Particle Cycle Times and Solid Circulation Rates in Conical Spouted Beds with Draft Tubes of Different Configuration

Particle cycle times (average, maximum, and minimum) have been measured in draft tube conical spouted beds for different geometric factors of the contactor (angle and gas inlet diameter), draft tubes (diameter, height of the entrainment zone, and width of the faces) and under different operating conditions (particle density). On the basis of the results, the effects of the type of draft tube and different factors of the contactor/draft tube/particle system have been studied, and those of greater influence have been determined. The results show that particle cycle times and solid circulation rates are highly dependent on the type of draft tube, solid density, and contactor angle. Open-sided draft tubes are the ones with the highest solid circulation rate with stable spouting performance. Therefore, this internal device is a suitable option for scaling up spouted beds with a hydrodynamic performance similar to those without tubes.