共查询到20条相似文献,搜索用时 78 毫秒
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介绍了环流式碳化塔内气固液三相的流动状况、温度分布和与索尔维碳化塔操作内容比较的简单操作方式,分析了降液管中物料流动的推动力和原降液管设计的缺陷,并在φ2600塔变换气制碱试车中出现故障以及改进解决的情况,借用工厂意见对环流式碳化塔的工业化实践作了阶段评价。 相似文献
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为了揭示气固两相流穿越液池过程中的气液固三相流动特性,建立了气液固三相实验平台和基于Euler-Lagrange框架下的数值模拟平台,对该过程中的气液固三相流动过程及颗粒运动分布规律进行研究。获得了5~15 μm、80~110 μm和380~530 μm 3种典型粒径颗粒在三相体系中的微观运动过程及其分布规律。实验与数值模拟结果均能反映出一致的客观规律。研究发现,颗粒浓度沿液池高度方向和径向均呈现多峰分布特征;5~15 μm粒径颗粒更易跟随气体一起穿越液池,其在液池内的浓度分布较为均匀;380~530 μm粒径颗粒与气体的跟随性较差,其浓度峰值主要集中在液池底部。随着下降管出口静态浸没深度的增加,液池内颗粒浓度分布趋于平缓。 相似文献
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汽液固三相循环流化床蒸发器已应用到盐化、烧碱、中药和造纸等工业中,表现出良好的防除垢性能。文中研究了这种新型流化床蒸发器的防、除垢机理。首先揭示出汽液固三相流剪应力对延长污垢的诱导期起主要作用,并对汽液固三相流剪应力和三相流剪应力增长率进行了定量计算,分析其影响因素。其次从污垢附着和剥蚀的角度,考察了固体颗粒的除垢作用。根据理论分析指出三相流剪应力对污垢附着需要的时间和污垢剥蚀比率的影响,从而计算了剥蚀比例和剥蚀速率及其影响因素。 相似文献
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许多单相及三相异步电动机工作起来后,没有固定的旋转方向或者由于高速旋转惯性较大,此时若改变旋转方向,由于电机没有完全停止,还会按照原来的方向旋转,这样很容易造成一些事故。文章对此故障采取了在二次控制回路添加时间继电器的处理,经过试验和实际运行,效果明显,解决了存在的故障。 相似文献
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川渝地区页岩气地层油基钻井液钻井过程中产生的岩屑离心液低密度固相含量高,粘度大,难以重复利用且处理费用高。针对上述问题,本文首先介绍了页岩气油基钻井液中低密度固相的特点、使用的油基钻井液絮凝剂和絮凝机理以及岩屑废弃离心液中的现场处理工艺,实验研究了油基钻井液絮凝剂与现场钻井液的配伍性,最后分析了油基钻井液絮凝剂的作用效果以及絮凝后离心液的回收处理方法。室内评价表明油基钻井液絮凝剂与现场钻井液配伍性良好,可以降低油基钻井液的粘度,改善其流变性。现场试验表明油基钻井液絮凝剂可以大幅度降低废弃离心液的低密度固相含量,处理后低密度固相含量与现场油基钻井液的低密度固相含量相当;且絮凝处理后的离心液按20%的加量加入到油基钻井液中对油基钻井液的性能影响很小。本文证明了油基钻井液絮凝剂可以提高油基钻井液的重复利用率,降低废弃物的数量。 相似文献
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The synthesis of methanol and other products from CO and H2 was studied over Pd catalysts prepared by adsorption of Pd(π-C3H3)2 on MgO, ZnO, La2O3, γ-Al2O3, SiO2, TiO2, and ZrO2 as well as over a SiO2-supported Pd catalyst prepared from PdCl2 and Pd black. Both the activity and selectivity of Pd were affected strongly by the nature of the support and the composition of the Pd precursor. The specific activity for methanol synthesis decreased in the order ? [derived from PdCl2] > > > PdTiO2 > [derived from Pd(π-C3H5)2] ? Pd black, while the specific activity for hydrocarbon synthesis decreased in the order > > [derived from PdCl2] ? [derived from Pd(π-C33H5)2] ≈ Pd black ? . Dimethyl ether production was observed over four of the catalysts and the activity for formation of this product decreased in the order . The effects of support composition on the catalytic properties of Pd are discussed in the light of current ideas concerning metal-support interactions and the acid-base properties of the support. 相似文献
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《Ceramics International》2019,45(10):13179-13186
Pb-free piezoceramics of K0.5Na0.5Nb1-xSbxO3 + 1 mol% CuO are synthesized via a solid-state reaction. Furthermore, the transformation of hardening to softening behaviors induced by Sb substitution is exhibited and the corresponding microscopic mechanism is proposed. The CuO-doped K0.5Na0.5NbO3 ceramic without adding Sb exhibits extremely hardening characteristics (i.e., ultrahigh Qm of ∼2426, low tanδ of 0.32%, and pinched ferroelectric hysteresis loop) due to the formation of defect combinations ( and ). Whereas, the addition of Sb dramatically reduces the levels of defect combinations, leading to obviously softening properties (d33 > 210 pC N−1, kp > 40%, low Qm, and normal single P-E hysteresis loop). Our results indicate that the decrease of defect combinations with Sb addition should be responsible for the hardening-softening transformation of piezoelectricity and ferroelectricity in CuO-doped K0.5Na0.5Nb1-xSbxO3 piezoceramics. 相似文献