Hydrodynamic Regimes in TPSRs with Internal Draft Tube

2 Hydrodynamic Regimes in TPSRs with Internal Draft Tube 

The driving force for the circulation between the riser and the downcomer is the difference in gas holdups in these sections. Bello et al. (1985) gave Equation 10.23 relating the holdups in the case of a BCDT for air-water system with air sparging in the annulus  

The BCDT system gave higher gas holdups than a corresponding external loop (EL) system. This was attributed to a longer connector between the riser and downcomer in the EL system, which allowed escape of snbstantial amount of gas. For rheologi-cally complex hqnids, Chisti et al. (1986) obtained Eqnation 10.24  

2 Gas-Liquid Mass Transfer Table 10.8 gives a summary of the literature investigations on gas-liquid mass transfer in BCDT. 

glycerol (35-65 vol.%), and glycol (70vol.%). Dynamic absorption of oxygen. 

---