共查询到19条相似文献,搜索用时 140 毫秒
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由于吸嘴周围风速的衰减特性,开放式气力吸送系统的运行参数有别于封闭式气力吸送系统。针对入口风速38 m/s、内径40 mm的立管吸嘴,采用圆柱状流域吸气模型对吸嘴周围的风速分布进行了模拟。结果显示,距入口断面10 mm至20 mm处,轴线上的风速由15.7 m/s衰减至6.5 m/s。基于模拟结果,提出了开放式气力吸送系统设计方法进而设计了气力吸送装置。研究表明:在相同的固气比下,开放式气力吸送系统的压力损失比封闭式系统高137%,设计风量比后者高186%。在实验装置上开展了玻璃球散料的开放式吸送实验,实验结果与模拟数值吻合较好。 相似文献
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落纱飘丝的原因是粗旦多孔丝摩擦阻力大,吸丝风力小,吸嘴吸力不足等。设备改造是将油轮导纱器单片改为双片,80°导向角优化成110°和160°。吸丝风机传动皮带张力调整为(20±5)N,加强吸丝口密封,制风机压力控制在2535 kPa。将吸嘴的通孔改造为锥孔,增大其气流孔径等。落纱飘丝由改造前平均14根降低至135 kPa。将吸嘴的通孔改造为锥孔,增大其气流孔径等。落纱飘丝由改造前平均14根降低至12根,真正实现了机台无人落纱。 相似文献
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微波技术与煤热解技术结合而成的煤微波热解技术可高效地治理传统煤热解技术中环境污染高和资源利用效率低的难题,为低变质煤的清洁高效利用和分级提质利用提供了新的思路。煤催化微波热解技术能有效改善热解升温特性和产物分布,从而受到较多学者的关注。本文从低变质煤催化微波热解技术发展历程着手,概述了国内外煤催化微波热解研究技术进展,通过加入Fe、Co、Ni和Cu等金属化合物或焦炭、活性炭等碳材料作为吸波剂,能显著增强煤对微波的吸收能力,提高热解升温速率、产物收率及产物质量,而有些金属化合物在微波热解反应中不仅起到吸波作用,还具有催化作用。碳基吸波催化剂作为一种性能优越的煤微波热解催化剂,具有优越的电磁和吸波性能、较好的催化性能和高经济性等优点,本文在煤催化微波热解技术研究现状的基础上,对碳基吸波催化剂进行了较为详细地分析,概述了碳基吸波催化剂的碳基体和催化活性组分的研究进展,对比了3种常见碳基吸波催化剂制备方法的优劣势。最后,总结了碳基吸波催化剂在研发过程中存在的难题,并展望了低变质煤催化微波热解技术的应用前景。 相似文献
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工业燃煤锅炉燃烧过程的自动调节 总被引:3,自引:0,他引:3
本文根据一链条炉排工业锅炉的实测对象特性,分析了它对燃烧过程控制的影响,提出了以送风量为主调节参数,给煤量为随动调节参数,根据蒸汽压力变化,自动按比例地“煤随风变”,以保持适当风—煤配比的控制方案。采用测氧仪监视燃烧工况,据烟气含氧量手动校正风—煤配比。文中还介绍了此控制方案的组成原理和实施问题。 相似文献
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关光森 《硫磷设计与粉体工程》2002,(1):34-37
为了提高气力输送重要技术指标之一的固气混合比 ,近年来洛阳工学院研制了新型吸送式气力输送实验装置。在该实验装置的供料器内 ,经喷嘴引入压缩空气 ,提高了供料器内的真空度 ,使物料能更加充足、均匀地进入供料器。着重从理论上论述了压缩空气喷嘴的流动参数计算方法和喷嘴射流抽引现象产生机理 ,分析了新型吸送式气力输送的原理与可行性 ,并对其进行了实验。实验结果证明 ,不但新型吸送式气力输送原理正确 ,而且比传统的吸送式气力输送固气混合比大幅度提高 相似文献
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就矿井目前煤层气抽放中存在的问题进行了深入探讨,指出了矿井煤层气抽放系统改扩建的必要性。 相似文献
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基于流道形状的改进,研制了一种高效的双流道自吸气叶轮,其吸气量为十二叶片Rushton透平的3.33~5.00倍,比传质系数为后者的1.32~1.95倍。和目前性能较好的三弯叶自吸气叶轮相比,其吸气量与比传质系数也分别高出50%~75%与6%~81%。 相似文献
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简述了焦炉装煤烟气除尘技术现状及捣固侧装煤焦炉除尘的方法,介绍了改进的U型管双抽吸烟气回收技术,重点介绍了在U型管双抽吸烟气除尘技术的基础上改进的新的烟气除尘工艺——捣固焦炉双集气管双抽吸工艺。新工艺进一步解决了捣固焦炉装煤烟气外逸的问题,同时烟气得到回收利用,实现了经济效益与环境效益的双赢。 相似文献
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Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%. 相似文献
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The turbulent flow (Re = 1.5 × 105) near a rough wall with narrow apertures has been numerically analysed to study the effect of the aperture geometry and wall suction on the flow characteristics. The aperture entry geometry is characterized by roughness height and roughness width. The roughness height is varied from 0.3 to 1.2 mm and roughness width is varied from 2.6 to 4.0 mm. The wall suction is characterized by slot velocity which is varied from 0.25 to 5 m/s. The flow characteristics in terms of fluid streamlines, flow resistance, wall pressure, and wall shear have been presented for several cases. The results show that the flow through the apertures is dominated by a separation vortex that covers the aperture. As roughness height increased (or slope of the roughness), the vortex size increased. With increasing wall suction, the vortex size decreased and moved towards the aperture opening. The flow resistance characterized by pressure drop across the aperture is significantly high for very low wall suction and it is increased with increasing roughness slope. At higher wall suction the slot velocity and roughness geometry has less influence on flow resistance. Wall pressure and skin friction coefficients are dependent on the ratio of roughness height to width. 相似文献
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Improving the suction performance of centrifugal pumps by using jetting device is presented. The theoretical analysis, experimental study and engineering implementation show that suction performance of centrifugal pump can be improved with jetting device and be used for delivering the liquid media requiring high suction performance, whereas the efficiency and head of the pump will decrease a little. The effect of feed-back jetting on suction performance is the most obvious at design point. The suitable rate of feed-back flow is 2%-5%. 相似文献
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卡尔曼滤波在管道泄漏检测中的应用 总被引:6,自引:1,他引:6
负压波法检测管道的突发性泄漏具有较高的灵敏度和定位准确度,在国内外得到广泛的应用,该方法的关键技术之一在于准确测定负压波通过上下游测量点的时间差。本文首次提出利用卡尔曼滤波捕捉压力波形拐点、进而获得时间差的方法。实验表明,该方法不仅可以有效地降低误报警率,而且可以对小泄漏定位。 相似文献
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Asterios Pantokratoras 《Chemical Engineering Communications》2013,200(3):332-343
The Blasius and Sakiadis flows of a non-Newtonian power-law fluid are considered. The plate is porous and fluid can be either injected or sucked through it. The boundary layer equations are transformed into a nondimensional form and are solved with a finite difference method. For the case of uniform suction, new results have been found, although this problem has been investigated in the past. Among them are analytical solutions for dilatant fluids of the Blasius flow and analytical solutions of the Sakiadis flow for all values of the power-law index. For the case of uniform injection, the characteristics of the flow until a separation state are investigated and discussed. 相似文献