共查询到17条相似文献,搜索用时 93 毫秒
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采用三级混合悬浮混合产品出料结晶器(MSMPR),搭建了头孢拉定连续结晶实验装置。通过单因素实验研究了养晶pH值、晶种添加量、原料液浓度、停留时间、结晶系统温度及搅拌速率等结晶工艺条件对头孢拉定连续结晶产品收率及粒度分布的影响,优化了头孢拉定连续结晶工艺参数。通过实验获得优化结晶工艺参数:结晶温度293.15 K,搅拌速率180 r·min-1,养晶pH=2.85,晶种添加量为3%(质量分数),头孢拉定原料液浓度11%(质量分数),停留时间33.3 min,此条件下可以获得平均粒径为85.3μm,收率为76.53%的头孢拉定连续结晶产品。 相似文献
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石膏两步法制硫酸钾中K2SO4结晶工艺条件研究 总被引:2,自引:0,他引:2
运用连续流动法,在MSMPR结晶器中系统研究了石膏两步法制硫酸钾第二阶段中停留时间、结晶温度、进料配比及硫酸铵浓度、添加适量NH3对K2SO4结晶过程的影响,确定了适宜的结晶工艺条件;在此条件下,可得到粗大均匀且产品质量达到农用硫酸钾优等品标准的K2SO4结晶;其结果可为石膏两步法制硫酸钾工业化结晶器的设计与放大提供基础数据。 相似文献
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本文研究了丁炔二醇在MSMPR结晶器中的结品分离。发现丁炔二醇与水可形成比较稳定的过饱和溶液,介稳区较宽,属于低产率的结晶体系;还发现,结品温度、进料浓度对丁炔二醇冷却结晶都产生较大的影响,选择不当将使结晶操作趋向不稳定。另外,由于具有较低的生长速率,为了使结晶更为完善,有必要使晶体在结晶器内有足够的停留时间。 相似文献
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Narayan S. Tavare 《Chemical Engineering Communications》1989,80(1):135-152
The application of the theory of both concentration and temperature multiplicities is extended to the case of a reactive precipitation system in a continuous mixed suspension mixed product removal (MSMPR) crystallizer. A process involving elementary homogeneous chemical reaction with first order reaction kinetics with respect to each of the reactive components and subsequent crystallization described by conventional power law growth and power law magma dependent nucleation models is considered; the temperature dependency of each of these kinetics is described by Arrhenius relations. Exact uniqueness and multiplicity (i.e. multiple steady states) criteria are developed. The stability of these steady states is analysed using small perturbations around the steady state 相似文献
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The possibility of multiplicity in an isothermal continuous mixed suspension-mixed product removal crystallizer is explored using the bifurcation theory.A process involving agglomeration controlled precipitation is considered in which secondary nucleation occurs simultaneously with primary nucleation.The determinant equations for the existence of multiple steady states are developed and the multiplicity boundaries dependent on the physical and kinetic properties and operational parameters of the process are obtained by resolving these determinant equations.The number of steady states in the precipitator for various multiplicity regions is determined and the linear stability of these steady states is analyzed by using the Routh criterion. 相似文献
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The possibility of multiplicity in continuous isothermal MSMPR precipitators has been explored for agglomeration controlled conditions and general criteria, independent of nucleation kinetics, are developed for stability and multiplicity of the steady states. For the Volmer model of primary nucleation and the magma dependent power law model of secondary nucleation, parameter regions are determined in which multiple steady states exist, and their linear stability is analyzed. The analysis holds in general for all types of agglomeration kernel. For the Volmer nucleation kinetics three steady states exist in the region of multiplicity with the “middle” one always being unstable. The analysis for magma dependent power law model showed multiplicity regions having as many as four steady states, the number depending on magma and kinetic order. Unlike the case of molecular growth control, limit cycle behaviour is not possible, and the approach to the steady state is always asymptotic 相似文献
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The possibility of multiplicity in continuous isothermal MSMPR precipitators has been explored for agglomeration controlled conditions and general criteria, independent of nucleation kinetics, are developed for stability and multiplicity of the steady states. For the Volmer model of primary nucleation and the magma dependent power law model of secondary nucleation, parameter regions are determined in which multiple steady states exist, and their linear stability is analyzed. The analysis holds in general for all types of agglomeration kernel. For the Volmer nucleation kinetics three steady states exist in the region of multiplicity with the “middle” one always being unstable. The analysis for magma dependent power law model showed multiplicity regions having as many as four steady states, the number depending on magma and kinetic order. Unlike the case of molecular growth control, limit cycle behaviour is not possible, and the approach to the steady state is always asymptotic 相似文献
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尹秋响 《中国化学工程学报》1998,6(2):138-148
The possibility of both concentration and temperature multiplicities has bcen studied for the case of acontinuous adiabatic mixed suspension mixed product removal(MSMPR)reactive precipitaior.A Process in-volving homogeneous chemical reaction in first order reaction kinetics with respect to each of the reactive compo-nents and subsequent crystallization described by conventional power law growth and power law magma depen-dent nucleation models is considered.The temperature dependency of each of these kinetics is described by Ar-rhenius relations.Parameter regions are determined in which multiple steady states exist.The linear stability ofthese steady states is analyzed by using the Routh criterion approach. 相似文献
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Dragomir B. Rukur 《Chemical engineering science》1978,33(8):1055-1060
An investigation of uniqueness and multiplicity of the steady states in an isothermal fluidized bed reactor and continuous stirred tank reactor is presented. Material balance equations for the two phase model of Davidson and Harrison and the modified Partridge and Rowe model, are transformed into a single equation which is of the same form as the material balance equation for an isothermal continuous stirred tank reactor. Exact uniqueness and multiplicity criteria are derived, and numerical examples illustrating the influence of some parameters on the steady state multiplicity are presented. 相似文献
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Mathematical modelling and experimental validation of a novel periodic flow crystallization using MSMPR crystallizers 下载免费PDF全文
Qinglin Su Chris D. Rielly Keddon A. Powell Zoltan K. Nagy 《American Institute of Chemical Engineers》2017,63(4):1313-1327
The challenges of insufficient residence time for crystal growing and transfer line blockage in conventional continuous mixed‐suspension mixed‐product removal (MSMPR) operations are still not well addressed. Periodic flow crystallization is a novel method whereby controlled periodic disruptions are applied to the inlet and outlet flows of an MSMPR crystallizer to increase its residence time. A dynamic model of residence time distribution in an MSMPR crystallizer was first developed to demonstrate the periodic flow operation. Besides, process models of periodic flow crystallizations were developed with an aim to provide a better understanding and improve the performance of the periodic flow operation, wherein the crystallization mechanisms and kinetics of the glycine‐water system were estimated from batch cooling crystallization experiments. Experiments of periodic flow crystallizations were also conducted in single‐/three‐stage MSMPR crystallizers to validate the process models and demonstrate the advantages of using periodic flow operation in MSMPR stages. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1313–1327, 2017 相似文献