Besides, a polymerization system in a CSTR is less influenced
by the formation of thick polymer layers at the walls. However,
only detailed simulations of the flow pattern and the kinetics for
a given reactor with a specific geometry allows identifying the
optimal reactor type. To develop an appropriatemodel for this type
of reactor, a computational fluid dynamics (CFD) model must be
developed for the flow field generated by the impeller in combina-
tion with the kinetics of the reaction [1]. Mixing can also affect the
polymer properties. Rapid increase in viscosity withmonomer con-
version causes drastic variations of heat and mass transfer in reac-
tion mass. Good mixing can be achieved by mechanical agitation,
which breaks up the fluid elements into small parts, and molecular
diffusion, which homogenizes the level of species concentration
gradients inside the small parts [5]. Real flow in continuous poly-
merization reactors usually presents intermediate flow pattern be-
tween the completely micro-mixed and completely segregated
conditions. The degree of micro-mixing may have little effect on
the conversion of monomer throughout the reactor, but it can
strongly affect the molar mass and branching distribution [4].
Besides, a polymerization system in a CSTR is less influencedby the formation of thick polymer layers at the walls. However,only detailed simulations of the flow pattern and the kinetics fora given reactor with a specific geometry allows identifying theoptimal reactor type. To develop an appropriatemodel for this typeof reactor, a computational fluid dynamics (CFD) model must bedeveloped for the flow field generated by the impeller in combina-tion with the kinetics of the reaction [1]. Mixing can also affect thepolymer properties. Rapid increase in viscosity withmonomer con-version causes drastic variations of heat and mass transfer in reac-tion mass. Good mixing can be achieved by mechanical agitation,which breaks up the fluid elements into small parts, and moleculardiffusion, which homogenizes the level of species concentrationgradients inside the small parts [5]. Real flow in continuous poly-merization reactors usually presents intermediate flow pattern be-tween the completely micro-mixed and completely segregatedconditions. The degree of micro-mixing may have little effect onthe conversion of monomer throughout the reactor, but it canstrongly affect the molar mass and branching distribution [4].
การแปล กรุณารอสักครู่..
