Simulation of Solid–liquid Suspension and Scale-Up of Agarose Gel Activation Reactor

Abstract

Agarose gel activation reaction, which is of great importance in preparing the carrier of the column packing material for blood purification, would be significantly influenced by the configuration and parameter of reactor. In order to optimize the structure design of the reactor and operating parameters of the process, the characteristics of suspension system composed of agarose gel, NaOH, water, 3-allyl bromide, and activated alumina were simulated numerically utilizing an Eulerian multiphase flow model and multi-reference frame (MRF) approach. The effect of impeller configuration was studied with three typical impellers, including Rushton disk turbine (DT), pitched blade downflow turbine (PBTD45), and pitched blade upflow turbine (PBTU45). The results showed that the optimum solid suspension was obtained using PBTD45 impeller with a diameter of 100 mm and critical suspension speed of 570 rpm in a 20 L stirred reactor. In addition, the critical suspension speeds using the three impellers were calculated § Corresponding author. and the errors were all within the engineering allowance. Finally, the feasibility of scaleup design for agarose gel activation reactor was preliminarily discussed. The results would be useful to the optimization and scale-up of relevant reactor design. NomenclatureB : Impeller width, mm C : Impeller off-bottom clearance, mm C D0 : Drag coefficient in still liquid C D : Drag coefficient in turbulent liquid d P : Particle diameter, m D : Impeller diameter, mm H : Liquid height, mm k : Turbulent kinetic energy, m 2 /s 2

Study on Scale-Up of Anaerobic Fermentation Mixing with Different Solid Content

“…The appropriate scale-up index x under this condition was 0.93, closer to the scale-up criterion with the same blade tip speed (x = 1) rather than constant unit volume power (x = 2/3). Zhou et al [12] found that the velocity field was similar before and after scaling up according to the same blade tip speed. The solid concentration distribution in most regions of the tank was relatively uniform, with a high local solid volume fraction only appearing at the bottom of the stirring tank and near the baffle.…”