نوع مقاله : مقاله پژوهشی
نویسندگان
مرکز مهندسی و مدل سازی چند مقیاسی جریان سیال، دانشکده مهندسی شیمی، دانشگاه صنعتی امیرکبیر، تهران، ایران
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
The quality of the gas-solid contact and mixing of the solid particles have profound effects on polymerization reactions of polyethylene in fluidized bed reactors. Hydrodynamic behaviors of the fluidized beds that are used in Basell and Mitsui technologies have been investigated. For this purpose, a two-phase model with the kinetic theory of granular flow was used. The model was first comprehensively validated against experimental data and then this validated model was used for further analysis. Results showed that the quality of solid distribution enhances from the bottom to the top of the reactor and reaches its maximum at the top of the bed. In addition, it was shown that a higher fraction of gas passes through the emulsion phase (in contact with particles) in the Mitsui reactor compared to the Bassel reactor, which reflects a better gas-solid contact in the Mitsui reactor. Additionally, the time-averaged axial velocity of the solid particles at different heights showed that the particle motion intensity is higher in the Basell reactor. At a normalized height of 0.72, the axial velocity of the solid particles is approximately 2 m/s in the Basell reactor and 1 m/s in the Mitsui reactor. Based on the axial velocity parameter, it can be said that the quality of the solid particle mixing in the Bassel reactor is better that that in the Mitsui reactor.
کلیدواژهها [English]
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