共查询到19条相似文献,搜索用时 109 毫秒
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在本文 (Ⅰ )报的基础上 ,将反应器系统的纯组分进料拓展到任意组成进料的情况 ,提出了选择性最大曲线的概念 ,利用选择性最大曲线将二维和三维浓度空间的可得区分成三个区域 ,即完全混合区 ,PFR区和非操作区。通过分析不同区域及其连接边界的特性 ,可以简捷 ,方便地拟定适宜的反应器网络流程结构 相似文献
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利用水-醋酸-煤油体系,研究了喷射式外环流反应器的传质性能,得到了反应器结构参数与物料流率等对传质性能的影响规律。根据反应器中的流体动力学特性,将反应器划分为底部区域、预混区、混合区、环流区和分离区。反应器底部区域几乎为水相,其传质性能可以忽略。首先利用实验数据回归得到了醋酸在水相中的平衡浓度与其在油相中初始浓度的经验关系式,之后分别研究了反应器内其他4个区域的传质性能。反应器各区域的传质性能均随油相表观进料速率和水相表观进料速率的增大而提高,在混合区内设分配管可显著提高反应器各个区域的传质性能,且分配管进料速率越大,传质性能越好。相同实验条件下,各区域的体积传质系数由大到小的顺序为:预混区、混合区、环流区、分离区。 相似文献
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以碱式氯化镁纳米棒为原料,采用沉淀转化法制备出氢氧化镁纳米棒滤饼;在不同干燥介质温度和不同物料床层厚度下,通过干燥动力学实验,得到了干燥速率曲线和干燥温度曲线。研究结果表明:在恒定干燥条件下,随着干燥介质温度的提高(或物料床层厚度的降低),氢氧化镁纳米棒的干燥速率加快,干燥时间缩短。当干燥介质温度较低(或物料床层厚度较大)时,对于某一干燥介质温度(或物料床层厚度)下的一条干燥速率曲线,氢氧化镁纳米棒的干燥过程可以分为升速、恒速、第一降速和第二降速四个干燥阶段。随着干燥介质温度的提高(或物料床层厚度的降低),干燥速率曲线中的恒速干燥阶段范围逐渐变小,直至消失。整个干燥速率曲线图可以分成为升速干燥区、恒速干燥区、第一降速干燥区和第二降速干燥区。 相似文献
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反应—分离循环系统最佳工艺条件的确定 总被引:11,自引:2,他引:9
本文从化工过程综合优化的角度出发,以定态,等容反应过程为研究对象,在可得区内考虑分离回收的循环物流,通过几何方法分析总收率等值线与可得区的关系,导出了通用的反应-分离循环系统的最佳工艺条件方程。将该方程曲线与可得区相结合,可在反应器网络综合的基础上确定最佳工艺条件。采用两个等温反应的例子在两维浓度空间辅之说明。 相似文献
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氨合成最大反应速率模型及计算 总被引:1,自引:0,他引:1
建立了计算最佳温度下的氨合成最大反应速率模型,提出了模型的数值解方法;以三套管冷管并流式氨合成塔为例,分别绘制了氨合成反应速率与氨摩尔分率、转化率和反应温度的关系曲线,并与实际反应曲线进行了比较,结果表明,本文所绘制的曲线不仅可以直观地反映氨合成最大反应速率随氨摩尔分率(或转化率)和反应温度变化的动力学规律,而且可以表示出催化剂床层内实际反应速率与最大反应速率的偏离程度。 相似文献
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Polarization data of BH-4 oxidation on Cu anode in alkaline solution were measured at steady state by a self-made experimental cell. The experimental polarization curve showed three regions:the region at lower over-potential η(below 0.4 V approximately),the region at higher η(above 0.6 V approximately)and the transitional region at medium η. It was found that the limiting current density is caused by the limiting elemental step rather than the external mass transport. The apparent reaction order with respect to BH-4 changes from 0 to 1. The active energy is about 40 kJ·mol-1 in both regions with lower and higher η,and is higher than 40 kJ·mol-1 in the transitional region. With the experimental temperatures and NaOH concentration,the hydrogen production rates released by the electrode reaction were measured at [BH-4]/[OH-]ratios of 1∶40,1∶20,1∶6. 7 and 1∶4,which is strongly dependent on the over-potential. The apparent number of released electron n by the reaction was calculated by using the measured amounts of hydrogen and coulomb. Higher value of n was obtained at lower [BH-4]/[OH-]ratio,higher temperature as well as higher over-potential. Under the experimental conditions,the value of n varies from 0 to 7,while in the transitional region it is just in the range of 3 to 5. The experimental results indicate that the limiting current density or n value will increase by virtue of proper experimental conditions. However,to considerably increase the current density at lower over-potential requires a modified anode with higher activity. 相似文献
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We present a Mitscherlich-related response surface for two variables. The curve for one of the variables, with the other fixed is similar to a Mitscherlich curve, but the curvature changes as the other variable changes. This surface is useful for fitting growth and other responses to two nutrient treatments. 相似文献
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Theoretical equations and a calculation method giving cloud point curve (CPC) for a multicomponent polymer 1/multicomponent polymer 2/single solvent system (i.e. quasi-ternary system) were derived on the basis of the Flory-Huggins solution theory. The systematic calculations based on this method were carried out to examine the effects on CPC of the type of molecular weight distribution, the polydispersity and the weight-average degree of polymerisation of the two original polymers, and three thermodynamic interaction parameters between solvent-polymer 1 (X01), solvent-polymer 2 (X02) and polymer 1-polymer 2 (X12). The shape of CPC sensitively depends on the polydispersity of the original polymer and, with an increase in polydispersity, the immiscibility region becomes wider. 相似文献
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