210 m/s;涂层组织和力学性能也得到改善,喷涂Al涂层和3Cr13涂层时,结合强度分别提高了55%和39%,硬度值也分别增加了26%和9%,涂层的显微组织更均匀致密,孔隙率更低.     

A study of the corner wear in cylindrical plunge grinding

The tolerance on the corner radius is quite important in a number of cylindrical grinding operations and hence the corner wear is critical. Preliminary investigations have shown that the corner wears off in increasing arcs of radii and could be simulated by dressing the corner to specific radii. A possible method of in-process monitoring of corner wear is by monitoring of the grinding forces during the process. This paper briefly discusses the nature of corner wear and the force fluctuations encountered in plunge grinding due to corner wear, as also the possibilities of using this data for in-process monitoring of corner wear. Another possible method of in-process monitoring of corner wear by using air-flow technique is also discussed briefly.     

A MATHEMATICAL MODEL FOR THE CONTROL OF AIR-FLOW STATES IN MINE VENTILATION NETWORKS

应用流体运动方程、能量方程、状态方程和连续方程研究了矿井通风网路中一维风流流动状态。这些方程考虑到了风流的可压缩性和能量交换过程。讨论了控制通风网路中风流状态的数学模型。最后,举例说明应用电子计算机研究矿井发生火灾时网路中风流状态的变化。     

Regenerating deuterium absorption of Ti36Zr40Ni20Pd4 icosahedral quasicrystal

Ti/Zr-based icosahedral quasicrystals are a kind of promising hydrogen storage materials, however their absorption regeneration after oxidation-poisoning has been scarcely studied. This work is intended to investigate the deuterium-storage regeneration of a suction-cast Ti₃₆Zr₄₀Ni₂₀Pd₄ quasicrystal. It was found that only through hot vacuuming the quasicrystal could be refreshed from air-flow poisoning to absorb deuterium in two cycles. During the first absorption course, a pregnancy period was observed before the real deuterium uptake while deuterium was loaded rapidly during the second one. The deuterium concentration in the alloy can reach 0.011 mol?D₂/(g?M) (corresponding to a hydrogen mass percent of 2.2%. D₂ and M denote molecular deuterium and the metallic alloy). But the loaded deuterium was very difficult to release completely even by eight-stage desorption at different temperatures. After the second desorption, the quasicrystal phase remained in a small volume, as though the desorption temperature was beyond the crystallization temperature of the quasicrystal. This probably is attributed to the solution function of residual deuterium in the alloy.     

Ablation resistance of tungsten carbide cermets under extreme conditions

A cobalt-free tungsten carbide cermet (WC-FeNi) has been subjected to oxyacetylene flame tests to simulate extreme operating conditions such as a worst-case fusion reactor accident. In such an accident, air-ingress to the reactor may impinge on components operating at surface temperatures in excess of 1000 °C, leading to tungsten oxide formation and its subsequent hazardous volatilisation. Here, the most challenging accident stage has been simulated, where the initial air-ingress could lead to extremely rapid air-flow rates. These conditions were simulated using an oxidising oxyacetylene flame. The separation between flame nozzle and sample was varied to permit peak surface temperatures of ~950–1400 °C. When the peak temperature was below 1300 °C, the cermet gained mass due to the dominance of oxide scale formation. Above 1300 °C, the samples transitioned into a mass loss regime. The mass loss regime was dominated by liquid-phase ablation of the scale rather than its volatilisation, which was confirmed by performing a systematic thermogravimetric kinetic analysis. The result was unexpected as in other candidate shielding materials, e.g. metallic tungsten, volatilisation is considered the primary dispersion mechanism. The unusual behaviour of the cermet scale is explained by its relatively low melting point and by the lower volatility of its FeWO₄ scale compared to tungsten's WO₃ scale. The substantially lower volatility of the WC cermet scale compared to metallic W scales indicates it may have a superior accident tolerance.     

Φ函数负荷分配在热连轧中的应用

Ф函数负荷分配方法,是一种无迭代的负荷分配方法。在热连轧规程分配中采用Φ函数负荷分配方法,计算得到热连轧精轧轧制规程,用热连轧厂负荷分配实际数据,验证了Ф函数负荷分配方法模型的实用性。分析了热连轧生产中的过程数据,在理论和实践上证明此方法的可行性。     

Single-peak distribution model of particulate size for welding aerosols

A large number of particulate size distributions of welding aerosols are measured by means of DMPS method, several distribution types are presented. Among them the single-peak distribution is the basic composing unit of particulate size. The research on the mathematic models and distributions functions shows that the single-peak distribution features the log-normal distribution.The diagram-estimating method ( DEM ) is a concise approach to dealing with distribution types, obtaining distribution fiLnctions for the paniculate sizes of welding aerosols. It proves that the distribution function of particulate size possesses the extemting property,being from quantity distribution to volume, as well as high-order moment distributions, with K-S method verifying the application of single-peak distribution and of DEM.     

轧制力比率负荷分配方法在热连轧中的应用

主要介绍了热连轧精轧机组轧制力比率负荷分配方法,阐述了初始厚度分配以及负荷分配的原理。采用模型经验值并在轧制过程中进行适当修正,得到较为合理的目标负荷分配比率。由机架出口厚度初值的计算结合Newton-RaPhson法进行反复迭代,最终可得到最佳的厚度分配值。实践证明轧制力比率负荷分配方法能够保证精轧机组运行顺稳,满足在线控制的要求。