(237y) Local Hydrodynamics Characteristics of Cylindrical Split AirliftReactor via Radioactive Particle Tracking (RPT) Technique

Internal-loop airlift reactors have been widely used in chemical, biochemical processes and extensively applied for cells cultivation such as microalgae, where good mixing and high mass
transfer are required. Since the airlift reactor is an opaque system involved complex multiphase flow behaviors, the substantial knowledge base for such reactor design and operation of the bioreactors has many unknowns and uncertainties. Additionally, the information of the local flow dynamics parameters such as shear stresses, liquid velocity field, and turbulent kinetic energy is still unclear yet and need more essential details.

Therefore, in this work, an advanced radioactive particle tracking (RPT) technique have been used to find out the details of the multiphase flow dynamics in a cylindrical split airlift reactor. The cylindrical reactor is a Plexiglas column in 5.5-inch (0.14m) inner diameter and 59 inches (1.5m) high, with a thin Plexiglas split plate (3mm) which divided the column into two equivalent section, riser, and downcomer, which supported above the column base in 5 cm. Air is bubbled through a 5 cm diameter ring sparger installed it in the riser section. This sparger had 5mm diameter and made from a stainless steel tube with 15 holes each one has 1mm diameter drilled facing upward.

The measurements covered the entire reactor, as well as in the individual structure regions, the top (above the split plate), the bottom (below the split plate), the riser, and the downcomer 2 sections; all are also characterized. Good liquid distribution, unharmed shear stress values, high turbulent kinetic energy in the upper regions which is over split plate have been found in all reactor region. Also, high shear stress and turbulent kinetic energy were observed in the nearness of the sparger ring. The outcomes also propose that the flow
framework and structure have considerable effects on the performance of the bioreactor. These results provide benchmark data for computational fluid dynamic (CFD) simulation,
design, and scale-up. The experimental results and conclusions will present at the conference.