A hierarchical and computationally efficient mathematical model was developed to explain the polymerization of high-density polyethylene (HDPE) in an isothermal, industrial, continuous stirred tank slurry reactor (CSTR). A modified polymeric multi-grain model (PMGM) was used. Steady-state macroscopic mass balance equations were derived for all species (namely, monomer, solvent, catalyst and polymer) to obtain the final particle size and the required monomer and solvent input rates for a given catalyst input and the reactor residence time. The interphase mass transfer coefficients were calculated for the industrial CSTR using the operating data on the reactor. The present model was tuned with some data on an isothermal industrial reactor and the simulation results were compared with data on another set of industrial reactor. The comparison revealed that the present tuned model is capable of predicting the productivity and the polymer yield at various catalyst feed rates and the mean residence times. The effects of variation of two operating variables (catalyst feed rate and mean residence time) on the productivity, the polymer yield, the polydispersity index (PDI) and the operational safety were analyzed. The present study indicated that an optimal value of the reactor residence time (for maximum productivity per catalyst particle) exists at any catalyst feed rate.

中文翻译：

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工业淤浆相乙烯聚合反应器的建模和仿真：反应器操作变量的影响

建立了分层且计算有效的数学模型，以解释高密度聚乙烯（HDPE）在等温，工业，连续搅拌釜浆料反应器（CSTR）中的聚合。使用改良的聚合物多颗粒模型（PMGM）。对于所有种类（即，单体，溶剂，催化剂和聚合物），导出稳态宏观质量平衡方程，以获得最终粒度以及对于给定的催化剂输入和反应器停留时间所需的单体和溶剂输入速率。使用反应器上的操作数据计算了工业CSTR的相间传质系数。利用等温工业反应堆上的一些数据对本模型进行了调整，并将仿真结果与另一套工业反应堆上的数据进行了比较。比较表明，本发明的调谐模型能够预测在各种催化剂进料速率和平均停留时间下的生产率和聚合物产率。分析了两个操作变量（催化剂进料速率和平均停留时间）的变化对生产率，聚合物产率，多分散指数（PDI）和操作安全性的影响。本研究表明，在任何催化剂进料速率下，反应器停留时间的最佳值（对于每个催化剂颗粒的最大产率）都存在。分析了多分散指数（PDI）和操作安全性。本研究表明，在任何催化剂进料速率下，反应器停留时间的最佳值（对于每个催化剂颗粒的最大产率）都存在。分析了多分散指数（PDI）和操作安全性。本研究表明，在任何催化剂进料速率下，反应器停留时间的最佳值（对于每个催化剂颗粒的最大产率）都存在。