Solid-liquid suspension of microcarriers in stirred tank bioreactor – Experimental and numerical analysis

AbstractSolid-liquid suspension characteristics in a stirred tank with four pitched-blade impellers, circle package impellers, and punched circle package impellers were studied via computational fluid dynamics (CFD) simulation. A classical Eulerian-Eulerian approach coupled with the standard k-ε turbulence model was adopted to simulate the solid-liquid two-phase turbulent flow. The effects of impeller speed, power consumption, impeller type, aperture size/ratio, solid particle diameter and liquid viscosity on the solid particle suspension quality were investigated. Results showed that the solid particle suspension quality was improved with an increment in the impeller speed. Punched circle package impeller could reduce the just suspension speed and improve the level of homogeneity for solid-liquid mixing process on the basis of four pitched-blade impeller and circle package impeller. The optimum aperture ratio and aperture diameter were 11.8% and 8 mm, respectively, for solid particles suspension process in this work. Smaller particle diameter led to smaller settling velocity and higher solid particle suspension quality. More viscous liquid was easier for sustaining the solid particles in suspension state. Meanwhile, punched circle package impeller can reduce the power consumption compared with four pitched-blade impeller and circle package impeller at the same impeller speed, and enhance the solid integrated velocity, turbulent kinetic energy, and turbulent kinetic energy dissipation rate of solid-liquid mixing system at the same power consumption.

Download Full-text

Numerical simulation of solid-liquid suspension in a stirred tank with a dual punched rigid-flexible impeller

Advanced Powder Technology ◽

10.1016/j.apt.2017.07.025 ◽

2017 ◽

Vol 28 (10) ◽

pp. 2723-2734 ◽

Cited By ~ 9

Author(s):

Deyin Gu ◽

Zuohua Liu ◽

Zhaoming Xie ◽

Jun Li ◽

Changyuan Tao ◽

...

Keyword(s):

Numerical Simulation ◽

Stirred Tank ◽

Liquid Suspension ◽

Solid Liquid

Download Full-text

Mathematical modeling and experimental study on solid–liquid suspension separation in ultrasonic standing wave field

Journal of Low Frequency Noise Vibration and Active Control ◽

10.1177/14613484211022984 ◽

2021 ◽

pp. 146134842110229

Author(s):

Yajing Wang ◽

Liqun Wu ◽

Yaxing Wang ◽

Yafei Fan

Keyword(s):

Standing Wave ◽

Sound Pressure ◽

Acoustic Radiation ◽

Sound Field ◽

Radiation Force ◽

High Energy ◽

Factors Affecting ◽

Liquid Suspension ◽

Ultrasonic Standing Wave ◽

Solid Liquid

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.

Download Full-text