Churn-turbulent flow regime

The effect of moderately high viscosity (> 100 cP) is to prevent the formation of the churn-turbulent flow regime so that the bubbly flow regime persists at higher superficial gas/vapour velocitiesj(see Annex 3). . , -4... 

The reactor contains 2610 kg of reactants, has a volume of 3.6 m3 and a diameter of 1.45 m. The reacting mixture has been shown not to be inherently foamy. It is low viscosity and so the churn-turbulent flow regime is assumed. Data at the maximum accumulated pressure of 7 bara are as follows ... 

The bubble rise velocity for the churn-turbulent flow regime can be found from equation (A3.3) ... 

Methods are given for the bubbly and churn-turbulent flow regimes within the vessel. 

Krishna R, van Baten JM (2001) Eulerian simulations of bubble columns operating at elevated pressures in the churn turbulent flow regime. Chem Eng Sci 56(21-22) 6249-6258... 

Krishna, R., and EUenberger, J. (1996), Gas holdup in bubble column reactors operating in the churn-turbulent flow regime, AIChE Journal, 42(9) 2627-2634. 

Vandu CO, Krishna R. (2004) Volumetric mass transfer coefficients in slurry bubble columns operating in the churn-turbulent flow regime. Chem. Eng. Process., 43 987-995. 

The fate of bubbles in the slurry reactor is a complex issue since they undergo formation and breakup [110, 111]. Single-bubble and two-bubble models have been evaluated [112]. Two models for the churn-turbulent flow regime were developed, and a comparison indicated that increasing reactor... 

In recent years, new hydrodynamic models for the churn-turbulent flow regime in BCR have been developed [13 - 17]. Though these models use different approaches, they lead to equations describing liquid velocity profiles, slip velocities, circulation flow, etc. The ADM and its various modifications are generally thought to be a rather realistic description of BCR. However, the ADM presupposes the existence of turbulent eddies which are small in comparison to characteristic dimensions of the reactor. In view of the conclusions drawn from hydrodynamic BCR modelling one has seriously to question, whether... 

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